8fun crank drive kit

Kudoscycles

Official Trade Member
Apr 15, 2011
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d8veh....I noticed on the exhibitor plan that Bosch had a big stand in the ebike hall. Did you get the impression that Bosch are trying to sell their motor system into China?
Hope you are enjoying the show.
KudosDave
 

Geebee

Esteemed Pedelecer
Mar 26, 2010
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Shemozzle, very interested in the link once you have the details.
A crank drive on my recumbent trike would allow me to start riding it again.
 

shemozzle999

Esteemed Pedelecer
Sep 28, 2009
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If you want to go it alone, I will PM you Geebee, as you are in Australia and I suspect delivery and currency charges would be different to the UK.

You need to first satisfy yourself it will fit your trike before ordering one.

It would be nice to know what the minimum/maximum width of bottom bracket it could accommodate.
 
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trex

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May 15, 2011
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d8veh, which motor you think is the best at the moment?
 

Marctwo

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Dec 1, 2012
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i was wondering if the gearshifter had a sensor in it, the same as a brake has, to cut power to the motor,when shifting gear would this not work ,to stop the gear changing problem , or even a sensor on the gear cable, like the hidden brake wire type.:confused:
You can fit a couple of micro switches to your lever and patch it into the brake cutout. If you're using the normal type of PAS sensor it isn't exactly smooth though. A smoother alternative is to patch into a 3spd switch if your controller supports it... which I presume these won't.
 

shemozzle999

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Sep 28, 2009
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In answer to my own question, from the drawings on the data sheet it appears it can be fitted on bottom brackets from about 70mm width but it gives no maximum - but please don't accept this as gospel.
 
D

Deleted member 4366

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d8veh, which motor you think is the best at the moment?
Best at what?
The Bosch is still the best crank drive.

The Chinese ones are all similar to the Woosh in performance, including the Bafang. The 750w Bafang is about the same torque as a Bosch - maybe a bit more.

No Bosch crank-drives are at this show.

My favourite overall motor is still the Bafang CST. Hub motors are much better than crank-drives as long as you have enough torque. 18 to 20 amp controllers are now becoming more common. They give much better torque than the previous 14 or 15 amp ones, which swings the advantage back to hub motors unless you have extreme requirements.

The controllers that come with Chinese hub motors offer more flexibility, better gear-changing and a more relaxing ride.

Sent from my GT-N7100 using Tapatalk 2
 

trex

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May 15, 2011
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I am looking for a kit that can be fitted to a carbon bike. The Bafang CST would put too much strain on spokes and rim. the 8-Fun crank drive is just about light enough, fitting wise, nearly identical to Sunstar SO3+. Problem is battery, may end up using a triangle bag.
 
D

Deleted member 4366

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I am looking for a kit that can be fitted to a carbon bike. The Bafang CST would put too much strain on spokes and rim. the 8-Fun crank drive is just about light enough, fitting wise, nearly identical to Sunstar SO3+. Problem is battery, may end up using a triangle bag.
I'd need to see your bike to give best advice.
They have a bike on the Keyde stand with front and rear motors and two batteries. One in the frame and their tiny bottle battery. We tried a bike with a single Keyde rear motor and hidden frame battery (33v 6ah?), and it felt quite powerful - maybe because it only weighed 15 kg. It was the ultimate stealth bike.

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trex

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May 15, 2011
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There are quite a few tempting adverts of carbon bikes on preloved and gumtree - almost all of them have carbon forks so that rules out hub motors. Have you seen other battery suppliers besides keyde offering small 36V bottle batteries?
 
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amigafan2003

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Jul 12, 2011
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almost all of them have carbon forks so that rules out hub motors.
No it doesn't - I've been running a carbon fork for nearly two years.



You just need to make sure the motor is fitted properly (c washers etc).
 

103Alex1

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Sep 29, 2012
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The Bosch is still the best crank drive.
Is it ? I'm beginning to think it's as much about the controller as the motor now.

Took a fairly long 14% slope at 16mph today in 7th gear without any undue labouring. Making me think a lot !
 
D

Deleted member 4366

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Absolutely correct. The Chinese have taken their hub-motor technology and tried to apply it to crank-drives. It works to an extent,but they didn't figure out the importance of cutting the motor to change gear. I think it'll be next year before we get new controllers and software to make it like like a Bosch or Panasonic.

Sent from my GT-N7100 using Tapatalk 2
 

shemozzle999

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Sep 28, 2009
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Absolutely correct. The Chinese have taken their hub-motor technology and tried to apply it to crank-drives. It works to an extent,but they didn't figure out the importance of cutting the motor to change gear. I think it'll be next year before we get new controllers and software to make it like like a Bosch or Panasonic.

Sent from my GT-N7100 using Tapatalk 2
I didn't know that Bosch or Panasonic came with this technology - the only one I have heard of is this one but can't find any real life reviews to confirm if it works:

Bike Europe - TranzX PST Presents New Shifting Sensor for Entry Level E-Bikes
 

Artstu

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Aug 2, 2009
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I didn't know that Bosch or Panasonic came with this technology - the only one I have heard of is this one but can't find any real life reviews to confirm if it works:

Bike Europe - TranzX PST Presents New Shifting Sensor for Entry Level E-Bikes
I'm guessing you know it doesn't work quite like that. Can this new motor cut the power instantly when you stop pedalling and also vary the assistance dependant on rider input? or is it just start pedalling and it switches on, on full power, stop pedalling and it stops two seconds later like the cheaper hub motors?
 

Artstu

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Aug 2, 2009
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Try reading the article Artsu
My reference was to the motor this thread is about, not the one you've just linked to.

Edit. I see the linked article was over a year ago, are there any bikes with that system on?
 
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shemozzle999

Esteemed Pedelecer
Sep 28, 2009
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Can this new motor cut the power instantly when you stop pedalling and also vary the assistance dependant on rider input? or is it just start pedalling and it switches on, on full power, stop pedalling and it stops two seconds later like the cheaper hub motors?
I don't know.

It has a throttle but I don't know how it is incorporated into the system as no one has test ridden it.

If it operates independently then you would have the ultimate wireless gear changing technology at your finger tips.

Re: the other motor, as I said, I can find no real life feedback on it.
 
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