Originally Posted by
motogeek
Swin, I measured my GRs this a.m. and here's what I've found. The '72 has a chainstay length of 17" (43.5 cm). Both the '75s have a c/s length of 16-3/4" (42.5 cm). On all 3 the seat tube is shorter (52 cm) than the top tube (55 cm). (My '72 is pictured in a post above.) I'm running 700C wheels on the '72 and 27 x 1/14 on both '75s.
Yours appears to be somewhat newer than mine so things probably changed a lot over the model years.
Hope that bit of trivia helps.
That's interesting thanks for doing that! So you're running 27s on the bikes with the shorter chainstays, both which match the chainstay length on my 82/83. I'll have a look at the catalogs from '75 and see what size wheels they ran. I'm just curious if they just used similar geometry through the years and moved to 700c at some point. I don't have the original parts for this frame, not that they were very exciting anyway, and doing a ground build with reasonably priced early 80s Suntour etc. I want to have a go at a Vitus frame, more than any expectation the bike will have much resale value when I'm done. Never owned a French bike before. Thanks again!