sub-frame bolt sheared...case closed

[Thor Lancelot Simon]

On Tue, Aug 19, 2008 at 06:08:30PM -0000, boulder_adv_rider wrote:

> > Conclusion: Simply I replaced the 8mm x 1.25 x 30mm grade 10.9 bolts > with the same dimensions but upped to 12.9 grade. Cost was $2.50 for > the 2-bolts (Ace Hardware), and I'm done vs. ordering and fiddling with > getting jiggy drilling. I know it might not be the "best solution" > here, but I live to learn from time. Plus, after 16k rugged smiles, I > only broke one bolt; these 12.9 bolts will add more tensile strength > and around perhaps 19% more shear strength.

They're more brittle, though, and thus more likely to break if they get loose. An undersized, hard bolt will be strong, but only so long as it *really* stays tight (which does *not* mean overtightened, either, of course). It's the simplest fix for this application but requires that you actually check the bolts periodically even if you Loctite them in place. As for the footpegs, a larger, softer bolt is a better choice but a lot more work. It will be easier to remove if you do break it, too...