I am working with Sweetpea Bicycles in the design stage of my first ever full custom bicycle. I'm soooooo excited. I've been through a multi-hour fit session with one of the best bicycle fitters in the country (Micheal Sylvester) as well as Natalie Ramsland, the owner of Sweetpea.

Based on my measurements, Natalie can build me a bike that fits with either 650c or 700c wheels.

There are pros and cons with each size wheel.

650 Pros
1) Bike design in more aesthetically pleasing (the small frame size looks in proportion with the smaller wheels
2) Lighter wheels and less rotational mass. Small wheels accelerate faster than large. Very nice wheel sets are available in 650 (many triathletes use 650s)
3) Fewer toe overlap issues

650 Cons
1) Fewer tire choices - both in width & color
2) Fewer fork choices - there is a carbon 650 fork, though
3) No stock 650 forks have fender clearance. Not a huge big deal, as I could use a race blade on front if necessary.
4) Spare tubes not as readily accessible - no relying on ride mates for an extra spare if you have an unlucky day.
5) Can achieve the same gearing as on a 700C bike, but need larger front chain rings to do it (ie bumping up to a 53x11 or 54x11 to get the same gear inches as a 52x12 with 700c wheels)

700 Pros
1) the world is your oyster on wheels, tires, forks, etc
2) every shop on the planet has replacement tires/tubes. Most of you r ride mates will have 700cs as well

700 cons
1) very small frame looks odd with larger wheels. Frame geometry has to change a fair bit to achieve the same position/fit
2) greater rotational mass on the larger wheels - accelerates more slowly
3) toe overlap


I'm sure there are other pros/cons... What are your thoughts?

Susan