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Technique
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zentime



Joined: 22 Jan 2005
Posts: 831
Location: Massachusetts USA

PostPosted: Thu Mar 03, 2005 1:24 pm    Post subject: Reply with quote

Again, thought provoking posts from Larry Hal and Claude. Hal touched on the fact that there are significant differences in riding and the set up of a conventional rig and a HPS rig. I couldn't agree more.
Quote:
Typically, in full race mode, cornering is very nearly damn near flat with perhaps just a minor lift of the sidecar wheel so the talk of countersteering with a HPS rig is really absurd. But it can happen.

While undeniably traditional and HPS rigs share some common attributes, it's crystal clear to me that much of the conventional sidecar wisdom simply doesn't apply to the HPS world.

Quote:
So - by making your rigs lower and wider you get a more stable rig -but then - you knew that already without me telling you anyway

Laughing Laughing good point but it makes for interesting conversation. Wink Hopefully this forum will become a resource for anyone looking to move beyond traditional sidecars and this kind of material will be beneficial.
bill
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bmcsheehy



Joined: 22 Jan 2005
Posts: 977
Location: Massachusetts USA

PostPosted: Thu Mar 03, 2005 2:50 pm    Post subject: Reply with quote

This whole topic was way too technical for me.
I only a few hundred miles on HPS.
I think the best way to learn is by doing. Start slow then gradually increase the speed.
Also, every rig may behave differently, I need to learn how to ride my rig.
My main objective;
On a right hander, keep the sidecar wheel on the ground. On a left hander, keep the rear wheel of the bike on the ground.
If either of these two things happens, and you’re out of control, you’re going too fast.
I also think that driving these HPS things is more an art form than a science.
Confused
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Bill
High Performance Sidecaring... ...There is nothing "HACKED" about it.
2006 ZX-14 / HANNIGAN HP.
2011 Concourse / California Friendship III.
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www.Yankee-Engineering.com
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docmike



Joined: 27 Jan 2005
Posts: 630
Location: Eastern NC

PostPosted: Thu Mar 03, 2005 2:56 pm    Post subject: Reply with quote

This seems to fit with what I've been learning by experience.

Prior to getting my rig on the road I read all I could find on sidecar driving. It can be a little intimidating. After reading the "yellow book" I wasn't even sure I wanted to continue with this. All talk of steering reversion and sidecars flipping into the weeds. My wife read all the same information, it took a while to convince her to even get in the sidecar.

The first week I had the rig I almost had a pasture experience when I overreacted in a right hand turn.

Occasionaly when the the sidecar wheel did come off the ground, I just kept the same track and came out OK. It did have me wondering what was going on, I never experienced the sudden change of direction I was expecting.

Lifting the wheel happens a lot less with the sway bar. (Ya hear that Jay. Smile )

I have been trying to follow the late apex line when possible.

And Ralph, its hard to learn by following you when I cain't seem to keep you in sight most of the time Worship
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legalr



Joined: 30 Jan 2005
Posts: 163
Location: Wallingford, Vermont

PostPosted: Thu Mar 03, 2005 2:56 pm    Post subject: Technique and Other Things. Reply with quote

Quote:
On a right hander, keep the sidecar wheel on the ground. On a left hander, keep the rear wheel of the bike on the ground.
If either of these two things happens, and you’re out of control, you’re going too fast.


I'm going to remind you of that at Maggie Valley this June. Big Grin Laughing
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bmcsheehy



Joined: 22 Jan 2005
Posts: 977
Location: Massachusetts USA

PostPosted: Thu Mar 03, 2005 3:00 pm    Post subject: Reply with quote

That's so funny.
You probably will.
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Bill
High Performance Sidecaring... ...There is nothing "HACKED" about it.
2006 ZX-14 / HANNIGAN HP.
2011 Concourse / California Friendship III.
1936 Ford Fordoor Humpback
www.Yankee-Engineering.com
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Paul



Joined: 27 Jan 2005
Posts: 182
Location: Utah

PostPosted: Thu Mar 03, 2005 3:22 pm    Post subject: Steering reversion Reply with quote

swaybar2002 wrote:
Flying the chair with steering reversion in effect and hard cornering with the sidecar wheel off the ground ARE NOT the same thing.


It would seem that steering reversion would depend on the tire profile.

A typical Harley outfit, with motorcycle tires, may well experience reversion very soon after the chair leaves the pavement. But, with car tires, the same isn't true - with the chair only slightly off the ground, the bike is still riding on the flat part of the tire, and so will steer normally.

I had the entertaining experience of riding a sidecar bike solo once - a Kawasaki with EML wheels and car tires, without a sidecar. It most certainly did NOT handle like a normal motorcycle. On the straights it handled like a sidecar bike - steer right, go right. But in a curve, when you got up onto the corner/sidewall of the tires, it would countersteer. Like I said - a very entertaining experience.
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hal



Joined: 03 Mar 2005
Posts: 4
Location: Houston, TX

PostPosted: Thu Mar 03, 2005 3:57 pm    Post subject: Reply with quote

Paul: I cannot really explain the unusuall steering effect you experienced when riding the sidecar bike as a solo machine except to say that typically the trail is smaller, and the steering damper is much tighter. This makes steering input considerably different from normal solo handling where you expect the bars to be free. Free swinging bars and sidecars do not go together. Any bike set up for sidecaring would feel "funny" regardless of whether the tires were round, vee, or flat.

As far as the H-D going into a steering reversion - it also obeys the fundamental laws of physics as does the HPS rig - it does not do this until the overturning moment is equal to the restoring moment which means that the sidecar wheel is way way up there in the sky. The center of gravity must be directly OVER the line between the tipover line between the front wheel and the real wheel.

Go to our website at http://photos.groups.yahoo.com/group/SCT/lst
and look at my photos numbers 14, 15, and 16 to see just how high the sidecar rig must be in order for steering reversion to occur. With the sidecar wheel less than this the rig is just cornering normally, albiet perhaps aggressively, and is this not what this is all about?

Enjoy.
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Paul



Joined: 27 Jan 2005
Posts: 182
Location: Utah

PostPosted: Thu Mar 03, 2005 7:12 pm    Post subject: Reply with quote

Hey Hal, long time no see.

hal wrote:
Paul: I cannot really explain the unusuall steering effect you experienced when riding the sidecar bike as a solo machine except to say that typically the trail is smaller, and the steering damper is much tighter.


This bike had the standard Kawasaki forks, and no steering damper. (No chair = nowhere to attach the other end of the damper!). Really a stock bike other than EML wheels and the 125/15 car tires.

Solo bikes steer by leaning - the turning of the bars really just initiates the lean. Leaning a flat-profile radial car tire isn't that easy to do - so the bike wanted to stay dead upright. Hence steering normally worked for small corrections. Large steering inputs would indeed initiate a lean, which is where things got strange.

hal wrote:
Free swinging bars and sidecars do not go together.


Why? If the steering geometry is correct there shouldn't be a need for one, or at the very most a very light one. The traditional VW beetle damper is way too stiff for any sort of enjoyable motoring. (Of course, I *like* fast light-steering motorcycles, what others usually call "twitchy").
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hal



Joined: 03 Mar 2005
Posts: 4
Location: Houston, TX

PostPosted: Thu Mar 03, 2005 7:42 pm    Post subject: Reply with quote

Gotcha - but did you check how TIGHT the steering head bearings had been pulled down? Many sidecarists do not use the old fashioned VW type stabilizers but much prefer to tighten down or pinch down on the steering head - a cheap form of the old friction damper which I personally favor. I would check that out.

If you had a solo machine with standard forks and a friction damper then for solo riding you would back off all tension and the forks would be swinging freely. For sidecar work you would apply just sufficient tension so that the tank slappers do not come upon you, but still allow you to retain easy steering. The steering should still be light enough that the rig should self straighten automaticly and easily after you turn without any effort on your part. Many times with heavy VW stabilizers this will not happen and yoiu have to wrench the rig into a corner then wrench them back to straighten them out again. Way too much dampening.

But back to the point. If you take a bike which has a friction damper and drive it solo, then if you gradually crank up the friction on the damper to where you would as if you were actually pulling a sidecar, then you would find that the same bike would have an entirely different set of riding characteristics. It would be almost unridable. This I have done. It would seem as if everything you did was wrong and all your gut instincts had been turned upside down. You would be leaning over the wrong way. It would be balls up. A helluva bad experience. A solo bike must have free swinging bars.

Maybe, this is a similar experience? I do not know, but it sure sounds like it. Or maybe it really is the tires. Just another viewpoint.
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Books on sidecaring available free at:
http://www.sidecar.com/links3.asp
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JayBoy



Joined: 26 Jan 2005
Posts: 234
Location: Lexington, KY

PostPosted: Thu Mar 03, 2005 10:14 pm    Post subject: Reply with quote

Quote:
Lifting the wheel happens a lot less with the sway bar. (Ya hear that Jay. )


Or the proper shocks. Very Happy I'm all ears, really I'm anxious to get my sidecar shock back from Penske, once that's dialed in we'll work on the front....after that we might need a swaybay. Big Grin

Quote:
F = m V x V / r;


Critical to negotiating Right handers in Zoom Zoom mode is in the approach...as someone said slow in fast out. Fast in has its own simple formula:
F=fear when mv (mucho velocity) x V (Vigor) / r (reason) Shocked

I've just been riding a sidecar for two years so I have very little experience but I have noticed a few things;

Right handers: If the sidecar wheel comes up before the apex...you're screwed. (translate...slow down asap and look for a safe exit!)
If the sidecar wheel comes up at the apex a slight fethering of the rear brake has a nice settling effect on on the sidecar as the sidecar starts to fly.
If the sidecar wheel flies after the apex...hammer it and hold on!

I can't wait to test these theories!
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