RCMoeur 

One of the riders in my group rides 650C / 571 - she's four foot something teeny and rides a 43 frame (the size of which doesn't seem to work well with anything bigger than 571s). I'm always on the lookout for tires for her as she rides a lot and 571 performance quality tires are sometimes not the easiest ones to source.

I don't see any purpose for those wheels except on a bike built for them. Don't even think 1080 reach brakes would be enough. But then again, maybe another (cough) thread has ideas for mounting much smaller wheels on a given frame?

LarrySellerz

The wheels are a statement, those who know what they are know

Herzlos

What's the statement? That you bought wheels without checking they fit your bike?

LarrySellerz

I mean riding with them

Herzlos

If you're moving on a bike the wheels are virtually invisible. If you're stopped, then everyone will see how bodged it is, unless you manage to find a suitable tri bike.

Eric F 

They aren't saying what you think they are saying.

JohnDThompson 

The main problems with 700C wheels on a small frame are pedal overlap with the front wheel and the very short head tube allowing the frame to twist in a disconcerting manner. Both these problems are mitigated with smaller diameter wheels. The main downside to 650C wheels is availability of tires. They are available, but often need to be special ordered and are priced accordingly.

N.B. Wheelchair supply houses that cater to wheelchair racers often carry a surprising range of high quality tires for unusual rim diameters.

big john

She had a custom steel Curtlo with 700 wheels before she got the little wheeled Moots. I guess the toe overlap didn't bother her but when she got the smaller wheels she felt the handling suffered and the tire availability wasn't as good. Plus she couldn't score a tube from anyone on a group ride. Then there is the wonky gearing. None of these things are a deal breaker for some people, I'm sure.

Doug Fattic 

A bicycle with 650C wheels does not have ''wonky greeting". For most normal people not riding in fast pace lines, 650C wheels puts their gearing in a more suitable place. The difference is roughly the same as going 1 tooth smaller in the back. For example a 53 X 13 on a 650C bike is about the same as using a 53 X 14 on a 700C bike.

Also a frame properly designed for 650C wheels does not suffer from poorer handling. I know because I built my own go-fast bike with 650C and enjoy its advantages - especially on fast trining rides. I can tuck in slightly closer to the wheel I'm sitting on and like their faster acceleration.

If your short friend did a proper bicycle fitting and her frame was designed around that fitting, she would have massive toe overlap with 700C wheels. Massive. The way production companies get around that problem is by designing frames with very steep seat angles combined with very swallow head angles. That combination means she is probably sitting way too far forward compared to where it would be best for her. And vary shallow head angles are best for utility bikes with upright handlebars.

650c wheels also makes small frames look more normal. Short women hate having their bikes look like kids bikes. Because on a 650C frame the down tube will be 1" lower from the top tube, the frame won't have that squished together look that emphasizes its smallness.

I will concede that she will have to buy and carry her own spare tubes (when riding her 650C) instead of being able to bum free ones off of riding friends.

big john

I can only relate what she told me about the handling and feel of the bike. After riding the Moots for a while she preferred the ride of the Curtlo. At least she wished the Moots felt more like the Curtlo. I don't know what geometry was used on either bike.

And, yes, a lot of fast pacelines and some cat 4 racing. It's all academic now because she doesn't ride anymore, as far as I know.

MoAlpha

650s are also used for fat tire/fender conversions of racing frames. You can get long-reach brakes for that purpose, but for those wheels it may not be worth it.

shelbyfv

Yep but those are 650b. 650c is a different size and unfortunately there aren't long reach brakes that will work.

LarryMelman

I bet he needs less lamination than your average rider. Just guessing.

LarryMelman

You could fill them with nickels.

Kapusta

LarrySellerz is what makes BF worth visiting.

Keep up the good work

john m flores 

Agreed. My 650c Serotta was a fine handling bike. Gearing was not wonky, and yes the frame and wheels had nice proportions on my 52cm frame.

The issues being described are not endemic to 650c bikes.

Germany_chris

650b is 584
650c is 571
700c is 622

I think we probably need a sticky somewhere on the forum so we all have clarity on wheel sizes, for example there are 3-4 26” wheel sizes only one is the common 559.

Doug Fattic 

My reason for posting is that your short friend expresses the common misconceptions surrounding 650C wheels. They don't realize that designing a small frame with 700C wheels most likely severally compromises their bicycle position. Although for small true racers not so much because their bicycle position will be further forward and a steep seat angle can make them more aerodynamic like they want riding at speed. And toe overlap is not as much an issue because when going fast they turn by leaning over their bike (and not by turning their handlebars like one would if turning around in the road). Short normal recreational riders want to have their weight balanced over their pedals and that is achieved by a shallower seat angle resulting in a lot of toe overlap with a 700C front wheel. And women in particular like to sit up a bit more with higher handlebars to take the weight off fo the sensitive areas of their crotch. The higher the handlebars, the more seat setback is required - which is achieved of course by relaxing the seat angle.

Some short people can benefit using even smaller diameter MTB 559 size tires. There are slim tire widths available in that size. These used to be common but now have mostly been replaced with 650B (or 27.5" - same thing) tires. I just had a 5' 5" guy in his 60's take my framebuilding class. It was really important to him to have toe clearance. In his case 559 tire was his best option because he was no longer able to lean over on his bicycle like he could when he was younger and had a slimmer body. I made frames for both my 5'5" wife and 5'4" daughter using 650C wheels and they really like how they ride.

cyccommute 

I have a 5’ tall lady in my house who has zero regrets with using 650C wheels. The 700C wheel bike she has is the proper size for her but it has a significantly higher stand over height.

big john

Do the 2 bikes have a similar bb height? Just curious about that and some of the other differences. My friend with the small wheeled Moots was able to ride with a flat back and was able to get in a line with fast riders and get pulled along.

The joke was if you got behind her you could feel the draft on your legs but that was about it. She was so low it made her cornering amazing.

Didn't a winner of RAAM use 650c wheels one year? I rode a bit with her at the Solvang Century when the winners of RAAM would show up to help promote the event. She was so low and her back was flat like a table. Cathy something, I think. I cold look it up, I guess.

All of the smaller women in my club are using 700c wheels. There have been a few on 650 set ups but it's rare. There have been a couple of Terry Symmetry bikes in the past.

cyccommute 

I took the pictures above from a tripod in the same position (for insurance purposes) so they can be compared directly. You can see that the bottom bracket of the Terry is slightly lower than the green bike (a repainted Specialized Vita) but the difference is due to the difference in wheel size which is about an inch. The standover on the Vita is much taller than the Terry because of the wheel size first but the Vita also has a much more sloping top tube to accommodate the taller 700C from wheel. Look at where the top of the top tube on the Vita is in relation to the garage door to see the difference.

That’s because the bicycle industry is crap at designing bikes for small women. That’s the whole industry, not just the frame manufacturers. For the longest time, the smallest bike you could get was a 49 cm frame (19”). My wife should be riding a 43cm frame at the most and would probably do better with a 42cm or even 40cm frame. But that size frame just doesn’t really work with 700C wheel…see the Vita above to see what compromises have to be made. Georgena Terry has a very deep dive into what is wrong with bicycle design.

But the problems go even further than that. Controls aren’t made for small hands. Brake levers are too far away. Shifters require too much strength for smaller hands and the paddles are in the wrong place. Bike weight is an issue. There are loads of “regular” sized carbon bikes for large riders that weigh in at 14 lbs but not many small bikes that go much less than 25lb. Trek’s carbon bikes smallest size are 44cm. They might fit someone who is 5’ or less tall but they won’t fit all that well. Would you ride a bike that is one to two sizes (or more) bigger than what you ride now? Would you ride around on a 1/4 your body weight?

One thing I learned last summer on our tandem was that her cranks were not just the wrong size but that they could injure her severely. I hadn’t even thought of the problem with her using 175mm arms. We did a two day event in Nebraska that was a 50 mile ride to a town south of Lincoln. At the end of the first day, her knees were in agony and we still have 50 miles to go to get back. When we got back home, I started doing research and found that this is a common problem for stokers. It got a set of cranks from my co-op and redrilled them for 140mm crank length. They work much better for her now.

But all of this is common for those of us with pixies in our houses because while women in general are ignored by the bicycle industry, small women are particularly ignored.

t2p

so there is where all the M770 cranks are !


( btw - the bottom bike is extra sweet )

t2p

had a friend that built a number of custom frames / bikes (lugged steel) for small women triathletes

to my knowledge all those bikes used 700c wheels

can’t recall the reasons - but I’m sure one reason was wheelset / tire / tube availability

( many of those tri’s went thru a lot of tires etc - significant amount of training / miles )

and not a good idea to see them travel to Wisconsin ... Tennessee ... Hawaii ... wherever ... with a bike they could struggle to get a tube or tire

cyccommute 

So you are aware of how hard it is to find an M770 crank in 165mm length? And, honestly, those are at least 2cm too long for her.

I have two more sets on Schwinn’s tiniest Homegrown mountain bikes.

t2p

not positive - but I believe a NOS M770 crankset with 165 mm arms was listed on eBay within the past month

( close - March 30 )

https://www.ebay.com/itm/134510411753