I have checked the forums and couldn't find an answer. I have been riding a 58cm road bike for everal years and want to buy a fixie to shoot around town etc. I want to buy through the nest and was wondering if there are any broad and basic size conversions between road and track. For instance is a 58 road frame equivalant to a 57 track etc? I know the geometry is different and there are a lot of other factors etc, but just generally

same size, or maybe slightly smaller for any bike that you will be mounting/dismounting a lot.

I ride a 58cm road bike and a 57cm track frame works for me.

I ride 58touring/ 56-57track and road

typically, a track frame has a higher bottom bracket than a road frame. hence, if you want the same standover height with both frames, the c-to-c measurement of the seat tube needs to be slightly smaller on the track frame.

uh, but, i don't know the BB height difference - is it like a cm or 2?

Unhelpfully, it depends on the bike.

If you want a fixie to shoot around town you could consider a fixed-specific bike with road geometry; track geometry might be more fun though. If the bike you want actually has track geometry maybe go a touch smaller, check standover and top tube length.

Forget about standover height and seat tube length. Who cares how many inches your nads are above your frame when you are standing over your bike? Use the (horizontal) top tube length as your main criterion for frame size. I have frames with c-c seat tube lengths ranging from 62 cm to 58 cm. All of them have 57.5 cm top tubes with 110 mm stems and all of them fit essentially the same. You can make minor adjustments with stem length, stem angle, headset spacers, bar type, and saddle position. But first you want a frame in your range of fit. Chances are very likely that frames with your tob tube length will have a standover that varies as much as 4-5 cm, you will probably be able to standover all of them. The most important size criteria are the relationship between saddle, bars, and bottom bracket. You'll have a better chance of getting a frame thats within your fit-range if you size by top tube length.

Thanks everyone. I went to a Bianchi dealer today and they put me through this fitting system and I'm right in the middle between the 57 and 59. They, of course, didn't have either. I'm thinking more towards the 57 as I can futz around with seat height and stem length, whereas if the 59 was too stretched it would be more difficult to change. I'm 6 ft 2 200lbs if that helps