GT iDrive conversion

[itsy]

Hi folks. Within a budget of approx £600 I'm seriously thinking of converting a GT iDrive. It's given me a few years of reliable service & seems built like a tank so it's making more sense to convert rather than buy an 'affordable' bike for my needs such as a Big Bear. I'm a 6Ft + 100k fella, 50/50 steepish long hills & flats, will be commuting 30 miles return for about 10 weeks then just casual/leisure use. The GT iDrive would need a rear carrier to support a battery, I really don't think a bottle battery would fit in the frame.

How is this combination looking:
Motor:
https://bmsbattery.com/ebike-kit/348-bafang-bpm2-48v500w-rear-driving-bike-conversion-kit-ebike-kit.html#/rpm-260
Battery:
https://bmsbattery.com/ebike-battery/403-48v-15ah-li-ion-alloy-05-case-ebike-battery-pack-battery.html

 

[Nealh]

Can you post a pic of your bike.
A few months ago I started bidding for an I- drive with full sus and gear/drive train but stopped when I realised that a down tube battery would not fit , though it was a great looking frame. The rear battery/ rack if you can needs fitting as close to the seat post and as low as you can get it to go to make handling better also with a heavy rear hub as well it will be all rear end weight. A crank drive would improve handling a bit better by shifting some weight centrally.

 

[itsy]

I have the v brake version of this. The GT iDrive Comp.
I agree that there will be a lot of rear end weight - maybe too much.
I can see the iDrive mechanism providing a huge potential problem for a crank drive. So I'm thinking a front hub now?

 

[Nealh]

Other battery options although not ideal is to fit a usb09 on the top/cross bar or vertically if room allows behind the seat post may be better than a rack type.

 

[Deleted member 4366]

I'm pretty sure that the controller in that kit is the KU123, which is 30 amps. 30A is a bit on the high side at 48v. It'll give a lot more torque than what you need. At 48v, 20A is a nice compromise between range and torque. Also, the battery is rated at only 15A, so it's a bit weak for that controller. You need one with a higher discharge rate.

Rear racks are never good when you have full suspension - even worse with a rear motor. If the 09 battery won't fit, I'd get a different bike with disk brakes.

 

[itsy]

Good advice, thanks to you both. Think another bike is in order.
d8veh - what would be the right 15Ah battery for that particular wheel?
With my weight and the terrain/distance I have to cover I can't see the 09 battery making it, what do you think?

 

[Nealh]

When looking for a suitable mtb if you go for full sus make sure the rear sus
/shock is the type fitted up along/under the cross bar which gives more triangle space for the battery, something like the Cube AMS or D8veh's Rocky Mountain.

 

[Deleted member 4366]

Good advice, thanks to you both. Think another bike is in order.
d8veh - what would be the right 15Ah battery for that particular wheel?
With my weight and the terrain/distance I have to cover I can't see the 09 battery making it, what do you think?

The 11.6Ah 48v Panasonic battery does about 30 hilly miles if you pedal moderately. You can double that if you carry a spare. Pedalling with a bit of effort, you can get between 40 and 50 miles.

The 36v battery will take you a bit further, but only because you get less power.

If these batteries aren't enough for you, then you need something like this one on a hard-tail bike:

https://bmsbattery.com/ebike-battery/609-high-c-rate-48v15ah-li-ion-alloy-07-case-battery-pack-battery.html

This one is also quite good:

https://bmsbattery.com/ebike-battery/445-36v-20ah-li-ion-shrink-tube-ebike-battery-pack-battery.html

 

[itsy]

d8veh - can you point me to the 11.6Ah 48v Panasonic battery please.
For use with:
https://bmsbattery.com/ebike-kit/34...g-bike-conversion-kit-ebike-kit.html#/rpm-260

Thanks in advance.

 

[itsy]

No matter, found it:
https://bmsbattery.com/ebike-battery/701-48v116ah-bottle-09-panasonic-battery-torque-sensor-battery.html
It comes with - S-LCD3, One Thumb throttle, A pair of Brake Grips, One B.B. Torque Sensor.

So is this motor kit ok or will I have too many redundant components
https://bmsbattery.com/ebike-kit/348-bafang-bpm2-48v500w-rear-driving-bike-conversion-kit-ebike-kit.html

Is there a better choice?

 

[Deleted member 4366]

You'll have redundant items. The battery comes with everything except the motor. The only additional items you need are a torque arm, a speed sensor and some cable ties. If you get the motor from BMSB, you'll probably beed to change the connector. They provide a long adapter cable, but then you have about a meter of wire too long, so I cut and joined them for a neater installation.

 

[itsy]

Thanks. I can get the overly long cable cut and resoldered using the supplied components then I take it.
Which speed sensor would be recommended - and which rotation speed for the motor - how is that decided?
Given that the battery comes with most of what is needed is there a better wheel to choose to avoid replication of components. I would like to have pedal assist & throttle of course. Thanks for your guidance here, I'm trying to get this made as cost effectively as possible, then stretch to making something suitable for my Wife soon afterwards.

 

[Deleted member 4366]

This motor. Make sure that you select 260 rpm and the correct wheel size:
https://bmsbattery.com/ebike-kit/586-bafang-bpm2-48v500w-rear-driving-e-bike-motor-wheel-ebike-kit.html?search_query=Bafang+BPM2+48V500W+Rear+Driving+E-Bike+Motor+Wheel&results=2

This speed sensor:
https://bmsbattery.com/ebike-kit/661-king-meter-speed-sensor-ebike-kit.html?search_query=King+Meter+Speed+Sensor&results=1

The kit comes with a pedal sensor.

 

[itsy]

Bookmarked, thanks. Can I expect to pay customs etc, if so what might be an approximate figure for the wheel, battery & sensor (approx £472 in total inc shipping)

 

[Deleted member 4366]

£25 +/- £5

 

[itsy]

Remarkably reasonable all things considered. Thanks. Hope others are finding this useful too. Any comments folks?

 

[ps4customgamer]

I'd measure up a bottle battery to see if it would fit it looks like it could be tight but doesnt look too small to me.