I finally installed the GOLDIX Road SL 11-28T 11 speed cassette which I bought last summer.
It shifted very well when on a bike stand, but on the first ride I noticed the chain skips / jumps on 15T sprocket (the 4th sprocket, counting from the smallest 11T). All other sprockets work perfectly.
The symptoms are the same as when you put a new chain on a worn cassette.
I had to avoid the 15T gear for the duration of the ride.
What I tried to diagnose this problem:
* New chains of different brands - the original chain I tried this cassette with was a new SRAM Red 22 Hollow Pin, I then also tried with a new Shimano 11 speed chain. Same problem with skipping on 15T.
* A different GOLDIX cassette (I have purchased 2 of them from the same AliExpress seller GOLDIX Store, with about 1 month between the orders, after reading mostly positive reviews). The problem can be observed on both these cassettes, with both of the chains mentioned above.
* Shorten a chain by 1 link (as short as I can go) to see if slightly increased chain tension will help - nope, same problem.
* Adjust the B-screw as much as possible to move the pulley as close to the cassette as possible, to make the chain wrap the cassette a little more - didn't help.
* I tried a new SunRace 11-28T cassette - and it works perfectly on all gears, with both the chains. So the culprit is definitely the GOLDIX cassettes.
So, I think I either got super unlucky and got 2 cassettes from a defective batch, or my rear derailleur (SRAM Red 22) is not working well with these cassettes.
Anybody else had similar issues?