To the guys who say you can't break these botls by over-tightening them, I beg to differ. I've had several 3W bolts break off flush in the hub while being tightened. The fracture point was inthe threaded portion of the bolt, leading me to conclude that not only fatigue, but also the smaller diameter at that point (inner part of the threads diameter) tends to weaken the bolts in that area over a logn period of time.

I've taken to buying 30 or so 5mm bolts of the proper length from Microfasteners, and keeping them in sets of 6. I always "feel" the tension while tightening the bolts, and I've stoppe dshort several times as a bolt got "soft". When that happens now, I jsut toss the entire set of bolts and install all new ones.

The bolts from Microfasteners are Grade 5 bolts, if memory serves me correctly. Also, as stated above, about the only way you will break an entire set at once, while the engine is running, is by them being loose, or by not having a full set installed. I've actually considered drilling my 3W hubs for the smaller 100cc pattern, and installing hardened anti-rotation pins in the inner diameter hole pattern. Probably tremendous overkill, though.