complete, what next?
Join Date: Oct 2012
Location: United Kingdom
The wheel bolts are in tension only and put a huge
clamping force on the hub, disc and wheel faces so all the shear forces are through these faces
If this was not true, then how could a torque
be transmitted to the wheel
Don't get me wrong, hub centric is important and it ensures a proper fit, but bear in mind plenty of aftermarket wheels do not have this alignment feature (they use wheel nuts with conical seats, this is called lug-centric.)
Accidents happen when flat seated
wheel bolts/nuts are used without the hub-centric fit - this has given rise to a lot of mis-information out there
sorry, hope this makes sense just got back from pub
Well said that man. As an engineer I have to do these calculations frequently, it's called bolted joint analysis. The clamping force required to resist any applied shear force is a function of the coefficient of friction between the two materials and the applied load. In the case of the wheel there will be torque from acceleration and deceleration as well as direct shear from the loading and unloading of the suspension. If the clamping force on the bolts was insufficient to withstand these loads then the wheel would move around on the hub; albeit by a small amount initially as the hub centre would stop it. This would soon a) completely loosen the wheel bolts and b) the soft alloy of the wheel would be worn away on the harder steel hub enlarging the hub centre and as it twists the wheel bolt holes.
The hub centre is only there to ensure that the wheel is central.
So be safe kids, make sure your wheel bolts are torqued correctly to ensure sufficient clamping force. You'll have to wait till bed time for me to tell you what happens when you over tighten the wheel bolts; there's a man named Hooke in it, but it's not Peter Pan.
"When I see an Alfa Romeo I lift my hat" - Henry Ford