Chain issues

[finiusj]

My son has a '76 CB500. He put on a new chain and sprocket and now says the chain is wearing down the sprocket at an alarming rate (he's noticing metal shavings around the sprocket). I had no anwers for him but I told him I would ask here as there are some mechanical geniuses lurking that may be able to help . My advice was to find a bike with shaft drive (a lot of help I am!).

[hunzee]

Sprokets wear out chains. If one needs replacing, they both do.

[old dad]

chain is improperly tightened, or too loose.

mark f

[JN]

It seems to be on to tight, which could also cause it to snap off and take a chunk of the bike with it. If the bike has any suspension in the rear the chain has to be able to adjust to that movement. A lot of times people put chains on like its a BMX bike and just tighten it as much as possible causing this problem. If it is on to tight I would check the manual to see the exact ammount of play it should have.

[gat803]

It could be a number of things, too tight as has been suggested.
The rear wheel may not be aligned properly = Most likely. Are the rear wheel bearings ok?
Was the sprocket installed correctly? Are the chain and sprocket both the same size?
What is the sprocket made of? Aluminum sprockets wear very fast. Even some cheap steel ones wear poorly.

[Pavogg]

Depending on how worn out the original chain is it is necessary to look at both sprockets to determine if they are worn enough to be replaced also, As a chain wears the length between the rollers grows causing the chain to wear one side of each tooth on the sprocket(s). It is usually noticable by each tooth havning a "hook shape" See the illustrations here http://www.sheldonbrown.com/chains.html

If the sprockets are worn from a stretched chain a new chain will devoir the srockets and ruin itself in the process.

[finiusj]

Thanks for the replies. Both the chain and sproket were new. I'll have him check the rear wheel bearings. My guess is improper alignment. Any suggestions for checking this? Thanks.

[ycroosh]

Pavogg,
The distance between teeth can't grow by definition (it would mean that the perimiter would grow, and that would require an increase in diameter).
The most likely reason for the "metal shawings" would be a misalighned rear wheel (i.e. sprockets aren't on the same plane). The story about sprockets wearing the chain down are "overrated" (the other way around is a more serious issue). I usually get 2 (RK O-Ring) chains per a set of sprockets. The second one lasts for around 10-15% less than the first one.
A friend of mine tried to install new rear sprocked with an old chain and by the time the chain was busted the rear sprocket was worn about as much as the older front one.

Hope this makes sense.
Yuriy

[Pavogg]

Please reread my post, I said nothing about the distance between the teeth growing, my reference was to the chain as follows"As a chain wears the length between the rollers grows causing the chain to wear one side of each tooth on the sprocket(s). It is usually noticable by each tooth havning a "hook shape" "