Some advice appreciated

[oddjones]

Hi all. I've been reading with interest for some weeks and am about to take the plunge. I don't want to buy another bike (I've got a shed full of 'em!). I am ready to purchase a Suzhou Bafeng 8Fun motor - 36v/250w to lace into the 700c front wheel of my Ridgeback Velocity Hybrid. I have noticed beeping sleauty's post here regarding the control equipment and reckon I'm just about ready to go - I'd just like a sanity check before I commit myself if that's OK?

1. Am I right in assuming a 36v setup will offer better hill-climbing/acceleration than a 24v setup?
2. Battery - I've been looking at YESA's website as they seem to offer reasonably priced LiFePO4 packs.... but I'm a little confused as to what I should be going for... Do I need a 20Ah setup? or will 10Ah suffice - what's the difference in short?
3. I will be travelling 5 miles to work - 5 miles back, mostly flat except for one steep (half mile) hill - but I'm more concerned in getting a nice, flat battery pack which I can integrate into the rack whilst still leaving room for panniers - Yesa's 10Ah pack would fit nicely - the 20Ah pack (as well as being significantly more expensive!) would give me quite a significant "bulge"

Am I over-speccing for my requirements? (I'm only really interested in using the bike for commuting - I'm not a "serious" cyclist!). Can anybody recommend a good 36v 10-15Ah battery pack (preferably fitted into a nice aluminium box) which would save me the hassle of doing this myself? Price is very important - I'm prepared to pay up to £200 ish for good quality - which is why I'm looking at a LiFePO4 setup - but I'm not buying a bionx or heinzmann coz I can't afford it!

 

[flecc]

Some answers:

1) The 36 volt setup will be better with this motor.

2) You definitely needa 20 amp setup, 10 amp is nowhere near enough for the current drain on this powerful motor.

3) This is an overspecced outfit for a 5 mile each way really, though it could be enjoyable. The only thing that worries me after the experience of the poor Torq 1 hill climbing with the 8fun in a 700c wheel is how you will manage if that hill really is steep. The Torq was specified as ok for up to 10% hills, but it gets progressivly hard work on steeper than that.

However, I'm not sure if the kit 8fun has the same internal gearing or controller torque/current setup. Perhaps others can advise on that.
.

 

[john]

Battery - I've been looking at YESA's website as they seem to offer reasonably priced LiFePO4 packs.... but I'm a little confused as to what I should be going for... Do I need a 20Ah setup? or will 10Ah suffice - what's the difference in short?

10Ah is more than enough for your 10 mile round trip. It is rated at 25A max discharge so you should be ok with that. You can check with SAM at Yessa. You can talk to him on MSN, his english is quite good.

I came across a LiFePO4 in a case at hub motor, brushless motor, bike conversion kit, power wheelchair,wheelchair controller,electric wheelchair, golf trike,EV battery,brushless hub motor ,golf trolley,regenerative braking controller, µç¶¯ÂÖÒγµ,¸ß¶ûµÇ¿Æ¼¼ÓÐÏÞ¹«Ë¾
Might be worth considering at the price.

Are you planning to get your 8FUN motor from ecrazyman?

 

[flecc]

To clear any confusion from the conflicting advice, if the LiFePO4 really does have a 25 amp discharge rate, the 10 Ah battery will be fine in my opinion too.

My original comment stems from experience of the failures of other battery types with this motor.
.

 

[oddjones]

10Ah is more than enough for your 10 mile round trip. It is rated at 25A max discharge so you should be ok with that. You can check with SAM at Yessa. You can talk to him on MSN, his english is quite good.

I came across a LiFePO4 in a case at hub motor, brushless motor, bike conversion kit, power wheelchair,wheelchair controller,electric wheelchair, golf trike,EV battery,brushless hub motor ,golf trolley,regenerative braking controller, µç¶¯ÂÖÒγµ,¸ß¶ûµÇ¿Æ¼¼ÓÐÏÞ¹«Ë¾
Might be worth considering at the price.

Are you planning to get your 8FUN motor from ecrazyman?

This is all good - that saves me quite a lot of ££ and space too!

Yeah, the Yesa people seem very approachable and it seems good value.

I've seen that cased battery before but it's completely the wrong shape for me - I've seen quite a few bikes for sale which seem to be built around it (it's obviously a standard size for something else) - and they look completely wrong to my eyes.

Getting the motor from 8Fun direct (they have a baffling range and I wanted to make sure I got the right one), but have bought the ancillaries from ecrazyman - it's all very exciting dealing direct with China - I feel quite the international wheeler-dealer!

 

[coops]

Hi oddjones

Regarding the motor, the rpm & controller current limit will determine the torque level (for hills/acceleration) & top speed: basically lower rpm = more torque, lower top speed & vice versa for higher rpm. Higher current limit = more power & torque.

Torq1 motor is around 260rpm I think (measured under load, around 300rpm or more no-load rpm) but in 700c wheels & with a 36V 22A max (delimited)power ~800W gross around 600W net, top speed motor only 20-22mph but only rated for hills up to 10% but a bit more with lots of pedalpower or low bodyweight .

For better hill climbing either a lower rpm motor or more power, but the latter makes it more of a high consumption, low range motorbike!

Hope you find that useful & let us know how you get on

Stuart.

 

[john]

Getting the motor from 8Fun direct (they have a baffling range and I wanted to make sure I got the right one)

Yes, the web site is not very clear.

Does anyone know what is the fork dropout width needed for these motors and are the all the same? Ideally it should be 100mm for a standard fork but one or two people seem to have found it to be more than this.

What is the Torq fork dropout width?

 

[coops]

Hard to measure exactly John but looks about 125mm on my Torq1 with SBF motor; the main 'body' of the motor is about 100-120mm wide with the extra protrusions close to the axle and a 5mm spacer - I'm not sure what the absolute minimum motor width is cos I can't tell which of the extra bits are motor & which are addons, if you get me .

110mm which others have said sounds about right and the motor width is still 9cm at 4.5cm above centre of axle, so fork spacing at that height must be more than that .

Stuart.

 

[flecc]

Yes, 125 mm on the Torq 1, but kraeuterbutter has reported 110 mm on the kit motor.
.