chain tensioner

mtnsal
mtnsal Posts: 2
edited January 2011 in MTB general
i came across a mountain bike that has a chain tensioner. i have read a little about chain tensioners and i am confused because i can only find information about tensioners used with single speed bikes. the mountain bike that i came across has a rear deraillure. what is the purpose of the tensioner if the mountain bike has a rear deraillure?

Comments

  • Anonymous
    Anonymous Posts: 79,667
    It helps to stop the chain coming off the front chainring.

    Some single speed dirt jumpers wedge a sprocket in the chain between the front chainring and rear sprocket (the chain tension holds it in place), in order to make the cranks stiffer to turn. So, when they do tailwhips etc, the pedals stay where they were when their feet left them, instead of spinning around. This makes it easier to get your feet back on the pedals for landing.
    Maybe a chain tensioner has a similar, if smaller, effect on bikes with rear gears?