The spacing for my disc wheel and training wheel is different enough that it requires some adjustment of the rear derailleur. It struck me that the limit should not change if I’m using the same casette, but that I would only need to adjust the B screw? Is this correct?
How is it diffrent? It should not be. I can go wheel to wheel to wheel with no touchups on anythign.
If they whole cassette is shifted they you should adjust both screws.
You could also shim the cassette or put a thin(er) washer under one of the axle nuts.
Edit:
Of course then you would be messing with the dish of the wheel.
jaretj
The disc wheel with the same cassette is almost one full click (STI) closer to center than my Velomax Circuit, so just swapping without touching anything means the chain goes off the smallest cog into the frame.
You shouldn’t touch the B screw unless the size of the cogs is very different. (B screw impacts the vertical clearance of the top pulley relative to the cogs.)
It is not uncommon to have slight differences in the lateral position of the casette, even with the same brand of wheel. Two different brands are even more likely to be different.
I have pretty much just resigned myself to potentially redo the shifting adjustments (end stops and tension) whenever I put the race wheels on my wife’s bike. The higher the number of gears (i.e. 10 speed), the more sensitive the system is. On her old 9 speed bike the spacing between gears is a little broader so it seemed like there was a little more room to work with.