Chain Grind Diagnostics

I’ve been running an Izumi chain for about 18 months now without any problems, but as my rear wheel was creeping ever so close to the end of the dropouts I decided a new Izumi chain was in order.

When I put it on I took it for a test ride and noticed a grinding sound - quite loud. I thought I must have tensioned the chain too much so I let it off a bit and repeated the test ride. It was a bit better, and seemed okay when going down a slight downhill, but when I turned around and applied some extra pressure to climb the incline, back came the grinding.

I’m not sure if it was coming from the chainring (Cycle Underground) or sprocket (Dura-Ace), but it wasn’t constant, as if the chainring was bent or crooked. Having to ride the following day, I put the old chain back on and all was well.

Has the old chain been on for so long a new chain won’t engage with the teeth? Surely I shouldn’t have to replace the chainring and sprocket every time I get a new chain? Do I need to persist with the new chain until it wears it’s own, er, groove? - That doesn’t sound right.

Any ideas/comments/suggestions/compliments welcome.

Not sure of the exact cause, but i often find a new chain will make noises for the first few days, and will quickly disappear.

18 months is way too long between new chains isn’t it? i start feeling guilty after about 3 months, been thinking of getting a chain wear gauge.

3 months?!? The last chain I bought was to replace one that was over 2 years old…

it might wear in but the teeth on most likely the rear could have a bit of a _/ thing going on in stead of a / thing in which case a new cog is in order as well… i’ve seen this on road cassettes with the chain not been changed often enough and the space between the teeth elongates as the chain elongates… on the road cassettes in question it caused the new chain to skip… that said it might wear in just fine…

New chain, new drivetrain. When you leave it for so long, consumables become consumed.

I had this happen to me. The old cog and old chain had worn in to each other and the new chain made a horrible grinding sound on the old drivetrain. Id recommend replacing your rear cog first as it’s cheaper and see if that works.

Try turning the front 'ring around?


Plus check to see if your cog is worn at all like SK suggested. Surly cogs were a fave, and Phil Wood are even better cos they take forever to wear out.

Thanks all, looks like the weekend will be spent in the shed :smiley: