Well, more issues on the way... I realized yesterday a flaw on the 2 shaft configuration I was planning the second shaft didn't get enough speed to engage the clutch... so I came up with (I hope) a final solution that I'll test on the bike this weekend, it is based on the same design than the schema below, but all the stuff I have on the main shaft will be on the secondary one and the main shaft and the secondary one will be connected wit two 10T sprockets, spinning at the same speed and at the same time having more room to fit the clutch.
- First gear will be on the right side of the wheel using a freewheel 44T sprocket (SBP has the freewheel adapter and sprocket), maybe a 48T if 44 is too small.
- Second gear will be on the left side of the wheel using a regular 40T sprocket.
- Centrifugal clutch will be as before on the shaft and will act as "freewheel" when on first speed.
- I'll use bike chains well lubricated and avoiding tensors as much as I can.
- Longer shaft will be hold on the right side with a jackshaft bearing to keep it in place.