Dutch bikes, hubs and crank drives.

Alan Quay

Esteemed Pedelecer
Dec 4, 2012
2,351
1,076
Devon
I have been asked to convert a funny Dutch bike to electric (Batavus I think).
I say funny, as I'm more used to Mountain bike components. The bike will be used as a demo in a local bike shop, and possibly also rented out on occasion.

The bike is steel, as are the front forks, but they look perilously thin, so front hub is a non starter. So I'm left with rear hub or crank drive.

The wheels are 26", 590mm, so if I go hub I will probably have to build a custom wheel. A bit of a pain, but probably not insurmountable. The rear drop out is 126mm, so it will probably need a bit of a stretch as well.

T'other option is to go crank, with a BBS01. My reticence with this option is having to instruct the public on the 'procedure' for changing gear (tapping brake lever to cut power etc).

What are your opinions?
All opinions will be gratefully received, and this a genuine post. I'm not trying to start a fight!
 

hoppy

Member
May 25, 2010
330
50
Better not fit a throttle or enter it in a race then:)
I'd use the most powerful legal hub motor that will fit, with a torque sensor and a throttle. I love my crank drive but Joe Public would wreck the gears in no time!
 
D

Deleted member 4366

Guest
If it's a real Dutch bike, it'll have a back-pedal brake, which means no crank-drive or rear hub-motor unless you want to find a special version from somewhere.

Even thin steel forks will be strong enough for a 250w motor. Maybe fit one rorqie arm.
 

Alan Quay

Esteemed Pedelecer
Dec 4, 2012
2,351
1,076
Devon
If it's a real Dutch bike, it'll have a back-pedal brake, which means no crank-drive or rear hub-motor unless you want to find a special version from somewhere.

Even thin steel forks will be strong enough for a 250w motor. Maybe fit one rorqie arm.
No back pedal, and 5 speed derailer freewheel.

I'll see if I can get a picture of the forks. It's the dropouts that concerned me most, very small.
 
D

Deleted member 4366

Guest
With no back-pedal brake, you can do what you want.

Are your forks thinner than thus one I've just done?

 
D

Deleted member 4366

Guest
No, I've tried the original Q128. It was nice and smooth, but gutless, and it didn't respond to increased current. The Bafang SWX was much more powerful, though noisier. I must admit that I'm a little sceptical of their 800w rating, but someone needs to try one to see.
 

1boris

Esteemed Pedelecer
Sep 10, 2013
344
58
Yes I am waiting for a review ;) but it looks like it need a lot of dishing