Bad front sprocket bearing sound

[mechanical1]

I finally got my xs bobber project off the lift and on the ground. Took it around the block and brought it in to adjust clutch and clearance the fender /chain area. On the lift in neutral spinning the tire, I get a bad bearing sound every couple of rotations on the front sprocket. If I depress the weld on chain tensioner so it isn't making contact with chain and spin, the sound goes away. Any help as to why this is occurring???

 

[hotdog]

Exactly the reason I don't run any tension on my chain roller. The Monstercraftsman tensioner looks cool but I think there is going to be a hike in output shaft bearing failures in the future as it places far too much additional pressure on the gearbox bearings when fully adjusted (which it needs to be to stop it from flipping over). It has waaay more tension than say the old xt/tt 500 style tensioners. If your running axle adjusters, it's just not needed IMO or should have less spring pressure.

 

[mrriggs]

Are you using new chain and sprockets? Worn out or misaligned chain/sprockets can cause a crunchy-poppy sound like a bad bearing.

 

[Ketis]

the monstercraftsman tensioner i have has a stop on it to prevent it from flipping over

 

[mechanical1]

Are you using new chain and sprockets? Worn out or misaligned chain/sprockets can cause a crunchy-poppy sound like a bad bearing.

New o-ring chain old sprockets but they have good teeth(no ovaling or sharp edges). I used a Motion Pro chain alignment tool to line everything up. I took off chain tensioner and noise went away.

 

[mechanical1]

the monstercraftsman tensioner i have has a stop on it to prevent it from flipping over

Mine also has a stop to keep it rolling over but it seems to be putting excessive tension on front sprocket bearing. Took off tensioner and crunching sound went away.??

 

[Shifty2932]

Interesting. Wish I would have found this thread before I installed mine. I literally just got my bike back together and running and was rolling out of the garage yesterday and heard the same thing. Was wondering if maybe something was misaligned. But I am going to remove the monstercraftsman tensioner and try without it and see if the sound goes away.

Bummer though as I wanted a tensioner so that the chain stopped slapping my electrical compartment under the seat.

 

[fredintoon]

- - - Bummer though as I wanted a tensioner so that the chain stopped slapping my electrical compartment under the seat.

Hi Shifty,
try swapping the spring-loaded tensioner for a teflon slider like you see on dirt bikes.

 

[fredintoon]

New o-ring chain old sprockets but they have good teeth(no ovaling or sharp edges) - - -

Ha! Those old sprockets may look OK to the naked eye and they may even work OK on an old chain but old sprockets and new chain don't get on well together.
Chain & sprockets are best installed as a set.

 

[Shifty2932]

So I inspected the chain again and was thinking it might be a bit tight.....and yes it was. So I backed off the tension a bit and the grinding noise from the front sprocket was gone. I will keep the tensioner for a bit and monitor the set up and see how it works.