Advice on converting a rockrider

[T1000]

Hi All
I'm think about converting my current mtb which hasn't been ridden much at all.
I'm a big lad so need some help getting up hills not flats. I will mainly be using the bike along the vast amount of canals near me.
I was thinking about this kit

https://www.yosepower.com/en/product/Hub-Motor-48V1000W-E-bike-black-Hub-Motor-Conversion-kit-Rear-wheel-26%22-with-7S-Shimano-Freewheel-125.html/

A couple of things popped up during my research. The kit comes with a 7 speed cassette bike has a 9 speed. Can I use the existing 9 speed on ? Also my bike has hydraulic disc brakes which appears to be a no no with most kits. Can I change just the rear to cable operation?

Anything else I should look out for before I take the plunge.

Thanks in advance

 

[Nealh]

The rear gear cluster is a screw on freewheel, your existing nine gears are a cassette/freehub this simply sits on a splined hub body with a screw on end that's keeps all in place.
The brake cut out if required can be modified to fit by removing the wired sensor and a bit of imagination.
If not wanting to invite trouble you are best to buy a 250w 48v kit though a more costly option.

 

[tonyw]

I think you could keep your derailleur, but would have to change your gear shifters (fairly cheap). You might be better off with a centre drive kit to get you up the hills though

 

[vfr400]

There are two versions of the Yose kit. One has a freewheel motor and the other has a cassette one. You want the cassette one, which has a standard Shimano cassette spline, so is good for 9-speeds.