I installed that 42teeth rear sprocket and it feels great. I believe that bike should come with 42t sprocket stock. It feels miles better than the 40t, very natural. Its still not good for off-road use but its rather perfect compromise, or at least it feels this way for me. Maybe I just couldnt get used to tall gearing but now I never get that engine struggle moment which would happen quite often with the 40t sprocket.
I will be installing 44t but I will wait a little to get a new chain.

The 42teeth sprocket from taobao is a tad imperfect. The inner diameter (that hole in the middle) is 130mm while the stock is 126mm so there is 2mm gap after installing. The bolt holes are in the right places. 44teeth sprocket can be found with 126mm inner diameter.


also, I have a question of a different nature

Is it ok to run a tubeless tyre with a inner tube inside? I have a chance to get some good tyres but they are tubeless and the rear is 140/80-18 (stock is 130/80-18)
I did google and it would seem that riders say one can run tubes in tubeless while professionals (revzilla. bike magazines) say do not do it.....

The size difference should be ok me thinks