Zwift had been getting a bit squeaky. No worries, probably a bit dusty inside the trainer, I'll give her a cleanup.
Pull it apart, not looking too bad, belt looks good. Give it a good blow out, clean up with isopropyl, and a bit of silicon spray on the belt to rejuvenate?? It.
While the bike was off, took the opportunity to give the drivetrain a damn good scrubbing, and relube.
Hmmm, those derailleur pulleys look a bit shit.
Back on the trainer, smooth as silk. Oh yeah, that's where all my watts have been going. Recalibrate with the Saris app and put it to bed.
Get on this morning, ready to drop some fresh watt bombs on the final 2 races. About 300m into the warmup, the squeaking returns, but with a new, amplified intensity.
Fuckwit!! Those bloody pulley wheels. The gunk, pre cleaning must have been what was keeping them going.
Hit up the LBS for new pulley wheels. Pulling it apart, discovered the real culprit, so stole a replacement from my spare xt derailleur.
Hopefully I remember to replace it before I need it.