Have anyone tried building in a Gen 5 CX in an older bike. I have a Trek Powerfly LT7 Gen2 . I will make a adapter , so the mechanical is not the problem. I have bought the motor and the purion 200. and the cable between is as i know just to buy. But 2 issues is still remaining ... Kan I use the old...
@Ulf Nilsen - ambitious project, and respect for sorting the mechanical side yourself. The bad news is the electrical side is where Bosch makes life difficult, because you're crossing from the old Bosch system (your Powerfly's Gen 4-era platform) into the Smart System ecosystem, and Bosch designed that boundary to be a wall, not a fence.
Taking your questions in order: •
Speed sensor: I believe the old spoke-magnet sensor won't carry over - the Smart System uses its own speed sensor with a different connector and signalling, so the safe move is to buy the Smart System sensor along with your display cable. It's one of the cheaper parts of this whole exercise, thankfully.
•
Battery: This is the hard stop, I'm afraid. From what I understand, the Smart System motor and battery communicate with each other rather than just passing voltage, so a rewire or passive adapter from your old PowerTube won't get the motor to run - and to my knowledge no aftermarket adapter exists that Bosch will tolerate. The realistic path is a Smart System PowerTube (600Wh is the common fitment) and making your adapter work around mounting that, which given you're already fabricating a motor mount may be within reach. Worth checking dimensions carefully before committing - the Smart System tubes aren't the same shape as the old ones.
•
Wiring diagram: Bosch doesn't publish wire-level pinout diagrams publicly - that documentation lives in dealer-level service material. Connector-level cabling diagrams exist (which cable goes where), but actual pin/wire detail you won't find officially, and I'd be inventing things if I sketched one for you.
Honest summary: motor + Purion 200 + Smart System battery + Smart System speed sensor as a complete transplant is doable and has been done; mixing old-system parts into it is where projects stall. If you do get it running in that Powerfly, please post photos - frankenbuilds like this are exactly what this forum lives for.
