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Three-Wheeled Vehicles
A few sobering realities

By: James R. Davis



I must admit, converting my Wing to a trike has been thought about. So, too, have I thought about adding a sidecar. If two wheels are fun, three might be all the better, right?

Perhaps, but not for me.


I suffered from a delusion that many of my fellow riders seem to have - that three wheeled vehicles would be easier to drive because they are more stable as a result of lacking any lean. Yes and no.

People have sent me many messages regarding their experiences on three-wheelers and I will use this Tip to share with you what they had to say.

  • There is NO COUNTER-STEERING involved when driving a three-wheeler. If there was no other reason to be careful about these machines, this one should at least tell you that you need to practice driving one before you take it out onto public streets!


  • Front wheel traction is COMPROMISED in turns. You must drive more slowly in a curve than you would with a normal motorcycle because unlike with a two-wheeler which leans and therefore almost always has the front wheel aligned with the bike's body, a three-wheeler must be steered by actually turning the wheel. Thus, the bike's inertia is constantly trying to straighten that wheel, or ride over it. At similar speeds a three-wheeler will lose front wheel traction sooner than will a two-wheeler.


  • Both rider and passenger are substantially stressed during turns. The bike stays level so they are both forced by centrifugal force towards the outside of their seats. Indeed, one person actually told me that he installed a SEAT BELT for his passenger on his trike for this reason!


  • Trike handling is generally superior to that of motorcycles with sidecars, particularly those that do not allow some lean of the motorcycle on curves. Sidecar handling in a curve is typically described as "constantly pulling to one side when accelerating or decelerating, and requiring constant steering adjustments in turns."


  • Changes to a standard motorcycle that are ideal for making a sidecar handle better (such as shortening the trail of the front-end or using a flatfooted automobile tire on the sidecar), make the motorcycle almost unrideable without the sidecar (if detachable - a rather dumb idea, in my opinion) or if there is insufficient weight in the sidecar.


  • With or without an automobile tire, an empty sidecar proves to be more difficult to handle than when occupied with a passenger or load, for some people. One person reports that the sidecar manufacturer actually advises that he put a 50 pound load into it if unoccupied, for stability and handling.


  • Unlike the conclusion that riding a two-wheeler leads you to, a sidecar's wheel can be lifted (dangerously) only when turning TOWARDS it (to the right, if mounted on the right side, for example.) This is the result, as described above, of having to steer the bike by turning the front wheel rather than by leaning it. Note, please, that as soon as the sidecar's tire leaves the ground you will once again be a two-wheeler. Since the bike would at that point be leaning heavily away from the curve you would INSTANTLY get a severe COUNTER-STEERING push in the direction of the lean!!!

(Actually, one person advises that this is not really a severe reaction and manifests itself somewhat gradually - depending on the height of the lifted wheel.)

  • Similarly, and just as unexpected based on two-wheel experience, if you take a turn too fast in a direction AWAY from the sidecar you run the risk of actually lifting the REAR wheel off the ground and nose diving the rig (i.e., a highside.)


  • Despite the fact that a flatfooted automobile tire would be ideal, the tires found on sidecars are almost always NOT a standard automobile tire. It has been found on some occasions that Honda 15" motorcycle rims were fitted with standard 15" automobile tires with less than comforting results. Automobile rims actually have a SMALLER inside diameter than do motorcycle tires. Unless the rim has been specifically designed to automobile specifications you should NEVER mount an automobile tire on a sidecar. I suppose it also could go without saying, but while I'm at it, one should NEVER inflate the tire on a sidecar (indeed, any tire) in excess of the pressure recommended by the tire manufacturer (they have been known to KILL when exploding.).


  • Mounting a sidecar on most motorcycles will void the motorcycle warranty and many (possibly most) dealership shops will not take them in for service.


  • Both acceleration and mileage are less with either a sidecar or a trike rig than a standard motorcycle.

This Tip is designed to forewarn rather than to discourage. I know several elderly riders that can no longer manage a two-wheeler who routinely ride three-wheelers without any trouble at all.

On the other hand, I know a woman who decided to 'practice' driving her husband's Wing with its new sidecar on the public streets. She put her daughter in the sidecar and her husband rode as passenger. There would be no high speeds for her - this was just a 'get familiar' ride.

At the very first turn she had to make at normal highway speeds she lost it. The daughter was flung out of the sidecar and was hurt, but not badly. The husband sustained a broken collar bone. But the motorcycle landed on top of the lady. It destroyed many of the organs in her pelvic area as well as broke many bones. (She survived it - barely.)

Thus, the point of this Tip is that three-wheelers do not handle like two-wheelers and REQUIRE practice other than on public roads before you should feel confident to venture out among 'em.

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http://www.msgroup.org

(James R. Davis is a recognized expert witness in the fields of Motorcycle Safety/Dynamics.)

     
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