to support eddie, it could be something as minor as a rusty chain. do your wheels spin freely and then 'rock' back and forth with the weight of the valve (they should do)? is your chain too tight? is it rusty? are your wheels pointing straight, not skewed in the dropouts? sounds simple but any of these hinders speedy progress.
to support eddie, it could be something as minor as a rusty chain. do your wheels spin freely and then 'rock' back and forth with the weight of the valve (they should do)? is your chain too tight? is it rusty? are your wheels pointing straight, not skewed in the dropouts? sounds simple but any of these hinders speedy progress.