700cc wheels vs 650cc wheels

carls10

I'm still new to the biking scene in general.  I'm a little peep and most of the bikes that truly 'fit' me run 650 wheels.  I have been very hesitant to get a bike with 650 wheels even if it may fit me better.  I have little to no experience but 'have heard' that 650 wheels will decrease your speed compared to effort on 700 wheels, ? harder to find tubes/tires/wheels parts in general, less support at races etc. 

Is this all foolishness or is there some validity to these concerns?

Nemo Brauch

Hi there fellow l'il peep! I'm in the same boat, and here is the run down from my perspective.

IF (big if) I could find a bike that truely fit me with 700 wheels, I'd choose it over a 650 any day. Not because 650's are bad, just because they are a little more annoying. When out on a ride you have to be more self-sufficient (if you run out of tubes you can't easily borrow someone elses). Going to TOC I shipped an extra tire for the SAG van 'cause if the tire tore there's certainly no one else with a spare I can use and it's possible whatever little bike shop we stop at for supplies would be out of them. Tubes and tires are not all that hard to come by, but your options are greatly limited and you sometimes have to wait for orders. Frankly, in some ways I don't find this to be a big negative because it keeps me from getting wrapped around the axle on discussions about rolling resistance and other crap- limited choices is sometimes a good thing for me!

I don't think there's much to the decreased speed issue. There are gearing considerations and adjustments, but it's just not that big a deal. And frankly, with 650 wheels on a TT bike, I am soooooo low to the ground that I gotta believe I'm way more aero :-0

The one trouble with buying a bike with a 700 wheel when a 650 frame would be a better fit, is that you can run into toe over problems with the front wheel. So just watch out for that as well.

Bottom line for me, even the frames with 650's are barely small enough for me, so it's really my only option. I actually fear the day manufacturers stop making bikes in my size with 650's.

kjanracing

i THINK the gain in a properly fitting bike would far outweigh the minimal difference in the two wheel sizes. From a frame building standpoint, a lot of compromises arise when a frame gets that small. It makes so much more sense to use smaller wheels and be able to build it with "proper" geometry rather than building it around minimizing toe overlap.

brianrobkelly@hotmail.com

hi, i have a race bike that i just won't give up, and it has 650 wheels..but my training bike purchased later has 700 wheels..the 650 tubes, tires, are a bit more difficult to deal with, but no issue to me..the issue to me is the power meter..i do not train with one..probably would consider it more, but which bike do i use it on??? can't switch wheels....just make sure all your bikes end up the same..not like me..in a paradox!

GMAN 19030

Posted By brian Kelly on 18 Jun 2011 05:28 AM

hi, i have a race bike that i just won't give up, and it has 650 wheels..but my training bike purchased later has 700 wheels..the 650 tubes, tires, are a bit more difficult to deal with, but no issue to me..the issue to me is the power meter..i do not train with one..probably would consider it more, but which bike do i use it on??? can't switch wheels....just make sure all your bikes end up the same..not like me..in a paradox!

You would have to use a crank based power meter like a Quarq or wait for the Garmin pedal based power meter.  You could then swap the power meter between the two bikes with a little bit of effort (swapping cranks) to very little effort (swapping pedals).