| Member |
 Discussion Topic  |
|
thorolson
New Member
16 Posts
Minneapolis, MN
USA
BMW
R1200RT
|
 Posted - 09/24/2007 : 10:17 PM
|
After my first encounter with a rainstorm on my ride home tonight, I wondered if there would be advice in this forum to help build skills for this common event. I found a posting by James about the reduction in friction on a wet road that limits the permissible g-force on a curve from 1.1g down to 0.8.
I also found various opinions ranging from "avoid at all costs" to "don't worry, modern tires work well in the rain" (I'm paraphrasing, trying to depict the lack of a single party line on this topic).
I don't have a built-in sense for how much "lean" a bike can manage in a turn on dry pavement yet, much less wet. And I don't know what a 1-g turn feels like, but I do know that I took the route home with the fewest turns, and took all of them s l o w and w i d e.
There has been some wonderful discussions here about turning: right turns, left turns, tight turns, U-turns, delayed apex turns, etc. How about "wet turns"?
Thor.
|
|
|
Indiana Randy
Moderator
1951 Posts
[Mentor]
Fort Wayne, Indiana
USA
Honda
2000 Magna V4 750
|
Posted - 09/24/2007 : 10:37 PM
|
Welcome to the board Thor. 
In general, your tires will retain 80% of their traction in rain compared to riding on a dry surface. The typical cautious rider rarely if ever reaches 80% of a tire's ability to hold the road. Therefore, the answer is to do as you are doing and slow down in the rain.
The hazards in the rain are standing water and debris washed on to the road. Normal safe riding speeds can be done with confidence in the rain.
Next time it's raining, go to a parking lot and practice. Chances are you will be surprised how well your tires hold the surface even in the rain.  |
 |
|
|
Sigil
 Senior Member
432 Posts
[Mentor]
Nijmegen, Gelderland
Netherlands
Yamaha
FZS600
|
Posted - 09/25/2007 : 3:52 AM
|
Some tips for riding in the rain:
-Stay off of the white road markings and off of metal manhole covers. They are slippery and may present a danger when cornering and braking.
-Stay smooth. Brake smooth, accelerate smooth and take the curves smooth... |
|
|
|
Azraz Racing
Starting Member
4 Posts
Melbourne, VIctoria
Australia
Honda
RS125 CBR400 VFR400
|
Posted - 09/25/2007 : 4:16 AM
|
Riding in the rain should not be intimidating, to put it in perspective
its kind like when you first learned to ride on the road. Your mind is
trying to process everything your doing, after some time in the saddle
the skills you learned became instinct or second nature.
I ride every day rain or shine. Our winter months here in Australia
tend to rain for weeks at a time. When wet, I gear up and go riding.
I love riding and don't let the wet bother me anymore. I break a little
earlier while upright, set my speed for the corner and ride thru as if
its dry. The more your become confidant in wet weather, the better you
will be in dry conditions. |
|
|
|
Linkeroo
Junior Member
98 Posts
Akron, OH
USA
Honda
CB250
|
Posted - 09/25/2007 : 7:32 AM
|
Keep in mind the road will be the slipperiest when it first starts raining. Once all the dirt and oil washes off, traction is fine. Just don't drag any pegs in the corners, and watch for the rainbow circles (oil drops) at intersections.
I like riding in rain for the challenge of staying dry. Once you get some rain gear it's really cool to be riding out in the open in a downpour and still be dry and warm
-Ryan |
|
|
|
Sigil
Senior Member
432 Posts
[Mentor]
Nijmegen, Gelderland
Netherlands
Yamaha
FZS600
|
Posted - 09/25/2007 : 7:38 AM
|
Another small tip for riding in the rain:
If you're gloves aren't as watertight as you like, try wearing some latex gloves underneath. If you're allergic to latex of the powder inside there are always other gloves (also powderless)... |
|
|
|
sineide
Starting Member
4 Posts
Xenia, OH
USA
Harley-Davidson
Night Train
|
Posted - 09/25/2007 : 8:55 AM
|
 All the replys here are good, AND, I might add, slow down and de stay in your comfort zone. |
|
|
|
Cash Anthony
 Administrator
1184 Posts
[Mentor]
Houston, Texas
USA
Honda
Magna 750
|
Posted - 09/25/2007 : 9:29 AM
|
A couple of other pointers about riding in the rain (every time we go to West Texas, it's beautiful on the way out and while we're there, and then we get to do 350 miles back in rain -- without fail):
Don't be riding in a track or on a surface where you can't see what's under the water. If it's accumulating that much, better to stop. You can miss a really deep hole covered by murky water, and that will cause you major grief. Or there can be wet leaves plastered to the pavement that will slide once you're on them.
Wet-from-rain paint on the roads in any color -- white, yellow, red -- will likely be more slippery than you'd believe. If you have to cross painted lines, do not brake while your tires are on them if you can help it. Especially avoid any sudden, hard braking when on wet painted lines.
The biggest issue I have about riding in rain is that it becomes hard to see where you're going and pick up details that would be visible if the streets were dry. In addition to anti-fog products that go on your windscreen or visor, there are gloves made that have a little built-in 'squeegee' on the thumb or the back of the hand to let you wipe water away while you ride.
As long as you're keeping a lookout for hazards on down the road, you can usually take two seconds to get your visor clear again if your vision is obscured, even if someone comes by and tries to drown you with a big splash. Just keep on doing what you're already doing that's right, and hope the odds are still with you until you can see clearly again. Notice I said seconds, and realize how far you've traveled during that time. 
I've also tried to train my eyes to "look around the raindrops" and ignore them until I can either stop or clear them away.
If you wear rain-gear that has elastic 'stirrups' on the bottom of the pants, cut them off. It's hard enough to get on and off a bike when you're bundled up like the Michelin man in your raingear, you don't need to worry about having that piece of elastic foul your feet. BTDT, by the way. 
Hope this helps. The other suggestions given above were great.
Cash
|
|
|
|
tmonroe
Advanced Member
693 Posts
[Mentor]
Seattle, WA
USA
Kawasaki
ZX-10R
|
Posted - 09/25/2007 : 10:04 AM
|
IMO, you're most likely to crash in the rain from abrupt control input. (IE, snapping off the throttle, braking while in the curve, jockeying the throttle, or abrupt "re-steering" inputs).
You don't need to get anywhere near the lean limits of the motorcycle to have it slide out from underneath you if you're using bad technique.
Concentrate on the technique you learned in class. Focus on things like smooth braking coming up the curve, and a smooth roll-on of the throttle throughout the curve. Make sure you look all the way through the curve - that way you'll see the entire curve, and are less likely to be startled by something part way through.
If you're nervous, I would try to find and empty parking lot that you can use to practice riding in wet weather, and build more confidence. While I believe it is healthy to have a respect of motorcycles, too much fear can be paralyzing, and just as bad as too much confidence. It might not hurt to make plans to take care of yourself if you get stuck in the rain again... quite honestly, the rain shouldn't be enough to deter any rider... but your reaction to it could literally be a reason to stay off the road (at least until you're more comfortable).
As a new rider, I would say as long as you're on regular DOT approved street tires, and they have a reasonable amount of tread left (50% worn or less), then tires aren't going to change things much one way or the other.
|
|
|
|
flashy
New Member
18 Posts
Baraboo, Wi
USA
Yamaha
Virago 750
|
Posted - 09/25/2007 : 9:02 PM
|
Ha!! i found this topics timing really funny.. i stopped home for lunch and saw the post and some of the replies. Tonight as i walked out of my work place( in the rain )i was thinking of the post and replies. I made my way home from work in a mild steady cool rain. It's been at least 25 years since i rode a motorcycle in the rain.
my only concern came from the wet grass that I have to cross in my front yard before i get to the concrete slab where i park for the night. I just did as i always do being a new rider- drove cautiously and kept aware of what i was riding on. |
|
|
|
thorolson
New Member
16 Posts
Minneapolis, MN
USA
BMW
R1200RT
|
Posted - 09/25/2007 : 9:42 PM
|
Thanks for all of these helpful comments and suggestions. I conclude that I should not become "paralyzed", that my bike is actually not crippled on wet pavement; I should take the turns at maybe 3/4 the lean and 4/3 the radius, and a good set of clothing will help me laugh at the the elements.
This latter comment is ironic, since I actually had raingear in my panniers, but to put it on I must STOP, and get off the road to access it and put it on. When trapped in a center lane in stopped traffic, I was unable to perform this maneuver until I was adequately drenched.
I recall reading on this forum or tips that the advisory speed limits for curves were determined by a procedure from the 1930's based on a centrifugal angle of 14 (?) degrees. If so, I am pretty sure that the wear on my tires does not exceed 14 degrees from the contact point, either side.
So should I take as a guideline the 75% rule? Reduce the lean to no more than 10-degrees or so? (Never mind that I have no sense yet for how much lean I take on in a curve).
Every day a new adventure,
Thor. |
|
|
|
Tburd
Senior Member
406 Posts
Waukesha, WI
USA
Suzuki
Boulevard S50
|
Posted - 09/25/2007 : 10:32 PM
|
As Sigil said "stay off of the white road markings and off of metal manhole covers." While pavement may still have 80% traction when wet those painted marks on the road and metal covers can become very slippery.
From personal experience I'd add to that list tar strips. I was out on wet roads today going around a large radius curve when I felt the bike jerk a little as it slid off a tar patch. I generally avoid tar strips because they can hide cracks, uneven pavement, and get soft in hot weather. It never occurred to me that they could be slippery when wet, and if it was mentioned in the BRC I missed it.
I'll be more careful from now on.
Regards,
Mike |
Edited by - Tburd on 09/26/2007 8:22 AM |
|
|
|
tmonroe
Advanced Member
693 Posts
[Mentor]
Seattle, WA
USA
Kawasaki
ZX-10R
|
Posted - 09/26/2007 : 12:32 PM
|
quote:
Originally posted by thorolson
So should I take as a guideline the 75% rule? Reduce the lean to no more than 10-degrees or so? (Never mind that I have no sense yet for how much lean I take on in a curve).
It almost sounds like you might think you can change the amount of lean for a given turn.
The truth is, you can, but only by adjusting your speed. The amount of lean for a given turn can be calculated if you're given the speed and the radius of the turn.
In other words, the only way you can control how much you (IE you + bike) lean is by adjusting your speed... or riding a different radius curve...
(to be technically correct, I should probably say something about leaning your body into the turn leans the bike out... that's what I mean by "(IE you + bike)"... add to one, take away from the other).
Which tells you that to decrease your lean angle on a given road, you're going to be riding slower.
Here is where the advice to a newbie comes in - don't ride on a road with heavy traffic in the rain, where you feel like other vehicles are "rushing you". In other words: any turn can be made by any rider at some speed, but if you're going far too slowly, at some point, you're going to start to feel pressure from frustrated motorists behind you who are bothered by the fact that you're taking that corner marked as safe for 35 MPH at 16 MPH. At that point, some drivers may start to ride too closely behind you, or do other, more aggressive things to "hurry you along".
I also wouldn't get so caught up in trying to gauge G forces or lean angles at this point. You should pretty much feel comfortable riding corners in just about any conditions at the rated speed (the speed on the cautionary signs) - if not, I wouldn't ride on the streets yet. After you ride enough different corners, you'll start to get a feel for how fast you should be going on a given corner before you enter it - even if it doesn't have a sign.
Racers measure cornering clearance (lean angle) by sticking their knees out to touch the ground... you should never, ever be ANYWHERE NEAR that far leaned over on a public street.
If you are interested in performance riding, I would recommend looking for a track school - but only after you have more experience. I've taken several, and I believe they make me safer on the street - but I still don't ride on the street like I do on the track.
|
|
|
|
thorolson
New Member
16 Posts
Minneapolis, MN
USA
BMW
R1200RT
|
Posted - 09/26/2007 : 11:12 PM
|
quote:
Originally posted by tmonroe
quote:
Originally posted by thorolson
So should I take as a guideline the 75% rule? Reduce the lean to no more than 10-degrees or so? (Never mind that I have no sense yet for how much lean I take on in a curve).
It almost sounds like you might think you can change the amount of lean for a given turn.
The truth is, you can, but only by adjusting your speed. The amount of lean for a given turn can be calculated if you're given the speed and the radius of the turn.
No, I know the lean is the effect, not the cause, of the turn. I was trying to find some way of judging how much slower I need to go when I find myself on wet pavement. It is a bit of a problem however, since even on dry pavement I make turns that are at the edge of what is "comfortable" for me, without knowing how much margin I actually have from losing the tire's grip on the road.
I have read on this forum that tire friction is around 1.0, permitting up to 45-degrees lean. How can I judge what my lean actually is, and how close to that (dry pavement) limit I am?
Thor.
|
|
|
|
Bodhislackva
Junior Member
70 Posts
The Redneck Riviera, FL
USA
Ducati
900 SP
|
Posted - 09/27/2007 : 2:10 AM
|
quote:
Originally posted by thorolson
I have read on this forum that tire friction is around 1.0, permitting up to 45-degrees lean. How can I judge what my lean actually is, and how close to that (dry pavement) limit I am?
Here's a redneck data acquisition technique. You'll need a plumb bob, a level, a protractor, a magic marker, and duct tape. These are usually on the floor of the pickup in front of the passenger seat. You can use masking tape if you don't have duct tape, but it won't be as accurate. You're going to build a simple attitude indicator just like on an airplane but different.
Put your RT on the centerstand. Tape the plumb bob on about 10 inches of string to the top center of the inside of your windscreen. Run a line of duct tape at level from edge to edge of the windscreen on the inside—just stretch it across so the plumb bob's line transects the tape; the tape doesn't get pushed against the windscreen, it just floats in the breeze. Use the protractor to measure 10-degree increments on the tape by swinging the plumb bob across the tape and reading its angle on the protractor. Adjust as needed and mark your angles.
Now you will have a gravity sensor hanging off the inside of your windscreen and an artificial horizon made of duct tape with witness points for various degrees of lean. When you corner, the plumb bob will do a good imitation of remaining at vertical and appear to move across the tape as the bike leans. Accelerate and brake gently since the plumb bob exhibits substantial inertia and will illustrate Newton's first law of motion all over the place.
Conduct your cornering study in an empty parking lot since you'll be too distracted to cope with traffic. |
|
|
|
D R
Advanced Member
727 Posts
[Mentor]
Northern, Virginia
USA
BMW
R1200RT
|
Posted - 09/27/2007 : 2:53 AM
|
quote:
Originally posted by Bodhislackva
quote:
Originally posted by thorolson
I have read on this forum that tire friction is around 1.0, permitting up to 45-degrees lean. How can I judge what my lean actually is, and how close to that (dry pavement) limit I am?
Here's a redneck data acquisition technique. You'll need a plumb bob, a level, a protractor, a magic marker, and duct tape. These are usually on the floor of the pickup in front of the passenger seat. You can use masking tape if you don't have duct tape, but it won't be as accurate. You're going to build a simple attitude indicator just like on an airplane but different.
Put your RT on the centerstand. Tape the plumb bob on about 10 inches of string to the top center of the inside of your windscreen. Run a line of duct tape at level from edge to edge of the windscreen on the inside—just stretch it across so the plumb bob's line transects the tape; the tape doesn't get pushed against the windscreen, it just floats in the breeze. Use the protractor to measure 10-degree increments on the tape by swinging the plumb bob across the tape and reading its angle on the protractor. Adjust as needed and mark your angles.
Now you will have a gravity sensor hanging off the inside of your windscreen and an artificial horizon made of duct tape with witness points for various degrees of lean. When you corner, the plumb bob will do a good imitation of remaining at vertical and appear to move across the tape as the bike leans. Accelerate and brake gently since the plumb bob exhibits substantial inertia and will illustrate Newton's first law of motion all over the place.
Conduct your cornering study in an empty parking lot since you'll be too distracted to cope with traffic.
You could obtain an inclinometer(see link for an example) and attach it with double sided tape.
http://www.riekerinc.com/M-Inclinom...s_BrochW.pdf
Of course it may not be as easy to read (at a glance) as the redneck version, but it would be less distracting. |
|
|
|
sporty
Senior Member
310 Posts
north liberty, ia
USA
Harley-Davidson
Dyna & Sportster
|
Posted - 09/27/2007 : 7:22 AM
|
What's the point of measuring the lean
angle when the bike's not moving????
(think carefully)
:-)
-Willy
|
|
|
|
thorolson
New Member
16 Posts
Minneapolis, MN
USA
BMW
R1200RT
|
Posted - 09/28/2007 : 8:31 AM
|
quote:
Originally posted by sporty
What's the point of measuring the lean
angle when the bike's not moving????
(think carefully)
:-)
-Willy
Yes, that was my initial reaction too-- Why would a plumb bob (or inclinometer) respond to gravity, but not centrifugal force? I think it would take the same angle as the bike, always reading a lean of zero.
The idea of establishing a virtual horizon line is a good one though. I could look through the windshield at the actual horizon, and estimate the angle it makes with the windshield baseline reference.
Thor.
|
|
|
gershon
Ex-Member
|
Posted - 09/28/2007 : 9:46 AM
|
quote:
The idea of establishing a virtual horizon line is a good one though. I could look through the windshield at the actual horizon, and estimate the angle it makes with the windshield baseline reference.
When I taught students how to fly, I used to tell them that if they focused on the windscreen in order to determine their horizon, they would be able to see any other aircraft between them and the windscreen, so I don't think what follows is a good practice in reality.
There really is no need to determine your lean angle. Just keep a safe speed for the conditions and your lean angle will determine itself.
So, what follows is for fun.
First sit on your bike and look straight ahead through the windscreen and put a dot on the windscreen and a dot on your helmet visor. These two dots will have to be lined up in order for it to work.
Then have someone hang a big protractor in front of you sideways. And you will have them make a mark where each 5 degrees is seen through the windscreen. Do this on both sides and then you will have something that looks like the tips of cat whiskers.
The horizon would line up with each degree marking and you would know your lean angle.
The only problem with all this is your lean angle is determined before you enter the turn by the speed you enter the turn. So, for real life, I'd recommend reading "Proficient Motorcycling" starting on page 56 for cornering lines. There is also some good information for recognizing a negative camber and how to recognize how sharp the curve is.
When I was starting out, I found a 30 mile route that had a good number of curves and not much traffic. I practiced them 5 mph below the speedlimit focusing on maintaining a perfect line through the curves and rolling on the throttle just a little bit in the curve. I kept doing this until naturally found myself going faster. I also observed the advisory limits which are pretty good in Colorado, but more of a dare in Montana. It is a good idea to determine the speed you will enter the turn independent of advisory limit signs and just use them to confirm your decision.
I don't have a lot of experience in rain, but I just go a little slower and don't worry about it. If it rains too hard, I stop to eat. |
|
|
|
twc
Advanced Member
659 Posts
[Mentor]
Fort Collins, CO
USA
Harley-Davidson
Electra Glide Ultra
|
Posted - 09/28/2007 : 10:43 AM
|
quote:
Originally posted by thorolson
Yes, that was my initial reaction too-- Why would a plumb bob (or inclinometer) respond to gravity, but not centrifugal force? I think it would take the same angle as the bike, always reading a lean of zero.
Hmmmmm. I'm not sure it's quite that simple, but I'm going to wait for Jim to weigh in after he's moved this discussion to the "Physics" section .
My intuition says that a clinometer would be affected to some degree (Sorry!) by centrifugal force, but the needle wouldn't read zero. A quick search produced evidence of patents to counteract the effect of centrifugal force on clinometers, suggesting that design would have an impact.
In any case, it's an easy and inexpensive experiment to try. I knew sailboat racing would eventually have some cross-domain applications!
|
|
|
|
James R. Davis
Administrator
14909 Posts
[Mentor]
Houston, TX
USA
Honda
GoldWing 1500
|
Posted - 09/28/2007 : 11:13 AM
|
LOL
The idea of using a plumb bob on your windscreen to show you what lean angle you are describing will work only if the bike is NOT moving. (You lean the bike and can read what its lean angle is from the protractor.)
If the bike is moving then that bob will react to centrifugal force and will point to zero. That is, it will always point to where the combined bike/rider center of gravity is. If you lean your body into or out of the turn, then the pointer will show you how much you have affected the lean angle of the bike (only).
As to reading specifics in the article about advisory speed signs ... if you ride your bike on any curve (with a constant radius) that has an advisory speed of 35 MPH, you WILL be leaning somewhere between 10 and 14 degrees because that's how the signage was determined. All that means is that NOBODY should ever lose control of their vehicle in that curve from loss of traction if they are moving at 35 MPH while doing so. Now, if the roadway is wet and you are traveling it at 35 MPH, your lean angle will still be between 10 and 14 degrees, of course. A roadway that has a coefficient of friction with your tires of, say, .8 when it is dry will still have a coefficient of friction of about .64 when wet. Since a lean angle of even 14 degrees is only experiencing a lateral acceleration (centrifugal force) of about .22g's, you will be nowhere near losing traction while riding that wet road at 35 MPH.
Also, as to reading too much from the specifics found in other articles ... your tires have a MAXIMUM coefficient of friction with a roadway of about 1.1 assuming that roadway is dry, is made of coarse concrete, and your tires are made of good (street) rubber with plenty of tread on them. But most roadways provide a coefficient of friction of no more than about .8 (asphalt is lower than concrete, for example). |
|
|
|
Discussion Topic |
|
|
|
|
Most Recent Posts
|
Activity History
|
Safety Tips
Riding in the rain, aka "wet turns"