Classic Bike FAQ

FAQ Artwork

An FAQ that focuses on maintenance advice for MTB and hybrids from the 1980s and 1990s.

How do I get a stuck seat post loose? 

The suggested problem solving refers to a setup where an aluminum seat post is mounted to a steel frame. It takes advantage of the fact that in dropping temperatures aluminum will shrink a lot more than steel (i.e. the two materials have different thermal expansion coefficients).

Just put your bike outside during an icy winter night or, alternatively, apply some coolant spray (if you live in a warmer climate). This will help breaking the bond between both materials. Mount a spare scrap saddle to the seat post and repeatedly hit it from both sides with a rubber mallet. Apply some penetrating oil such as WD40. You should see some small movements after a while.

If a seat post is fixed to a frame unchanged for years, the problem may become inevitable. Using anti-seize lube on the mount surfaces can help prevent it.

How can I fix a shifter that fails in clicking into certain gears?

This problem almost exclusively affects Shimano STI rapidfire shifters from the early 90s. The grease applied in production hardens to such a degree that the latches get blocked from clicking in. Flood the shifter with penetrating oil such as WD40 through the holes in its casing. Switch the lever back and forth through all gears again and again until you notice a change.

Can I mix and match drivetrain components from SunTour and Shimano?

Shifters, derailleurs, cassettes…