My commuter/road bike has a 9 speed Sora groupset. I've owned it from brand new and it's 1 year old. In that time, it's done about 2,600km
The first chain and cassette was worn after only 6 months/1,200km. I let the chain go way too far, to the point where it was visibly standing off the chainrings and skipping when I put any power in. All was well after I replaced the chain and cassette.
I was a lot more diligent with cleaning and lubing my chain every week after the replacement, and using a chain checker.
Fast forward another 6 months and 1,300km, the chain checker (ParkTool cc3.2) showed the chain was now past 0.5% worn, but not yet 0.75%. This is supposed to still be an acceptable level of wear for a 9 speed?
I replaced the chain, thinking I'd got ahead of it and wouldn't need to do the cassette this time. But no, the cassette is clearly worn because after replacing the chain I started getting slow shifts and shifts that skipped the cogs I use most often. I fannied around reindexing the gears, but could not get it quite right. I replaced the cassette once again and everything was instantly fine, shifting was perfect once more.
Is it normal for a chain and cassette to wear out so quickly over such a short distance? I am a bigger rider (95kg) and this is my commuter bike so I do ride in the rain and over winter.
Is it possible that worn chainrings could be shortening the life of new cassettes and chains and I should replace those too?
It's hardly the end of the world if I have to spend £35 on a new chain and cassette every 6 months, but the distances I'm getting out of these components seems substantially less than the 3,000 to 5,000 miles I see quoted everywhere.
Thanks :)