Having a much bigger and wider rear tyre, means that a standard chain drive won’t be usable anymore. In search for the best solution I balanced out the pros and cons from three different options. Electric, hydraulic and the regular drive with two extra sprockets on an axle in between. I opted for the latter.
Here’s why.

• Electric

When using this option, the bike’s crankshaft would power an aggregate, which delivers the necessary current for an electro engine that would be mounted on the rear wheel.

+ By mounting an electro engine on the front wheel, too, you get 2-wheel drive. This increases the grip and pulling power.
+ The current can also be used to power the electric heated clothing and to charge the extra starting battery and batteries for cameras and suchlike.

– Where to place the aggregate? In the space where now the transmission is fitted?
– Aren’t we going to lose too much horsepower this way? To find out we need lots of time and even then we are not sure if this is a real option!
– I expect that electronics are more sensitive to interference than when using the existing concept, in which the speed is regulated via my right-hand and a gearbox.

• Hydraulic

In this case the bike’s crankshaft -or the axle that holds the front sprocket- would drive a hydro pump. The produced oil flow would run via a pipe to a hydro pump, that would be mounted on the rear wheel.

+ Building a 2-wheel drive is possible.

– Where to place the pump?
– The time-consuming search to find out if the loss of horsepower is acceptable.

• Chain and sprockets with an axle in between.

When going for this option, the bike’s front sprocket brings the power over to the axle which will be placed in front of the rear wheel, using a short chain. Parallel to the power receiving sprocket, there will be a sprocket which passes the power on to the rear wheel. Depending on the width of the rear tyre -and by that the position of the rear sprocket- the distance between the two sprockets on the axle that sits in between could be as much as 15 to 20 cm.

+ Little fuss, which makes it easier -and therefore quicker and cheaper- to build.
+ Little can go wrong, because there is not much that can fail or break.
+ By juggling with the size of the sprockets that sit on the axle in between, I can reduce the speed from the Arctic Superbike like I desire, without having to use a huge and heavy rear sprocket.