My cousin didn't really understand how to operate the Sora thumb buttons on my nearly-unused Burley tandem, and snapped off the left one. I was about to blame the seller of the bike for selling me something that must have clearly had significant plastic fatigue already, but then heard from a mechanic in a bike shop, as well as in other threads on the forums, that this part is fairly prone to breakage. I can't really blame my cousin, since this part really has no excuse for having been engineered in such a way that it would be *that* easy to break.
Now, I know the obvious solution here, since Shimano doesn't sell parts for rebuilding its brifters, is to either replace the whole left brifter with anything that can shift a triple, or to very carefully cobble together the parts from another differently-broken Sora brifter. But I'm nerdy and I'm cheap, so I'd really like to try to see what I can do to plastic-weld it back on. I mean, it was plastic in the first place, so how much force should it really need to take? I suspect that by using a very strong epoxy and "bandaging" the broken joint with the stuff, I probably ought to be able to reinforce it to the point that it might even be stronger than it was to begin with. I'm not averse to filing off a bit of the plastic around the slot between the hood support and the brake lever, to accommodate the thickened thumb lever arm after its plasticky reinforcement is in place. I've also considered the idea of drilling into the remaining part of the arm and attaching an improvised lever to that, but I imagine that would be unlikely to work unless I tried something along the lines of what this guy did: http://bikeforums.net/attachment.php...6&d=1153880455
Actually, I suppose a really cool fix could be to replace the whole plastic part with a piece of metal machined and bent to be an exact replacement, but I don't want to try to undertake that complicated and time-consuming of a fix before at least trying the plastic weld idea.
Anyone here have any suggestions (other than "replace the whole thing", which I am already considering but hate the idea since the rest of the brifter works perfectly well)? Any particular recommendations for epoxy materials to try for the bandaging approach? Any input would be much appreciated.