Spring loaded chain tensioner



New Member
Jun 6, 2016
New South Wales
Im toying with the idea of making a spring loaded chain tensioner and was wondering if a) someone has made their own and might have a bit of advice for me (do's or dont's) or has it been tried and its a time waster or b)is there a thread out there I haven't came across about this engineering marvel (haha). I've got my own ideas rattling around in that empty bucket perched between my shoulder blades but if anyone has any info that would be hugely appreciated as I'm sure there would be quite a few better ideas than mine or something I could adapt to my concept, see how we go. Cheers everyone. Shiny side up people!! .duh.


Well-Known Member
Jun 3, 2012
Vancouver, British Columbia
Hello, most of the experienced builders here don't like spring loaded tensioners because they will allow slack in the top run of the chain on start up and deceleration. That slack can pile up the chain and jam in the casing. A spring loaded tensioner will also cause pre-mature wear of the idler wheel.

If you really want a spring loaded tensioner then design it so it has very little travel to avoid the slack chain issue. But you'll still be wearing out the idler wheel.

The best fixed chain tensioner design, in my opinion, is the arch tensioner from custommotoredbikes. It spans the chainstay and seatstay which makes it almost impossible to pull the unit into the spokes.

good luck
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Staff member
Sep 15, 2008
Littleton, Colorado
Ditto to what Chaz said. Spring tensioners have no place on a motorized bicycle. They work but only on industrial applications where they are not subjected to deceleration forces that will allow slack when you don't want or need it.

The best method is to use no tensioner but if one is necessary the type mentioned above is the best alternative. The kit supplied tensioners will work too but must be installed correctly and in such a way that they can not loosen and rotate into the spokes. Lots of information here regarding this subject. Type 'tensioner' into the Search and you'll have plenty to read on the pros and cons.

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