Fast chain wear

[mjr]

it is a sacrificial part that is designed to wear out and be replaced before it gets bad enough to damage the more expensive parts that it runs around, this is why chains snap, before teeth shear off.

I was agreeing until "this is why chains snap". A snapped chain can do a heck of a lot of damage if it flails through the rear mech or some spokes! Replace it before it's in any danger of snapping, if possible.

 

[Pale Rider]

I think judging cassette wear by eye can be difficult because the teeth on Shimano cassettes have various clever, but odd, shaped profiles to aid shifting.

 

[bpsmith]

As @Drago said, I get through chains in around 1,500 miles also. I tend to change around 0.75% if I remember to check.

 

[annirak]

Well, the new chain is on order and is supposed to arrive tomorrow. Thankfully, they both have master links, so if the new one slips, I'll put the old one back on until I can get a new cassette.

 

[annirak]

New chain is fitted and it isn't slipping, but it makes a bit of a deep grinding noise on the small front cog. I assume this means that I've managed to wear out the small front cog.

 

[Tom B]

Is the ring clean, grinding suggests grit or grot on the ring

 

[annirak]

Is the ring clean, grinding suggests grit or grot on the ring

I didn't have time to clean the whole drivetrain last night when I changed the chain. I'll give it a scrub tonight and see if it gets any better.

I would have expected grinding on both the front chainrings if it was just a question of grit on the rings, which is why I'm asking about replacing a chain ring.

The answer to that question seems to be yes, but they're not common. I may have to special order a replacement chainring from Germany.

 

[bpsmith]

Sacrilege to fit a new chain to a dirty drivetrain!

 

[Tom B]

Grit on the front is always more noticeable. I suppose you can feel it better as you are connected directly to it. It always seems to build up where the chain sits and pushes it down, and then dries out.

On the rear I suppose it is a bit more protected and it spins faster and gets thrown off better.

Get a white spirity rag and or some degreaser and a trimmed up paint brush and set to. Little and often is always better.

This grittyness will also explain your poor chain life.