Hi,
I'm planning to build a quadricycle e-bike. I want to still pass as a street-legal pedelec in the EU, so limited to 250w continuous power. The bike will also be quite heavy (80kg). In spite of this, I still want good (albeit slow) climbing capabilities. So I'm thinking to build the drive-train as follows (all linked with chains):
My preferred cadence is around 85.
My question is what gear ratio I need between the cranks and the motor; whether I should aim to let the freehub on the motor spin at around the same RPM as I would like the motor to spin at? I am wondering how the freehub RPM and motor RPM interact and how that divides the power contributed by the rider and the motor, if that makes any sense.
As a second question, if anyone has some input on a rear hub motor that is regen capable and can be legally used in a pedelec in the EU with the (arguably non-sensical) 250w continuous power rating, I'd be very happy with any advice. I've read some other posts on this forum on the topic and nobody seems to know for sure whether there needs to be a 250w marking on the motor or not.
I've seen the PUMA motor sold here https://www.ebike-solutions.com/de/...terradmotoren-250w-mit-drehmomentstuetze.html which looks like GMAC motor with different windings speeds (and a clutch unfortunately). Does anyone have any experience with this motor?
Thank you in advance
I'm planning to build a quadricycle e-bike. I want to still pass as a street-legal pedelec in the EU, so limited to 250w continuous power. The bike will also be quite heavy (80kg). In spite of this, I still want good (albeit slow) climbing capabilities. So I'm thinking to build the drive-train as follows (all linked with chains):
- Cranks
- Rear-hub motor (ideally Shengy SX2 with locked clutch or GMAC motor to have regen/reverse operation, open question whether I can still be considered a pedelec with these motors in the EU)
- Rohloff speedhub (will need to get the freewheel disabled in order for regen to work)
- Samagaga differential
My preferred cadence is around 85.
My question is what gear ratio I need between the cranks and the motor; whether I should aim to let the freehub on the motor spin at around the same RPM as I would like the motor to spin at? I am wondering how the freehub RPM and motor RPM interact and how that divides the power contributed by the rider and the motor, if that makes any sense.
As a second question, if anyone has some input on a rear hub motor that is regen capable and can be legally used in a pedelec in the EU with the (arguably non-sensical) 250w continuous power rating, I'd be very happy with any advice. I've read some other posts on this forum on the topic and nobody seems to know for sure whether there needs to be a 250w marking on the motor or not.
I've seen the PUMA motor sold here https://www.ebike-solutions.com/de/...terradmotoren-250w-mit-drehmomentstuetze.html which looks like GMAC motor with different windings speeds (and a clutch unfortunately). Does anyone have any experience with this motor?
Thank you in advance
