BMX: What are "chain tensioners" and what do they do?

Question

Can I add tension to the chain by just moving it farther back on the frame?

Answer 1

Actually what mirageguitarworks is talking about is a "chain tug".

A chain tensioner is for any single speed bike and is a idler pulley mechanism styled after a derailleur that keeps the chain tense.

A lot chain tugs for BMXes are just called tensioners because they do the same thing but actual chain tensioners are attached to a derailleur hanger so they can't be used on a BMX.

Like everyone else said, they keep the chain tight without having to play around with your wheels to do it for you. It's a very convenient addition.

I should also mention that another difference is that a chaintug can't be used on anything but a horizontal fork end and a chain tensioner is used on dropouts.

Answer 2

Both answers are right on.

Being a bike mechanic, I wish they were mandatory!!  There is nothing worse then having to tighten a chain.

Answer 3

BMX chain tensioners basically surround the rear axle at the ends and pull the rear wheel back to place tension on the chain but that isn't their real purpose.

Their real purpose is to stop the rear wheel from moving forward and keep it aligned when a lot of pressure is placed on the chain.

Correct chain tension is when you are able to bend a link into a "V" shape, removing any slack from the chain. One should never tension the chain to the point that it is difficult to pedal or where obvious "clunking" of the chain is apparent as you pedal.

Answer 4

when your riding your bike you want your bikes chain to be stiff so it doesnt fall off but ever once and a while it loosens and the chain tetioner tightens your chain by moving your back wheel a small amount to prevent slack