Rim tapes are needed for most clincher rims.
The only exceptions are for closed clinchers (Like Tufo) and certain rims with no spoke holes (Eg Mavic Ksyrium).
Select the correct width carefully.
If a rim tape fails on a ride you will be walking home after wasting your innertubes.
If the tape looks weak replace it, you will not regret it!
Tubulars 
