In essence AliExpress was generally cheaper than eBay but goods took longer to arrive. Now the prices are loaded with VAT and/or Customs Duty its no longer a cheaper alternative.
Do you have a cassette? Have you pulled the derailleur right back? Does your derailleur have a clutch that needs releasing?
give us more info and I’m sure help is imminent!
I covered 1000 miles on mine when the chain started jumping in the 11t cog. I was advised to get a new chain and cassette. For the sake of £4 from AliExpress i bought a new Shimano 11t cog and rverything was good again. Although I know I’ll have to replace the chain (and probably the cassette)...
Back to the OP. My observations are that it tends to be your lycra lout type who wears all black, you know the ones, they ride in packs, 2 or 3 abreast. Not long ago these guys were done up like power rangers. So it must be a fashion thing !
I’m 6’1” and nigh on 20st. Ive got a Decathlon Rockrider E-ST900. Size ‘L’. I could even get away with an ‘M’. Don't get an XL unless you’re over 6’4” or have seen the bike in the flesh!
@PC2017 sorry, all packaging binned. It was a large sticker on the back, stipulating description of contents and value. Not too dissimilar to what it used to be pre-brexit!