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I tried to size up a road bike today since mine is too large. I'm 5'5" with a 28" inseam and they put me on a size 50. Anyway I noticed the wheels were 26" instead of the standard 700cc (28"). They told me the 700's would be too big for such a small frame but I can't imagine Iban Mayo (the small basque rider?) riding in the tour de france with such a disadvantage and able to crack lance in the mountains.
 

· Spicy Dumpling
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My wife rides a 47cm Basso coral with 700c wheels. She had a 650 (26ish) trek that didn't fit her as well as the basso. She has no problems with toe overlap. The nice side effect is that with the larger wheels the bars are a bit higher. The trek 650c bike had a short head tube and coupled with the 650c wheels made for a lot of drop without a steep stem.

I don't know of many 650c bikes above the 47-49 cm sizes. Usually at or above 50 everything is 700c.
 

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This subject is one of Grant Pederson of Rivendell's pet peeves. You CAN put a 700c on a 47cm frame, but you ain't gonna have clearance for anything bigger than 25's, and fergit about fenders or the like. And it looks odd. But it works. Think a 47cm frame is kind of a natural for the 650 or 26" persuasion.
 

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flankwood said:
They told me the 700's would be too big for such a small frame but I can't imagine Iban Mayo (the small basque rider?) riding in the tour de france with such a disadvantage and able to crack lance in the mountains.
I don't understand this. What is the disadvantage of 650c wheels? Don't some triatheletes and TT'ers use them because they "spin up faster"? Personally, I doubt there is an advantage other than toe overlap for a shorter rider, but I don't see a disadvantage either.
 

· haole from the mainland
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Seems a bit weird. I'm half and inch shorter than you overall, but with a 31" inseam. Obviously, my torso is shorter than yours (I'm a chick) and I ride a 49cm frame with a 52cm top tube, short head tube and 700c wheels. Any smaller of a frame and there would be some serious design compromises, such as a too-steep seat tube angle if smaller wheels weren't used, though.

But the small wheels aren't a disadvantage. In fact, they're going to be a bit lighter than bigger wheels. I am coveting the Cervelo RS, which uses 650 wheels in its smallest (my) size. And if I bought a tri bike, I'd get one with 650 wheels.

But, you sound big enough for a road bike without weird geometry compromises to use 700 wheels.

flankwood said:
I tried to size up a road bike today since mine is too large. I'm 5'5" with a 28" inseam and they put me on a size 50. Anyway I noticed the wheels were 26" instead of the standard 700cc (28"). They told me the 700's would be too big for such a small frame but I can't imagine Iban Mayo (the small basque rider?) riding in the tour de france with such a disadvantage and able to crack lance in the mountains.
 

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My oldest son is about 5'1", and he rides a 46 cm bike with 650c wheels. He loves it, and it works very well for him. I have to keep more spare tubes around, and tires can be a bit of a pain, but overall the bike has been a great thing, because it fits.

I'm getting past aesthetics these days, and using what works. I just put a 46-36-26 crank on my commuter, with a 12-27 cassette. I love it for pulling my BOB, and for commuting. I don't really go much over 25 mph anyway. It looks funny, but it sure works.

You can get a 50cm frame with 700c wheels though. I have seen lots of those.
 

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My Own Private Idaho said:
I don't understand this. What is the disadvantage of 650c wheels? Don't some triatheletes and TT'ers use them because they "spin up faster"? Personally, I doubt there is an advantage other than toe overlap for a shorter rider, but I don't see a disadvantage either.
Well I would imagine if you had smaller tires you would need a larger gear ratio orr a very high rpm rate to keep up with the other riders. I used Iban as an example because he is about my size, about 25 lbs lighter. On the hills the wheels might not matter much but how did he keep up on the flats? He either switched bikes, uses 700c on his small frame bike or accomadates for smaller wheels with a super high rpm (hard to do since lance is known for his high cadence) or bigger gear ratio. Larger tires are going to roll farther for each pedal stroke.
 

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Discussion Starter · #10 ·
jorgy said:
Seems a bit weird. I'm half and inch shorter than you overall, but with a 31" inseam. Obviously, my torso is shorter than yours (I'm a chick) and I ride a 49cm frame with a 52cm top tube, short head tube and 700c wheels. Any smaller of a frame and there would be some serious design compromises, such as a too-steep seat tube angle if smaller wheels weren't used, though.

But the small wheels aren't a disadvantage. In fact, they're going to be a bit lighter than bigger wheels. I am coveting the Cervelo RS, which uses 650 wheels in its smallest (my) size. And if I bought a tri bike, I'd get one with 650 wheels.

But, you sound big enough for a road bike without weird geometry compromises to use 700 wheels.
Your'e a chick? I thought girls didn't like that word.:) Coveting? In a sinful way?:) I tried the 50 but it still felt like I was stretched out pretty far. Maybe Im not used to a road cycling position.
 

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Doggity said:
This subject is one of Grant Pederson of Rivendell's pet peeves. You CAN put a 700c on a 47cm frame, but you ain't gonna have clearance for anything bigger than 25's, and fergit about fenders or the like. And it looks odd. But it works. Think a 47cm frame is kind of a natural for the 650 or 26" persuasion.
Funny, I've seen 45s with 700x32Cs.

Grant has a way of saying things are impossible, when what he means to say is that they don't appeal to him personally.
 

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flankwood said:
Well I would imagine if you had smaller tires you would need a larger gear ratio orr a very high rpm rate to keep up with the other riders. I used Iban as an example because he is about my size, about 25 lbs lighter. On the hills the wheels might not matter much but how did he keep up on the flats? He either switched bikes, uses 700c on his small frame bike or accomadates for smaller wheels with a super high rpm (hard to do since lance is known for his high cadence) or bigger gear ratio. Larger tires are going to roll farther for each pedal stroke.
The gearing difference is small, and can easily be made up with one or two teeth on the chainrings.
 

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PeanutButterBreath said:
Funny, I've seen 45s with 700x32Cs.

Grant has a way of saying things are impossible, when what he means to say is that they don't appeal to him personally.
Yah, but by the same token, Grant's Bleriots fit 650bx42C. Rawland's Sogn all-arounder allegedly fits 650bx58C. Surly's Long Haul Trucker tourer fits 26x2.1, IIRC.

Most bikes w/700C really don't have that kind of clearance, particularly in smaller sizes.


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My Own Private Idaho said:
The gearing difference is small, and can easily be made up with one or two teeth on the chainrings.
In the 'rings, you might need more than one or two teeth, but your point stands. :thumbsup:

Actually small wheels can be a nice advantage gearing-wise, if your current cassette doesn't start with 11. Because then you can go with a smaller/tighter 'sette and save a little rotating weight, while getting more 1-tooth jumps, and not sacrificing much/anything in how low your low is. Your high gear is preserved too.

For example, a 12-23 'sette w/700C might become an 11-21 on a smaller-wheeled bike. If you're a sticker for the math, 650b will reduce a typical roadie outside wheel diameter by about 5.5% as compared with 700C, and 26" will reduce it by about 9%.


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flankwood said:
So 650 cc? What kind of size is that? Do all bikes had a frame for this wheel size or is it only certain companies that can handle 650. Is 650 the same as a 26" wheel?
650 is the approximate (very approximate) outer tire diameter, in millimeters. The c (not cc) refers to the rim cross-section.

650c is a designation of the tires that will fit the rim. The acutal rim outer diameter is something like 571 mm (without looking it up). It is very similar in size to a 26 inch wheel, but not the same. The tires are not interchangable, although in some cases the tubes may be.

Not all manufacturers make bikes using these wheels. They are becoming popular again though, and the tires aren't particularly difficult to find.

For more info the link to Sheldon Brown is gospel. Believe Sheldon before you believe me.
 

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Perhaps it was said above and I missed it, but some knowledgeable people believe that very small frames should have smaller wheels. For example, if the buyer insists on 700C wheels for a (traditional) sub-50 cm frame, the frame builder needs to change some frame angles to fit the wheels in. These changes can degrade bike handling slightly. Going to smaller wheels would allow the frame builder make handling the first priority again.
 
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