How tight should a BMX chain be ?

daazzaa

Likes Bikes
Hi

Posting on behalf of my son as he is too young to be on these sites etc, anyway we are quite new to bikes and more into mountain bikes if anything. Anyway, bought a 2nd hand Norco Nail for my son as he wanted to do more jumps etc and told him no to doing it on his expensive MTB! The bike is in real good knick etc, looks like very little use, 1 question I have though, not understanding how bmx work (gear ratios etc), when you pedal it, it (pedals) seems very stiff/jerky until you get them moving faster. The chain is very tight and no slack in it at all. I'm assuming that is the problem; the chain needs to be loosened of a bit ? But I'm getting mixed messages on reading up on it/videos etc. How much slack should the chain be ? Or could the problem be in the pedals/bearings/cranks area?

BTW



Many Thanks
 

Peter650

Likes Dirt
Take the chain off. Then rotate the cranks, see how they feel, then spin the back wheel. If all feels good, check that none of the chain links are binding. When you put the chain back on. Turn the cranks, if they are hard to turn, slacken the chain a hair and try again. It won't take you to long to find the sweet spot between the chain being to tight, or to loose. You might have to adjust the brake if you move the wheel, position adjusting your chain.
 

daazzaa

Likes Bikes
Take the chain off. Then rotate the cranks, see how they feel, then spin the back wheel. If all feels good, check that none of the chain links are binding. When you put the chain back on. Turn the cranks, if they are hard to turn, slacken the chain a hair and try again. It won't take you to long to find the sweet spot between the chain being to tight, or to loose. You might have to adjust the brake if you move the wheel, position adjusting your chain.
Thanks Peter650. It is that tight that I will have to loosen the back nuts holding the back wheel just to get the chain off. Sorry what do you mean by chain links binding ? So the chain should be tight so the cranks are easy to turn but not too tight that the cranks are hard to turn? Since I reckon the bike has barely been ridden, do the chains start off tight then loosen a bit over time, ie take time to bed down/stretch ?

Cheers
 

Peter650

Likes Dirt
Kids can give the chain a hard time (grinding). This can cause the links to bind, from damage. Maybe if you go to a bike shop. Check out how tight their bmx chains are. The dropouts are so short, these days. You don't have a lot of room for adjustment. Bmx brakes can be a PITA to adjust. If they are not working correctly, it might be wise to take it to a shop for a service
 

daazzaa

Likes Bikes
Kids can give the chain a hard time (grinding). This can cause the links to bind, from damage. Maybe if you go to a bike shop. Check out how tight their bmx chains are. The dropouts are so short, these days. You don't have a lot of room for adjustment. Bmx brakes can be a PITA to adjust. If they are not working correctly, it might be wise to take it to a shop for a service
Thanks mate, I loosened the back nuts off and when the chain was looser, the cranks went around fine, so tightened them up again with a little black of slack in the chain but no where near enough to get chain slap, made sure back wheel was aligned and brakes fine. All good now. Thanks.
 

The Duckmeister

Has a juicy midrange
You want about 1/2" vertical deflection in the chain. Too loose it can bounce off the sprocket or chainring, too tight & it will wear almost every moving part of the bike out very quickly.
 
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