I am about to install a 10 speed Shimano Ultegra casette on an Ultegra hub.
The cassette did not come with a 1mm spacer, but I have read that I needed to install a 1mm spacer first.
Is this true? If so, what kind of spacer do I need? I have a couple 1mm freewheel spacers laying around that I have used behind older 5 and 6 speed freewheels, will that work?
What is the purpose of the 1mm spacer?
Any help is much appreciated!