Spacers + Bolt lengths

[Schon]

Already discussed on previous posts but I was looking for a definitive answer.

With 10mm spacers it seems that 35mm bolts are the preferred choice.
But would slightly longer bolts be advisable or is 35 seen as the 'safe' option?

cheers

[c_w]

Yes 35mm is right since the factory bolts are 25mm (measured thread length).

[Schon]

grand - thx

[h4pry]

Additionally it's good to buy premium quality extended bolts. The cheap ones badly corrode and are very soft.

[exdos]

This was a relatively new one from Demon Tweeks that twisted on me.

http://www.z3mcoupe.com/photopost/data//500/48failed_wheel_bolt.jpg

[ZZZEMMCO]

You have me worried-----all my 42mm bolts for front 13mm spacers came from DT supplied to them from Germany.

[stoney]

Hi that bolt looks like it has been over tightened and streched.
Ive seen this several times before at work.
I might be wrong but it looks very similar to what Ive seen.
you can see by the difference in diameter at the middle of the bolt.
The part that is a smaller diameter is the part that was not actually into the thread on the wheel hub when it was tightened up.
Stoney

[c_w]

I've seen bolts shear before but never stretch like that!

I think a lot of wheelbolts are overtightened in general though - if I ever have a wheel fitted at a garage I tend to go straight home, undo them and retighten them to what I consider a normal tightness.

The problem also with wheel bolts is that if you remove your wheels a lot it puts a lot more stress on the bolts constantly undoing them and retightening them.

[exdos]

That stretched wheel bolt was only a few weeks old and had only ever been tightened/undone with a ordinary hand wheel-brace. I never tighten wheel bolts/nuts tighter than I can undo with a hand wheel-brace. Over the past 30 years I've done a lot of engineering and never seen metal twist like that bolt did when at ambient temperature. It felt like twisting toffee when it happened and as if Uri Geller had touched it. Strangely, it felt very stiff on undoing the bolt when I was expecting the bolt to shear leaving the thread in the hub.

[stoney]

That bolt was on the very edge of shearing you were lucky to get it out.
Perhaps the bolt was a little soft. There would be strict manufacturing specefications that the bolt was made to.
But ive seen things get past the inspection and slip thro the net so top speak.
I personnely would use a torque wrench if you have 1 to put the bolts back in.
Did you check the others are they all ok?
Stoney

[exdos]

A little soft? :lol::lol::lol:

The wheel bolts are stamped as 10.9. I do have a torque wrench and I find that I naturally torque the wheelbolts to around 110lbs/ft. Any more than that and I have to use my bodyweight.

None of the other bolts were affected, but I still obtained a whole set of new bolts and then sent the originals batch back after I'd got the new ones to be sure I didn't get the same ones back.

It was weird how the metal was so malleable whilst cold.