This FAQ covers maintenance topics of 18-/21-/24-speed hybrid and MTB models which were at their zenith in the 80s and 90s.
How do I get a stuck seat post loose?
If you have an aluminum seat post sitting in a steel frame, try cooling down the post by either using a coolant spray or putting the bike outside in an icy winter night (if you live in a climate zone with winter frost).
While steel remains mostly unchanged in freezing temperatures, aluminum will shrink considerably in volume. This helps to break up the bond between both materials. Put a spare scrap saddle onto the seat post and hammer on it sideways with a rubber mallet, while applying some penetrating oil such as WD40. You should see some small movements after a while.
The problem is rather common, with seat posts remaining unchanged in their fixed position for years and years. You can prevent it in the first place by using anti-seize lube when mounting the post to the frame.
How can I fix a shifter that fails clicking into certain gears?
This problem affects almost exclusively Shimano STI rapidfire shifters from the early 90s. The factory-applied grease hardens to a point where 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 through all gears back and forth repeatedly until you notice a change.
What is the best Shimano groupset for MTBs and hybrid bikes?
Considering the key factors performance, durability, and price, you will end up with a hierarchy as follows:
– Deore XTR:
– Deore XT:
– Deore DX:
– Deore LX: