Sourcing an in-line chain tensioner

[GeeTwo]

I assume you don't want this for wheels, since the tensioner would be unable to go past the sprockets.

We built our lift chain tensioners into the lift plate. We just bought some thumb screws, drilled holes big enough to pass the pin from a master link through it, and used the master link to connect the chain to a screw at each end. The lift plate has two holes which are in the same line, large enough to pass the threads through, and far enough apart so the screws can't meet. We used jam nuts to tension the chain and lock it down.