Off-Road Mainly, Conversion Ideas

[Moto]

I've been reading the forum for a while now, and considering my next move.

I ride pretty much only off-road and am looking to convert one of my bikes, either a Specialized Rockhopper or GT Avalanche, from around 2008, both 17.5" frames. They are both very good bikes and to me makes sense to use one rather than buy a complete bike which would be lower spec unless I spent a lot of monies...


My experience so far is limited to riding a Scott E-Aspect, which was good fun but way out of my budget!

But I did feel as though I wanted more power at times, on big hills and the like, so am pondering options a little bit over the normal legal 250W, without going too far and having an obviously “powered” bicycle rather than “electrically assisted” should I end up on a road. So maybe a 350 or 500? Range would ideally be a couple of hours, 20-30 miles, with pedalling obviously.

Both bikes are 9 speed derailleur, will the chain be OK?

The Scott was a torque-sensing mid-drive but I definitely want a throttle option, and would I be correct in assuming a rear hub drive would not be so good for climbing steep slow stuff?

I’m also curious, at what power chain and sprocket wear becomes an issue as I see 750W and 1000W drives available, surely at that power the chain and sprockets must be under some strain?!

My immediate thoughts are a 500W 36V 25A BBS02B kit c/o Woosh, but open to suggestions and advice!

Steve

 

[Deleted member 4366]

A Q128C rear hub motor at 48v and 20A would trounce that Scott in any hill-climbing test. For a bike on the road and light trails, that combinagtion takes some beating; however a crank-drive bike would be better for seious off-road use because of the more centralised weight. Both systems can work with your present gears.

The Bafang crank-drive kit comes in several power variants, so you choose one with the power you want. The 36v 25A BBS01 from Em3ev.com is legal and has 25% more power than the Scott. If you want more power than that, it's the 48v 25 amp BBS02, then the BBSHD.

A word of warning though. The Bafang crank drives are not 100% reliable but spare parts are not too expensive and the motor is fairly straight-forward to disassemble.

Regarding chain wear, the Scott puts 5 times the strain on the chain as you'd get on a non-electric bike, the 25 A 36v Bafang about 6 times as much strain and the BBSHD about 8 times as much. Obviously, things will wear out more quickly, but thats still not enough to break anything directly. The hub-motors reduce strain on the chain and gears because thet drive the wheel directly.

 

[Benjahmin]

It's not the wattage rating of the motor that matters, but the current rating of the controller. So a '500w' motor backed by a 15A controller is going to give less power than a '250w' motor backed by a 20A controller.
It's the maths. P=IV Power = amps x volts. So 20A at 48v will give you 960watts on max setting.Eat ya heart out Bradley
I think a rear hub with triangle battery would give you a good weight balance with low centre of gravity. That suggestion at the top of D8veh's post sounds the bizz.
I ride the hills of west Wales with an Ezee front hub, (bpm type motor with 20A controller) I haven't found a hill I can't get up, yet. 'Course that's road riding, wouldn't recommend a front hub for off road.

 

[scunna]

Dillenger 1000w offroad kit

 

[Charliefox]

What kind of trails are you riding? Blue and red trails like the 7Staines in Scotland or something altogether steeper? I have not found any of these trails that my 350W rear hub motor can't manage. I get around 2 hours on a 10Ah battery on trails and up to 3 hours on tarmac.I have a spare too.The rear hub, a Bafang with Cassette and brake disc fittings has survived several tumbles. The only problem has been possible water ingress behind the cassette....too enthusiastic washing perhaps, but watch that and put grease down there. (thanks d8veh!) I had thought of a centre motor but did not like the price and the low mounting...well in line for roots and rocks.I was stuck with having both hub and battery at the rear but this means not much chance of headers over the bars and the downside of light steering when going steeply uphill is easily coped with. I lent it to a friend at the Glenlivet trails 2 days ago and he came back with a smile all around his face.Go for it!

 

[Moto]

Thanks all for the replies, lots of things to consider then!

I must admit that a hub drive was not in my head originally, but has me pondering....

Some of my hills are real nasty, see pic, but that's the exception. This bridleway out of Swanage I can only make it perhaps one 1 out of 5 attempts as its quite loose.

Point is, would this, or another I can think of about 1/4 mile bottom gear, sat on the nose of the saddle to keep the front down, overheat a hub motor?

Or stick to the crank drive option...



Steve

 

[anotherkiwi]

Thanks all for the replies, lots of things to consider then!

I must admit that a hub drive was not in my head originally, but has me pondering....

Some of my hills are real nasty, see pic, but that's the exception. This bridleway out of Swanage I can only make it perhaps one 1 out of 5 attempts as its quite loose.

Point is, would this, or another I can think of about 1/4 mile bottom gear, sat on the nose of the saddle to keep the front down, overheat a hub motor?

Or stick to the crank drive option...

400 metres? Only if you aren't pedaling...

My test hill is paved but 900 metres long and nope, not even warm. 3.4 km of 7% at assistance level 5 and me not participating much because in town clothes? Luke warm.

 

[grldtnr]

View attachment 20091




Dillenger 1000w offroad kit

HEAVY Man !!!!!

 

[Deleted member 4366]

You need a low speed motor if you're going to tackle very steep hills. Something like a code 15 Bafang BPM would manage that easily with about 20 amps, but it would max out at about 15 mph.

The 48v Q128H would eat that hill for breakfast. It's max speed is 19 mph with a fully-charged battery, so about 15 mph when empty. The Q128H is lighter than the BPM, so would be my choice.

With a hub-motor, you have to choose between serious hill-climbing and speed. You can't have both.

 

[scunna]

 

[BornAgainCyclist]

I imagine that is what a young Batman did his paper round on

 

[Deleted member 4366]

It looks nice in gold and black.

 

[scunna]

I imagine that is what a young Batman did his paper round on

I wish i had it when i had a paper round.

 

[scunna]

It looks nice in gold and black.

Thank you

 

[scunna]

Thank you

 

[Woosh]

Thanks all for the replies, lots of things to consider then!

I must admit that a hub drive was not in my head originally, but has me pondering....

Some of my hills are real nasty, see pic, but that's the exception. This bridleway out of Swanage I can only make it perhaps one 1 out of 5 attempts as its quite loose.

Point is, would this, or another I can think of about 1/4 mile bottom gear, sat on the nose of the saddle to keep the front down, overheat a hub motor?

Or stick to the crank drive option...

View attachment 20126

Steve

Hello Steve,

For this hill, the Bafang G06 fat motor like this one on the Woosh Rio FB is the one to go for.

80NM max. torque on the rear wheel!
Road legal and equally good on made roads too.

 

[Moto]

Ah a voice of reason has spoken.

Let me back-track - much that I would like 1000W of raw power, as I will be riding on public bridleways, and realistically some road, my aim is for a bike that still looks like a bicycle at this stage.

I would like to buy a kit, from a UK seller, as I don't have the knowledge or experience to go completely DIY, and I would also like some kind of warranty!

So, Mr Woosh, the Bafang G06 is there a kit, or at least a 26" wheel available? What would be the disadvantage of this compared to a "normal" 250W motor, heavier? less top speed?

Thanks all for the replies so far, interesting stuff.....

Steve

 

[Moto]

So, from the lack of further replies am I going to have to actually talk to a few suppliers rather than confuse myself with 10 wildly different opinions from a handful of prominent poster on the internet ?? !

 

[Woosh]

the Bafang G06 is there a kit, or at least a 26" wheel available?

I don't have the G06 as a kit at the moment because the market for fat bike kits is still small. The reason I did not suggest any kit before is because you want to go mainly off-road, for which the G06 and a fat bike would be a better fit. All the kits I sell have either rack battery or downtube battery, their fitting won't survive a jump.

250W kits: SWX02 and XF08C. Both have noload speed at around 23-24mph on 26 inch wheels. 17A or 18A HL controller which is integrated to the cradle of the HL downtube battery.

You need to check two things:

1. Cassette for freewheel?
If you have 8-speed or more at the rear, it's cassette.
The kit I would suggest is the rear XF08C 26 inch with 18A controller, thumb throttle, LCD, sensored brake levers, cableset and 13AH battery for £499. If it's a freewheel, then we would supply the Bafang SWX02 instead of XF08C.
It comes with everything you need

2) square taper or high tech bottom bracket?
if you have square taper, then you can choose to have the pedal sensor installed to the left or to the right (drive side). Left side pedal sensor is high tech, easier to fit. If you have Isis, Octalink or Hollowtech, there is no space between the chainring or crank arm and the BB's ballbearings, we supply one that is suitable.
Cost including post: £499 with 13AH battery or £599 with 17AH battery.

For further information and links to download the manuals, visit:
http://wooshbikes.co.uk/?hubkits

 

[Deleted member 4366]

So, from the lack of further replies am I going to have to actually talk to a few suppliers rather than confuse myself with 10 wildly different opinions from a handful of prominent poster on the internet ?? !

That should help. You'll have 20 opinions then, so if you choose the right one, you've got a better chance of getting the best solution.

You won't find a kit in the UK that meets your needs. Don't even think about one of those 1000w direct drive hub-motors. They're not suitale for what you want and will give less powerthan the other options.