I found an old racing road bike with a 50 cm frame. I would like to build it out and use it, but I am concerned it may be too small for me. I'm 5' 7.5" and I think I should be riding a 54 cm frame, but I'm not sure. Would that 4 cm difference be an issue?
-
If it's any help I'm the same height but ride 56cm.– Dan KMay 29, 2020 at 8:49
-
Do you have an existing bike that you find comfortable to ride? If so, use a tape and measure from the BB axle up to the top of the saddle, staying parallel to the seattube on your known-good bike. See if the other bike can replicate this measurement without exceeding the "minimum insert" mark on the seat post. Mine's 83cm, anything less than 81cm is uncomfortably small.– Criggie ♦May 29, 2020 at 12:11
-
I'm the same height and rode a 50cm frame. I had the longest seat post & stem I could find to get a good position on the bike. It worked OK for me for many years, but as I got older, it got less and less comfortable.– FreeManMay 29, 2020 at 16:07
1 Answer
I'd say "proceed with caution." The main question is whether you can get your contact points where you need them. And you probably can, but there may be compromises.
- A smaller main triangle, ridden by someone with bigger feet, will increase the likelihood of toe overlap.
- You'll obviously need to jack up the seatpost, and if you're past the limit line, you may need to get a new seatpost.
- You may need to put a longer stem on the bike in order to get the right "reach," and this can have consequences for handling. You'll probably want to put on a stem that has a fair amount of rise, to make of for the frame's smaller "stack." Otherwise you'll either need very good hip and torso flexibility or a willingness to ride with discomfort.
Also, for whatever it's worth, small bikes (such as 50 cm) often have innate geometry compromises in order to fit the frame around 700C wheels.