I’m trying to install a FSA compact crank onto a Kestrel KM 40 (no seat tube) and running into problems with how low I can get the front derailleur. Since the big chainring diameter obviously decreased when going from a 53 to a 50 tooth ring, the front derailleur needs to be lowered to compensate. the problem is that the “braze on” metal piece (bolted to the carbon post coming out from the down tube) does not allow any further downward motion of the derailluer. i.e. the derailleur was all the way at the bottom of the slot already with the 53 tooth ring.
I asked kestrel if they had any bolt-on attachements with more travel and got back a short reply stating no, and warning that I would void the warranty if I altered the current one.
Are there any front derailleurs out there with a greater distance between the bolt and the bottom of the cage? I’ve tried an ultegra double, a really old ultegra double (this one was a little deeper, but not enough), and a new IRD compact-specific without success. The new IRD compact specific one was actually the shortest of the lot, which seems to be a design oversight.
I was thinking of trying a triple front derailleur, in the hopes that it would have a deeper cage. Does anyone know if this will work, or have any other suggestions?
Unfortunately, I don’t have my own machine shop where I can just make a replacement attachment to the frame with greater adjustment range. Maybe next year.
I tried the IRD compact-specific front derailleur yesterday with no success. It has an even shorter distance between the attachment bolt and the bottom of the cage then the standard shimano double FD does. Like I said above, this seems to be a design oversight in a front derailleur that is intended to be used with smaller chainrings. I picked up a triple front in the shop today, the cage looks a little lower, maybe it will work.
IRD works fine on my Guru and Scott. But neither are a Kestrel like yours, though I ran a regular DA10 on my Talon for a while with compacts until I sold it.
Are you putting compacts on a 650c bike? First I have heard of that. Doesn’t a 53-39 on a 650c bike pretty much get you to the same spot that compacts on a 700c bike would get you? Maybe a 52-38 would get you lower, but I think a 50-34 would be like riding 46/30 on a 700c bike.
yup. This is for a female customer. i’ve got a number of other short women riding 650s with a compact (34-50) crank and a 12-27 cassette. We live in northern california where the climbs can be steep, and just about every downhill where you’d be going over 35mph you’re more concerned with braking for the upcoming corner and holding onto your bike with the crappy bumpy pavement then you are with pedalling. Big gears don’t have a lot of use around here. I ride a 34-50 with a 12-27 in back on a 700c (road) bike, and i’m far from a weak cyclist. Having the low gears opens up a lot of back road, partially paved terrain to explore. fun stuff.