On the tubes-If you have the threaded valve stems with a nut for tightening to the rim-Throw the nut away.
Most tighten the nut down to hold the stem firmly in place but if you overtighten them what you will be doing is pulling the tube up into the exposed valve hole in the rim. This can cause some abrasion but at worst will give you a sharp edge of the hole to cut into the rim. I also use a thick foam rim tape instead of the thin rubber OM version that comes on most new bikes.
For this reason I try to buy the non threaded valve stem tubes- just so I am not tempted to use the nut.
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How long was I in the army? Five foot seven.
Spike Milligan