The chain tensioner thing has always been a source of annoyance for the builds I've done here at the shop. I usually put the kit piece in a vise and use an adjustable wrench to tweak it a bit so that the roller tracks true to the chain.
On the Jaguar, the chain stay tube is 5 degress off parallel to the chain, so I milled the 5/8" slots at a 5 degree angle. The roller now tracks perfectly for this bike.
This bike does not have deep slots in the drop-outs, Brett has been teaching me bike terminology.
Soooo...There is no way to adjust the rear wheel so that the chain can be pre-tensioned.
Long story made short...for this bike it becomes a specific combination of links removed from the chain vs. the number of teeth on the sprocket.
I did not try a 44 tooth, as I wanted to end up at 40. With 2 links removed from the kit chain; the chain was too slack for the 40. Had I removed the next link, the chain would not have fit. I made a 41 tooth...still a bit too much slack for my liking. 42 ended up good. I had planned on removing the next link to see what the next sprocket size, down, would be. I didn't have time, but i'm thinking 38 maybe 39.
As soon as I get the engines done, (which will give motorized bicycle time to test), I will finish off this kit and make 50 or so.
I think this is going to be a real benefit to those just getting started in MB's. Due to all of the different geometries from one manufacturer to the next, it is virtually impossible to make an inexpensive "universal" kit. Even this bike is built with different components. For someone new with limited experience, and very few tools...I think this kit will be a "must have" if the builder is considering a beach cruiser style bike.