If I have standard rear wheel bolts and I add 10mm spacers onto the rear of the wheel, will my wheels be secured properly and safely?

Thanks in advance

Should be, the bolts would bolt into the spacer, so there would be no change in the length.

The spacer then bolts into hub with 4 different bolts.

Depends if you have 'bolt on' spacers or simple sandwhich spacers - if so then you'll need longer wheel bolts to go through the wheel & spacer then into the hub

Chris

No Truffle, you're talking hubcentric, I'm talking general spacers....the ones with holes in that simple allow the wheel bolts through them

Well who wouldnt buy Hubcentric?

I'd be looking to use longer wheel bolts, Phil.

You need to go AT THE VERY LEAST 12 mm into the hub with your bolts.

Excuse Me?!?!

Nail and head - thanks

No.

But you already knew that!

I believe the formula goes something like.....

A = Standard bolts length
B = Spacer thickness
C = New wheel bolt length

A + B = C

Shall I put this as a how to guide?

What about the maximum depth the bolt screws into the hub? What is the tolerance here? Is the original bolt length the optimum or is there room for more depth?

Thus the equation should read...

A = Standard bolt length
B = Spacer thickness
C = Maximum depth possible of thread in hub
D = Levels of laziness of question bearer (this is the unknown variable)
E = New wheel bolt length

A + B + C ±D = E

Amendment

A = Standard bolt length
B = Spacer thickness
C = Maximum depth possible of thread in hub
D = Levels of laziness of question bearer (this is the unknown variable)
E = Torque said bolts are tightened to (determines actual depth into hub)
F = New wheel bolt length

A + B + C ±D + E = F

Amendment 2

A = Standard bolt length
B = Spacer thickness
C = Maximum depth possible of thread in hub
D = Levels of laziness of question bearer (this is the unknown variable)
E = Torque said bolts are tightened to (determines actual depth into hub)
F = Depth of paint on back of wheel upon joining the hub
G = New wheel bolt length

A + B + C ±D + E + F = G

I'd go hub-centric Phil, the sandwich type are cr@p and you get monumental wheel wobble above 40mph.

I was told by an alloy wheel dealer, the bolt should engage into the hub by the same amount as the diameter of the bolt being used.

I've read that too - makes a lot of sense

Personally, I wouldn't dream of using spacers on any car, unless they were just a couple of mm in order to clear the brembos (and thus meaning you'd still be locating on the hub as normal)

Doesn't "hubcentric" mean they are not "plain" disc but have a centering ring, as on a hub, NOT defining the fixing principle? They can be "bolt-through" (with longer bolts) or "bolt-on" (with wheels that bolt onto spacers, rotated by 45° on 4-stud patterns).

I've never seen "bolt-on" type thinner than 20mm, you need to cover the 1st bolt heads.

I think there's no problem to go with 10mm longer bolts, as long as the spacers are hubcentric (correct centering of the wheel) and bolt are quality stuff, eg. 10.9 or 12.9 grade...
You put more tension and shear, but I think stock bolts are 8.8 so there's reserve with quality bolts.

Bolt grades

Each to their own then Nigel

Good post Marko

I had spacers on my old coop, as well as wobbly bolts. Wouldn't hesitate to run them again. I had to get longer bolts, although I can't think where from. I had non hub-centric to start with, they were awful. Then GrahamL gave me (!) a set of H+R Hub centric's and all was well.

I accept that my dislike of spacers is probably unfounded, but I just can't bring myself to accept that its a safe idea

Its even worse with the bolt-on hubcentric spacers - you're bolting your wheel to a chunk of metal that's bolted to your hub - that's just not right....

I can almost cope with the idea of bolt-through hubcentrics, but given the choice, I would always choose to fit a wheel that didn't need any adapting

Heck - I don't even like having to use spigot rings....

I feel the same way really. I think I'd cringe everytime I drove over a hefty bump in the road, even if they're perfectly safe

IIRC

the standard bolts are 30mm thread length

The hub is 12mm thick (A)
The disc is 8mm thick (B)
The spacer is however thick you buy them (C)
and the sleeve depth of the standard wheel is 10mm thick (D) (other alloys will vary)

so

A (12) + B (8) + C (Variable) + D (Variable) = required thread length




At a pitch of 1.25mm thats approx 9.5 full turns



the threads are 12mm dia, and the hubs are 12 mm thick............ makes sense

Ninja

(this information may not be 100% accurate, use at your own risk)

Look at it the other way. The hub is 12mm thick. If it were possible to save a few pennies on the casting by making it thinner, they'd have done it. Therefore you need to screw into the entire depth of the hub.

Oldest trick in the book - the argument-from-authority fallacy

Oh, whatever you decide on, make sure the yellow pointy things can still be properly attached.

.....common sense REALLY if you wish to live long

what ever the diameter ( OD ) of a bolt / thread is, then the engagement depth should be as a MINIMUM the same ( you effectively have max thread strength then )

IN reality, flanges / threaded holes are usually double this or triple, as bolt strengths play a MASSIVE factor i.e. Gr4.6, Gr8.8, 12.9 etc....so you apply a higher torque / clamping force.

So in this case of a soft wheel hub & softer alloy, a 12mm depth will do, any further & it'll probably destroy the ABS sensor behind the hub flange !