Pedals Old

Why do the pedals of my mountain bike just spin?

I have an old mountain bike that I really don't care to fix up. Only one or two gears work. The problem is when I pedal, usually after I have coasted, the pedals will just spin. They will catch again but sometimes it takes awhile sometimes not. This is very annoying. The chain doesn't come off. Is there an easy way to fix it or just get rid of it.

This could one of three things. Either the chain has stretched and can no longer engage with the teeth of the chainrings and gear cassette; or the chainring and cassette teeth have worn so badly that the chain can no longer engage with them or the freewheel/freehub has seen better days.

The first two will require a new chain, and almost certainly new cassette and chainrings too. The second will require a new freewheel/freehub. A stretched chain and worn teeth are a problem because they can cause a phenomenon known as chainsuck, when the chain belongs entangled and locks up the rear wheel - if you're travelling any faster than walking pace, this may well lead to injury.

Since you don't want to fix it up I assume you're not experienced in cycle maintenance, and getting it done in a bike shop is likely to cost more than I suspect the bike is worth. So, all in all, you're probably best off just getting a new bike.

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