I'm considering getting a set of 12mm front and rear 4X108 wheel spacers for my CQ. I know I'll need longer wheel bolts but would it put too much stress on the axles?

 

I don't know!!!
sorry

 

I too have also wondered about this. Perhaps the axle will be as before, and any extra load borne by the wheel bearing alone, but I tend to agree that you would be making the wheel into a longer lever, and something has to resist that extra leverage. The bearing is that fulcrum.

If one was able to move the entire suspension, inner mounting points and all, outboard; then the wheel bearing would not see a change in load.

I have two other concerns, one is drive-ability, the other more a body-work maintenance thing that may be affected by such a track change:

a.) steering geometry change; &
b.) fender damage.

Our cars have what is termed negative scrub radius steering geometry. This is dependent on the relationship between a theoretical point on the ground inline with a given wheel/tire's steering axis, and the centre of that wheel/tire's contact patch. This feature makes these cars more inherently stable in conditions of unequal traction and in cross-winds. As you move away from OEM design conditions, you degrade this feature.

Our wheels constantly spit off gravel which is largely contained within the plastic wheel-housings. As you move the wheels outboard, you will see more eventual damage to the paint-work. For instance, the extreme lower edge of the fender lip, and the rear fender arch in front of the rear wheel picks up a lot of damage.

Whether the above is of any concern at the distance you mention, others who have done this may be able to say.

 

where would you get the longer bolts? i would like to get some 8-10 mm spacers myself....