WORK RESUMES ON BUILD No. 3....
Our upcoming move to Spain is held up pending a Deputyship application which will enable my wife's sister to sign-off the house sale on her behalf. Never saw that one coming - so I've uncrated Build No. 3 and picked-up where I left off prior to packing-up all our belongings in anticipation of the house move.
Pics here show the 3 x driveline chains & sprockets now installed. Left side drive chain from the jackshaft to the rear wheel sprocket is as yet unfitted with a tensioner. As fitted, chain length is perfect. So I may or may not fit a tensioner, depending on how much the chain stretches after putting some miles on this ride.
Right side pedal chain - which I'll only use for back-pedaling when applying the coaster brake - is fitted with a really cool eBay sourced tensioner pivoted from the derailleur bracket.
Primary chain is only temporarily installed 'cause it took me forever to locate a sprocket for the jackshaft which matched my Gnome Rhone motor's output sprocket. Only one UK supplier could sell me the correct chain for this particular application - and finding a matching sprocket proved impossible. In the end, the chain supplier sold me a 1/2" pitch x 3/8"wide sprocket and recommended I machine-down the tooth width from 3/8" to 3/16". My lathe and tools are all packed up ready for the move - so the machining will have to wait till after I get to sunny Spain. For the time being, I've pictured the primary chain installed round an incorrect sized sprocket to show how it'll look. Whether or not I'll need to fit a tensioner to the primary chain will depend on whether I can get away with using a half link - which the chain supplier provided.
The good news is all 3 x chains fit without any clearance issues. Almost like I designed it that way! Ha!!!
I've also rigged-up a neat arrangement to secure the rear rack to the frame. Look closely under the seat in one pic and you'll see I used a pair of chromed Munsen rings (same type I used to suspend the tank from the frame) threaded onto a pair of turned steel tube extensions. Turned out perfect.