Anyone knows if one can find compact crancksets for 650C wheels? What would be the equivalent of a 50/34 for a 650C wheel?
Thanks.
53/39 is roughly the same as having compact on 700c.
As long as you don’t tell the wheels, you can use compact cranks with 650 wheels. I use 50/34 with 650 wheels.
I have used 55/39 for a couple of 650 wheeled tri bikes with good success. That gives you the compact-like spread, and about the same gear inch range when used with similar cassettes.
Monty uses a compact on his 650 P3. He runs a 52/36. The 36 is low enough that it allows him to stay in his aerobars and spin up almost anything and having a 52/11 is still a big enough gear that he doesn’t have to coast the downhills until he hits 36ish mph+ at which point he advises tucking anyway.
I switched to a set of cyclocross chainrings (48-38) on my 130 crank with my 650 wheels. Combined with a 27 tooth rear cog it climbs pretty well. Front shifting isn’t the greatest but the price was right.
Pete
on my 130 crank
OMG Lilliputions ride bikes! Kidding, my girlfriend is an optimistic 4’10’', and we have her on 155’s. Smallest std MTB crank is 165, so that’s what she pushes offroad.
While there are 130mm cranks (I have them from 125 and up), he’s talking about 130 bcd… and my 4’9" daughter pushes 170 cranks on her mtb and does just fine 
To answer your question “What would be the equivalent of a 50/34 for a 650C wheel?” that would be around a 47/31 but I think you’re asking what would duplicate 700c w/ 50/34 on a 650c and that would be something like a 53/38.
You can calculate the gear-inches yourself here: http://www.panix.com/~jbarrm/cycal/cycal.30f.html
As long as you don’t tell the wheels, you can use compact cranks with 650 wheels. I use 50/34 with 650 wheels.\\
That’s too funny, I wonder how many people really get it…As Triabto said, I use compact 52/36, with an 11/23. I can go up just about anything spinning, and I can go over 55 mph downhill, spinning out and coasting…It is plenty of gear for 99% of the triathlon population, provided they have the right cadence built into their quivers. ANd my 650c wheels know, but they don’t mind…(-;
There are profile and I think FSA cranks for MTB down to 145mm FYI.
-SD
IF you have gearing questions, go to Sheldon Browns website. That will give you the answer.
As for 650, basically keep a normal crankset 53-39? and the 650 wheel automatically turns it into effectively a compact crank setup.
It was Dan’s article about compact cranks, posted years ago, which inspired me to go compact. He mentioned that you use them with 650 wheels. I figured if it works for you, it ought to work for a MOP like me.
Two major equipment decisions I’ve made have been based on stuff I’ve read here: compact cranks and friction shifting (allowing cheap upgrade from 8 to 10 spd). I never would have learned about either option otherwise. In addition to entertainment (not to take anything from Paulo, AC and crew 
), there’s good stuff here.
Those must be pretty big hills to require compacts on a 650 wheel (for the last time people there is no such thing as 650c unless you are riding on monster truck innertubes). My wife is a beginner and rarely shifts out of the big ring around here on her 650 bike, of course we have NO hills.
Actually there is, from Sheldon Brown’s site:
650 A 590 mm French version of 26 x 1 3/8; Italian high-performance bikes for smaller riders
650 B 584 mm French utility bikes, tandems, and loaded-touring bikes; some older Raleigh and Schwinn mountain
650 C 571 mm Triathlon, time trial, high performance road bikes for smaller riders
.
I had planned to ride a 700 bike with 50/34 and 11/26 for a week of major major climbs. I have to change to a 650 bike so I needed to know the best equivalent.
Thanks to everyone for your answer,