Thanks for the comments guys. The stays are pretty skinny, but then so are all of the tubes, especially when you see it next to a modern bike which is one of the thing I love about it and why I'm on here. Acceleration is pretty lively though, especially given that the wheels are OK (Sunn by Sachs hubs on Sunn, possibly by Mavic, rims) but not superlight. Been thinking about changing them, as well as some of the drivetrain (a mix of STX RC, Alivio and Sugino) for something that performs better but keeping the old parts so I can always put it back. Any thoughts?
I agree there aren't enough Sunn's around. I always wanted a Revolt too
Possibly the wrong place to ask but does anyone no anything about modern Sunns? Are they still the same company or did they get bought out?