# 650 vs 700 wheel size



## CougarTrek

Hi all. I'm considering a new road bike in the moderately near future.

Being 5ft I'm on the line in which some manufacturers squeeze standard 700 wheels on the bikes and others opt for 650 wheels.

My current road bike, a Giant OCR3w, extra small, has standard 700 wheels and I'm quite happy with the bike's performance overall. Reasons for the upgrade are a) I feel I may be a *hair* stretched and want to try some different brands and sizes b) I'll admit it, I want a nicer carbony race bike, even if I stink!

I'm curious what others in a similar boat feel about the performance, ride quality, comfort, whatever differences there are between the two wheel sizes. I see people suggest the 650 wheel in order to get a better fit to people my size and below, but what's the downside/tradeoff? If two bikes fit equally well but one has 700 and one has 650 what is the performance difference?

I've only ridden standard 700 wheels on a roadie and am a little afraid of going to 650's (smaller radius=less angular momentum=don't stay rolling as well...or so my physics brain says). However, I'm very interested in Orbea's bikes and unfortunately I'll only be able to try the 49cm bikes (with standard wheels) and will likely need their smaller size (with 650 wheels) thus I'd not be able to test the new wheel size out before buying. 

If this has been discussed I apologize; feel free to point me to old threads. I wasn't having much luck with the search function. Thanks!


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## pdh777

650 wheels are used on smaller frames primarily to eliminate toe overlap. As you shrink the frame size your toes become closer to the wheel - obviously this can cause problems when you are turning. If you have big feet this is a problem - small or average feet for your size, not so much. 

From a convenience factor, it is harder to find 650 tubes at the LBS if you need one - also in group rides not many other people will have one. Also replacement wheels / rims are harder to find if you were to crash. Further not nearly as many options out there.

Since you are right on the cusp of one size to another - my recomendation would be to find a bike that fits with 700's. They are available from a variety of manuacturers. It used to be that any frame 47 and below had 650's - now most manufacturers are equippping 47's with 700's.
If you feel stretched out you may want to check your seat position and stem length. Have a professional fitting done to find your optimal measurements for a bike - then decide on the bike that will accommodate your measurements best.

If you are not a high level racer than the performance difference will not be noticeable - go for convenience, 700's.

Good luck, Do some research and ride a variety of bikes and find your correct measurements.


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## jorgy

A bigger theoretical reason (than just eliminating toe overlap) for using 650c wheels is to be able to produce a geometry that is more in line with bigger sizes, e.g., 73 degree STA. In practice, though, this isn't done nearly enough.

The problem with 700c bikes that are built for someone your size is that you will end up feeling stretch out. These bikes will have steeper STA, which will increase your reach because you have to move your saddle back to be in an optimal position for power.

Look at the Orbea's geometry. The 49cm bike has 700c wheels but a steeper STA than the 46cm. That happened because they were trying to shrink the top tube length. About 49cm is marginal for using 700c wheels; anything smaller really should be built with 650c unless is a custom frame for someone with freakish geometry. I say this as someone who's 5'4" and riding a unisex 49cm. Someone 5'--who is not racing and not in need of neutral wheel support--should really be on 650c wheels and not anywhere near the line between 650 and 700.

As far as worrying about differences regarding momentum and spin-up, it's really a wash with regard to wheel sizes and not worth worrying about.


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## Sacha

I am 5-1 and have two road bikes, with different geometries, both with 700c wheels:

Comparisons:
Brand...........Specialized........Pinarello
Size..................44cm...............42.5
Gruppo........... Record.........Chorus/Red
Top Tube...........49.6................50.0
Seat Angle........76.0°...............74.5°
HT Angle.......... 70.5°..............70.0°
HT Length..........105.................115
Standover......... 68.9................70.0
Weight*.............14.3 lb............16.4 lb.
Toe Overlap.......None..........Very slight
Use.................Mountains........Flats

The main reason I prefer 700c wheels is because of the availability of different kinds of wheelsets: climbing, training, racing, aero, etc. With 700c wheels I can swap sets with friends or test them out before buying. It also helps with support. I wouldn't go with a 650c bike as my main ride, but because I already have 700c rides as my mainstays, I woudn't mind experimenting with smaller wheels.

*Weight: With carbon bottle cages. Specialized weighed with Rolf Elan Aeros/Speedplay X-1; Pinny weighed with Fulcrum Racing 3s/Speedplay X-2.

(P.S. I did test ride the smallest 700c Orbeas – the Onix and Diva, and I couldn't pass the standover test)


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## CougarTrek

Thanks for the opinions everyone!

Now to start the fun journey of test rides. I don't think I'll completely rule out the 650 wheels, but I don't think I'll be considering them unridden anymore either.

Sacha, those are very different geometries. Looks like I'll actually have a few options, which means this will be lots of fun compared to my recent mountain bike shopping  (after 2 years off and on I finally found one that FIT instead of "worked").


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## MB1

If you look at the "Bikes Women Ride" thread you will see that all of Miss M's bikes use 650C wheels. Because of the Triathlon and Time Trial markets there is a great variety of wheels and related parts available in 650C so no worries there (in a pinch I have folded over a bit of 700C tube and installed them in 650C wheels with no problems) AND 26x1 tubes are readily available in the MTB section of shops and they are exactly the same as 650C tubes (26" tires are not interchangable with 650C).

There are lots of reasons she rides 650C wheel bikes but the #1 reason is fit. When you look at the side view pix of her on the bike she could any size person on any well fit bike; there are no visual clues of odd frame angles or short head tubes to let the viewer know how small she is.

I'd say go for the 650C wheel bikes if they fit.


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## adimiro

5 feet even here...I've done alot of research, reading, analysis on this question.

Years ago, the options for 650c wheels were minimal and hence, why I have 1998 Ti road bike with 700c wheels

Today, many choices of high-end 650c wheelsets and tube availability, thus, my new 'custom' road bike is equipped with 650c wheels.


The argument of availability is very weak IMHO...first, I'm always self-sufficient regardless of what bike I'm riding...second, with all the on-line stores, you can just order a bunch of 650 tubes and be set...third, in case of a real dilemma, you could always make due with a larger tube (700) to get you back home.

I don't think there are too many valid objections against 650c's in today's bike world. Good luck and go custom if $$ allows (a worthy investment for the benefits and for something you'll likely be holding onto for some time).


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## flyingheel

The other good thing about the 650c size is that if you shop ebay, you can literally get Zipp, HED and other high end wheelsets for about 1/3 to 1/2 the price you will pay for the 700c. Its almost obscene to see 650c Zipp 404 wheelsets for $350 or $400.


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