If you ever have to replace the cranks on a twin chain giraffe unicycle you will need to “tune” the chain system so that the two chains work correctly together. You will know if you need to tune the chain system if one chain is tight at the front while the other chain is and visa-a-versa.
Depending on how much adjustment is needed there are 3 processes than should be followed until you find the one that tunes the system for your giraffe.
At the wheel you will see 2 plate sprockets. These are held on by 12 bolts (6 per sides). Loosen these bolts by a single turn each while the chain is in place. If there is only a small amount of adjustment required the chains automatically centralise the sprockets in the correct place. If this is the case, tighten up the sprockets and the tuning is done. If this is not the case, go to method 2.
Repeat method 1, but this time take all the bolts out of the sprocket that has 12 holes on it and allow it to it rotate until you can use the second set of holes. This should allow the sprocket to rotate further than the tolerance in the holes allowed in method 1. If this does not work – or makes it worse, go on to method 3.
Remove the wheel from the frame and remove the 12 hole plate sprocket and flip it over. Now re-apply it (loosely to begin with). Re-mount the wheel and repeat firstly method 1 and should that not work then method 2 will work.
Good luck with your maintenance. Remember; to do regular checks on all bolts and lock-nuts on your giraffe to be sure that they are tight. Damage can occur (both to the giraffe or yourself ) if the giraffe is ridden when parts are loose.