Originally Posted by
Fentuz
There are several things to look at.
If you take the wheel off, can you see a noticeable difference between to fitted 11T cog and the new one (shark tooth shape).
Is the new chain the same model as the existing one? I had several issues with KMC and problem went when I fitted back SRAM chains.
Is your derailleur properly adjusted? (stop screw).
Whatever the answer to the questions above are, you need to look into maintenance - clean/lube the chain ~every 100miles to prolong the life of the components. @
800miles, the chains will be "dirty", full of old lub a dust/dirt that will create a lapping paste grinding the components away instead of protecting them.
Then, the chainring. if 48 was too easy, it's good to go to 52 but you seem to say that you spend loads of time on 11T cog (gear 8). Gear 8 has not got an optimal chainline, the chain has to bend causing wear on both chain and cassette. This gear should be kept for occasional sprint and down hill.
Assuming your G6 is a 15T and G7 is a 13T, you should go for a 56 (possibly 60) chainring so that you don't spin out and get a better chainline but you need to consider the hills which affect G1.
Shimano Capreo came with a 9T and was known to wear out quickly when over used. On my e13 cassette, I use the 9T cog on downhill or Sprint only, I tend to stay on 12-15T on flat tarmac/dry gravel
You have given me some sound advice.
I have started lubing the chain more often.
The optimum chain line issue is true between G8 and the chainring. I checked my gear ratio chart and 60T barely does the job but will the drivetrain (ie BB or rear der) have to be adjusted.
the 60T G7
While live in an area that has some steep hills, I haven't used G1 thru G3 so far. That, of course, would change where 60T with G3 would be a tad higher than 52T with G4 but still leaving me G2, G1 for emergencies.