Question re what conversion kit will allow slow-pedalling/give knees a rest

[jonathan75]

Hi,

I need a bit of advice on which kit to buy, and hope you all don't mind me borrowing your knowledge, please.

I thought I would go ahead and buy the BBS01 from Woosh but have discovered you have to pedal a lot with it. This is a problem for me frequently, I suffer from a difficult to treat knee condition (fat pad tendonitis), and so I need something which will frequently allow me to pedal gently or not at all and still go places quickly, strictly legally (so 250w only), and go up the many hills in my part of North London/Hertfordshire. My bike has 28" wheels, although I imagine I could find a donor bike with 26" wheels if needs be.

I've heard good things on this forum about the 250w Bafang CST kit, because of its torque, but, does it have the pedalling characteristics I need? It says on the page "integrate[d] speed sensor: optional". It's elifebike, are they safe to purchase from? Is it possible to cheaply service the motor in this country if anything goes wrong?

Or should I be looking at Woosh's 250w MXUS XF08C kit (26")? Will that give my knees a break?

Many thanks indeed, Jonathan

 

[JohnCade]

Can't you fit a throttle with the Woosh kit? I had a Woosh CD with that motor which had a throttle.

 

[jonathan75]

Can't you fit a throttle with the Woosh kit? I had a Woosh CD with that motor which had a throttle.

Yes, thanks for replying, I think you're right it does come with the option of throttle only, I just don't like the idea of spending all that money on something which isn't as well suited as possible - the BBS01 unfortunately seeming to act as either a moped on one hand, or on the other hand requiring me to use force/quickness of pedalling I might not possess. It would be nicer to have something more relaxing, where merely pedalling even a little bit, and slowly, triggers the motor properly.

Maybe the BBS01's torque sensor does do that better than a cadence sensor, maybe it's the best compromise. Probably I ought to ask to visit them and try out bikes with each.

 

[Deleted member 4366]

You can get the Woosh BPM kit in this country, which is a good price:
http://www.wooshbikes.co.uk/?hubkits

Or, if you want a bit more torque, BMSBattery do the 500w BPM and CST kits.

You're correct about having to pedal a lot with the BBS01.

That Woosh MXUS kit is not bad, but will probably lack the torque that you need.

 

[jonathan75]

Thanks Dave. I'm warming to the idea of the Woosh BPM. Do you know is there a minimum "cadence" which one must pedal to make it work, please? It would be nice to be able to use it when legs are only feeling like doing 20 or 30 rpm. The Woosh BPM says it's a "code 13" which I read means 235rpm (I don' t know if that bears on the cadence question).

 

[Deleted member 4366]

The minimum cadence is zero. It has an independent throttle. I did a complete lap of the Redbridge circuit without pedalling apart from a couple of turns just to get up the steepest part of the hill. Russ, the forum administrator, got up there without pedalling at all.

I forgot to mention that if you want a cassette motor. The Oxydrive kit has the same motor as that Elifebike one that you mentioned. It's a really classy kit, and It also has an independent throttle:

http://www.oxydrive.co.uk/electric-bike-kit/oxydrive-cst-ht-13ah.html

 

[Geebee]

The advantage of the hub motor is that you can select a higher gear so that you can pedal at your desired cadence whilst the motor does its thing.

 

[trex]

]jonathan75, the BBS01 kit has a thumb throttle to rest your legs.

 

[Geebee]

]jonathan75, the BBS01 kit has a thumb throttle to rest your legs.

The issue with a crank drive though is that it likes to rev to stay in the sweet spot, no problem if you don't want to add your own power just turn slowly and add no power but if you want to do some work you need to spin faster or force the motor to lug severely.
I prefer the almost unlimited climbing ability of the crank drive via the gears but going off Johnothan's description not so suitable.

 

[Nealh]

I only have experience of 18a BBS01, I am about 84kg. In the slightly lower gears(4-6 out of 9) it effortly propels me along with light/moderate input up to about 12-15mph on the flat( if I use the thumb throttle as well I get another 2 or 3 mph. In higher gears I use pas on 7 for fairly speedy cycling on the flat but around town find 6 is a good setting giving me ample speed. On hills much more effort is needed to keep up around 14 -15 mph otherwise throttle only in a lower gear will give 7-10mph. The higher pas settings uses battery(15a) charge up quicker but gives 30-35 mile range.To be honest you do need to try the differing options out their to get the one that will suit you.

 

[jonathan75]

I only have experience of 18a BBS01, I am about 84kg. In the slightly lower gears(4-6 out of 9) it effortly propels me along with light/moderate input up to about 12-15mph on the flat( if I use the thumb throttle as well I get another 2 or 3 mph. In higher gears I use pas on 7 for fairly speedy cycling on the flat but around town find 6 is a good setting giving me ample speed. On hills much more effort is needed to keep up around 14 -15 mph otherwise throttle only in a lower gear will give 7-10mph. The higher pas settings uses battery(15a) charge up quicker but gives 30-35 mile range.To be honest you do need to try the differing options out their to get the one that will suit you.

Thanks. From what you say, the 18a crank drive model sounds like the most flexible among those I'm reading about - allows gentle input as you say, has thumb throttle, and allows for controlled exercise for those times when I'm feeling well, too.
I read that Custom Ebikes can reprogram the 250w so it works at 350w Does anyone know if this has all the same characteristics after that reprogramming, as the off-the-shelf 350w? Does it become essentially the same motor?

 

[Nealh]

Jonathan don't rule out a hub motor as it is said they make for a more relaxed ride, I have no real experience of them albeit a couple of rides at Redbridge this year.

 

[Deleted member 4366]

Thanks. From what you say, the 18a crank drive model sounds like the most flexible among those I'm reading about - allows gentle input as you say, has thumb throttle, and allows for controlled exercise for those times when I'm feeling well, too.
I read that Custom Ebikes can reprogram the 250w so it works at 350w Does anyone know if this has all the same characteristics after that reprogramming, as the off-the-shelf 350w? Does it become essentially the same motor?

A crank motor won't be suitable for what you want. You need to keep the cadence relatively high to keep it in its efficient zone. If you slow down the cadence by selecting a higher gear, the motor and controller will overheat. Crank-drives are for people that like to pedal. You need a high torque hub motor.

 

[Kinninvie]

I have both a hub and crank drive and agree with above,the crank is no good with dodgy knees unless you are prepared to use it on mainly throttle and sacrifice some range.

 

[jonathan75]

You need a high torque hub motor.

Thanks. From what everyone's been saying I'm pretty decided on the Bafang CST 250w in kit form (partly as it seems to be a 350w in disguise). It doesn't come with an LCD meter though, and it looks like buying one means buying a new controller.

I've emailed elifebike to ask but wanted to check if anyone here had a view. Would anyone have any recommendations for an LCD meter and a controller, please? I saw one on Greenebike but couldn't tell what Amps cutoff it had.

The elifebike LCD/controller set seems to be limited to 14A which doesn't sound very much. It also seems to imply it might only work on their "QQ" series motors (although that's vague).

Oh, and is it important to buy a speed sensor as well as a PAS wheel thing with lots of magnets on it (or are the standard 8 or so enough)?

 

[Deleted member 4366]

You can get the whole kit as the Oxydrive kit. It's a good quality plug-and-play kit. By the time you've bought the motor, a decent controller and battery, the cost will be nearly the same. If you buy the kit, you get a guarantee and support.

 

[Nealh]

d8veh would you say that the cst option is a better one than the 350w bpm woosh kit ?
£300 difference that on paper looks very much similar, I'm assuming the cst has a bit more umph.

 

[Deleted member 4366]

d8veh would you say that the cst option is a better one than the 350w bpm woosh kit ?
£300 difference that on paper looks very much similar, I'm assuming the cst has a bit more umph.

The CST motor takes a cassette, so much better gearing options. It's also wound for a slightly higher speed (270 rpm).

The Woosh BPM kit is pretty good too. Assuming that it's the same as the Big Bear, the main difference you'd feel while riding is that it's more sedate than the Oxydrive, which feels much more sporting.

 

[jonathan75]

So the Chinese company which sold me the Bafang CST/BPM 250w kit for about US$260 ($423 including shipping and upgrades), and which I paid through Paypal, sent the $100 SWXK kit instead, which I've discovered on opening the package. Feeling pretty down about this. I did without a holiday this year to get this kit.

On the bright side, Paypal's "buyer must pay to return wrongly sent goods" clause hidden in their smallprint, because it makes a mockery of their buyer protection claims seems V much something any small claims court can potentially order be struck out if it considers it unfair in an individual instance. It's an EU law rule and Paypal being in Luxembourg means any UK court can apply it - in fact intra-EU consumer transactions are governed by the law of the purchaser's state anyway so it would be fine even if it were just a UK rule.

But it's just more fighting and time.

 

[Nealh]

What a bummer Jon , have you emailed the Chinese co yet? With pay pal you still have to use a credit card try speaking to the card co as well. Don't give in and except some inferior cheaper kit.