Chain Suck Sucks, Why do I get it?
 

Do single track quite often here in Northern VA and have recently been getting major chain suck. Nothing hurts a climb more than pushing the crank and having it lock up. This occurs most frequently when my components get bogged down with mud, but I have also had it occur in dry riding conditions. Why does this happen and how do I fix? Is my chain too loose? too old? or is it not lubed properly? Any insight would be appreciated...
A

Obvious reasons:
The mud alone would do it.
Insufficient lubrication would do it.

Less Obvious:
A friend of mine had a chain with a bent link that was giving him chainsuck. He would encounter it on almost every ride we went on. Once he discovered the chain problem and replaced the chain he never had chainsuck again.

There are probably other reasons that I am not aware of.

Happy riding.

Thanks Greenfix, I will check the chain out. Anybody else have insight?

deraileur spring worn out?

Are you riding a Trek or a Gary Fisher? They are famous for chain suck.

Check your chainrings. If there are burrs on the teeth, that'll lead to chainsuck. You can get creative with a round file or a dremmel tool to knock the burrs off. I've also seen where some people with flip their chainrings over. I don't recommend this as the ramps and pins to improve shifting will be rendered useless.

Another thing to try is to remove one link from your chain. Remember one link = two 1/2 links one inside 1/2 link and one outside 1/2 link. The shorter chain will provide a bit more tension on the rear derailleur spring.

Keep your drivetrain clean and well lubed. Also make sure you're not in a "cross-chaining" situation.

L8R

Why is that? It is funny you write that. The guy I was riding with that got chain suck rides a Sugar.

edited for spelling.

I worked at a shop that sold Gary Fisher's. The Sugar's and the Trek Fuel's are notorius for chainsuck. I think their chainline is "off". Their recommendation now that I think about it was to upgrade your chain to XT/Ultegra level.

L8R

Thanks for the advice
it is a 1999 Specialized Stumpjumper...what do you mean by "cross-chaining" situation?

Gracias Raiyn

Before I bought my Fisher Cake 2DLX, I read it had major chain suck problems (www.mtbr.com). I contacted Fisher and they were aware of it and said they fixed the problem by using a thread locking compound on the rear suspension pivot bearing. This implied the drive line would get out of alignment and cause chainsuck.

I did buy the Cake and in over 500 miles of riding the dry Southern CA hardpack, I've never had a chainsuck incident. I ride 60% fire road, 40% single track.

I used to get occasional chainsuck on a Schwinn Homegrown hardtail in the mud / wet conditions; however, I learned that a clean and well lubed chain prevented chainsuck.

I am a firm believer in a clean chain. I clean and lube my chain after every 2 or 3 rides.

Chainsuck ain't fun.

Clean the chain extremely well and lubricate, usually takes care of it. If it doesn't your chainrings are probably worn. Replace them, the cassette and the chain at the same time ideally.

Thanks guys and gals, all good tips.
A

.....

It will only get rid of it temporarily. But chainsuck will return.
Good crank rings will NOT suck not matter how muddy or poorly lubricated your chain is.