There are two options. The first involves using the Tormek leather wheel, which has a slightly smaller diameter. In this case, you need to adjust the angle slightly with the KS-123, as the wheel diameter is smaller.
If you don't want to do this, you can use the 250 mm leather wheel, as mentioned here. That's the one I use too. When sharpening a long knife, you'll need to take it off for a moment. No problem, it's back on in a jiffy. With my 250 mm leather wheel, there's also a margin when you buy it, meaning the diameter can be a millimetre larger or smaller. So the KS-123 comes in handy again.
But there are also situations with my 250 mm leather wheel where I need to adjust the angle slightly, because the type of steel needs to be honed at a slightly larger angle (example: sharpening at 15 degrees and honing at 16 degrees). So the KS-123 comes into play again.
I think it's a utopian-dream to assume that there's ever a situation where both the grinding wheel and the leather wheel always use the same grinding angle and where the leather wheel can always remain on the Tormek.
If you don't want to do this, you can use the 250 mm leather wheel, as mentioned here. That's the one I use too. When sharpening a long knife, you'll need to take it off for a moment. No problem, it's back on in a jiffy. With my 250 mm leather wheel, there's also a margin when you buy it, meaning the diameter can be a millimetre larger or smaller. So the KS-123 comes in handy again.
But there are also situations with my 250 mm leather wheel where I need to adjust the angle slightly, because the type of steel needs to be honed at a slightly larger angle (example: sharpening at 15 degrees and honing at 16 degrees). So the KS-123 comes into play again.
I think it's a utopian-dream to assume that there's ever a situation where both the grinding wheel and the leather wheel always use the same grinding angle and where the leather wheel can always remain on the Tormek.