Stud length for new Caterham 8 spoke wheels

[Shaun_E]

I have fitted the rear wheels now after some fettling of the De-Dion tube. However, I am not entirely happy with the length of wheel stud protruding through the new wheels.

 

Does anyone know if the new 8 spokes are thicker than the old KN Minataurs?

Do all new cars have longer studs?

Should I fit longer studs? If so what is involved.

 

Thanks,

Shaun

 

Yellow SL #32

[F355GTS]

Shaun

 

I noted on Adrian's car that the stud length seemed too short, probably only 7 turns to tighten nut, Caterham assured him it was OK and they haven;t fallen off in the Year or more I've known him.

 

I've always worked on the 1.5 x diameter(I read on here was good practice) so 18mm of thread protruding, new studs are cheap (Autocross in Wokingham do them as does G Polley) only downside is having to strip the hubs to fit.

 

 

 

Mark

[Shaun_E]

I thought that might be the case. I really don't want to replace the studs if possible as I haven't actually driven the car this year ☹️ and just want it back on the road. Rear wheels are fitted but I still need to raise the ride height at the front to fit the new fronts (gone from A048Rs to CR500s) and if I can do that on Saturday I might actually get to drive the car on Sunday. The new engine has been in for over 2 months and I still haven't given it full throttle 😳.

I will check carefully how many turns the wheel nuts make and if it is 7 turns I'll live with it for the time being.Cheers.

 

Yellow SL #32

[Dave McCulloch]

I've just gone from 15" prisoners to 13" minators, and the standard studs are too short - only 6 turns to fully tighten the nuts, which is only 9mm on a 12mm dia stud.

 

Shaun - I share your frustration. I too have yet to experience full throttle on the new engine despite having had it set up at emerald on 9 December. First of all oil surge issues (with pileups too ), so fitted DS system, and now I've just had to order longer studs from CC which I need to fit.... The list of tasks goes on!!

 

Dave

[stevefoster]

Minimum rec is thread length of 1.5 X the diameter of the stud.

Shorter than this and I would def replace them with longer studs. Not such a bad job.

You have to split the discs and hubs.

Best to grind off a socket so that it's square and bites well (5/8" from memory) for undoing the disc to hub bolts as they have shallow heads...

 

Hants (north) / Berkshire club here

Area meeting pics here

My Racing here

 

[Shaun_E]

Thanks for the advice. I can't even use the old wheels as the tyres are down to the wear bars (and some ).

 

Daft thing is that I have 13" Minataurs and they are fine - really annoyed that the new wheels are thicker still. It was bad enough having to attack the De-Dion tube ends with an angle grinder but this is getting ridiculous.

 

And why don't Caterham parts tell you this stuff when you order the new wheels? A few simple questions as to what car you are fitting them to and you could order all the parts you need in one go!

 

Yellow SL #32

 

Edited by - Shaun_E on 8 Feb 2006 12:27:24

[Stuart Faulds]

We've been running these rims and standard wheel studs on R400 race cars for 2 seasons without a failure yet - the only reason we're changing to the new longer ones this year is that they're a pain to get on in a hurry.

[MikeE]

Stuart, so how many turns to full tight would that be?

 

I bought some Superlite Ultralites and with my standard studs there's only 4.5 turns, I checked my standard 8 spoke CC wheels and I think they were only about 6-7 turns. I asked Simon Lambert and he seemed to think 4.5 - 5 turns was OK

 

I don't understand this 1.5 * stud diameter rule of thumb, surely many nuts used in the suspension are less than 1.5 * the bolt diameter

 

Shaun - are you also using the CC wheel nuts for the 8 spoke or are you reusing the Minataurs ones?

 

R400 Duratec Build and Modification Pictures here

[Rob Walker]

stud lengths are now checked at SVA.

[stevefoster]

That 'RULE' is in the 2006 MSA blue book J 20.7.2

"Have all nuts securing road wheels, excepting those of centre-lock type, of steel and in thread contact over a minimum length of 1 1/2 bolt/stud diameters".

 

It has been the same since my first Blue book in 2002.

 

Wheel nuts are far more likely to come off then most other types of nuts - left hand side wheels esp. Other critical nuts are threadlocked or nyloc'd.

More thread = more frictional contact

 

 

 

Hants (north) / Berkshire club here

Area meeting pics here

My Racing here

 

 

Edited by - stevefoster on 8 Feb 2006 15:23:24

[MikeE]

Steve - thanks for the explaination

 

Approximately how long does it take to change the rear studs then?

 

cheers

 

R400 Duratec Build and Modification Pictures here

[stevefoster]

Hmm, easy enough. I've had my hubs off for various reasons a few time...

Stand on brakes. Loosen big hub with 1M bar / 42mm socket- watch out for LH thread on LH side.

Jack up, remove wheel, remove brake caliper/suspend, undo hub nut, slide off hub/disc, undo 4 disc to hub bolts, knock out old studs, knock in new studs.

Be careful not to damage the dust seal or get dirt in the bearings.

Reassemble

Stand on brakes again and retorque hub nuts (using new ones ideally or old ones with threadlock) to 200lbft I think it is - check that in the manual though.

 

 

Hants (north) / Berkshire club here

Area meeting pics here

My Racing here

 

 

Edited by - stevefoster on 9 Feb 2006 10:02:40