I have a good friend who is in the market for a new ride. Both her road bike and tri bike are custom with 700 wheels. As part of her diligence for the new bike, she went to a bike shop and the owner is pushing her to go with 650 wheel size since she is pretty small (5’2"). I had thought that 650s were largely relegated to history but are they a prudent option for her or should she stick with 700s? She has had no problems with her current wheels. What are the benefits/detriments to 650s?
Thanks.
at 5’2" 650 wheels are probably a good idea.
all else being equal 700c bikes are usually ‘faster’ in both aerdynamically and in terms of rolling resistance.
BUT, when you are short, a 700c bike may not let you get as low as you need to, and may have toe overlap issues.
If she can get in the position she wants on a 700c bike, and toe overlap isn’t an issue, then that may be ok.
Some of the pragmatic downsides to 650c bikes is getting the best tubes and tires is impossible.
an upside is used aero wheels are often cheap.
I have a good friend who is in the market for a new ride. Both her road bike and tri bike are custom with 700 wheels. As part of her diligence for the new bike, she went to a bike shop and the owner is pushing her to go with 650 wheel size since she is pretty small (5’2"). I had thought that 650s were largely relegated to history but are they a prudent option for her or should she stick with 700s? She has had no problems with her current wheels. What are the benefits/detriments to 650s?
Thanks.
People with 650 bikes say they accelerate faster. I don’t really know if that’s true. I was on the cusp of 650/700 and went for 700 because of more wheel and tire options.
Coincidentally, there was just a thread here about someone who flatted at IMLP and was out 'cause the sag wagon didn’t have 650 tubes.
You can use 700c tubes in 650c wheels if necessary…obviously you can’t do the other way around though!
You can use 700c tubes in 650c wheels if necessary…obviously you can’t do the other way around though!
I’d bet money you can, and probably more easily than stuffing the extra from a 700 into a 650.
I’m also short. My Felt tri bike has 650 wheels and I have HED 650 race wheels. They were on the bike when I got it and the bike is a great fit for me. i dont know about any other advantages to riding 650s. I havent had any problems getting tubes/tires but the owner of my LBS also rides 650s, so she has plenty in stock. I’d prefer 700s on my next bike so I can steal tubes from my husband 
How I wish that I would have known this 4 days ago… and surprised that the Gear vehicle at Placid didnt either. Great to keep in mind for future reference though. Is there any trick to it?
I haven’t had any problems getting 650 tires either but I get most of mine online.
There are a few less choices but still some very good ones.
jaretj
all else being equal 700c bikes are usually ‘faster’ in both aerdynamically and in terms of rolling resistance.
Show me the proof of that.
haven’t we already had that argument?
in the case where a 650 bike is not required to get as low as desired, the extra had tube length outweighs the smaller wheels and fork, aerodynamically. the difference being very small. this, according to cervelo.
the rolling resistance bit is just simple tire science.
except tire science isn’t simple
lol
all else being equal 700c bikes are usually ‘faster’ in both aerdynamically and in terms of rolling resistance.
Show me the proof of that.
People with 650 bikes say they accelerate faster. I don’t really know if that’s true. I was on the cusp of 650/700 and went for 700 because of more wheel and tire options.
Coincidentally, there was just a thread here about someone who flatted at IMLP and was out 'cause the sag wagon didn’t have 650 tubes.
I feel like my 650 bike did accelerate better. Purely anecdotal, but I feel like it’s harder to get up to speed as quickly on my 700s.
Dunno…I had 650s for years, and when I bought my new tri bike this year, I had to get 700s, and I really prefer the 650s. Unfortunately, I am 5’9", which isn’t a size that gets 650s anymore–unless I go way out of my price range (a custom build or a Ceepo, for example).
I’m 6’0" but with whatever weird inseam/trunk measurements I had a 52" bike fit me the best - and it came with 650s.
Don’t be afraid to go with the 650’s. I am short and the fitter recommended me to go with a 650 bike. It does seem to me to accelerate alot faster than my 700c road bike. I also can climb better on it but that may be due to the weight of the bikes. The only downfall is there isn’t as many choices for buying wheels. That can also be a plus cause you can pick up some dang good deals on used wheels. I got a set of tri spokes for mine that are used but in excellent shape for $600. I order all my tubes and stuff online so that is not a problem for me.
I have a 650 HED disk she could buy cheap…if that helps. 
Nothing wrong with 650c, especially for that size bike.
My old 55cm Litespeed Tachyon had 650c wheels and was awesome, but almost all the new bikes in that size come in 700c now.
I have a HED disc and Jet front, and a HED DEEP Jet rear and Jet front for sale if she is interested. (all tubular)
If she’s riding an aggressive aero position, then she should try a 650.
I also am 5’2" and with the typical longer legs-shorter torso found on many women. The geometry of 700c bikes usually won’t work.
Integrated headsets reduced stack heights and allowed flat-back positions for some smaller riders on a 700c-wheeled frame.
That said, at 5’2" your friend is probably better off on a 650 bike.
I’m short as well, 5’2", so when I was looking for a new bike, I ended up getting fitted into a 650cc bike. I have to say that I don’t feel nearly as stretched out as I did on a larger bike. I got very sore in my lower back and shoulders when I rode my 700cc bike. And I’ve had it fitted numerous times because I thought it would help. I’ve only had my tri bike fitted once, and I haven’t had a single issue. Also, my speed averages instantly went up on my new bike. Obviously there are many factors that can attribute to that, but the simple fact that I’m no longer twitching around like someone on whippits during my ride is a testiment to the size and fitting.
The only bike I like riding better than my new tri bike is my MTN bike.
However, it is funny to see some of my taller friends ride it around. They look like a Russian bear riding a tricycle.
I’m 5’2" with a 28" inseam and short torso. My first real road bike was a trek WSD women’s specific w/650s. I had no idea how well it fit me until I got the next one and spent the last few years in fitting agony, trying to find something that worked. That one was an Orbea Diva with 700s. We finally (mostly) reconciled the problems with a 50mm stem and shoving the seat way forward, which was only a compromise solution as that configuration introduced other issues.
I recently bought a Felt tri-bike with 650s and have been really happy with the smaller frame/wheels. I’ll be trading in my Orbea road bike for the smaller size with 650s this winter. There are a lot of great articles on here that address the reasons you may want to go with a smaller frame/wheels. The biggest one is flexibility. Bikes that are “small” but have 700 wheels have very little flexibility in how you can configure parts and part sizes. Also, my understanding is that shorter stems make a bike harder to maneuver; although, with a tri-bike, how can you tell?
I’m really happy with my 650 wheels and wouldn’t go back, despite spending 2 years in denial and wanting a wheel size that everyone else has. Yes it can be a hassle, but the benefits outweigh the cost, in my opinion.
Sascha