View Single Post
Old 11-02-2009, 01:37 AM
meatwad meatwad is offline
Motorized Bicycle Newbie
Join Date: Nov 2009
Location: vancouver wa
Posts: 3
Default Re: The *BEST* Solution for "THE" tensioner/pulley

Here's the real deal. It's not a tensioner. Shouldn't be called one. Its a guide. Tensioners are for bikes with rear suspensions that have a large distance from the front sprocket to the swingarm pivot which effectively makes the chain different lengths at different angles of the swingarm. Even then it's purpose was not to put any kind of load on the chain but to take up the slack that would otherwise cause the chain to come off. In the old days dirt bikes had so little travel in the rear that they didn't need them.

If one can shorten the chain as you did that is the best way to go. However the reason it is sometimes necessary to use the guide is not because of the chain length or the desire to "tension" the chain (which in fact it shouldn't be), it is due to the style of the chainstays one has on their bicycle.

The guide when properly used is to route the chain above the chainstay of the bike to a point where it can drop down at an angle as to not interfere with the chainstay.

Take my elgin for example. No ammount of chain breaking or lengthing would do the trick. The problem was the angle of the chainstay in relationship to the position of the motor. The solution is to use a guide or mount the engine as high as possible. In my bikes case the engine can not be put up high enough to make the chain clear the chainstay.

IOW one frame might need to use one while another may not . It's all about the frame.

I suppose however one could use the guide to take out the slack that comes with chain wear .

It may be of some use to note that the smaller the rear sprocket the less chance of this kind of interference .
Reply With Quote