Cycling UK Forum

HI - I have a client with a dutch bike which I have recently renovated and serviced after it had been in a shed for 30 years. The bike is a standard dutch bike with a 3 speed Sturmey Archer AW rear gear hub. The client's idea was to convert it to an e-bike to help her get up the local hills. I assume her idea was to fit some kind of electrical assistance motor. However she is now undecided as to whether to just sell it and purchase a new bicycle with more gears. She has asked me for advice.

1. I could reduce the front drive sprocket in order to improve the gearing
2. I could find a different rear wheel hub with more gears
3. I could find an electrical assistance motor which she could try and see if its effective enough for her but if not she could return it?

Any advice would be welcome. I have attached a picture of the bike - unfortunately I returned it so don't know how many teeth the front sprocket currently has but I did notice when I had the bike that that the gearing seemed more appropriate for the flats of Holland than the local hills round here some of which can be very short but sharp.

The cog at the back is a sprocket, the cog at the front is a chainwheel
Easiest way to get lower gears is to fit a bigger sprocket, if there is room inside the chaincase

agbrindle wrote:3. I could find an electrical assistance motor which she could try and see if its effective enough for her but if not she could return it?

I'm not sure on what basis you could take that on.

I'd recommend that she tries an eBike.

Jonathan

Where would you put the batter on that bike? It would have to go on top of the rear rack and from the photo that doesn't look terribly strong.

Cyril Haearn wrote:The cog at the back is a sprocket, the cog at the front is a chainwheel
Easiest way to get lower gears is to fit a bigger sprocket, if there is room inside the chaincase

Neither of them are cogs - cogs have teeth which engage with other cogs...
Sprockets have teeth which engage with a belt or chain...


Anyhow...

Dropping the gearing is an option, as is pushing up any particularly steep short hills.

I'd want to keep the bike basically as it is, because it's very well adapted to what it does.

Firstly ...................
It's only got one brake!
Illegal on UK roads.

It has a Sturmey Archer AW, so has no back-pedal brake for the rear wheel.
Looks like a "Nurse's Lock" on the rear wheel where the rear brake should be.

From memory bikes of this ilk generally came fitted with an 18t sprocket. S.A. make sprockets up to 24t, although how big you can go on that bike before you start having problems with the chaincase is problematic. A smaller chainwheel is a more sensible option but I don't know what the availability of small cottered chainsets with gearcase clearance and std length cranks is like but I would imagine it's not good. If she wants to go down the electic assist route then the std gearing would probably be fine. There are various kits on the market but the obvious choice for this set up would be a front wheel hub drive. Do you know what size wheels the bike has. They look to me like they might be 700C in which case a suitable kit is easy enough to find. If it's 26x1 3/8 then you might have to get a wheel made up. This is the sort of thing available in 20" (460?), 26" (I assume 559 and not 590 for 26x1 3/8), 650B (584) and 700C.

https://wooshbikes.co.uk/cart/#/product ... ah-battery

Mick F wrote:It has a Sturmey Archer AW, so has no back-pedal brake for the rear wheel.

It could be an AWC and we can't see the brake arm for the chain case.

One brake is not completely illegal on UK roads but it is if the bike is permanently resident here.

I would suggest that a good scheme might be to lower the gearing, but that IMHO fitting an e-assist wouldn't be a good match on this bike.

The e-assist would add weight and speed to an already marginal frame design/braking system; not a good combination at all. The bike probably rides like it has hinge in the middle already, and adding ~15kg of extra crap to it will probably just turn it into an unwieldy hinged monster.

In fact it may be that the brake (s) (is there a rear hub brake...? Photo?) are sub-par for use in hilly terrain in any event.

cheers

Brucey wrote:I would suggest that a good scheme might be to lower the gearing, but that IMHO fitting an e-assist wouldn't be a good match on this bike.

The e-assist would add weight and speed to an already marginal frame design/braking system; not a good combination at all. The bike probably rides like it has hinge in the middle already, and adding ~15kg of extra crap to it will probably just turn it into an unwieldy hinged monster.

In fact it may be that the brake (s) (is there a rear hub brake...? Photo?) are sub-par for use in hilly terrain in any event.

cheers

All very fair points.

mjr wrote:

Mick F wrote:It has a Sturmey Archer AW, so has no back-pedal brake for the rear wheel.

It could be an AWC and we can't see the brake arm for the chain case.

One brake is not completely illegal on UK roads but it is if the bike is permanently resident here.

Good points.

Given that this a UK forum, we should expect that posters are UK based.
However, the OP hasn't been back as yet.

If it doesn't have a coaster brake (though I don't think I've ever seen that type of bike with just a front brake; just a back brake, often, but if there's a front there's a back too) then maybe replacing the current hub with one that includes either a coaster or lever-operated hub brake would be the way to address both issues in one go. Presumably the AWC has the same ratios as the AW, so you'd be looking at something non-Sturmey. Brucey should be the person to recommend an appropriate geared hub...

But it may well be that, give the cost of either relacing the wheel or getting a new wheel, this would be more than the owner deems worth spending on it.

Brucey wrote:In fact it may be that the brake (s) (is there a rear hub brake...?

Only one brake lever, and it's on the RH side.

Hi thanks for all the advice, The bike has two brakes, a front rim brake and a rear coaster brake, The wheels are 700.
I may look around for an e-assist which may fit to the front wheel but I know little about them.

agbrindle wrote:Hi thanks for all the advice, The bike has two brakes, a front rim brake and a rear coaster brake

Excellent!