the rear wheels on my locost currently have a big positive camber. having a de-dion axle, i guess the only way to fix this is to use shims.. but where? surely shims used between the wheel and the hub would make the wheel vibrate?

i drew this to illustrate my current problem... a possible solution might be to use a shim between the hub carrier and the brake backplate, but i realized that the bolts would not fit squarely, requiring machining on both the hub and the hub carrier...

what can i do to solve this? any ideas? sorry fot the crude drawing: i'm on a laptop thanks in advance
Tom
Rescued attachment rear_shim.jpg

Hello Tom,
Shiming is fine, I'm done something simliar with my de dion, on mine though I can shim the hub carrier as the brake disk,etc is mounted on the hub carrier.
I just thought I would add, I've only needed to shim a very small amount to get the desired effect, I made a jig and tried to get it as close as possible to what I wanted.

In your case will you not need to shim behind the drum back-plate to keep the hub carrier, drum brake relationship correct other than that it should be fine

Cheers
David

[Edited on 19/2/08 by Minicooper]

cheers david,

i'm still confused though... by shimming do you mean grinding away the hub carrier to compensate? or making a profiled plate to fit between the hub carrier and the hub?

Camber wedges, can be cut in half to aid fitting and are a simple copy of the hub carrier them milled at the required angle, the Robin Hood guys have been making them and fitting them for years.
Rescued attachment Camber wedges.jpg

A point to remember is that the bolt pattern of the disc brake set up is the same as the drum brake but rotated 90 degrees so you need to state which you have also the angle is build specific and you can have it milled in two planes to set rear toe as well as camber.

Camber wedge thread

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In your case will you not need to shim behind the drum back-plate to keep the hub carrier, drum brake relationship correct other than that it should be fine

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Hi is it simply not easier to tweek the dedion beam it's self as done on the caterhams. And live axles in general.

Cheers Matt

How amusing, I tried fitting sierra rear suspension to my Falcon but gave up due to the camber I was getting. Never even considered shims...tisk

if the de Dion tube is steel run a bead of weld o the top of tube at the centre then quench cool --- this will contract the top of the tube, give nore negative camber..

Caterhams run alloy blocks to mount the rear hubs each end of the de-dion axle.

They are pre-machined with a certain castor and its not at all unheard of (not that we would do anything that is against any regulations of course!! ) to machine them to alternative angles!!

The weld and shrink won't move em very far at all.

Shims are your best bet after using a press to get it somewhere near to start with.

Hacksaw blade stock makes excellent shim for the job.

ps wedge or block goes between hub carrier and its mounting on the beam, and no, the bolts won't be square, but for the amount they will be out it doesn't matter.

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Originally posted by robertst
cheers david,

i'm still confused though... by shimming do you mean grinding away the hub carrier to compensate? or making a profiled plate to fit between the hub carrier and the hub?

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here's a better pic, the left wheel has a larger camber than the right one, but i guess if the ratio is 3:1, then i wont need such a thick wedge.

the washer idea is a good one... i'll do that to measure how much i need.

final q: where can i get these wedges or do i have to make them myself?

thanks a lot for your help, i thought i wouldn't be able to get the camber fixed up.
Rescued attachment DSC_0179.jpg

they are a make it yourself job, basically use washers or measure accurately to work out the angle required in both planes. Then over the hub carrier height/width work out the thickest bit of wedge required (if you see what i mean) assuming a small thickness at the thinnest point.

Then get some steel or alloy plate of that thickness, set it up at the required angle in a millign machine and mill it down until the "thick" and "thin" sides are the required thicknesses, which should happen simultanously if you got the angle right!!

This is how I have done some which of course weren't for use on a caterham racing car.

Alternatively, drill strips of steel shim stock to the bolt centres of the hub carrier in the appropriate place, and sandwich in there before bolting up.

The first method is much better, the second much easier!

I'd tweak the whole axle in a friendly garage's hydraulic press first though to get the "least wrong" wheel correct, then shim the other one.

got it... great help, thanks a lot