A NCX seat post is the answer to a lot of people's back problems, myself included.
Personally I have 2 and wouldn't ride a bike without one.
It's a subject that crops up quite often so a forum search should give you an idea of there popularity.
Personally I have 2 and wouldn't ride a bike without one.
It's a subject that crops up quite often so a forum search should give you an idea of there popularity.