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Proper wheel size??(3 posts)

Proper wheel size??soulholler
Aug 17, 2001 3:16 PM
Isn't it true that many manufacturers are getting away from the 650c wheels? And if so, why? I just purchased a 48cm Colnago Dream and assumed that I would equipe the bike w/ 700 wheels, but a friend said,"wrongo!" I don't think I have a choice because the frame is made for that 700 wheelsize or does the rear triangle and fork allow for 650's to fit properly?. To me, it seems that do to the small frame proportions that 650's are an automatic fit. Is this true? Also, if I HAVE TO go with 700's, won't my the front of my foot skim the tire when make turns? Thanks.
Frame is designed to fit only one wheel size.Spoke Wrench
Aug 17, 2001 4:12 PM
I don't know about that particular bike. If I had to guess, I'd say it,s probably designed to take 700c wheels, but a frame that size might well be designed to use 650's. Frankly, if I were designing a 48 cm frame, I'd design it around 650 wheels.

If you really do have a 700c frame, and you try to use 650c wheels, your brakes aren't going to line up with your rims. Conversely, 700c wheels won't even fit onto a 650 frame.

Toe overlap is an interesting topic. There are several ways of designing a frame to avoid toe overlap. Some designers just don't worry about it because if you do have toe/tire interference, it will only affect you when you are riding at about 5mph. Usually it only happens in the parking lot with all of your friends watching.
re: actuallyAkirasho
Aug 17, 2001 7:13 PM
There is a resurrgence in interest and use of 650C wheelsets. In days gone by, the 650C was relegated to specialty use on TT and or Tri bikes (I've even got a 61cm GT that uses 650C wheels... an odd sight). Today, in an attempt to capture larger market shares (and at this point, it's a good thing for the consumer) many makers are designing frames specifically for shorter riders who'd directly benefit from a smaller wheel.

The current downside is that you're hard pressed to find inexpensive 650C wheels... 700C still rules the roost in that respect. You'd have to search a bit to find 650C rims with the same amount of variety as 700C... but I suspect that this will change.

As far as frame design and wheels... 'tis true, a frame is generally designed with a specific wheel size in mind and the two don't mix (again, my GT represents a complete departure from all my other road machines, requiring a special outlay for 650C wheels and rubber... ironically, one of my riding partners rides on two 700C wheeled roadbikes (can't remember the frame size but they are small), but races TT's on a 650C wheeled Trek Hilo which he likes... special outlay for him too).

This is not to condemn older smaller frames that ride on 700C wheels. It just points to one of the better trends in road cycling today (IMO). This is the current trend, and I hope it continues. It only makes sense since one size does not fit all...

Be the bike.