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Newby question
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Posted 7/31/2012 6:34 AM (#66005)
Subject: Newby question

What causes the ”chair” to come off the ground? How do you prevent it and get the chair back on the ground? Thanks
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Posted 7/31/2012 9:34 AM (#66006 - in reply to #66005)
Subject: Re: Newby question

Posts: 4833
Location: Boise, Idaho
When the car lifts in a right turn (US) it is because you do not have enough ballast in it to overcome centrifical force. In a left turn the car works as an outrigger.
A good check for enough sidecar weight is to turn the bars to the right and stand on the left footrest, pull away from the bike and if the sidecar raises easily you need more weight added. Preferably to the rear and away from the bike side. This can be soft removable ballast or permanent weight attached to the frame of the car.

More about this ia available from books that can be seen at this website.

Northwest Sidecars
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Reardan Tom
Posted 7/31/2012 11:04 AM (#66008 - in reply to #66005)
Subject: Re: Newby question

Posts: 1198
Location: Reardan, WA
Instinct might tell you to turn left to make the car sit back down. Instinct won't necessarily tell you in that moment that driving into oncoming traffic is much more detrimental to your health.
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Posted 7/31/2012 1:04 PM (#66011 - in reply to #66008)
Subject: Re: Newby question

Posts: 1642
Many things can cause the chair to come up including if the chair is to light. How wide it is mounted, if you hit a bump, your passenger moves or any number of other things. If at all possible take a sidecar class, you will learn a lot. if you can not do this buy a copy of David Hough's book "driving a sidecar outfit" also known at the "yellow book" and read it and pracitce what is in the book. White horse press offers the book as do we. $34.95 from us. We also have the book on ebay.
Jay G
DMC sidecars
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Posted 7/31/2012 4:40 PM (#66019 - in reply to #66005)
Subject: Re: Newby question

Thanks guys! I will get the book ordered.
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Posted 7/31/2012 6:22 PM (#66021 - in reply to #66019)
Subject: Re: Newby question

You can also download Hal Kendals books here for free and start reading right away.

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claude #3563
Posted 8/13/2012 6:14 PM (#66236 - in reply to #66021)
Subject: Re: Newby question

Posts: 2498
Location: Middleburg, Pa
..Here is an email that Hal Kendal recently copied me on regarding lofting the chair. What you will lread below is Hal's reponse. I think his reponse was quite good.

Hal Wrote:
""You are correct in that flying of the chair is the source of widespread ignorance and consequently ill judgement at times. The problem is that there is not one physical concept but two entirely different physical concepts at play, and the false tales arise when one tries to combine both concepts into a single package.

The first is when the rig is driven in a spirited fashion. This by definition may be turning slowly but with a very light chair, or turning sharply, again with a light chair. Yes, it is very easy to "loft" the chair. By contrast, a light bike with a very heavy chair might be driven hard and tight and not lift the chair, or is very difficult to lift. Both these extreme cases are in fact similar and obey the basic physical laws of motion and turning, which induces a force acting through the center of mass or gravity outwards. This in turn produces an overturning couple or moment tending to cause the rig to lift up. Countering this is a restraining couple or moment made up of the total weight of the rig (plus occupants or gear) tending to keep the sidecar tire and wheel planted on the ground. At first, you will just compress the suspension of the bike and unload the compression on the sidecar spring. The rig will just feel a trifle lighter.

As you either increase your speed, or tighten the turn you will reach a point where the sidecar tire and wheel is just off the ground. This also happens to ANY two track or three track vehicle, whether a trike, a car, or a truck. And as you increase your speed or tighten you turn a bit more so the sidecar tire will begin to come off the ground, just as the inside front wheel of any sports car will come off the ground. No biggie. But the problem is that under these conditions you are NOT flying the chair - just driving the rig in a spirited fashion. To go right you turn the bars to the right, and to go left you turn your bars to the left. This is because your center of gravity, even when the rig is slightly airbourne is to the right of the tipover line between the bottom of your front tire and the bottom of your rear tire.

Now, either go faster or turn even more tightly. As you do so so the point where your center of gravity meets the road surface begins to edge closer to the tipover line and the rig gets even lighter. But, as long as it is to the right, then normal steering continues. Again, just spirited driving. And you are still in command of a two trak vehicle, abiet a lopsided one with a lousy weight distribution.

However, when the center of gravity finally reaches the tipover line all hell breaks loose. You are no longer driving a two track vehicle but a lopsided single track vehicle, like a bicycle or a solo motorcycle. And just as you steered your solo at speed by countersteering so you must now control your rig by countersteering. And you are truly flying.

This state of affairs came about by a misguided solo expert who claimed that even when the rig was on the ground and you were going straight that if you hit a pothole you would indeed have to countersteer. This unproven concept was unfortunately upheld by a vast sidecar population and took several years to get this misguided concept out of the general sidecar population. It is worth noting that this idea that the sidecar was indeed flying at any time the sidecar tire left the ground has never found favor in Germany, the UK, Japan, or Australia going back as far as the early 1900s. By not distinguishing under what condition it takes to actually make the rig fly this has been the source of the confusion.

It is also worthy of note that any car with a positrack rear end or locking differential can be made to fly about as easily as a rig if you know how to do it. And even large trucks and semis with trailers can also be made to fly. They all follow the same physical laws. In this there is nothing special about a rig. One must learn to deal with its eccentricities - by practice, practice, practice.

A final note, flying the chair is just as illegal as is a stoppe or a wheelie on a solo. And if a bobby, smokey, or copper observes this he is just as likely to write you a ticket for dangerous driving. A few years ago I personally served as an amicus curie or friend of the court for a sidecarist who, while driving in a spirited fashion was ticketed by a smokey in backwards, LA. I got him off by advising the court on the dynamics of a sidecar rig. Had he been actually flying the chair I would not have intervened.

This is explained more fully in my manuals, available on the USCA website, No charge. Just download.""

Hal Kendall

Edited by claude #3563 8/13/2012 6:15 PM
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Posted 8/14/2012 4:10 AM (#66242 - in reply to #66005)
Subject: Re: Newby question

Thanks for the very through explanation. I did purchase a copy of Driving a sidecar out so now it's just waiting to get my new hack and practice practice practice . Thanks Claude.
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