is there any current data on which wheel size is faster? I know the current trend seems to be back to 700c. is this for comfort, sizing, marketing, or speed?
what do you think?
I think a lot of it depends on how big you are. I’m 6’6" 193 lbs and I think that 650s would be both hard to find and useless for me. eric
In theory the 650 wheels were supposed to be better on hills and accelerating. Bikes fitted with them are supposed to be less aero because of the the longer steerer tube.
You get a better selection of tires with 700. If you’re over 5’9" or so, you’re probably better off with 700 size.
given the same gear inches on a 650 and a 700, i dont see how acceleration or climbing could be affect. if you ran the exact same chainrings and cassette, well, then you dont have the same gear inches.
650 wheels are only marginally less aerodynamic than 700… however if you cant get the front end low enough on a 700, then the 650 may be much more aerodynamic when factoring in the rider.
Anyway, the bike that fits is the correct one. I would put the threshold at about 5’10" or 5’11" for 700c wheels, but that again depends on the person and fit.
After much debate, I went with 650c wheels. I’m 5’8’’ so it made sense for me. But I can definitely see an improvement in my climbing - just easier overall. Cornering and bike handling has improved significantly as well.
Only downside thus far has been a slightly less comfortable ride going over potholes and bumps in the road.
Here is Dan’s take on the rolling resistance of 650 v. 700 (there is no demonstrable difference): http://www.slowtwitch.com/mainheadings/techctr/rolling.html#Anchor-47857
I also think I remember him saying that for someone who is “vertically challenged”, i.e. <5’9", it makes no sense whatsoever to go with 700 wheels.