I have Shimano 600 groupset on my (1980's?) Somec. 53/39 and 13/23 on sprints. I couldn't find a compact chainset that would fit without swapping the bottom bracket so stuck with the 53/39. I scrounged a 6 speed uniglide with a 28 large sprocket and rebuilt my 7 speed uniglide to incorporate this. Then decided I didn't want to das-assemble my sprints so sold them and built new 700c wheels with a 7 speed hyperglide cassette 11/28. This has dropped my bottom gear from 46" to 38". I'm happy with that and may fit compact chainset....eventually. This was a budget rebuild of my bike... and it's growing !