Convert my Rockhopper help

[Andrew2505]

Hi Trex, do you mean two chargers per 5s pack?
I was thinking a couple of the battery alarm units that plug in to the balance connector on the packs and give an audible alarm if you get to the LVC point would be a good shout.

Thanks jackhandy, it's always difficult when you're first starting out getting it right. I've got form for buying stuff that I think will work together until I actually tried to plug it in!

 

[RobF]

Is this build throttle only?

I know a green lane motorbike is throttle only, but only having a throttle on an ebike will be a real pain, particularly off road.

Keeping a constant opening is much harder than on a motorbike, and you grip the bars differently leading to involuntary twists.

The throttles are relatively fragile and break easily in these circumstances.

Keeping the throttle constantly controlled is surprisingly wearing, even if you can do it.

 

[mfj197]

... so it's either going to have to be two packs slung either side of the top tube that are narrow enough that my knees don't clout them whilst pedalling ...

I'm not sure this would be a goer personally. The knees should be pretty close to the top tube anyway for efficient pedalling without stressing the knee joints. I have hairy legs (I don't shave them!) and in normal pedalling on the road bike my leg hairs are just touching the top tube either side. I wouldn't have space for anything mounted each side.

Michael

 

[trex]

@Andrew: no, one charger per pack. As you have 36V 8AH, one charger would take 7 hours (limited to 50W max) for a full charge from flat, two chargers would cut that down to half.

 

[Andrew2505]

I wasn't intending it to be throttle only but I do want the thumb throttle option.
I was, however, envisaging that if I'm actively using the thumb throttle I'm not pedalling.

battery mounting looks like the biggest hurdle to be honest. I've had this bike since new in 2000. We've been through a lot together and she was extensively rebuilt about 5 years ago. I would prefer to have the batteries on the bike but I'm struggling to come up with a physically and aesthetically acceptable solution at the moment.

 

[Andrew2505]

cheers Trex, yes, I already have one of these chargers and if I end up going the two pack route with these batteries I'd definitely go for a second charger

 

[Cyclezee]

cheers Trex, yes, I already have one of these chargers and if I end up going the two pack route with these batteries I'd definitely go for a second charger

Hi Andrew,

I would second Jackhandy's suggestion of an eZee kit with the battery in a back pack, I think it ticks all your boxes, plus we are based in the UK so no problems with warranty, import duty etc.

Oh, you can spec the kit with half width twistgrip or thumb throttle.

 

[Andrew2505]

Cheers John,
can I spec the kit completely including the 500w CST rear motor and s12s controller through you?
That didn't appear to be an option on your site. I would certainly rather buy from a uk supplier with it's consequent back up but from everything I've read on here the 500w motor is going to be a must for my off road application.

 

[Cyclezee]

Hi Andrew,

We only supply eZee kits with a 20amp eZee controller, the connections are not compatible with other brand of controller, in any case it would invalidate warranty.
As for CST, eZee rear hubs use 'screw on' freewheels, so I guess it doesn't quite tick that box.

You could of course have an eZee front motor.

Yes I am well aware of the different schools of thought regarding front motor for off road use, but with a suitable MTB tyre you have in effect 2 wheel drive, front electric and rear human powered with no compromises with gearing.

 

[MikeRo]

Hi Andrew,
John's suggestion of front wheel drive isn't as crazy as it sounds- I did just that as I didn't want to disturb my rear hub, using a 36V 350W code 13 BPM kitkit from Woosh. At the moment, I have a 2.0" front tyre which gives plenty of grip even in mud (until the tread is filled up)- 2wd is really good fun! Only downside is risk of alloy dropout failure (you'd want two good torque arms) - I'm using a steel jump fork instead:


Obviously wheelies are more difficult, but stoppies are easy...

I removed the granny ring to replace with the pedelec sensor and then restricted the grip shifter with a rivet:


I'm 13st and find the power plenty, at 11st I'd be surprised if you needed more than 20A...

Like you, I'd had my bike for a long time- the feeling when it comes 'alive' is incredible!

 

[Cyclezee]

Hi Andrew,
John's suggestion of front wheel drive isn't as crazy as it sounds- I did just that as I didn't want to disturb my rear hub, using a 36V 350W code 13 BPM kitkit from Woosh. At the moment, I have a 2.0" front tyre which gives plenty of grip even in mud (until the tread is filled up)- 2wd is really good fun! Only downside is risk of alloy dropout failure (you'd want two good torque arms) - I'm using a steel jump fork instead:


Obviously wheelies are more difficult, but stoppies are easy...

I removed the granny ring to replace with the pedelec sensor and then restricted the grip shifter with a rivet:


I'm 13st and find the power plenty, at 11st I'd be surprised if you needed more than 20A...

Like you, I'd had my bike for a long time- the feeling when it comes 'alive' is incredible!

Hi Mike,
Good point about the torque arms, we supply our own with every kit and they are very strong so one set is enough.

You can see them here http://www.ebay.co.uk/itm/261639387270?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649

 

[Andrew2505]

Cheers John/Mike, my main use of the motor is for the uphill slog bits where the front end is often so light that I have to take care not to 'wheelie' off the back of the bike. I definitely couldn't lose the granny ring.
I'm pretty certain for the type of riding I do I wouldn't want to be driving that wheel. Although never say never!

 

[MikeRo]

Fair enough, I could have fitted a longer crank axle and kept the granny ring. I do still find I can climb better than before by keeping a little weight forward on the front wheel though- the constant torque helps

 

[Cyclezee]

Fair enough, I could have fitted a longer crank and kept the granny ring. I do still find I can climb better than before by keeping a little weight forward on the front wheel though- the constant torque helps

and of course you have the weight of the motor on the front wheel.

 

[jackhandy]

Definitely fit a throttle for offroad use.
Pas is great for general tracks & trails, but it'll give you a surge right when you don't want it when negotiating a tight switchback.

No need to lose the granny - put the pas ring & sensor on the left crank.

 

[RobF]

Looks like you are having a powerful motor.

If you believe the 'having a dog and barking yourself' saying I doubt you will need granny.

 

[Andrew2505]

I've just seen the Haibike sduro all mountain and gone a bit dribbly.
and I'm rethinking and reconsidering mid drive now.