2B: Dead Axle Pivot

Tensioning

To accommodate chain stretch over the course of a season and reduce backlash, an active tensioning system is required. If enough chain length is available, inline tensioners such as turnbuckles and Spartan tensioners are the simplest way to tension the chain.

If there isn't enough space for an inline tensioner (if the chain moves too much, the tensioner might run into either of the sprockets), other methods, such as moving the position of one of the sprockets with a sliding or rotating gearbox or stage, may be used.

A chain and sprocket moving with a turnbuckle tensioner. The turnbuckle is located on the bottom half the chain.

Two types of inline tensioners: a turnbuckle (left) and a Spartan tensioner (right).

Reference Design

For this design, enough chain length was provided for a simple inline spartan tensioner to work well.