I have a YT bike, Izzo CORE 3 Black Magic M, year 2022. Nice bike, rides well on tracks with stones on them.
I ride 1hr, 3x a week, for fun and fitness, part tarmac, part tracks. Nearly 70 so nothing too crazy
Reasonably mechanically minded, have a workshop with a turret mill and a lathe. But not familiar with "modern" bikes and special tools required.
A year ago I changed the chain. Can't remember why. Same type
AFAIK. Immediately found it was skipping on the smallest gear. Well, yeah, old chain has a longer pitch. I gave it to a local bike service guy; he said the rear casette needs replacing to match. Kind of made sense. Few hundred quid! I got all that done and it was fine.
Last few weeks, I am finding the chain is behaving funny. I discovered that it is not "peeling" properly off the bottom of the front gear (SRAM 32T EAGLE XSYNC 2). But I see no obvious wear on the gear. So I guessed the chain is worn, too long again which I can see would cause that, so I got a new one. SRAM XX1 EAGLE 12-speed, £81. Cut it to length to match old one (117) and put it on. Immediately found it skipping not just the bottom gear but also the next two.
In the belief the chain is too long, I removed 1 link from in and it made no difference. But also the gearchange was not working as before and needed adjustment (why??) but I could not get it right. So I thought; maybe I need a new casette again, but they are 200-300 quid and I've been using the gears much more evenly than previously.
Eventually I gave up and put the old chain back. I ordered a new front gear; they are cheap £15 (are these counterfeit??). SRAM X-Sync 2 Steel Direct Mount Boost Chainring 32T. SKU: SRMCW8041004. I also bought that adapter with the 4 pins to remove the centre nut; found it pretty loose and about to fall out. But it does not hold anything; it is just a threaded ring.
The bike had a service a couple of months ago! It was obvious the shop refilled the tubeless fluid via the valves, not removing the tyres to get the old stuff out. He managed to mangle one of the valve inserts as well... and returned the bike with a load of mud in the gears.
Can anyone guess what is going on?
Maybe these "modern" bikes really get through the bits so fast? 3hrs a week is too much? Hardly. It would cost maybe £500 a year in parts.
Maybe I bought the wrong chain?
https://www.amazon.co.uk/dp/B08B2QYB48
Maybe over-oiled? Maybe there are many subtly different parts?
I have a bench clamp for the bike so can work on it easily enough, but I probably don't have the special tools for removing the rear casette.
Could be that the parts are made to very close tolerances and need to be set up exactly right. But how? How the gearchange works is obvious and should be adjustable visually.
Previous bike was a Sunn Shaman, 26" wheels, had it 10 years, never replaced anything, ran perfectly. Half the price of this YT one.
Thank you for any ideas.