Topic: Subtle tight spot in chain

[Adam_F]

Hey folks.  Quick question for ya.  I just replaced my drive chain and BOTH sprockets.  Sounds nice and smooth, but I noticed that there is a slightly tighter section of the chain when I turn the back wheel to a certain spot.  I had this issue before and figured that it would be resolved w new chain and sprockets... but alas... its still there.  The back wheel seems to be very true, so I'm guessing it could be an alignment issue!?  As far as I can tell, the bearing behind the front sprocket is in good shape as well (no noises or tight spots when I turn the sprocket).

I've researched this on the forum, but wasn't able to find an answer that I could visualize... so I apologize if this is redundant.  Anyone have any good suggestions for how to check the rear alignment?  Is it possible that its a problem with the rear wheel or axel?

Thanks!!!

[flybox1]

Are you feeling a tight spot on the chain, or a bad bearing(s)?

chain off and check for rivets too tight in one spot.
chain off check alignment between sprockets.
If its neither of these, i'd focus on the axle/bearings....

[Adam_F]

Are you feeling a tight spot on the chain, or a bad bearing(s)?

chain off and check for rivets too tight in one spot.
chain off check alignment between sprockets.
If its neither of these, i'd focus on the axle/bearings....

Thanks flybox.  The chain and sprockets are brand new (as of yesterday), so I'd assume that they're good to go.  I did check the alignment of the sprockets.  It was hard to tell as the front sprocket "floats" around slightly.  The back wheel is lined up evenly according to the notches on the frame.  Any way to measure if those are accurate? 

[77f2]

i had the same problem a while back. sounds like a bad link in the chain. rotate slowly and look carefully at the chain in the same spot. itll be easy to see if this is your problem.

[flybox1]

you didnt mention if you checked your 'new' chain for over-tightened rivets.
you didnt mention if you replaced the bearings in your hub...a wheel spinning, without the pressure of a chain, might 'feel' normal.

[Steve_K]

I have  heard of rear sprockets where the teeth were not concentric with the teeth.  I have measured several of mine, but never found any problems.

Steve

[Don R]

Mark the chain and the sprockets at the tight spot, rotate multiple turns and check to see if the spot stays the same on the sprocket or the same on the chain. If the sprocket mark is always the same it is there, if it's always when the chain mark is at the same place then it's in the chain.
 Like they said, remove the chain and look for a kinked or tight link.

[Don R]

 I cleaned and lubed the chain on my F last night and noticed the disc brake drags ever so slightly in one spot. A drum could do it too.

[CoachDoc]

Every chain and sprocket I've ever put on my 550 has had some slightly tighter spots even when new. My thinking has evolved to this- if the center of rotation of the sprocket is even slightly off from the center of the axle (and this position is fixed by the drilling pattern of the sprocket mounting bolts)
then the sprocket will rotate in a very slightly elliptical path, causing even a perfect chain and sprocket combo to have somewhat more tension in some positions than others. If so you'll find that the tightness corresponds to wheel and sprocket position and not a specific location on the chain. With you having installed a new chain and sprocket, I don't think I'd worry about it, especially because you probably won't be able to change the situation, nor do you need to as a practical matter.

[Adam_F]

Thanks everyone!