BMX - my chain always comes off!

I'm racing this year, and I have a major problem: my chain comes off whenever I go fast! It has come off 6 times in 3 weeks. It only has a half inch of slack, which is ideal for racing. How do I keep it from coming off? It's making me develop a fear of going fast.

Make sure that your sprocket isn't bent and that you chainring bolt and pinch bolts(on your crank, if you have a 3 piece) are all tight. If they're loose your sprocket could wobble side to side making it out of line with your chain.

that sounds like to much slack for me

One would assume that the answer for how to fix this problem would be obvious.

Tighten It!!!

I di but you see, on my bike when it is way tight it's hard to pedal. And I'm racing.

I would think it's gonna be hard to pedal with your chain tight.Isn't it better to have your chain tight

It's not any harder to pedal with your chain tight; if anything, it's easier.

i never have my chain too tight, it messes me up with kickflips

I should probably make a comment about how gay crankflips are, but I won't.

i dont really like kickflips if you're not doing anything else, but if you do it out of a grind or during a spin, it could be cool. these little ****** kids near my house do crankflips down stairs.

Wow, I've not heard of this problem, at least not as severe. In more years of racing
than I care to admit, I can count on one hand the numbet of times I've dropped a chain - always when shifting from the small to the large chain ring to sprint over the top of a hill. That was with the old Sedis chains and friction shifters.

It's gotta be a bent chain ring or frame or something that is causing misalignment
of the drive train. When's that last time you replaced the chain or for that matter
the cog set? Does the bike shift smoothly otherwise?

sun

ps: With decent derailluers chain slack shouldn't be an issue here unless it's
really slack. Used to cut them down from 120 to 108 links for racing. Worked for all
but big - big combination.

Wow, I've not heard of this problem, at least not as severe. In more years of racing
than I care to admit, I can count on one hand the numbet of times I've dropped a chain - always when shifting from the small to the large chain ring to sprint over the top of a hill. That was with the old Sedis chains and friction shifters.

It's gotta be a bent chain ring or frame or something that is causing misalignment
of the drive train. When's that last time you replaced the chain or for that matter
the cog set? Does the bike shift smoothly otherwise?

sun

ps: With decent derailluers chain slack shouldn't be an issue here unless it's
really slack. Used to cut them down from 120 to 108 links for racing. Worked for all
but big - big combination.


this forum is about bmx, and i don't think he has to shift gears

You realize that BMX bikes don't use derailluers or multiple gears, right?

Gee,

Should've checked the forum. I'm old and rode (at race pace)about 70 miles in the mountains today. So I'm tired too.

sun

have yall noticed that if someone from the mountain bike forums or the road bike forums comes and does something here and makes an honest mistake that they just take it and its all cool but if one of the bmx people makes a mistake and someone says something they bring up and attitude? dont wanna start nothing with no one but i just wanted to point it out

It's not any harder to pedal with your chain tight; if anything, it's easier.
Well, on my bike it creates a ton of resistance. Plus it's easier to break completely when it's real tight. That's how I broke my last chain.

Chaim should be fairly tight, 1/2" is more than I'd want racing. Is your chainring centered, meaning does it get looser/tighter depending on which point in the rotation the crank is?

Well, on my bike it creates a ton of resistance. Plus it's easier to break completely when it's real tight. That's how I broke my last chain.
get some lube or chain grease at a bike shop

turn the bike over and make sure the chain is going in a straight line between the freewheel and chainwheel (no curving between em). this was haunting me all last season in fact. the countless hours i put into messing with that chain. oy. anyway straighten out the chain by adding spacers to the cranks (moving them out more, hopefully alighned the gears). make sure ur backwheel is tensioned straight (not pointing to one side). u may also try gettin a good chain like the ACS one, which won't flex as much. oh and btw, for racing you should be able to run close to an inch of chain play. hope that helps dain, as i said i had to put up with that chain crap too.

btw, for racing you should be able to run close to an inch of chain play.
i disagree with running a bike with that much slack in your chain

get chain tensoiners.....or take links off your chain.... but if you race you want your chain just a little loose compaired to your street or dirt rig...
-taylor-