Hi Michael1971, first the tyres. I was a bit unsure about the “plus size” tyres at 2.6 inches, but after the last few days I have to admit they are a great tyre. I had them over very stony rough tracks, no problems at all.
On Tuesday I did a loop, which looked good on the map, only to find it was extremely wet boggy and muddy. The tyres again were great, the bike was sliding all over the place and I even had opposite lock to steer at times, but the tyres kept digging through and kept me moving forward.
Today was a long hard run down through the hills on more rough stony tracks and they performed well. Even when I am on the roads, by the time you hit the 15mph cut off on the motor, you are up to speed and the tyres just keep rolling. I have had it up to 32mph on the tarmac with no problems. If even if YOU don’t get on with the tyres you can always replace them, but I like them.
As for a dropper seat post, see the two pics attached. There is a cable entry point at the top of the downtube, with enough room for a second cable, as there are two going in the opposite side.
As for getting it past the motor, the second picture shows there is plenty room at the top of the motor, to get it passed. How you do that I don’t really know, but this bike actually comes with the option of a dropper post from Cube, which I didn’t get, so there must be space for it. Obviusly if you get the Cube option it will be Cube prices, but it looks like there is plenty room to go from the seat tube round to the downtube, but you would probably have to drop the motor.
Today was 28 miles up and down, some of the hills were easy 20% gradient and there was plenty power to get you up without killing yourself, love this bike.
Hope this helps.