When building the dry clutch we found out that we couldn’t use any parts from existing models who have a dry clutch. To make things worse the drive gear for the oil pump is situated at the rear of the primary gearbox gear and the primary gear shaft is to short to fit something else.
We found out we couldn’t use any other shaft and made a special nut and worked on the inner clutch drum to accommodate the nut and use it as a centre for the inner drum. The gear and outer drum had to be machined as well to make it all fit. The inner drum is made of aluminium and is bolted to the primary gear which still holds the oil pump gear. As you can see the side cover has now a large hole in it with clutch sticking out. At this moment there is no seal yet in the side cover but it will be made later. It will be the same set-up as modern bikes have.
When this clutch is tested we will let you know, as you can see in the picture we are still in an experimental fase but we did come a long way.
Progression is slow like it always is when you are working on innovations. There hasn’t been a testdrive due to snow and terrible amounts of salt on our roads. But we did manage to get some parts together and build a bike just to try and fit the engine and see how other components will work.
Here is a picture so far. One of our engines is near completion and things are looking great ! If the weather gods are good to us there can be even time for a test drive.
The 350 GTV saw it’s life light in 1977 to replace the 350 GTL . At that time the 350 GTL suffered from failing crankshafts and bad electrics. But unfortunately the damage was done and the motorbike market wasn’t waiting for an other paralleltwin to go touring. At that time the Jap 2 and 4 cylinder engines had been widely introduced and where gaining popularity. In 1981 the last 350 GTV was produced and died a quite death.
One of the large problems with the Parallel-twin are the main bearings. They are not the actual problem but they tend to fail after a while. The crankshaft is pushed against the bearing flange on either side of the casings during acceleration or deceleration and are easy to wear out. This “shifting” in forces is caused by the primary drive’s helical gears. To get rid of these forces straight cut gears are in order but unfortunately the Parallel Twin was never equipped with that . . . . . . so now it is time to start experimenting ! Together with a dry clutch here are the results so far.
At this point we found out that we could not use some standard gears, it didn’t fit like it should and an easy alternative is not available. So for now we are postponing the straight cut gears and get on with other projects to solve the engine problems.