How tough are rear hubs off road ?

[alexsally]

I was just about to pull the trigger on a 350w rear hub conversion kit but I've just bought a nice Scott MTB, which is really nice on the trails... I'm going to go electric with one bike or other... The mountain bike tracks have a lot of uphill obviously, so the assistance would be great but what about clattering down the rough stuff on the way down. To be honest I "think" that battery might be most at risk from bumps and jarring.. anyone got any experience of treating a rear hub roughly and it surviving?
Alex

 

[Fordulike]

I tried a few years ago, and the only issue I was getting was the odd spoke breakage. It's important to make sure all the spokes are tensioned properly and on a regular basis.

I switched to Bafang mid drive, purely for the fact that I wanted to tackle the really rough stuff, without the worry about spokes breaking, torque arms failing, or having the PITA of repairing a puncture away from home.

 

[Deleted member 4366]

A hub-motor spoils the working of your rear suspenion a bit (a lot if it's a heavy motor) due to the greater unsprung mass. They're OK for trekking and bike trails, but for fast downhill riding, a middle motor would be better.

The battery would need to be fixed very well. Two 5mm bottle holder rivnuts won't be enough on their own. Fix at least a third one and put a tight wide velcro strap or two around the battery for rough stuff. Also, get a battery as light as possiblr, which means nodern high capacity cells, like Panasonic GA. The Luna Mighty Mini only weighs 3 pounds, but only has 300watt-hours.

Mount the battery in the centre of the bike too.

 

[Woosh]

about unsprung mass: one solution for that is to have the motor suspended and in-frame battery.

 

[Fordulike]

Totally agree with d8veh and Woosh. To maintain the riding feel of your bike, fitting a crank drive and positioning the battery inside the frame triangle, is the only way to achieve this.

Plus, if you encounter any very steep slopes on your ride, a hub motor will struggle to provide the low speed torque, needed to tackle such a climb.

I've used both a hub motor and crank drive on the trails and I wouldn't go back to the hub motor. I still like hub motors, but I personally think they are more suited to commuter rides than the tough stuff.

 

[alexsally]

Thank you all for your responses. I like the idea of suspending the battery in the frame. I think the big problem with describing the pros and cons of different electric bikes is individual ideas of what is "steep". And what is "tough ".
Broken down into it's component parts, off road is probably like dropping off a big pavement repeatedly, at least that's what it is for me. I don't race or do jumps.
As for the uphill struggles, I can do most of the work but would like 50% help.
Again living in mid Wales near the nant yr Arian kite feeding place, my idea of a steep bike ride is probably different from someone who lives and cycles in Surrey. I'm used to going up steep, and without any help. Mid Wales is very hilly wherever I go ! Which is the main reason I'm looking at the e bike kit!
I guess biting the bullet is the only way to know how it work for me. For me it has to be hub as the cost of mid drive unit + battery is getting on for the price of a cube/ Bosch bike that would probably be ideal.!

 

[Benjahmin]

Have you seen these guys? They are just outside Abereron, there's a young chap there who has built his own awesome mtb. Ask enough questions and he may just reveal it to you. They have a few demo machines but no Nant trails nearby.

http://www.cyclemart.co.uk/