The new pain killers...Would that be this thread, the pedelec forum, electric bikes, the internet or life in general
8fun crank drive kit
- Thread starter shemozzle999
- Start date
The various Chinese mid-drives are all about the same power, and gear-changing is a bit rough. Therefore there's not a lot of point thinking that you can convert a nice bike unless you want to have Nuvinci hub-gears to go with it. A nuvinci has no problem changing gears and is a perfect solution apart from the cost. If you must have a crank-drive, but can't afford a Bosch, Kalkhoff or Panasonic, the Woosh bikes are good value. I wouldn't pay much more until they sort out the gear-changing. It is better with XT gears. The Bafang I tried had them, and on the flat, they changed pretty well, although noisily, but they might not be so good going up a hill under high load. You'd get real problems with Shimano hub-gears, so don't even think about it.
Both versions. It was the 750w one that had XT gears. The 750w motor is only a little wider than the 250w motor and had a 48v battery. It felt about the same power as the Bosch, but without speed-limit, it could go faster. The GNG at 36v and 22 amps is about the same, or maybe a little bit more. With the 750w controller (30 amps) the GNG blitzes the Bafang powerwise, but is a lot more noisy.
Posted by D8veh
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The gear crashing comes from the controller running on after you stop pedalling. This keeps tension on the chain while you attempt to change gear. The more powerful the motor, the worse it is. Also it's worse when going up a hill because you can't stop pedalling. Changing up is not as bad as changing down. Planning ahead also helps. You can get used to it an adapt your technique to mitigate it to an extent, so it's not the end of the world, but just makes your ridding more unpleasant than a hub-motor or a German/Japanese crank-drive.
All the crank-drives I tried had throttles.
Posted by D8veh
All the crank-drives I tried had throttles.
Posted by D8veh
Can you recall if this was the same as you experienced on the Woosh as on the 8fun 250W version and was the 8fun throttle independent of the speed control?
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As long as the brakes have cut out switches this is not a problem, just tap either brake and you can shift silently and smoothly and by the time you have shifted the power is coming back on.
I don't know if all crank drives work as well as the Tonaro one doing the above but I suspect they will be similar.
This becomes automatic after a couple of rides.
The other option is spin up until the assist is tapering off shift and repeat.
I don't know if all crank drives work as well as the Tonaro one doing the above but I suspect they will be similar.
This becomes automatic after a couple of rides.
The other option is spin up until the assist is tapering off shift and repeat.
D
Deleted member 4366
Guest
Yes, but on a low-cost bike like the Woosh, you don't care so much. You still have the advantage of good hill-climbing, so plus and minus cancel out, if you get what I mean. The Chinese seem to have taken hub-motored systems (bikes, controllers, throttles, sensors, etc.) and simply switched the motors to crank-drives, so yes, you get an independent throttle.
D
Deleted member 4366
Guest
That works great downhill and on the flat, but some controllers have as much as a two second delay before the power comes back on, so when you're going up a steep hill, you touch the brake to change gear and then come to a stop before the power comes back. Some are better than others, but they all have the delay.
Yeah... like a clutch that needs a good service. You can get away with it, you can even get used to it, but it's still rubbish.
If you can adapt a 3spd switch for this purpose then I suggest you give it a go. It's responsive and you don't have to cut power completely.
A clutch is a good description of its use and effect.
I have a three speed setting if that what you mean but it is not going to help on steep hills, I don't know how you know using the brake lever is rubbish, because from using it I can assure you you can not get a smoother shift, the soft start even prevents sudden loads on the chain.
Yes its not a Bosch system but I don't know of any add on Bosch setups and if there were I suspect they may be a bit more expensive, also I recall comments along the line that you have to wait after you stop pedaling before shifting for a few moments? I don't know if that is the case as I have never ridden one, hopefully I will one day though.
I have a three speed setting if that what you mean but it is not going to help on steep hills, I don't know how you know using the brake lever is rubbish, because from using it I can assure you you can not get a smoother shift, the soft start even prevents sudden loads on the chain.
Yes its not a Bosch system but I don't know of any add on Bosch setups and if there were I suspect they may be a bit more expensive, also I recall comments along the line that you have to wait after you stop pedaling before shifting for a few moments? I don't know if that is the case as I have never ridden one, hopefully I will one day though.
It's true that hub motors make gear change on steep hills dead easy but I think chain banging is only small annoyance. Must say haven't tried a NuVinci but I tried a few Bosch bikes, the gear change on steep hills is as sticky as with ordinary push bikes, don't think they have programmed into their motor anything special.
The power does stop instantly when you stop pedalling, on hub gears you do need a brief full stop of pedalling to get a change, there's a bit of skill involved. The hub could well improve with a few miles on though, my none-powered nexus 8 did get better on gear changes with a few miles under its belt.also I recall comments along the line that you have to wait after you stop pedaling before shifting for a few moments? I don't know if that is the case as I have never ridden one, hopefully I will one day though.
I ride side by side with friends on quiet cycle paths and the Bosch is fantastic for matching the effort you put in, and matching my friends pace in any power setting.
No, I mean switch input on the controller that will allow you to switch to and from a lower power setting without introducing any delay. If you have a speed setting on a control panel then I don't know how you could use that smoothly.
I've used it. And it's rubbish.
Well, get this responsiveness from a clutch on a car or motor bike and try to convince someone that it works well...
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24v
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36v
http://www.aliexpress.com/store/product/36v-8fun-central-BB-motor-kit/612941_911007748.html
24v
http://www.aliexpress.com/item/8fun-mid-drive-motor-kit/910997760.html
36v
http://www.aliexpress.com/store/product/36v-8fun-central-BB-motor-kit/612941_911007748.html
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Hi Geebee,
I would not worry to much about the gear changing. Although there might be a delay for the power to resume you can always apply a boost with the throttle to drive through the dead spot.
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