8fun crank drive kit

amigafan2003

Esteemed Pedelecer
Jul 12, 2011
1,389
139
The way the bottom bracket looks extended down from the frame makes it look as though it was designed with that mid drive in mind.
That's actually a deceptive photo - this is the framke naked:-




Is that your normal seat height? crikey! you must have long legs.
Yeah I do - 5ft11" - but they only did the frame in med size :-( Although tbh that th seat at it's road height - I don't run it that high off road and with the motor optimum pedalling position wont be so much of an issue so I'll prob drop it down a couple of inches.
 

eHomer

Esteemed Pedelecer
Aug 20, 2012
635
164
It still looks ideal for the crank drive though, the swinging arm pivots are so high up, right out of the way, unlike on my Giant Trance.

I'm still mulling over the basic ergonomics of mid drives though, for my particular usage.

I'd considered the comments about the complications of easing the power when changing gear, but I've now noticed someone mentioning pulling away in high gear, and I hadn't thought about that.

It's similar to the difference on unpowered bikes between dérailleur and internal hub gears. With hub gears you don't have to change down at a "give way" sign just in case you need to stop, whereas with dérailleurs, you do, or it's murder getting going again.

A crank drive with dérailleurs would be just as bad, and maybe also with the danger of overheating the motor. Whereas with a hub motor and throttle start, no problem, pull away, then start pedaling.

As Dave had said, for "leisure" riding and commuting, the hub drives are like an automatic gearbox, letting you stay in a fairly high gear and just casually pedal assist at cruising speed.

The basic concept of mid drive still seems the neatest and most efficient way of purely electrifying a bike, but hub motors are much more versatile for pedal assistance for me.
 
D

Deleted member 4366

Guest
The Nuvinci N360 hub gears goes a long way to closing the gap between the two systems when used with a crank-drive up to 250w, but there's quite a weight penalty. The changer becomes a sort of speed control for the motor and pedals. It's a bit like using a throttle instead of PAS. It wouldn't work if you don't have a PAS with variable power control or something similar. Even, so, it adds complication when building a bike, so for the average guy just wanting a bike for getting around, a hub-motor wins every time providing that it has enough torque to get up the hills. There's now a lot of high-torque "250w" hub motors around. It's just a case of choosing the right one.
 

recumbyrider

Finding my (electric) wheels
Jan 12, 2014
8
2
62
Possibly a Magura - but best to check with the man himself if interested.
 

robwalley

Pedelecer
Apr 17, 2012
175
30
Gloucester
Just got myself a KTM TERAMO HS33 ROHLOFF with Magura hydraulic rim brakes and was thinking of a crank addition. Now I know the standard brake cutoff will not work and I will have to back off 7-8 gear and vise versa and there is a 500w48v BBS02 on ebay for £599 (way too much) but where would someone recommend importing from? there appears a lot of risk from everything I've read. There must be a reliable company to deal with in China somewhere??
 
D

Deleted member 4366

Guest
There must be a reliable company to deal with in China somewhere??
When you find one, let us know.

Most of them won't try and steal your money, but between the sellers' lack of knowledge about what they're selling and the difficulties with translation, there's still a chance that you won't get what you expected, and then you're stuck with it.

It's Chinese New Year now, so you won't get any sense out of anyone for two weeks. You can try Kevin Fang at BTN. He's a really nice funny guy, but he still makes mistakes. Make sure that you tell him what's important to you. After he sends you the pro-forma Paypal invoice, ask him to confirm again the things that you think are important before paying. Don't take for granted what's written down. Don't take too much notice of what's on his website. The same advice applies to any Chinese supplier. He can get and will supply anything.
http://b-t-n.en.alibaba.com/product/1147960035-218437809/electric_bicycle_center_motor_kit_48V500W.html

For anybody else wanting kits or anything else, have a look at his web-sites:
http://www.aliexpress.com/store/705369
http://www.b-t-n.cn/
 

robwalley

Pedelecer
Apr 17, 2012
175
30
Gloucester
When you find one, let us know.

Most of them won't try and steal your money, but between the sellers' lack of knowledge about what they're selling and the difficulties with translation, there's still a chance that you won't get what you expected, and then you're stuck with it.

It's Chinese New Year now, so you won't get any sense out of anyone for two weeks. You can try Kevin Fang at BTN. He's a really nice funny guy, but he still makes mistakes. Make sure that you tell him what's important to you. After he sends you the pro-forma Paypal invoice, ask him to confirm again the things that you think are important before paying. Don't take for granted what's written down. Don't take too much notice of what's on his website. The same advice applies to any Chinese supplier. He can get and will supply anything.
http://b-t-n.en.alibaba.com/product/1147960035-218437809/electric_bicycle_center_motor_kit_48V500W.html

For anybody else wanting kits or anything else, have a look at his web-sites:
http://www.aliexpress.com/store/705369
http://www.b-t-n.cn/
Any comment on http://www.greenbikekit.com/
 

Woosh

Trade Member
May 19, 2012
19,520
16,458
Southend on Sea
wooshbikes.co.uk

recumbyrider

Finding my (electric) wheels
Jan 12, 2014
8
2
62
Good to know - and glad to hear that ebike development continues.
 

Geebee

Esteemed Pedelecer
Mar 26, 2010
1,256
227
Australia
I wonder if that means they will eventually be available at the Austalian Ezee dealers?
Good to hear of increased choice Hatti.
 

Erik

Pedelecer
Feb 20, 2008
198
3
As far as I can tell, no tax or duties, but they might come in later, as I had it delivered to work, where we send and receive dozens of DHL packages daily, mostly documents, from a few pages to dozens of cartons with 500 sheets of paper in each.
 

GBCS

Pedelecer
Jan 25, 2014
48
27
Hull
The likes of DHL and UPS usually invoice the "extras" including their admin charge ( which can be £20ish ) up to a fortnight after the delivery.
Anything arriving via the post office or parcel force gets held and won't be released until the duty is paid.
As for what you get charged, it seems to be a lottery.
 

eHomer

Esteemed Pedelecer
Aug 20, 2012
635
164
The likes of DHL and UPS usually invoice the "extras" including their admin charge ( which can be £20ish ) up to a fortnight after the delivery.
Anything arriving via the post office or parcel force gets held and won't be released until the duty is paid.
As for what you get charged, it seems to be a lottery.
I concur, that's exactly what happens for me, every time.

The Post Office don't deliver until the duty plus an "admin fee" is prepaid, and Fedex always send me an invoice through the post a couple of weeks or so after delivering the parcel.

The amount they ask for usually tallies with the calculation from this website: http://www.dutycalculator.com

I tried ignoring the first one, but they did persist, eventually threatening legal action very strongly....
 

Erik

Pedelecer
Feb 20, 2008
198
3
The bike is a huge success with my son, but I have trouble keeping up with him uphill.
He is now cycling with the same vigor as before his hip disease broke out.
I have the limiter set at 22 kph, but on throttle alone (disconnected when he rides) it takes me to 30 kph !!.
Does anyone know of an EU-source of bolt-on V-brake adapters for the rear brake?

This one is $25 at Danscomp https://www.danscomp.com/products/489051/V-Brake_Plate.html , but shipping is $40 !

Currently there's no rear brake, but he's used to using an efficient V-brake up front.