Cabose

So I took my MTB out the other day for the first time in a while and found that every once it felt like my chain would slip or jump, and I'm wondering if I just need to clean my gears/chain or take a link out of the chain, or if its something completely different.
Thoughts?
Cabose

Mike T.

It's possible that the cassette is plugged up with weeds or the chain has a tight link (back pedal and watch for the jockey wheel cage for a slight 'jump') but the likely cause, if the bike has lots of miles on it, is that the chain is badly worn. Measure it as per my chains pages.

Taking a link out of the chain will do nothing except make it shorter.

sooprvylyn

A couple of things can cause this. First check the things Mike T suggests, could be that there is something in the cassette/freewheel or there is a tight link.-Since you haven't ridden it in a while the chain could very well have a stiff link.

More Likely the chain is worn out_or conversely brand new. You can check this easily by seeing if there are some gears you get this skipping and others where you do not. Usually with an old chain you will get the skipping on gears you dont use as much.

Explaination: As you ride the bushings on the chain(the little rollers between the link plates) wear down on the pins that hold the plates together. This causes the rollers to gain play, in turn causing them to not engage the gear teeth properly(some people call this chain stretch-misnomer). Usually this will also have a wearing effect on the most used rear cogs too. When you shift into a cog you dont use as much it is not worn in the same way as the ones that you do use thereby causing the intermittent skipping.

The solution- You cannot just get a new chain as they wont mesh with the worn cassette/freewheel cogs and you will still have skipping. You need to get both the chain and the cassette/freewheel to solve this problem. These parts of a bike are both considered consumable parts and need to be replaced every 1000 miles or so depending on your weight, quality of thee parts and how hard you ride.

Retro Grouch 

Prop your bike against something and work the crank backwards with your hand. Watch where the chain emerges from the bottom of the derailleur cage. If you see the cage jerk, that's it. You have a tight link. Work that link sidewards with your fingers until is loosens up.

sooprvylyn

Sidewards? hehe. the proper way to fix this is with a chain tool. Find the stiff pin/joint and use the chain tool like you would step 2 of putting a new chain on your bike.

f4rrest

+1

-1
(step 2?)

sooprvylyn

-1?
you know
Step 1 push the pin into the broken link with the chain tool
step 2 move the link to the center fins on the chain tool and push the pin slightly to loosen the now tight link.

Or you can move your chain laterally and risk bending the links which are not designed to bend that way.

Your choice.

zacster

That's what frees them up.

Cabose

Thanks guys. I think I figured it out though. I tried working the crank backwards but nothing was happening. Then I noticed that one of the gears in the derailleur was covered in gunk so I took a tooth brush to it. Seems to be better.
Thanks again
Cabose