Crunchy Shimano GRX 1x

I use a separate wheel on the trainer than outside. As a matter of fact, I have 3 rear wheels, trainer, road and gravel. There seems to be consistent sound across all wheels. The trainer and road wheels have an 11-32 cassette and the gravel wheel has an 11-34. Ive looked at the B screw or “final adjustment” screw and it seems to be ok across all wheels.

Yes, Im working with 3 different hubs which could all be space slightly differently in regards to the read der.

why does the rear derailleur matter on a wheel-on trainer though? or for that matter, the chain or anything else discussed earlier.

if its a wheel on trainer and you get this same sound on all 3 wheels, but only on the trainer, its an issue with the trainer, no??

or is there some new wheel-on technology i dont know about

On a wheel on trainer, The rear der. adjustment would set where the chain lines up on the cassette. The cassette might be in a slightly different place on a different hub. What might be perfectly adjusted on my road wheels might be a mil or 2 inboard or outboard of that on the trainer wheel.

Anyway, to continue with my follow up, after a long outside ride on the road wheels today everything was smooth and silent. I think perhaps the noise is just different that the previous bike and I know that things are definitely louder inside than outside with the wind wooshing around and a warm winter cap on under the helmet.

Also, I think part of the blame could be placed on old vs new chains. The new chain, freshly waxed is quieter both inside and out, even though the old chain was not yet at the 0.5 wear mark.

I wanted to follow up on this. I noticed that the small rear der. cable outside the frame had a crack in it. Also, the shop loosened the clutch in the rear der. So far, that has made shifting more precise and much quieter.