E4RTH WORM JIM

Hello, I've just fitted a BBK to my car!

In order for the wheels to fit (rota slippy's 17/7.5"/+45) I need a 5mm spacer. When I fit the spacers and wheels onto the hub, the oem studs don't show much thread anymore.

My question is: what is a safe limit before the studs need to be replaced? I can get four full turns on the studs until the nuts are fully tight. Would you think this is sufficient?

I read somewhere there is a rule of thumb when doing this, which depends on stud diameter /thread type?

Thanks

eSeM

I have been using 5mm spacers on my front wheels for a few years now without changing to longer studs.

I remember reading that you need 5 full turns to be safe and I get 6 or 7 with a 60 degree tapered nut.

E4RTH WORM JIM

Thanks for the posting, but, your running different wheels with a different offset! So that's why you probably have more thread showing? (edit - and a different disk)

Have you still got the mugen's on? or a different wheel, with spacers?

eSeM

Yes, I still have the MF10s.

E4RTH WORM JIM

Thanks esem,

Mmmmmm. So it looks like they need changing then!

Can anyone else confirm this? Advice welcome

MB

Have you got a pic?

In the piping world we always want the stud flush with the nut as a minimum, or preferably 2 threads showing.

This is tricky with a wheel nut as the stud doesn't come out of the nut.

You can measure the exposed stud length with the wheel on and measure it with a caliper, and then measure the depth of the nut too.

Or count the threads.

But if you have lost 5mm I would be quite careful.

GavB

I agree with MB. I would not consider 4 turns to be enough.

No matter how many threads tall a nut is, it is correct that the majority of the load will be taken by the first three to four threads, however this would be at best 75-80% of the total load, with the reminder loaded in 5-6 and beyond in decreasing amounts.

Also bearing in mind that your studs/nuts are not new and will have been slightly deformed from previous tightening, the later threads would be relied on more than in a new nut.

They will work, but I would not be happy with safety factor you have now. I would change them.

Gav

E4RTH WORM JIM

Thats good enough for me.

You both have confirmed what thought/new, thanks!

I have never changed studs on a car before so don't know how much work is involved.

When I removed the OEM disks and calipers it looked like the studs have been pressed through a hole in the hub? May be it would be easier to buy J's racing hubs?

I've seen H&R do spacers though with longer studs as a kit, so it must be possible?

Which would anyone recommend? taking into account time/money.

Anymore advice on extending the studs is now welcome

E4RTH WORM JIM

It would seem the hub has to be removed and split. Then the studs pressed in and out and new bearing fitted (optional).

Gutted, more work.

loftust

Good luck