If you're just cleaning, don't bother. Clean them as best you can while there still firmly fixed in place.
I agree with the others though, some more informationa dn cleaner parts would help.
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“One morning you wake up, the girl is gone, the bikes are gone, all that's left behind is a pair of old tires and a tube of tubular glue, all squeezed out"
Sugar "Kane" Kowalczyk