Oval shaped chainstay issue

[ballinchestr]

I'm building a bike for a friend, and the chainstay is oval shaped. This makes mounting the tensioner very difficult, because tightening the bracket makes it turn outwards, when it should face slightly inwards to properly guide the chain. Anyone have a workaround for this?

 

[crassius]

no, oval is much better than round - try putting roller on other side & turning tensioner around, or try bending long side of tensioner in a vise, or many other ways to get it to line up

 

[2door]

I agree with Crassius but I'll add that the tensioner is not a guide. You should rely on proper chain and sprocket alignment, not the tensioner. It is a 'tensioner', not a chain guide.

Almost without exception the tensioner brackets need to be bent and/or twisted to get the tensioner wheel to align with the chain path. If the chain stay is oval that will help keep the tensioner bracket from rotating inward into the spokes if tightened correctly.
As they come from the factory all brackets are the wrong shape or angle.

Keep your chain tension at 1/2" to 3/4" of slack and your drive and driven sprockets aligned. Maintain chain tension with the tensioner. It should not drag the chain to either side but run true with the chain.

Tom

 

[crassius]

one note, if the chainstay is very small in diameter, I like to saw off an inch or so of old handlebar & cut it lengthwise to pack in as a hard steel spacer to help anchor the tensioner

 

[ballinchestr]

Thanks guys. I'll just bend it on the bench vice

 

[crassius]

as I've mentioned before, there is not one right way to do most things on these bikes, but many wrong ways - it is often just a matter of finding a way that works for you

 

[dirtyoldcrusier]

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