90's mtb frame size?
 

Hi all,

I have an old 90's litespeed unicoi mtb that I've been riding for a few years. I'm 5'10 and the top tube comes right up to my crotch area, such that I can stand over the bike but its snug. Center of bb to top of seat tube is 20.5in. Otherwise, I like how everything else fits on the bike.

Theres a litespeed frame on ebay from the same era as mine, but is just a little smaller. Center of bb to top of seat tube is 18.5in (supposedly). I'm curious if it would be worth buying a new frame for a better fit? I have little to no bike mechanic experience, so I will need a shop to swap most of the parts. Would this be a worth-while upgrade, or barely noticeable? Would it be more complicated than just swapping parts?

Thanks!

A 20.5" seat tube does sound long for someone 5'10". Most people your hieght would have been riding frames with seat tubes 17" - 19".

However, I go by the reach of the bike, not the seat tube. But still, the bike would have to be unusually short reach for that size, or you be very oddly proportioned for a 20.5" bike to not be too long.

I agree with the above. Everything should be easy to swap since the seat post most likely is 27.2, the front derailleur should have the same dimensions etc. You'll be more comfortable off road IMO since your "jewels" won't be as exposed. This would be a good time to purchase a few tools and learn basic bike mechanics (read Sheldon Brown).

Of all the reasons to replace a frame, getting a better fit would be one of the best. I'm 5'10" and I always rode an 18" frame in the 90s.

I can't tell you about the parts swapping out, but don't be surprised if a few things don't match, especially if the frames are different models. You might also find that the stem from the larger bike isn't the best length for the smaller one. The brake and shifter cables may need to be replaced, but that's a small expense.