Chains chain help needed

[blue 48]

hi i got a 36 tooth sprocket and new chain today and fitted it all is good apart from it makes this awful crunch somtimes. every things running true and it still rides. The old chain and sprocket done many many miles so has the engine sprocket ive been told that i should have changed the front as well. is this true? it is quiet worn. PLEASE HELP

 

[IbedaYank]

go down to the local bike shop and buy a new good quality BMX chain. and front sprocket.
They are things that you replace as set just like a fullsize cycle
that snapping/popping noise you hear is the chain trying to derail.
Don't ask me how i know...

 

[Andrew King]

HI,

Another thing you may want to check for (depending on where you got the sprocket) is if the sprocket teeth are beveled or not)....Most Factory sprockets or cheap aftermarket sprockets are not and that can also cause a chain to misfeed...

By bevel I mean the teeth are angled in slightly from side to side....can be done w/ a grinder or file.

Hope this helps you.

Andrew

 

[blue 48]

dont need a chain this ones new and quiet good. but the engine sprocket is completely worn. i put the old chain and sprocket back on and its soo smooth, so changing the engine sprocket should help the cause right? other than that the speed im getting out of the old girl is awsome with new 36 tooth given that take off is a lot slower i can live with that

 

[IbedaYank]

blue 48
the faster you go the faster the chain is moving and that means the more stuff has to line up so it does not have any problems any misalignment at max speed will cause problems

 

[blue 48]

well today i beveled the teeth on the rear, oiled it up and now it runs nice and quiet and free no clunking problem solved thanks guys very much appreciated and the alignment is perfect now, done using precision measuring equipment from work our machinist is a legend with this stuff

 

[happycheapskate]

It's good that you got this fixed, but one thing to watch for is "chain slap". (side to side motion). A stiff BMX 1 speed chain will likely fix it, but i've had problems before I added a roller tensioner.

 

[motorpsycho]

I disagree on the bmx chain because personally i think they are too small.
I like the bigger 415 chains myself.
A lot of people say that the 415's are overkill, but I have never had any problems out of my two bikes with 415 chains.
also, sometimes a bmx chain will not fit the teeth on the front sprocket because it could have a different pitch.

 

[IbedaYank]

I disagree on the bmx chain because personally i think they are too small.
I like the bigger 415 chains myself.
A lot of people say that the 415's are overkill, but I have never had any problems out of my two bikes with 415 chains.
also, sometimes a bmx chain will not fit the teeth on the front sprocket because it could have a different pitch.

1/2 inch chain is a half inch chain.... just some are wider with thicker side plates
the pitch can't change or it would not be a 1/2 pitch chain
there are some motors that use a metric chain aka pocket bike motors

 

[motorpsycho]

1/2 inch chain is a half inch chain.... just some are wider with thicker side plates
the pitch can't change or it would not be a 1/2 pitch chain
there are some motors that use a metric chain aka pocket bike motors

yes you're right, the 1/2 inch is the width.
i tried a bmx chain on one of my bikes just to see if it would work when i was building it.
the chain fit the rear sprocket perfect all the way around. but on the front sprocket, only about 4 links would line up with the teeth. Once past those 4 links, the teeth and spaces in the chain would not line up at all and the chain would not go all the way around the sprocket.