The gear does not work well. Adjusting the rear derailleur is possible - the chain runs in gears 4-9 without problems. When the chain is in gear 1 (largest sprocket), it runs rough. Also, the chain jumps 2-3 down from the top sprocket when the pedals are moved maybe 30 degrees BACK (e.g. when mounting the bike).
I suspect that the chain run is too extreme for gears 1-3.
2 spacer rings were fitted to the bottom bracket at the factory. Is this correct? Should 1 or2 be removed here? Do you have instructions for this with reference to any special tools?
It would be very kind if I could get technical support/advice from you.
With kind regards