I've got a copy of Roger Musson's (Mr WheelPro) wheelbuilding guide which is great and I'd recommend his cardboard dishing tool - see attachment for what it looks like (once you've cut it out of an old packing box).
You slide a steel rule against the middle portion until it's touching the locknut on one side, hold it with your thumb and then flip the wheel over to check it against the other side.
Also, you'll probably find that you need the wheel in reasonable true before you can really check the dish otherwise any wobbly bits will tend to give you a false reading.
Final thought - how much of an adjustment to the dish do you need to make? Much more than a few mm and you may find the drive side spokes start poking through the nipples...
I've got a copy of Roger Musson's (Mr WheelPro) wheelbuilding guide which is great and I'd recommend his cardboard dishing tool - see attachment for what it looks like (once you've cut it out of an old packing box).
You slide a steel rule against the middle portion until it's touching the locknut on one side, hold it with your thumb and then flip the wheel over to check it against the other side.
Also, you'll probably find that you need the wheel in reasonable true before you can really check the dish otherwise any wobbly bits will tend to give you a false reading.
Final thought - how much of an adjustment to the dish do you need to make? Much more than a few mm and you may find the drive side spokes start poking through the nipples...
Hope that all actually makes sense :-)
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