Funny to see this thread has woken up again.
Update - had my emtb for a year now. I def realise now my back pain was caused by hip flexors shortening while riding. Not having to grind up hills for an hour reduces the back pain however still a few pangs while throwing it down steep techy corners...
I can't comment on the Rail 9 as I have a 7.
I've been riding my JadeX for a few months now & though I initially found the pedal bob annoying and wondered if a X2 would have been a better option for me, I am used to it now so it doesn't bother me.
I found the traction on the rear incredible...
Fifth - push enter button occasionally :)
Cover your back brake on techy climbs until you get used to the overrun. Turbo on emtb can be bit of a bugger on stop starts. After a while you will be able to anticipate what your bike will do & the overrun becomes your friend esp climbing rocky tracks.
Maybe look at something along the lines of a polygon siskiu type frame where a motor could be fitted so it sits more horizontal.
I was hoping to convert my old bike but would run into the same kind of scenario. I then worked out buying a more appropriate 2nd hand bike with its' potential faults...
I respect what you're doing & was considering a similar thing to ride when my wife rides my bike but prepare for incoming when you show it with the motor hanging down ready to be busted off.
You do know that the bosch has a "boost" feature? All it is is that the motor will overrun for a second or two after you stop pedalling. It is to get over tree roots & rocks etc without pedal strike. This can also happen if you put pressure on the pedal while stationary - it may want to take off...
Noticing a slight growl going up hills. No noise when pedalling with motor off or when riding on the flat but going uphill it starts. Sounds similar to when the derailleur isn't in the correct position & the chain is rubbing.
I'll talk to the shop but has anyone had this? Done a search but not...
I had this happen on my rear brake going uphill around corners- Centered the brakes a few times then took it to the bike shop. They tightened the rear wheel (facepalm emoji).
Teachable moment though as I know know how much hand pressure is correct for tightening.