8" wide 13" rear 8 spokes on a mk.1 Superlight

[SUPERLIGHT91]

I've just bought a pair of 8" wide rears from Caterham (standard R400/500 rears) and fitted some 205 tyres to them to replace the standard 6" wide rears. they seem to foul against the anti-roll bar linkage.

 

Any comments on suitability of these wheels on the standard superlight? and what can be done to modify or adjust the roll bar linkage so I can run with these wheels?

 

Also there didn't appear many turns of thread on the nuts when I offered them up, but I suppose that could be a) the AR bar fouling the fitting, b) the new style stainless wheel nuts that have an unthreaded alloy washer before the threaded nut begins.

 

Superlight (mk.1) 1800k car #91

[naddy]

I have those wheels on my car (superlight No. 127) and they didn't foul the ARB at all.

 

I found it necessary to remove a little material from a thin ally plate that protrudes from the back of the de-dion (just inboard of each endplate) - and I believe it is common to need to do this - but it is easily ground/filed away with it in-situ.

 

As for the rear ARB... I may be well off the mark here but I seem to remember somthing about there being two ways to mount the links. Possibly I was lucky and they were in the appropriate position already and yours may need moving... Hopefully somebody will come along and confirm - or to tell me that this is nonsense!

 

I use the original nuts, they are fine.

 

 

edited for pour spellin'

 

Edited by - naddy on 12 Apr 2010 21:31:46

[SUPERLIGHT91]

Thanks naddy

 

That makes sense - I recall fitting a set to my SL 74 when the 8-spokes just came out but I can't recall if they were the 7" rears (that you can't get anymore) as opposed to the 8" rears. However it does look like I might be able to revers the ball ends to the inside of the roll bar arms, I recall bending the arms in slightly last time too, but I'll have a look later in the week in the daylight (no light in the garage its stored in on axle stands at the moment).

 

Thanks and any more info on rear ARB linkage would be appreciated.

 

Matt

 

Superlight (mk.1) 1800k car #91

[Shaun_E]

Mounting the drop links on the inside of the ARB should sort the problem. I also believe (but have not tried it) that you can't use the softest setting.

 

Yellow SL #32 - member of Drowned Rat Racing

[SUPERLIGHT91]

Thanks for that Shaun

 

I will have a look at swapping the linkage around on the ARB later today and report the results below. if the wheels clear when re-fitted.

 

regards

Matthew

 

Superlight (mk.1) 1800k car #91

[Slider7]

My 8" rears foul the DeDion ears ...

 

“Perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away” Antoine de Saint Exupery

 

Edited by - Slider@7 on 13 Apr 2010 09:41:43

[Shaun_E]

You will probably need to attack the de-dion ears with an angle grinder - depends which tube you have.

 

Yellow SL #32 - member of Drowned Rat Racing

[SUPERLIGHT91]

All done - ARB linkage swapped over, dedion ear's alloy plate 'shaved' with the grinder and spun on the axle stands to check for rubbing. (I even had to move the adhesive wheel weights 'inboard' to stop them rubbing on the dedion ears too).

 

I have come in one setting from the end on the ARB linkage too - I take it hole 1 (closest to the main ARB) is the softest setting, and hole 4 towards the rear of the car is the firmest. I am now bolted into hole 3 on the reverse, it will be interesting to see how that handles.

 

Thanks to everyone for the advice - they are a close fit bit seem to roll freely now.

 

Superlight (mk.1) 1800k car #91

[7 Sevens]

I did the exactly the same thing as you on Sunday. Rim fouling on the metal plate between tube/ear and against the ARB link. Now looking at the position of the link (inside the arm) that seems the more natural place to have it anyway.

[Shaun_E]

Hole 1 (as you describe it) is the firmest setting, hole 4 (which you can't use) is the softest so hole 3 is a good choice. Most people never move it from that setting although some disconnect it altogether.

 

Yellow SL #32 - member of Drowned Rat Racing

[SUPERLIGHT91]

Interesting thanks: while I had the grinder out I was tempted to remove 'hole 4' completely as there is evidence it has fouled the bodywork in the past (as some paint and alloy have been worn away in an arc). I will keep an eye on this after touching-up the paint in this area and trim the ARB ears in future, if I'm happy with the set-up on 'hole 3' which I'm sure I will be.

 

Superlight (mk.1) 1800k car #91

[SUPERLIGHT91]

as a follow-up... just wondering if there are different types of billet Dedion ears for the wider wheels/tyres. Reason I ask is I've just fitted a brand new set of CR500s on the rear, and want to make sure they wear evenly, and will look into changing the ears if necessary?

 

Superlight (mk.1) 1800k car #91

[GPBox]

I changed the ARB to the lower/newer version...pretty cheap and relatively easy....before changing, I found that although changing the drop link around etc on the 'old' arb allowed minimal clearance, when you get on track and put sideways loading on rear the tyre will rub on the arb or drop link........not what you want to happen......

 

G

[SUPERLIGHT91]

Interestesting - I will keep an eye on this when I get to corner sufficiently quick next - just taking it easy on bends and sensible in a straight line at the mo - while scrubbing tyres and brakes in (and the roads are aweful due to pot holes - keeping eyes peeled for those)