The chain can only be adjusted once the cranks have been set to the right leg length.

Shift firstly small chainring to small sprocket (both gear levers all the way forward) and check to see if it matches fig. 16.1. If the derailleur cage is sitting too high, fig. 16.2 there is excess chain which needs to be removed. If the derailleur cage is too low, fig. 16.3 chain needs to be added.

fig. 16.1    Correct Chain Length fig. 16.2    Too Much Chain fig. 16.3    Not Enough Chain

For tandems the procedure is the same as above but some tips for tightening the front chain are included in the Tandem section. Note if you change the crank position from your setting, re-check the chain length as derailleur damage could occur. Hint it is not always important to set the crank length for someone who just wants to go for a quick ride, as most people can slide up or down in the seat.

The chainline below suits GLR, GT, GTC, GTE, GTO, GTR, GTS GT3 and the REAR of all GTT’s.

On the right is the diagram showing the chain route for the front of the tandem. Five coupling tandems use two more pulley, but the chain still follows the same path.
The diagram on the right shows the chain path through the pulley/chain tube setup.