So I've been having an issue with my IP-057 with the drivetrain popping after an upshift or downshift. At first I kept thinking it was a problem with the rear derailleur or the chain. I looked things over, removed the rear wheel, removed the XX1 cassette, re-greased everything, re-assemble and re-torqued everything and it was still making the same noise. I continued looking and found the dropouts were loose, removed the screws, applied some blue Loctite to the screws and tightened them up. Still no improvement but I'm glad I found the loose drop out screws and took care of them before a more major problem occurred.
Finally, I swapped the rear wheels on my IP-057 and IP-036, the popping then started in the IP-036 so now I knew it was an issue with the rear wheel. So I removed the rear wheel and the cassette once more. I then disassembled the rear hub and found my problem:
Notice the broken hub main body at the base of the pawls and the chunk of metal on the table next to the hub.
I have been a fan of the Bitex hub due to the low cost and 6 pawl design. The hub really has 6 twin pawls, as there are twelve pawls in the assembly. Also the hub has 48T external tooth hub which gives it 7.5 deg of engagement. The 6 pawls giving more distribution of torque over a 3 pawl design.
These hubs have at least a 1 year warranty and I have only had them since about June of 2014 so I decided to contact BiTex directly. Being the weekend I did not expect a reply but amazingly enough, May at Bitex sent me an email saying they would be happy to ship me a replacement hub from Taiwan at no cost. However, they said they have gone to a 54T design (6.67 deg of engagement) and I asked them if the could send the older design as I don't want to rebuild the wheel. Perfectly happy with the 48T hub and I see no need to spend money to rebuild the wheel. Bitex responded saying they would ship a 48T hub.
I went ahead and cleaned and reassembled the hub, now that the loose chunk of metal is gone the hub is working fine even though the hub body is in poor condition. I won't ride the bike on the trails until I get everything fixed but in the meantime it is rideable. If Bitex was not going to warranty the hub, I had found a replacement Freehub for $35 on Ebay. I might still order it for a spare, just in case.
If I were to purchase another wheelset, I'd seriously consider going with DT Swiss hubs as they appear to be a superior design with their Star-Rachet pawl design. It's much simpler and would not be prone to breaking apart like this BiTex hub did. However, a DT Swiss hub as about twice as expensive to start with. HopePro Evo 2 hubs are also popular, they have a 4 pawl design and 40T (9 deg) of engagement and are about 30g heavier but are cheaper than the DT Swiss hubs and I would guess more robust.