10:25 PM


Sometimes old stuff are just a pain in the ass.  Even the ones that weren’t even used very much.  This seems to happen a lot with old freewheel and chain combos.  The scenario is this:  Old bike with low miles has been sitting for a long time without use.  I pick it up and get it working again.  I lube everything.  Chain is smooth and fluid.  Freewheel teeth are clean and barely show wear.  First test ride everything goes smooth, gears change smoothly.  Right when I put it on the highest gear in the rear (the smallest one) and give it a good amount of torque, the thing skips.  *SNIP SNIP SNIP*  the harder you crank it the harder it skips.

I’ve had this problem many times before and I’ve learned that its the chain trying to jump to the lower gear that’s causing the skipping.  Its not the derailer.  I think its something to do with the combination of the shape of the teeth and the fitment of the chain.  I’ve also learned that the quick and easy way to get rid of the problem is to change out your freewheel (or cassettes) and chain for a new set, this fixes it every time. 

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I guess it was the nice weather today or some kind of dark energy that drove me but i couldn't stand not figuring it out and spent the whole afternoon toiling with the problem.  Visually there are no telltale signs of the problem, and its really hard to see it happening because there needs to be considerable torque on the crank to get it to skip so you cant just put it on your bike stand and see what’s going on. 

Keep in mind that the original chain and freewheel combo were in excellent condition.  They were far from worn and the chain was lubed very well.  After an hour of toiling with the stock stuff, i decided to change out the chain.  That didn't work at all.   I don't understand how a new correct sized chain can skip on a perfectly fine looking set of gears.  I ended up spending hours re-shaping the problem gear to see if that would change anything.  I dremmeled down the edges or anything I thought would cause it to be pushed towards the other gear.  I shaped it down bit by bit and test rode the bike each time to see if any of that would help.

It didn't.  In fact in the end, i wore it down so much that the chain slipped completely over the teeth given enough toque.  haha, at least I don't have to worry about that specific freewheel anymore…

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I ended up just replacing the freewheel and the new chain and freewheel combo worked like a charm. But being as i am, I'm still bothered by why the old setup didn't work so if you have a good technical explanation why, shoot me an email and I’ll test the reasoning and update this post with the the best answer.