Re: Where can I buy curved chain tensioner that attaches to upper & lower rear wheel
Someone will have a link for you. I know there is at least one manufacturer that makes them. They span the seat and chain stay and is by far the best way to mount a tensioner, if you absolutely have to use one.
I've made several using 1/8" by 1" steel flat stock. I used a Bridgport mill to machine the slot then welded the bracket to the frame. A couple I heated and bent giving them a slighty curved shape.
Someone once suggested using an old alternator brack from a GM car. I never tried that but it looks like it should work if you have access to a welder.
Tom