Needing a bit of help on chain skipping :(

Hey guys, I currently have a problem with my bike; when going to skid my crank set jolts backwards, and when this happens, when i start to pedal forwards again it jolts forwards. In saying this, the crank set only jolts ONCE either way ie. if I skid and it jolts back, it will not jolt back again unless it has jolted back forward, which is totally mysterious to me.
Im sure you guys can understand my frustration when im trying to ride. I have no idea what is happening, all I know is that its the crank set that sticks chain links. I have tensioned the chain, and for some reason after it does the jolt thing the chain feels much looser, but then after half a revolution the chain eels much tighter, then loose again. And yes, im tightening my back wheel enough :wink:
I’ve got no idea whats going on but i would really liek to fix this problem, any idea anyone??
Thanks :slight_smile:

sounds like the lockring isn’t tight enough. Rotafix that cog (or ride up a hill), then tighten the lockring.

You’re cog is loose. Tighten it. If this doesn’t work buy a new bike.

I thought it could be the cog, but i looked at it the other day and the lockring is so tight that i cant even get it off, and my girlfriend today watched me as it happened as said its the chain ring/crank set that skips the chains.


This is what happens.

looks like the cog and (therefore) the lockring isn’t tight enough. Rotafix that cog (or ride up a hill), then tighten the lockring.

Post it in the help section?

Probably the cog is loose, and the lockring is not flush up against it despite being as tight as possible (as in, there is a gap between the lockring and the cog itself, meaning the cog can slip until it unscrews enough to contact the lockring). You should rotafix your cog then use the lockring only as a backup if the cog slips, or preferably rotafix and get a shim to fit between the cog and lockring.

Alright so the majority say its a cog problem, ill give it a shot tomorrow, and thanks for your help guys.

^ This

Some cogs can be narrower than the threaded section of the hub body. What this means is that when the cog is done up tight once the lockring goes on it either won’t budge or if it does keep threading on it will begin to chew out thread as it works its way onto the wrong thread. I’ve answered this same quesetion so many times on this forum that I made a handy diagram:

Get a spacer in there, or get a better cog.

Alternatively it could be that when you have tried to do up the lockring the cog is in the slightly loosened position? This would mean that although it is tight the first stroke forward will tighten the cog and thus the lockring will become loose. Rotafixing has been suggested but IMHO it isn’t required if you have good components and good tools to start with.

thank you very much antmandan. i just had a look and it turns out that was the problem, but i just took off my cog and lockring for the first time since i got the wheel set (the wheel set was just some thing i got off ebay for about 180 bucks that came with a flip flop hub) and once the cog came off with rotafixing, i saw the thread has been stripped on the hub. i can still screw on and rotafix the cog on since some of the threading is still there, and the lock ring can go on perfectly, but is this going to cause me problems? if so… does any one know where i can get a proper wheel made up in melbourne… haha.

wheelworks, member and site sponsor.
they build wheels that last.

I’ve heard nothing but good things about shifter bikes too

you pay cheap, you get cheap. you pay a lot, you get good

Thanks for that.
am i going to have problems with a partially stripped hub? key word partially?

In a word, yes. I’d say just go to a bike shop, with people that know stuff, and get them to have a look at it.

Meanwhile that problem of the chain going slack then tight again is caused by your chainring being slightly off centre. It’s a very common problem with cheap cranks. If there’s room for adjustment between the chainring and the crank spider you can sometimes fix it. If you don’t know what I mean, read more Sheldon.

Yeah I get what you mean, thanks for that mate.
Will any bike shop make up a wheel? Or only specialised stores?

I wouldn’t want to be running a stripped hub personally, especially if it was a more budget item/s (quandos?). Definitely not brakeless.

Try to spend a bit more on your drive parts, rear hub, cog, lock ring initially. Then you’ll have more money to pimp out your ride further down the track.

I’d absolutely have to agree with having a long trawl through sheldon brown.

On this…
I can recommend Surly cogs.They’re wider than your standard, cheapy cog. They come in 1/8 or 3 3/2.
Info here: Parts | Fixed Cogs
Buy them here: SURLY Track Cog 1/8 inch - Torpedo7

Any decent bike store will build wheels. Ask them how much they charge for spokes, and labour, because the price can differ by a large margin. High price is not necessarily indicative of a higher quality build.

Yeah man they were quandos, i knew i shouldnt have bought them.

allow yourself 6 months of these kind of screw-ups when first getting into riding fixed, you’ll learn from them and be better for it