More chain questions (sorry)

[arallsopp]

Howdo.

Got 3 x KMC DX10SC chains on the Furai, and just recently, the front granny ring has begun to slip. The chain lands on the teeth, fails to settle in, and just spins round as soon as I put any real pressure on it.

I can land it right, if I drop there from the big ring, but its still 50/50. Obviously, this is not what you want from a granny gear at all.

I'm wondering if its chain wear... I've got 2,061.67km on it as of writing. Assuming the bulk of the wear occurs where the chains get wrapped around teeth, I'd expect this to be shared pretty evenly between the 3 chains. That's less than 430 miles each chain, not good.

The granny ring gets employed extremely rarely (think about twice every few hundred miles) and when I do use it, its at fairly high cadence. To me, this suggests the other rings have worn with the chain, but this one is still 'as new'.

Should I get a chain wear tool, and if I do, will it just tell me to replace the chain, triggering a whole 'buy a new chain, find the new chain slips worse, buy a new cassette, buy new rings up front, etc).

I feel I should get a chain wear tool, if only for peace of mind. Do they all work on all chains? When I went shopping for missing links, they were very specific about the number of gears and chain manufacturer. Is this all width and nothing to do with length, or do I need to be careful.

Plus, if this will work, is it a reasonable buy?
http://www.probikekit.com/display.php?code=NP08354

Ah... So many questions. Still, best to get them out, eh?

 

[02GF74]

Howdo.


Should I get a chain wear tool, and if I do, will it just tell me to replace the chain, triggering a whole 'buy a new chain, find the new chain slips worse, buy a new cassette, buy new rings up front, etc).

don't really know what you are talking about - 3 chains - some sort of recumbant thing (that I know FA about).

chain is jumping on small front ring - are you sure the derailleur is set up correctly?

has is just started to do this or did you chage/adjust/damage something?

for years I used vernier caliper but this year splashed out on chain wear tool - chain reaction, 5 pounds or so. moeny well spent - makes it less hit an miss, very quick to check and to boot it all, my vernier method said chain was worn but gauge says not so I am ableto get more miles out of it.

If you think about it, the chains should match the teeth on the chain rings and cogs; since many chains are interchangeable - ignroing the widht for 7/8/9/10/11 speed, then the dimensions should be the same i.e. the chin tool should work on all chains.

 

[arallsopp]

Thanks for this O2GF74. That's a good call on chain sizes.
The chain has only recently begun slipping, and it only does it on the granny ring. The derailleur looks right. I haven't changed anything on it, nor knocked it at all. Cable stretch would move the front derailleur towards the big ring IIRC, so that's a possibility.

3 chains is indeed a 'bent thing. One loop, many links. Imagine the standard 3 rings, a 6ft run to the back, and a rear cassette.
To stop the chain bouncing all over the place, there is an additional idler around the midpoint. Its just a jockey wheel, and shouldn't really change much.

Thanks for your help. Will check chainreaction too!

 

[arallsopp]

Aha. Noticed this morning (advantage of daylight riding with the BB in line of sight) that when its slipping, its dropping onto the edge of the inner ring, and not engaging properly.

I call cable stretch on the front derailleur! It was once, but is no longer set up correctly.

Kudos to 02GF74.