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PostPosted: Thu Sep 29, 2011 19:52 pm 
Windbag

Joined: Tue May 24, 2005 21:27 pm
Posts: 64
Location: North Manchester
stix wrote:
Chair doesn't have to have suspension but it does help a bit,if no suspension you must use a steel wheel and not a spoked one as the forces WILL snap the spokes.
I understand you are on a tight budget but take a look at an indespension unit,small light pretty easy to fit and it will give you a reasonable amount of suspension.

http://www.indespension.co.uk/b2c/app/I ... 003&slnk=1

Stix


A chair without suspension will usually handle better because the steering geometry doesn't change. Spokes can be a problem but most sidecars in the 1930's managed and there was probably more about then than at any other time and the bikes had rigid rear ends as well. The platform must be fixed rigidly to the bike by at least 4 anchor points, 2 at high level and 2 at low. Search the net for Hal Kendal's sidecar manual, ignore all the other advice you get. Hal is probably the worlds leading expert on chairs and his stuff is superb. Yahoo sidecar groups is a good source of worldwide info as well, Hal posts on there sometimes.

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PostPosted: Fri Sep 30, 2011 06:31 am 
Hurricane

Joined: Mon Dec 13, 2004 11:12 am
Posts: 341
Location: Cumbernauld, Scotland
Agree bout Hal Kendal, he does have a lot of experience

I set mine up wi the recommended amount of lead but the front of the sidecar sat about 4 or 5 inches ahead of the front of the bike, same at the rear. Now as ny sidecar is the same length as the bike I moved it back until they were level at the front and the rear..... ie. If I hit a wall (not the best example I know?) they would both contact at the same time, can't remember how much lead I have now but it works ok for me.

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PostPosted: Fri Sep 30, 2011 08:07 am 
Apprentice

Joined: Sun Feb 21, 2010 19:05 pm
Posts: 21
Location: London
Lots of conflicting advice, which is never helpful as it causes confusion and doubt.

I agree with the Hal Kendall comments, he knows what he is doing. The most important piece of advice that Hal gives, is that there is no magic formula that always works, in terms of setup. All outfits are different.

However, If you start with 1/2" toe in, 2 degrees of lean out (with weight of a rider on the bike) and 8" to 12" of lead, you won't go far wrong.

As a sidecar manufacturer, I have some experience of setup and it's not rocket science, or black magic, but it is vital to get it right.

Here's Hal's advice on setup: Remember that he is talking about a right hand side sidecar, so reverse 'right' for 'left'.

1. There is NOT any single MAGIC number that will satisfy ALL bikes, sidecars, situations,



2. The range of generally acceptable values, including whatever H-D, BMW, and any other manufacturer suggest, is a starting place. The final value is what works for you, your driving style, the typical loading, the typical roads you drive over, whether flat super slabs or highly crowned county roads. Most seem to try for between 1/4 inch and 1-1/2 inches, or the equivalent in degrees if you have a new computerized BEAR toe-in machine in your garage. Sorry, I did add one too many zeros, it was near midnight when i posted. Say from 0.2 to 0.8 degrees.



3. The easiest way to measure is to line up the center of the front and rear wheels of your rig over a single straight painted line on the flat surface of a clean double garage. This eliminates the problem of how to take the difference in width of the front and rear tires into account. Make sure the front wheel is lined up dead ahead. Take a straight plastic pipe, 4" diameter, lay this alongside the sidecar tire. Cut the pipe to the same length as you measure from just in front of the front tire of the MC to just to the rear of the rear MC tire. The pipe guarantees that you get good tire point contacts on the front section and the rear section of the sidecar tire. Otherwise, take a 4" x 2" straight board, wide side flat, sitting on a front and a rear brick, again to get the reference points off the ground. Just at the rear of the rear MC wheel, measure from the line to the outside of the pipe, call this width "A". Just at the front of the front MC wheel, measure from the line to the outside of the pipe, call this width "B". Then toein is the difference, or the value "A" - "B".



4. This is your starting point. Test drive, Change until you get the very best handling. Do not make big changes.



5. All items work in harmony. Leanout, 1 to 2 degrees, or 1/2 to 1 inch, measured from the saddle. Use the line running up the centre of the rear tire to determine angle of bike.



6. Leanout wants to make the bike want to turn to the left. Picture a solo bike leaned over to the left, it wants to go left.



7. The drag of the sidecar wheel from its weight and the friction of the SC wheel axle and the drag of the SC tire, wheel, etc tends to want to make the rig go to the right.



8. The frontal area of the sidecar, build as a box with a drag of a stone, tends to make the rig go to the right, more so at higher speed.



9. The crown of the county road tends to make the rig want to turn to the right.



10. The toein of the sidecar wheel tends to make the rig turn to the left. Too much toein and you will get excessive tire wear, especially on the rear. I have shredded the rear tire from new in 700 miles with a near empty chair. You cause the tires to scrub against each other. If you see the tread is feathered you have a badly setup rig which will eat tires.



It is your task to balance all these right and left turning forces so that your rig goes straight ahead. A poorly setup rig will wrench your shoulder out of place in a few hundred miles. A well setup rig will be a pleasure to drive. This task is more easily resolved by fitting either an adjustable lean control, and/or an adjustable toe-in control



Bottom line - no magic numbers, just a place to start. If you have a BMW, begin with their recommendation, Same for H-D.



Remember, the smaller the trail, the more twitchy the steering. Racing outfits go down to near zero. Street hacks from 1.5 to 3.5 inches. For high speed solo tourers from 3.5 to 5.5 - no magic numbers. The larger the trail the larger the self-centering force. The smaller the trail the lower the self-centering force. Self-centering force is seen when the rig wants to straighten itself after you turn into a corner. It also helps to dampen the dreaded wobbles.



Lead is mainly to minimize the bike from flipping over on sharp left-handers. Keep weight in SC to rear. Too much lead causes more scrubbing force on lefthanders. Also on righthanders except that sidecar wheel is light because of centrifugal force. No lead makes for easier steering. Again, no magic numbers. Most seem to operate from 8 to 12 inches, some have gone to 15 inches.


<end of Hal's advice>

I would add that a well setup outfit, should track in a straight line on a neutral throttle on a flat road surface. On acceleration it will pull to the left. On braking or slowing, it will pull to the right.
If you ride mainly on crowned road surfaces (country lanes) then set your sidecar up accordingly.
Outfits with flat profile tyres front and rear will not normally need any lean out.
Narrow outfits (less track distance) will tend to lift the sidecar more easily, sidecar wheel lead is a factor in this, otherwise increase the track or use ballast when learning.

If in any doubt whatsoever, consult someone who knows what they are doing. A poorly fitted or badly setup sidecar can be extremely dangerous.
At best, you'll scare yourself and be put off sidecars (this happens a lot) or you'll hurt yourself.

Finally, reading about it is no substitute for experience.

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PostPosted: Fri Sep 30, 2011 08:50 am 
Windbag

Joined: Tue May 24, 2005 21:27 pm
Posts: 64
Location: North Manchester
Motopodd
I know you quote Hal, but yours is one of the best posts on the subject I have seen for years.

For myself (and I think on behalf of a lot of forum members) I thank you for posting.

Cheers
H

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PostPosted: Fri Sep 30, 2011 09:12 am 
Hurricane

Joined: Mon Sep 05, 2005 02:46 am
Posts: 332
Location: fordingbridge Hampshire
" Spokes can be a problem but most sidecars in the 1930's managed and there was probably more about then than at any other time and the bikes had rigid rear ends as well. "

They managed because the sidecar wheel HAD suspension,often in the form of a big rubber bush surrounding the spindle,if this is taken out of the equasion the spokes WILL snap,now ask how I know this!!!!!!.

Stix


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PostPosted: Fri Sep 30, 2011 09:14 am 
Apprentice

Joined: Sun Feb 21, 2010 19:05 pm
Posts: 21
Location: London
Thanks H,

I love sidecars and just want to promote their use, in all forms. So I'm always happy to give advice.
Sidecars seem to attract more nonsense-speak than almost any other form of transport, so it's good to try to dispel some myths.

If anyone wants to know anything else, just ask.

Cheers,

Rod

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 Post subject:
PostPosted: Fri Sep 30, 2011 09:21 am 
Apprentice

Joined: Sun Feb 21, 2010 19:05 pm
Posts: 21
Location: London
Regarding the spokes / suspension discussion, I can see no good reason not to have suspension on a modern, road sidecar, self built or not.

We use a roller bearing mounted swingarm, with a coil spring shock absorber.

Cost is minimal, even for the self builder, those indespension type units work well enough, the benefit is great. Handling is not a problem.

A heavily laden, unsuspended sidecar will transfer huge shocks through to your bike frame, plus, I'd be amazed if a spoked wheel could stay true for long taking this sort of beating, spokes would snap for sure at some point.

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 Post subject:
PostPosted: Fri Sep 30, 2011 09:41 am 
Windbag

Joined: Tue May 24, 2005 21:27 pm
Posts: 64
Location: North Manchester
stix wrote:
" Spokes can be a problem but most sidecars in the 1930's managed and there was probably more about then than at any other time and the bikes had rigid rear ends as well. "

They managed because the sidecar wheel HAD suspension,often in the form of a big rubber bush surrounding the spindle,if this is taken out of the equasion the spokes WILL snap,now ask how I know this!!!!!!.

Stix


I've ridden chairs for many years and include vintage outfits. My first was a rigid M20 with a rigid chassis. some chassis had rubber cushioning but this was usually on the higher quality ones, many didn't and the tyre was run a little soft to compensate .

I said 'spokes can be a problem' , I didn't say they won't snap. with proper care and maintenance, this can be minimised. My current road legal rides are 2 outfits ,both with spoked wheels , 1 has 156000 miles on the clock and the other has 12000. I can't remember changing a lot of spokes on chair wheels but it is certainly something that happens with the pusher. About 30 years ago, I did snap a sidecar wheel spindle on a rigid chassis (NO rubber bushes) and then modified the chassis to provide outboard support for the new spindle.

The best handling outfit I have ever ridden was a completely rigid kneeler racing unit running on wide car tyres and hub centre steering. Whilst I wouldn't have liked to ride it on bumpy roads, it was superb on a smooth race track. That said, suspension on a chair chassis is always a good thing to have but it needs to be fairly firm, soft suspension can make the outfit a horrible thing to ride. jus another part of the 'black art' to take into account.

I've heard of Motopodd's reputation and maybe 1 day , maybe I'll be able to get hold of one of his set ups to try.

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 Post subject:
PostPosted: Fri Sep 30, 2011 10:05 am 
Windbag

Joined: Thu Nov 25, 2010 21:30 pm
Posts: 65
Come on guys, let's not argue over this please. I know there are thousands of different ways to set a chair up properly and all can be correct.

By the way, I was very nearly born in the Watsonian DA chair attached to a Norton 16H of indiscriminate age.


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PostPosted: Fri Sep 30, 2011 10:23 am 
Windbag

Joined: Tue May 24, 2005 21:27 pm
Posts: 64
Location: North Manchester
billtr96sn wrote:
Come on guys, let's not argue over this please. I know there are thousands of different ways to set a chair up properly and all can be correct.



Who's argueing? just a very interesting discussion an one of my favourite subjects. It's not that often that so many afficianados turn up in one place :lol:

You've now got some very good advice, lets see some pictures soon to prove you've followed it.

BTW, welcome to the mad, mad world of sidecarists. :ROTFL:

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 Post subject:
PostPosted: Fri Sep 30, 2011 10:32 am 
Apprentice

Joined: Sun Feb 21, 2010 19:05 pm
Posts: 21
Location: London
No argument here!

As everyone agrees, there's more than one way to skin a rabbit. :)

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 Post subject:
PostPosted: Fri Sep 30, 2011 10:58 am 
Hurricane

Joined: Mon Sep 05, 2005 02:46 am
Posts: 332
Location: fordingbridge Hampshire
We use a roller bearing mounted swingarm, with a coil spring shock absorber.

Suspension then!!!!

No argument from me either just passing on my experiences from the 60.s when I lost my leg and had to use a chair for stability and family carrying.

stix


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PostPosted: Sun Feb 05, 2012 11:05 am 
Windbag

Joined: Thu Nov 25, 2010 21:30 pm
Posts: 65
Time for the pics you asked for. I have put a few hundred miles on it now and love it!

Image

In progress
Image

Image


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 Post subject:
PostPosted: Mon Feb 06, 2012 20:28 pm 
Apprentice

Joined: Sun Feb 21, 2010 19:05 pm
Posts: 21
Location: London
Glad you got it sorted Bill, and are obviously enjoying it! Great stuff!

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PostPosted: Mon Feb 06, 2012 21:56 pm 
Windbag

Joined: Thu Nov 25, 2010 21:30 pm
Posts: 65
I honestly think it is the best thing I could have done.

Thanks for the input you gave as well, much appreciated.


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