en-us Thu, 02 Sep 2010 12:19:15 -0500 ATM@msgroup.org 60 *All Things Motorcycle* - Contrary Opinions http://www.msgroup.org/forums/mtt/ *All Things Motorcycle* for Guest http://www.msgroup.org/forums/mtt/ http://www.msgroup.org/forums/mtt/rss_32.png *All Things Motorcycle* RSS Feed 144 47 Contrary Opinions - Tip # 83: ABS not designed to stop you faster??rkfirehttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=12203&REPLY_ID=116937Contrary Opinions Thu, 26 Aug 2010 06:50:19 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=12203 I've never seen actual test results showing that. Funny how they don't give any actual references to these "extensive testing". They do the same thing with a couple of other "myths, like a "study" showing lane splitters in California actually have are safer than staying in a lane. Did someone really do a study? If so, I am surprised that it's never been mentioned here in any number of lane splitting threads.]]>Contrary Opinions - Don`t get too close to the car, stopped too far ahead at a stop lightIgorhttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=10236&REPLY_ID=116464Contrary Opinions Sat, 14 Aug 2010 15:01:16 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=10236 Just being behind the crosswalk doesn't ensure a car will move forward the next time it moves. Something I saw once was a person who'd stopped at a light and placed their car into "park". Light goes green, they drop it into "R" and hit the gas... Crunch! Would have sucked to have been behind that one on a motorcycle!]]>Contrary Opinions - 2 Seconds is not enoughlessthanthreehttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=12081&REPLY_ID=116065Contrary Opinions Mon, 02 Aug 2010 11:56:13 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=12081 I unfortunately do not have time to finish reading through this whole thread, but I just wanted to add my 0.02 before I head home.

I got into a rear-end collision on the weekend after Thanksgiving driving home from Florida. It was rainy, the traffic was heavy and the speeds were varied from 0mph to 40mph, stop and go. I was in the far left lane (at that time it was inconsequential, but I find that in stop in go traffic it is best to just maintain your lane, especially if you do not plan on exiting soon). I saw an SUV go from the far right lane into the center lane, rather abruptly and it made me aware that the driver might do the same again into my lane. Traffic started picking up speed and a few minutes went by and while I was still concerned about this driver and before I knew it she crossed over into my lane with no signal, she was less than 10 yards in front of me. I immediately moved my foot to the break and eased it, and my eyes went to the rear-view mirror to check for traffic behind me so that I could get some distance quick, she was way to close. My eyes move back to the SUV and I see break lights, a rear-end collision happened immediately in front of the SUV, causing her to react and she had given me less than 3 seconds to react from the time she changed lanes to the time she slammed on her breaks.

From then on I adopted a four second rule, I would find an object on the side of the road (usually a sign post) and count to four seconds from the vehicle in front of me passing it until I passed it, if I was that distance away I felt comfortable.

However, recently I decided to test the four seconds (with no vehicle in front of me) with my watch. To my surprise my four seconds was only about 2.5-3.2 seconds.

For this reason I personally beleive that two seconds is not enough for most drivers if they are doing the counting in their head using the method stated above. Its better to over-do a principal of safety than to underdo it. If a driver counts out a two second gap and the gap is more like 1.5 seconds, then the 1.6 second threshold will not hold up.

If you do use the two second rule I highly recommend you familiarize yourself with this length of time and space between vehicles at various speeds.]]>Contrary Opinions - Turning causes leaning?rayg50http://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=11979&REPLY_ID=115583Contrary Opinions Sun, 18 Jul 2010 20:22:17 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=11979
quote:
Originally posted by CaptCrash

For me, the simple knowledge of counter-steering is the most important thing--know it does work, use it to your advantage.


+1]]>Contrary Opinions - Fall while stationary NOT the same as a fall at speedricbassmanhttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=11774&REPLY_ID=115295Contrary Opinions Fri, 09 Jul 2010 21:05:57 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=11774
quote:


When people claim to put on a helmet to move their motorcycle around in the garage or back it out of the garage into the driveway, I feel that they must either be exceptionally clumsy or have a way different assessment of the risk involved. I happen to feel that they are being a bit extreme when doing that.

I welcome opinions contrary to mine on this subject.



You can call me exceptionally clumsy if you want, but there are freak circumstances that may cause you to hit your head and not be able to brace yourself.

Two days ago, I was performing a U turn in a parking lot. Just moving my bike. I wasn't wearing a jacket, but I was wearing my helmet (I just got there and it's 100 degrees outside). Short story long... I dropped the bike on the left side. Maybe it was the heat, maybe I lost my head for a minute, but I picked the bike up without shutting it off first. The drop bent the clutch lever, which I was holding in as I picked up the bike. Because it was bent, it slipped out from under my fingers, causing the bike to launch forward.

Now picture this. My right hand was on the throttle, so as the bike took off, the throttle rolled back and I lost the bike. Back over on its right side, doing considerably more damage than the initial drop. Here's the puzzling thing that I just can't seem to figure out. I ended up flipping over the bike and landing on my right shoulder in front of it. My helmet has one hell of a scrape across the back side where my head hit. I have road rash on my forearm, shoulder, and up my back on the right side, where it feels like I've been rabbit punched with a ball peen hammer. For a walking speed mishap, I came out in pretty rough shape.

Now, that's not to say that every time someone drops their bike, they're going to get thrown three feet, but it can happen. I think if someone wants to be militant about wearing their helmet to push their bike from one end of the driveway to the other, I say go for it, it's not hurting me any.]]>Contrary Opinions - Harleys the "safest" bikes?aidanspahttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=1387&REPLY_ID=115088Contrary Opinions Fri, 02 Jul 2010 20:06:42 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=1387
quote:
Originally posted by Fajita Dave

As far as stopping distances go. I have a hard time seeing an 800 pound Harley out braking a 400 pound sportbike.
Read Safety Tip 125, Heavier Bike vs. Stopping Distance, posted 2/04.

Interesting discussion on Physics Forums about whether an ultralight car has a shorter stopping distance than it's larger cousin, and the consensus is that given each vehicle being equipped the appropriate brakes and tires for its size, the answer is "no".
]]>Contrary Opinions - Putting it in neutral at stop lightsoldhack62http://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=1331&REPLY_ID=113036Contrary Opinions Sat, 01 May 2010 21:42:09 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=1331 If I can't hold the clutch in through a traffic signal, THAT is a signal that I need to take a break from riding for a little while. Lunch. Bathroom break. Whatever.
Being in neutral at a traffic light is a little bit like being a pedestrian standing still in the middle of an intersection.
]]>Contrary Opinions - Tip014 CB helpRazzoohttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=11127&REPLY_ID=108584Contrary Opinions Thu, 10 Dec 2009 09:59:17 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=11127
quote:
Originally posted by Scooter rider




Well I have been a Ham now for close to 30 years.
An I do a lot of monitoring on the bands An the last thing I would do is to announce to the world on a CB
That I have broken down on the side of the road.

Use CB to keep abreast of road ,weather an traffic conditions.
As for calling for help I for one will pass.



I agree, but even go further - When riding I want no distractions, cell phone, ham radio, etc (but that is just me).

As for calling for help, You many not get anyone (due to lack of monitoring) or the wrong one (due to who is monitoring). Cell is much better in an emergency. One of the reasons I upgraded to a smartphone was due to my habit of riding out in the county roads.

Have an Advanced license, but need to be more active -- too many hobbies and so little time :)

]]>Contrary Opinions - Tip 45 - Dragging a pegAndrew Dresselhttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=8940&REPLY_ID=105972Contrary Opinions Tue, 22 Sep 2009 13:41:48 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=8940
quote:
Originally posted by whittlebeast

I was mostly looking at the unfiltered part of that trace (light blue/green). As the torque is climbing after the shift the vertical geez go positive (above 1) implying that the seat is rising as the power is coming back on.
I guess that it is possible that we are looking at tire shake or some other phenomenon but I doubt it as the acceleration numbers look as I would expect and there is very little filtering on that part of the trace.


I agree with your guess then: perhaps just bumps in the pavement. The oscillations at 492.5 seconds, with no obviously associated large change in forward acceleration, appear about as big as the spike just before 494 seconds, and so do not indicate to me any strong correlation with forward acceleration. If anything, the unfiltered trace still suggests a slight squat as forward acceleration peaks, and then a slight rise as you brake.

However, you obviously know you equipment better than I possibly can. I can only comment on how the graph looks.

In any case, it is fun to see some real data.

(edited to fix typos)]]>Contrary Opinions - Leather and hydrationHouse_of_Dexterhttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=10295&REPLY_ID=105912Contrary Opinions Mon, 21 Sep 2009 08:55:22 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=10295 I've now gone 2 seasons in the heat 105F+ Texas Summer in stop and go traffic in Dallas. The first summer was with Joe Rocket Black Textile. This summer I wore perforated Leather. My ability to survive was 2 fold. First I hydrated wearing a camelback. On weather 95F+ I wore an evaporation vest under my armor. The evaporation vest is the most important equipment I wear during these conditions.]]>Contrary Opinions - Tip 258 - 'Advanced' or 'Performance' TrainingHouse_of_Dexterhttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=10766&REPLY_ID=105611Contrary Opinions Fri, 11 Sep 2009 16:50:30 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=10766 I think one of the best arguments for track day...is to take it off the streets. Another forum that I frequent. We frown on riders showing risky behavior on the streets, they recommend track day so they can get it out of there system. These riders know there is a place for speeding and dragging a knee...and the public roadways are not that place.

]]>Contrary Opinions - Emergency Braking and Downshiftinghaithabuhttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=9609&REPLY_ID=105304Contrary Opinions Wed, 02 Sep 2009 15:21:05 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=9609 Good enough. Thanks for your critique, James. I can't say it has changed my original conclusion but it has added to my store of knowledge, which I always welcome. We all want to survive out there!]]>Contrary Opinions - Tip #48: Contact Patch moves back not forwardAndrew Dresselhttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=10500&REPLY_ID=103436Contrary Opinions Wed, 22 Jul 2009 15:22:00 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=10500
quote:
Originally posted by Proprioceptor
Foale provides an excellent diagram showing the front tire turned away from the direction of travel. See Fig. 5 at bottom. It matches the photos of actual high-speed cornering we see every day.


That figure, as the accompanying text explains, is for "speedway racing": that is "dirt track". On page 2-32 of his book, Motorcycle Handling and Chassis Design, he titles the same picture "Schematic for Drifting", clearly far beyond the realm of reasonable street riding.

On page 2-28 he explains that graph 2.25 for a hypothetical tire shows that "we would have to ... steer out of the corner" at lean angles less than 28", but I cannot tell if he is describing tires on pavement or gravel.

Cossalter limits his analysis to pavement and goes into much more detail on pages 125-130 of Motorcycle Dynamics (http://books.google.com/books?id=rJ...cle+Dynamics) with graphs of turning radius, velocity, steering angle, and roll angle for three different tire scenarios. Although he does state the need for negative front sideslip angles, he never shows a negative steering angle.

So far, I have yet to find an author that clearly states that a motorcycle will have to have a negative steering angle in a steady state turn on pavement.]]>Contrary Opinions - Tip 221James R. Davishttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=10549&REPLY_ID=102865Contrary Opinions Thu, 09 Jul 2009 15:58:10 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=10549 Fun to think with analogies, but yours are slightly wrong.

Horsepower is the amount of work done over time while Torque is the force doing that work.

As watts are a measurement of work being done over time (power), it is an apt analogy for horsepower.

If you apply a torque wrench to a lug nut and stand on it, torque exists (as a potential) but unless that nut turns there is NO horsepower. Thus, Volts is an apt analogy for torque.

Current is neither power not potential - it is the work being done. Current would be an apt analogy for the turning nut.

Despite these definitional differences it's clear that you actually understand the roles played by torque and horsepower.]]>Contrary Opinions - Counter-Steering (Oh-No)The Meromorphhttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=8813&REPLY_ID=102492Contrary Opinions Tue, 30 Jun 2009 22:21:20 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=8813
quote:
Originally posted by Moses

How about a bike with "beach" style bars that wrap around almost to the rider's sides? You wouldn't push forward or downward on those grips, but almost outward. The idea is to steer the bike COUNTER to the direction you want to go, hence the name COUNTERsteering.


Actually you should still push forward on that grip. If you try pushing sideways, I think you will find yourself actually turning the bars much more than you should, The turning that is used for countersteering is usually very small, small enough to be hard to see. The proprioception of it (the feel of it) is more like pressing than pushing. I think if you tried to push 'beach bars' sideways on the road, you might find the steering input wildly over exaggerated. Maybe that's why they're called 'beach bars'? You need the exaggerated steering inputs riding in sand?]]>Contrary Opinions - Tip #086 - First Aid KitsNieborhttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=10400&REPLY_ID=101681Contrary Opinions Sun, 14 Jun 2009 18:28:56 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=10400 Note to self: Add one large Roll 4" gauze to first aid kit. [;)]

I carry a dozen 3x3 pads, and now realize that's insufficient. It appears the elasticity of guaze would be very helpful in keeping other bandage material in place. I did add several triangular bandages awhile back, per James's well stated advice. Many legitimate uses for them came up. Though uses do seem to overlap, each has it's strengths. Carying both appears to be the best answer. LOL, I think it may be time to upsize my kit a bit. This one is beginning to burst at the seams.

I really wish the gal we hire to train us in first aid would cover topics like this. Against the rules though, we know how that goes...

Thanks Matt! [:D]]]>Contrary Opinions - Tip#254: A Case Against Counterbalancingrioguyhttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=10341&REPLY_ID=101449Contrary Opinions Tue, 09 Jun 2009 19:54:12 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=10341 Sibemol,

Counter-steering is one of my pet subjects, so I read every post with interest. Thanks for posting the quote directly. I absolutely agree the quote leaves room for confusion.

If you are at the point where you can safely practice, go out and practice. Then it would be interesting if you would put your perceptions and see how it compares to what we have read.

Be sure to practice keeping a light grip on the hand grips.



]]>Contrary Opinions - Why do bars have parking lots?bkikkerthttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=8724&REPLY_ID=100618Contrary Opinions Mon, 25 May 2009 08:28:13 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=8724
quote:
Originally posted by Texasphotographer


Do not have to agree with it, the fact is the police have a limited amount of latitude in which to do their job. Sometimes the law gets in the way.[:x)]


I suppose the line has to be drawn somewhere between 'to serve and protect' and a police state.]]>Contrary Opinions - To "Cone" or not to "cone"kinninghamhttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=8895&REPLY_ID=98410Contrary Opinions Mon, 13 Apr 2009 06:41:54 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=8895 With cones and without cones are both beneficial, just different training. One difference is psychological, like the difference between doing a Uturn between parking lot lines and doing them in an actual street with curbs.

I noticed recently my slow speed turns are more accurate if I lean back until the outboard arm is almost straight and I adjust steering by push and pull with my inside arm. I don't know why it helps. May be it's just a transitional technique as balance improves. Another thing I noticed recently is Uturns are easier when I'm expecting to tighten the turn as it progresses. The initial lean and turn of the wheel never seems like enough because it's not. When I plan to tighten the turn as it progresses things go better.]]>Contrary Opinions - Motorcycle Sales Foundationaidanspahttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=9346&REPLY_ID=98144Contrary Opinions Mon, 06 Apr 2009 19:21:17 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=9346 Allow me to welcome you to the site as well goatlocker95. We are glad to have you aboard, and look forward to your continued participation here.]]>Contrary Opinions - Motorcycle simulatrsAndrew Dresselhttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=9707&REPLY_ID=96011Contrary Opinions Tue, 24 Feb 2009 14:33:18 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=9707
quote:
Originally posted by tusome
The CV on a PID controller is the Control Variable, bascially the output of the controller.


In that case, no. The confusion is probably caused by the way I've labeled the plots. Sorry about that. I use the titles for stuff such as parameters I need to record for comparing different plots. The y-axis label contains the information about what is actually plotted.

The output, the "CV", is steering torque in the lower right.
The inputs to the LQR controller are lean angle and steer angle.

On a real bike, I would do state estimating to calculate things that would be hard to measure, such as lean angle, from things that are easier to measure, such as steering angle.

These guys in the Netherlands are doing the only public instrumented bike testing that I know of: http://audiophile.tam.cornell.edu/~...le/index.htm]]>Contrary Opinions - Theoretical Cornering Question - counter-steeringcostoshttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=9677&REPLY_ID=95961Contrary Opinions Mon, 23 Feb 2009 00:44:38 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=9677 Thankyou gentlemen, now I have some reading, research, deep thinking and sleepless nights to contend with while I digest all that information.... On a lighter note here is a video of what my pit-bull thinks of some of your comments;-

http://www.youtube.com/watch?v=AKJ-u9US4CQ

I'm only joking of course.[88]]]>Contrary Opinions - HornsThe Meromorphhttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=1677&REPLY_ID=92606Contrary Opinions Sun, 28 Dec 2008 20:47:40 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=1677 I posted it under a different section, but it seems appropriate to mention it here. I have succeeded in mounting a WOLO horn (exactly similar to the Stebel) on my bike. It's as loud as any I've ever had.]]>Contrary Opinions - premium (high octane fuel) is bettercaponerdhttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=4560&REPLY_ID=92588Contrary Opinions Sun, 28 Dec 2008 11:08:39 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=4560
quote:
Originally posted by bikerdave

I can't get the "experts" to agree on which fuel is better for a relatively low compression, small capacity V-TWIN engine with no real engine mods...
The dealerships say run premiun (95 - 98 octane) where as the manufacturer advises on a lower rating, as long as you dont get pinging (detonation).
Some even say that running a higher octane fuel than you need can lead to "incomplete combustion" as the fuel is much denser, and resulting carbon build up in the cylinder head (not a good thing I assume).

Anyone??


I run the lowest octane rating fuel that doesn't cause detonation. This is consistent with what every expert (as opposed to the "experts" in quotes) I've ever read or talked to has said.
High octane fuel is designed to burn more slowly in high-compression engines where lower octane fuel will detonate instantly rather than burn smoothly.
Havinge said that, you definately want to avoid detonation, as it drastically reduces power output, plus puts a lot of stress on internal engine components, and in extreme cases will result in a hole burning into a piston. (I've seen it happen)]]>Contrary Opinions - Stopping on yellow (not countersteering!)johncrosbyhttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=5690&REPLY_ID=91005Contrary Opinions Mon, 17 Nov 2008 10:36:26 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=5690
quote:
Originally posted by Ballbarian

I am somewhat worried by the apparent lack of respect given to intersections controlled by lights in the US, as described in this thread.


I have to say I do disagree with the wonderfully named Ballbarian. The UK misuse of traffic signals and totally inept traffic management encourages an opportunistic approach to navigating intersections.

Having lived and driven in Continental Europe for many years (more than in the UK thankfully), my subjective experience is that on the contrary driving standards are only superficially worse (more overt letter of the law rule-breaking) but in actuality overall more predictable and less erratic than the UK.

Foreign truck drivers are far more influenced by being economically encouraged to overdrive without a tach. Tiredness combined with driving on the left in a bleak dreary grey landscape for hours on end, eating the most dreadful pigswill at UK eateries, isn't the best environment to maintain alertness etc.

On the traffic signals, in Germany the lights are often set up such that if you drive at or around the local speed limit, you will mostly often reach consecutive green lights, turning to amber shortly after you drive through. This is honestly the best piece of intelligent thinking to do with traffic lights I'd ever seen. In the UK it's the polar opposite. A punitive stupid counter-productive setting up of the lights to deliberately reduce the flow of traffic (in some crazy effort to make car use less attractive compared to the joys of buses etc). The previous Mayor of London admitted on numerous occasions that Transport for London did syncronise lights such that if you don't speed you'd hit every singly red all along your journey. Nothing frustrates road users more or encourages dangerous and illegal amber/red running of lights more than this nonsense policy.

The US/Europe is nirvana in comparison to the UK, but only from a cultural, aesthetic, culinary and driver/rider perspective! [:)]


]]>Contrary Opinions - Tip # 234 Wide Open Throttle PreventionTecpatl4http://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=7580&REPLY_ID=89303Contrary Opinions Fri, 10 Oct 2008 09:11:13 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=7580
quote:
Originally posted by Hazex3

In the MSF I had the problem. Once or twice while breaking a rev'd the engine. I had spent no time at all on a motorcycle or even dirt bike till I took the class. I do have plenty of time on mountain bikes though.



I had the same problem when I first started riding my bike. But then in the BRC class the instructor pointed out to me that I was only braking with two fingers and keeping the other two on the throttle. Once I started using all my fingers on the brake the problem seems to have mostly gone away. After reading this, since I have to replace the clutch lever this weekend I may reposition the brake lever while I'm at it, to see if helps with comfort and control.]]>Contrary Opinions - re: Tip#083: Anti-Lock Braking Systems (ABS)James R. Davishttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=1223&REPLY_ID=87695Contrary Opinions Sat, 20 Sep 2008 08:25:59 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=1223 I have changed that safety article so that it now reads:

quote:
I think ABS makes sense for a cage, and maybe more sense for an 18-wheeler, but is of marginal value on a motorcycle EXCEPT IN THE EVENT THAT YOU ARE PRONE TO PANIC AND OVERUSE YOUR BRAKES (in which case ABS can easily save your life!).


Hope that addresses your concern and I appreciate your feed-back on the matter. The safety tips are generally not time sensitive. As ABS has become more available and better behaved, this tip became in need of some adjustment.]]>Contrary Opinions - Braking QuestionsAndrew Dresselhttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=8666&REPLY_ID=86547Contrary Opinions Wed, 03 Sep 2008 15:22:58 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=8666
quote:
Originally posted by Grumpy

Other factors:
1) If each tire is capable of providing traction for deceleration, doesn't it make sense that when both tires are on the ground, more traction is available? If one tire is capable of 1 g of acceleration front to back, two tires would be capable of 2 g's of acceleration (all else being equal--I know they're not, but bare with me).

2) When the front brake is applied, a mechanical force or torque wants to throw the center of gravity of the motorcycle forward and around the contact patch. When the rear brake is applied, the mechanical force or torque wants to throw the center of gravity of the motorcycle downward (at a tangent to radius drawn between the contact patch and the center of gravity) between the two tires. Both these torques are separate and distinct from weight transfer, which will do what it wants to do, as long as there is deceleration and a cg above the contact patches, regardless of whether deceleration force originates from the front, back, or both wheels. So we'll try to ignore weight transfer as irrelevant to this discussion to simplify and illustrate some factors, which may prove to be minor.

What we see in the above illustration, if true, is that while using the front brake removes weight and traction from the rear wheel, using the rear brake sets more weight between the wheels, thereby creating traction for the front wheel.


I read through all the replies and didn't see these points addressed, but I didn't check the links, so forgive me if this is already handled elsewhere.

1. In general, two tires would provide twice the braking force only if they didn't have to split the total vehicle weight between them. The simplest model of friction does not include surface area by the same principle. Of course, the interaction of relatively soft rubber on hard rough pavement complicates things, but not nearly enough to make two tires twice as good as one. I'd love to learn exactly how much, if anyone knows.

2. The torque due to the force couple of tire friction and center of mass deceleration is not located at any particular point on the body because the two forces are perfectly equal in magnitude and parallel in direction. The torque generated by the front wheel is indistinguishable from the torque generated by the rear wheel, except that they have different built-in limits. Neither is "better" than the other, both increase braking effectiveness from the front wheel and reduce braking effectiveness of the rear wheel equally, until the rear wheel comes off the ground.]]>Contrary Opinions - Braking strategiesNightcoderhttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=8644&REPLY_ID=85977Contrary Opinions Wed, 27 Aug 2008 07:49:41 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=8644
quote:
Originally posted by Misty Trane

Nightcoder, David Hough simply says if you habitually lock up your rear in that circumstance, then use only your front.


That would do the trick, I beleive. I think you're all right, and that it indeed depends on the motorcycle. The Nighthawk I crashed with only me on it was very light in the rear (as is my current bike), and I locked up the rear very easily when braking. The high riding position also increases weight transfer. But I shouldn't take that observation and try to make it everybody elses creed.

As for my accident - I panicked, and the brain wasn't involved in any way until after my face hit the asphalt (besides from taking me into the situation to begin with). It was reflexes that made me use the rear brake repeatedly, which - in combination with that particular bike and rider - didn't do me any good.

But again, I fold. Rider's observation and judgement skills based on full education on known facts wins every time.

Thanks for setting me straight! [:I]

And... be careful out there!
/Peter]]>Contrary Opinions - Bad Adviceradan2http://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=7135&REPLY_ID=83460Contrary Opinions Thu, 31 Jul 2008 21:54:56 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=7135 I agree, confronting someone is usually a bad idea. I would wait for the loudmouth to go away and quietly tell the newbie that the advice he had been given contradicts my experience and what I had read, then recommend either a BRC, the Hough book, or this website.

I have heard blowhards give obviously wrong advice from time to time. So far, they have done it in a crowd, and their own mates have jumped on them.

The worst advice I have ever heard given is similar to what you have heard: in case of a sudden stop, hit the back brakes hard and never touch the front brakes. This was at the end of a charity ride at a Harley dealership, and the general manager, obviously appalled, immediately jumped in to set the matter straight.]]>Contrary Opinions - Regarding tip 053 on the riding tips pagegymnasthttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=8222&REPLY_ID=82987Contrary Opinions Mon, 28 Jul 2008 22:13:53 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=8222 Mutabilus. It very well may be that in some cases, suicide by bike is a definite possibility but I am of an opinion that the larger problem is far less complicated and not nearly as controversial as some aspects of PTSD. The more common scenario that I think relates to the problem is more along the lines of "I did that over there and there were real dangers so now I can do this here at home (get a really fast motorcycle that suits my daring do image) because I have confronted danger successfully and it is now behind me".

An adrenaline buzz is useful when one is in a situation that they have been well trained for. It can be deadly in situations one is unprepared for.

]]>Contrary Opinions - Stoppie?? information onlyMrDude_1http://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=7586&REPLY_ID=82506Contrary Opinions Thu, 24 Jul 2008 09:46:08 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=7586 A STUNT style stoppie is NOT anywhere close to effective braking.
Actually it’s a perfect example of what not to do.

I wont go into 'how to' level details, but in a rolling stoppie they basically 'spike' the stopping pressure. This initial spike raises the rear. After that they BEARLY use the brake. It’s just to balance.

On a PROPER stop, you avoid this at all calls. You SMOOTHLY apply the brake. Because of this, you can continue using more brake, longer.
On some bikes (ie: sportbikes, supermotards, and anything else with a high center of gravity), doing a proper stop may lift the rear wheel, but this is NOT desirable or intentional.
There’s a point of diminishing returns... on a sportbike such as my ducati, or the aforementioned MotoGP bikes, the rear tire reguarly lifts about a half inch off the ground under maximum braking.
If we continue braking harder (trust me, we still have a lot of lever left) the rear will rise up more... at that point, we must RELEASE some pressure, and brake less... so we effectively lose braking ability. If you wish to pursue and find this limit on your sportbike, trackdays are wonderful ways to learn the skill of maximum braking. The street is not. Streets have crowns in the roads along with sand, and the fact that you have to go fast to even see this effect. The crown will make your bike step out.

Tecpatl4:
The reason using one wheel is more effective then two is simply because the limiting factor is not traction. It is not braking capacity; the limiting factor on a modern sportbike is the center of gravity. The CG is so high that the bike will lift. You can accidentally help it by being too aggressive on the initial bike and that will jerk you up, or you can avoid it by being smooth and stopping properly.

If you watch people riding sportbikes properly (racers or experienced riders) you'll note that under braking they pop up and back. One of the reasons for popping back is to move more weight backward and limit the amount the bike tries to lift. The lower you can keep that bike, the harder you can stop.

Please keep in mind this does not apply to cruisers, touring bikes, some standards, etc... It does apply to supermoto bikes and some standards though...
If your rear tire is on the ground, by all means use it to stop.

Just remember while we're all on 2 wheels on the same road, some of us are in totally different worlds. At 70mph on the interstate, some bikes will feel twitchy, some riders are cupping wind. While other bikes may be at 4% throttle and the rider COULD (but shouldn’t) take one hand off and feel like he’s on a walk through the park.

What applies and works for some bikes will not work for all. Learn how things work, think about them for yourself, and then apply that knowledge... and if you have a bike capable of stopping (or anything else) at levels beyond what is appropriate for the street, please take it to a track or other appropriate place.
]]>Contrary Opinions - Laying it downdfpd273http://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=1279&REPLY_ID=81708Contrary Opinions Thu, 17 Jul 2008 00:42:25 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=1279 The idea of sliding under a semi trailer, assuming the circumstances were perfect, may sound like a good idea to some but I would rather be upright if at all possible.

Not only do I not know how to lay a bike down intentionally, there is a lot of stuff under trailers. Sometimes there are spare tire holders or railings for added strength. Also whats the likelihood that the area you are aiming for would still be open when you got to it, as the semi would continue moving forward. It seems less painful to hit the side of the trailer (slower because you stayed on the brake) than to risk hitting a bar or getting stuck under a tire.

As far as the initial question of the guardrail. Who knows. I don't know how you would ever prepare for a situation like that, but I would like to think that trying to steer out of danger or panic stopping would be far more beneficial to my health than dumping the bike and hitting the rail.]]>Contrary Opinions - The Third Gyroscopepimariderhttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=7980&REPLY_ID=79952Contrary Opinions Mon, 30 Jun 2008 16:33:21 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=7980 As a result of one of James’ comments, last year, I went to my practice area and tried slow speed riding on my Honda Aero using high engine revolutions for additional stability. I was amazed at the extra stability the engine provided even at almost 0 mph compared to the stability at slow speed with the engine just above idle. Now that I have a Honda ST1300 with the engine crankshaft parallel to the longitudinal axis of the bike frame, increasing the engine RPM has no apparent positive effect on stability at low speeds. By the way, Honda has engineered a counter rotation in the power-plant design, so there are no rolling forces as one adds or reduces engine RPM on the ST1300.

PimaRider]]>Contrary Opinions - Low speed turningTburdhttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=7973&REPLY_ID=79945Contrary Opinions Mon, 30 Jun 2008 15:45:41 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=7973 This would have been a good time to do a little experiment but my bike is in the shop, again.

A good explanation of this along with a few nice illustrations can be found on pages 41 and 43 of "Proficient Motorcycling" by David Hough. It involves the rake angle and trail of the front end which I'm sure you are very familiar with.

The trail dimension is the distance the contact patch is behind the steering axis. When the front is turned so that the wheel points to the left for example, the contact patch moves to the other side of the steering axis which is to the right side of the frame. When looking at the top view on page 43 this makes sense, at least to me, except that Hough is showing a right turn in his discussion.

Actually if the bike is stationary the front patch doesn't really move, the frame makes a lateral shift. But it's the relative position that's important in this discussion concerning the cg relative to the contact (support) points.]]>Contrary Opinions - MSF article errorsWarlock622http://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=7950&REPLY_ID=79830Contrary Opinions Sun, 29 Jun 2008 09:35:11 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=7950 Night Train, I do appreciate the kind words and am glad I helped in some small way, but please don't change your riding habits because of my little experiment. Those habits seem to have kept you safe thus far.
IMHO, although your wife shouldn't "slam" into you even in an emergency stop, there's always the possibility that she won't hear you say, "OH S**T!" just ahead of that stop and will do so. It would definitely be a distraction and have an adverse effect on you. However, since you seem to be prepared for that eventuality, (through experience and safe riding practices), I don't see it as a major concern for you.
Your statement did get me to thinking though. So, I took my daughter with me last night to the parking lot (old Walmart lot, so there's PLENTY of room) and did a few "panic stops."
Did the first with no warning to her and sure enough, she slid up against my back pretty hard. As I was expecting this I was prepared for it and had no problem compensating for the distraction. She fussed at me for doing that to her, but got over it after I explained why and we went on to do some more stops, etc. She loves riding with me and trusts me not to do anything stupid.
Anyway, we did 6 more stops and even with the addition of her 140 lbs, had no problems stopping within the distance measured in my earlier experiment, (all my chalk marks were still there). So, IMO this just reinforces James' earlier statement that;
quote:
It is a FACT that weight is not a factor in determining stopping distance on a motorcycle provided it is within normal load carrying capability of the bike.

And it put all this "theory" etc., in perspective for me as well.
However, even with all this extra info (and the fun I had while doing this), I'll still "ride my own ride" and continue to do what has kept me safe these 40+ years of riding.
Ride safe!!]]>Contrary Opinions - Rubber HardnessVulcanV2Khttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=7728&REPLY_ID=78509Contrary Opinions Tue, 10 Jun 2008 19:46:51 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=7728 The rest of his message was deleted because of this part: JRD

quote:
Your argument is really weak and based on numbers that have an odor that hints where they were pulled from.


And that caused his departure from the board. What was deleted was, essentially, a statement that his tire contact patch is oval in shape and nowhere near 5 inches wide so that my commenting about a typical rear tire width was irrelevant. In fact, unlike car tires, when you add weight to a motorcycle tire its contact patch gets longer AND wider (because the tire is rounded side to side) so that as that weight approaches max capacity the contact patch approaches that width. In any event, personal shots are not the way to argue on this board. JRD]]>Contrary Opinions - 1st bike optionElwoodhttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=7687&REPLY_ID=77501Contrary Opinions Fri, 30 May 2008 09:38:49 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=7687 WZ, I just bought as my first mc a 98 Shadow ACE. I was a bit intimidated by it at first, but having ridden it for three weeks now, I love it. The price seems right and it sounds like a good deal. I know that others on this site would advocate for a smaller first bike, however, I wanted a 5th gear for highway speeds. I, as others will also, encourage you to sign up immediately for a BRC. I am really looking forward to taking the course next weekend. The slow drills and excercises are not nearly as easy as I thought they might be.

Love my ACE!]]>Contrary Opinions - What is a California Stop?Tamarack58http://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=4633&REPLY_ID=77488Contrary Opinions Fri, 30 May 2008 08:33:28 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=4633
quote:
Originally posted by BikeWhisperer

Just my .02 for this thread. Does or can anyone come to a complete stop, on a two wheeled vehicle and not put a foot down? And with that question, does anyone roll through a stop sign dragging a foot?


Don't mean to revive old dead posts but since the last entry to this one was a couple of weeks ago I'll add my thoughts. Won't debate the CA stop since that's been talked about to completion but want to respond to the above question.

I almost always (when safe conditions permit) TRY to come to a complete stop before I put my feet down. For some reason it's very satisfying to me to be able to come to a complete stop and stay stopped for a second or so before I need to put my feet down.

I guess it's similar to being able to make a full lock turn without using your feet. Just makes me feel totally balanced and one with my machine.

I better add a clarification to the above. When I am able to do this I DO NOT consider it my "complete" stop at a stop sign. I still "stop look and listen" before proceeding.


]]>Contrary Opinions - RE: Tip#171 - Helmet laws, bogus conclusions.gymnasthttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=1695&REPLY_ID=70063Contrary Opinions Fri, 29 Feb 2008 12:46:26 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=1695
quote:
Originally posted by Lockjaw

Food for thought. A friend of mine in college was getting driven home because he was drunk. He didn't want to walk back from the parking lot. The driver (who was already annoyed) did not want to stop. The guy dove out of the car which was only going 10-15. He hit his head on the curb. Almost died. Was in a coma for months. Also had a buddy who caught a flowerpot to the head (his eye came out). And one who got sucker punched with a beer stein in the back of the head. All of them were close to death, and none of them were ever the same again.

Heads are fragile!

Following up on your "Heads are fragile", most people have no idea of how fragile. Do a web or Google search of the term "Traumatic Brain Injury" or TBI and a person can become well informed of how little is required in the way of injury to produce trauma with life changing consequences. When a person tells me "helmets are dangerous" I know that I have met a person who avoids reality.
]]>Contrary Opinions - countersteering is only half of itdbalvarezhttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=1725&REPLY_ID=68213Contrary Opinions Mon, 14 Jan 2008 22:20:51 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=1725
quote:
Originally posted by James R. Davis

I will remind you that counter-steering works even if you replace the front wheel with a ski - no precession involved.


Mr. Davis, the first time that I read the term of countersteering, I didn´t beleive it. I tried it and it functions. But with your explanation I have no doubt at all, thank you.]]>Contrary Opinions - OK---so you think you know how to steer your bike now?jeffareidhttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=5542&REPLY_ID=65360Contrary Opinions Sat, 27 Oct 2007 17:07:21 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=5542
quote:
Wow, that was cool. But I didn't see any steering going on during that run, rear or otherwise.
He's steering:

Rear view, driver (pilot) has to steer to compensate for yaw, most of which is probably due to slight imbalance in the jet engines thrust.
http://www.youtube.com/watch?v=fr0KdxhYgfY

Cockpit view:
http://www.youtube.com/watch?v=vHnNxMJLfvA

update - actual picture of rear wheel steer bicycle from this web site http://www.rowvelo.com :



]]>Contrary Opinions - Tank Bags Safer Than Saddle Bags?scottrnelsonhttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=5553&REPLY_ID=61048Contrary Opinions Fri, 27 Jul 2007 10:17:23 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=5553 I consider tank bags to be more convenient than saddlebags. I like having my maps, camera, and extra pair of glasses in there. That's about all that I keep in the tank bag on normal one-day trips, though. There is no way I would put glass or anything sharp in there.

I mostly ride with my saddlebags on the bike and they weigh between 10 and 15 pounds total most of the time, with the first aid kit, tire repair kit, assorted rags and an extra pair of shoes that I normally keep in there.

When I take the saddlebags off I can tell a difference in the handling on twisty roads. The bike leans into turns quicker and is a bit more responsive.

I don't consider either one to be a safety issue. My tank bag can't affect steering, since the grips are at the level of the tank. Now those tank panniers would be a problem, though. I think those things are meant for narrow dirt bike tanks. I can't see using them on any bike I've ever owned or expect to own.]]>Contrary Opinions - How do you really steer your bike?BC KLR650http://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=5449&REPLY_ID=60291Contrary Opinions Tue, 17 Jul 2007 14:41:29 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=5449
quote:
Originally posted by nomad dan

quote:
Originally posted by James R. Davis

........
It is the righting force that you are maintaining pressure against ....


That makes sense to me.


Would you like a cookie? Some of us are still finding this confusing.]]>Contrary Opinions - Steering, ONCE AGAIN!Bodhislackvahttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=5578&REPLY_ID=59614Contrary Opinions Sat, 07 Jul 2007 00:42:02 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=5578
quote:
Originally posted by SteveM70…I've now began thinking that maybe "more would be better". I'll collect my thoughts and we can argue that one later.

P.S., Our local DMV motorcycle testing course is open to practice whenever tests are not being given. Although I have my endorsement I still swing by and go through the coarse whenever I find myself in the area…
Thanks. I look forward to disagreeing with you again in the future.

That DMV test course is a fine place for your wife to practice low-speed maneuvers. Low-speed skills are particularly important because they transfer directly to high-speed (anything over 20 mph) application. Beginners are able to quickly acquire low-speed techniques that can be very frustrating for us experienced riders to learn. Jerry Palladino's Ride Like a Pro IV video teaches low-speed riding techniques based on police motorcycle officer training and concentrates on doing difficult maneuvers with large bikes in small spaces. Beginners don't know it's particularly demanding but soon figure out it's fun. It might be something you and your wife could learn from together.]]>Contrary Opinions - Covering the front brakescottrnelsonhttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=5480&REPLY_ID=58430Contrary Opinions Sat, 23 Jun 2007 08:14:41 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=5480 Now we have two threads on this subject. I started one in the General section on the same subject. Any of my answers will be there.

http://www.msgroup.org/forums/mtt/t...OPIC_ID=5479]]>Contrary Opinions - RE: Tip #225James R. Davishttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=5373&REPLY_ID=57381Contrary Opinions Thu, 07 Jun 2007 07:30:49 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=5373 Thanks. I changed the tip to include the word 'USUALLY'.]]>Contrary Opinions - Tip #1 - "low speed damage"scottrnelsonhttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=4778&REPLY_ID=56212Contrary Opinions Wed, 16 May 2007 09:58:47 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=4778 It must have been too early in the morning when I gave my answer. Pushing forward is correct. Now I'm embarrassed. [:I]]]>Contrary Opinions - Re: 217: Your Motorcycle CANNOT Fall DownJames R. Davishttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=4916&REPLY_ID=53731Contrary Opinions Sat, 24 Mar 2007 19:04:54 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=4916 My intention was not to teach that you should not worry about low traction situations (that's a given), but that you need not worry about your bike falling over by itself because of an unfamiliar lean angle.

It is aimed at the newer rider who is specifically experiencing trouble (fear) in handling curves at highway speeds.]]>Contrary Opinions - Accelerating in a turn makes the bike lean more?IronAvatarhttp://www.msgroup.org/forums/mtt/topic.asp?whichpage=-1&TOPIC_ID=1740&REPLY_ID=50979Contrary Opinions Tue, 16 Jan 2007 09:46:05 -0500http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ID=1740 I have to say, I don't think I've ever seen so many people disagree on one subject! Maybe this is because, compared to normal car dynamics; bike dynamics are bloody hard to get to grips with and understand, even when you're an experience rider.

While I don't actually ride a motorcycle, I do have the benefit of having a rigid body simulation all set up with a two wheeled vehicle that I can drive around at speed.

I first got my simluation up and running with a basic two wheeled vehicle without any method of balancing. What happened at this point is pretty predictable.

If I turned the front wheel slightly without any form of balancing, the lateral forces generated by the front (and ofcourse the rear tyre slightly after) cause a rotation around the local z-vector. This cause the top of the bike to fall-away to the outside of the turn.

So no surprises there right? What I did next to get the bike to balance is not really an issue here, needless to say I came with a method that does not move the combined center-of-mass (CoM) around.

I now had to think how braking and throttle apply to a bike while it's leaning over. In order to lean the bike, a rider normaly hangs (to varying degrees) which shifts the combined CoM of the bike + Rider.

It's perhaps important to remind ourselves of a fact about rigid body dynamics; all forces act through the center of the body's mass

Why is this important? Well normaly, the position of the force generated from the rear wheel is in line with the combined CoM of the bike + rider. But when the bike is leaning into a turn with the rider hanging-off, this is no longer the case! The position of the force is offset from the combined CoM and this produces a turning torque.

And why does the bike lean more when accelerating? Probably because the rider is trying to balance the change in centripetal forces generated by the bike wheels, and the increaed torque this produces that would normaly tip the bike over to the outside.

Check it out for yourself. In order to calulate the torque generated by a positioned force;

C = CoM
P = position of force,
F = force vector,
T = resulting torque
x = vector outer-product (not multiplication)

T = (P - CoM) x F

]]>