I have posted this on other forums and It never gets answered. I have a 2003 Trek 2000WSD. It is 51cm. IT is ONLY a frame. It has NO fork, no headset, no bars, nothing.
This bike retails with 650 tires. I want 700c tires. If I buy a 700c fork can I put 700 wheels on, or will it throw off the geometry? Please help! I am new to cycling and this is just about the only chance I have at a decent bike on a college budget.
NO. If the frame fits ride it as is. Other than having to sometimes order tires and being diligent about having spare 650 tubes and perhaps a spare tire on long rides, there isn't any real disadvantage to the 650 wheels. Heck, they're actually more aero, lighter and accelerate faster...
Back to the sizing differences, it's an almost, but not quite as the critical geometry is very close between the 650c and 700c frames in that size. However, while you could fit the OEM 700c fork to get the correct brake position and off-set/steering trail and the rear stays are long enough for the larger wheels, the rear brake bridge is too low.
Rans Enduro Sport, Hase Kettweisel Tandem, Merin Bear Valley beater bike
Originally Posted by Kakadu
Thanks for the imput. Well, that sucks. I am just very weary of 650 wheels. You really don't think they slow you down?
It's the motor. Many people have this idea in their mind that all they have to do to go faster is to pedal a larger diameter wheel at the same cadence. They're right as far as that goes. The fallacy is that a larger diameter wheel is harder to pedal at that cadence so you won't be able to do it.
In the end, the power of your personal motor and your position on the bike are the two biggies that determine how fast you can go. Everything else combined is small potatoes.
I am just very weary of 650 wheels. You really don't think they slow you down?
Slow me down? Not enough to be of any consequence or that I'd notice. Again, 650c are lighter, they accelerate faster, they arguably have a lower front profile and may be a bit more aero. They decelerate a bit faster than the 700c, but that's about it. In fact, if 700c wheels were measureably faster than 650c wheels Tri-Geeks wouldn't use them.
The biggest "problem" with 650c is that you must plan ahead and carry your own spare tubes; few if any fellow riders will have anything but a 700c spare tube.
Originally Posted by Kakadu
And am I understanding right that this wouldn't work because the rear brake would not be in the correct position?
Sorry for opening up a can of worms. The operarative statement in my reply was NO, you can't put 700c wheels on a frame designed around a 650c wheel. Yes, if you compare the geometry charts for the 2000 and a 2000 WSD (Women Specific Design) the head tube, seat tube, and bottom bracket geometry "look" the same, the .5" difference in chainstay length doesn't seem like much, and you might be able to figure out that the change in fork length/rake would keep the steering geometry intact. The dead giveaway on just how different the 650c is vs the 700 is the rear triangle whre the rear brake bridge is .5" too low and would contact the tire and the stays are .5" too short which would put anything but a super-narrow 19mm rear tire up against the sides of the stays.