New to e-bikes, considering Brompton conversion.

[BobbyB90]

Hi, I’m Bobby, new to electric, considering Brompton electric conversion options Help, guidance would be appreciated Based in east of England.

My Brompton has son dynamo, wanting the option to switch to electric to power me along now

 

[Nealh]

East of England depends where ?
Woosh bikes one of the main forum sponsers are in Southend and offer Brommy kits or will undertake the conversion.

edited: spelling.

 

[BobbyB90]

East of Egland depends where ?
Woosh bikes one of the main forum sponsers are in Southend and offer Brommy kits or will undertake the conversion.

Hi Nealh, near Lowestoft, will contact Woosh, thank you

 

[Nealh]

Hi Nealh, near Lowestoft, will contact Woosh, thank you

Perfect .

 

[StuartsProjects]

I did a DIY conversion on a Brompton, I wanted it really light so it was OK to carry etc;

Long build thread here;

eBrompton Build

Why build an eBrompton ? The Brompton is a good bike for shopping or commuting and short range leisure trips. The neatness and compactness of the fold is a compelling advantage, you wont have trouble taking it on public transport or storing it in a corner etc. Fitted with a decent set of ‘easy’...

www.pedelecs.co.uk

 

[BobbyB90]

Thanks Stuart, I’ll take a look

 

[Nealh]

If one wants a light weight brommy option and long range isn't needed then Woosh can 3d a battery fitting to use a power tool battery.

 

[Kneebiker]

I did a DIY conversion on a Brompton, I wanted it really light so it was OK to carry etc;

Long build thread here;

eBrompton Build

Why build an eBrompton ? The Brompton is a good bike for shopping or commuting and short range leisure trips. The neatness and compactness of the fold is a compelling advantage, you wont have trouble taking it on public transport or storing it in a corner etc. Fitted with a decent set of ‘easy’...

www.pedelecs.co.uk

Loved reading through this as I look at my own options. I'm not keen to lose my dyno front hub and also can't really afford/justify the cost of getting my m3l down the 8.5kg starting weight you did.

So I'm looking at finding out more on thr Qiroll friction drive. I've trawled web and asked them directly. No answers yet but if I ever get anywhere I'll do a thread for it

 

[StuartsProjects]

So I'm looking at finding out more on thr Qiroll friction drive. I've trawled web and asked them directly. No answers yet but if I ever get anywhere I'll do a thread for it

I did look at the range of friction drives etc, and initially they look attractive.

However, considering how much you can spend overall on an electric Brompton, it was important to me that I could keep it on the road as much as possible. The implication of that to me was to stick to generic parts as much as possible, hence the KT controller, LCD4 display and fairly standard front hub motor.

It has not cost a lot to have a set of spares for all the electric bits, so at most the Brompton would be off the road for a day or maybe just a few hours in the event of a fault, with no waiting for specialist spares to arrive from heaven knows where.

 

[thelarkbox]

I understand the reluctance to loose the convenience of the dynamo fed lighting, but do you expect to ride the bike without electric assistance after conversion? if not since your carrying a battery anyway and the current lighting fed by the dynamo is not going to be a high drain, so your not going to loose much in terms of range by supplying the lights from the bike battery.

If friction is a viable option perhaps a friction driven bottle dynamo replacement might be an option if dynamo fed lighting is a must keep feature? It would be way more efficient used with a hub motor than a friction motor driving a hub dynamo could ever be.

 

[saneagle]

Loved reading through this as I look at my own options. I'm not keen to lose my dyno front hub and also can't really afford/justify the cost of getting my m3l down the 8.5kg starting weight you did.

So I'm looking at finding out more on thr Qiroll friction drive. I've trawled web and asked them directly. No answers yet but if I ever get anywhere I'll do a thread for it

It doesn't make sense to use a dynamo on an electric bike. You're using the power in the battery to drive the bike, which turns the wheel to generate electricity to work the lights. That means that there are two low efficiency conversions, which probably lose more than 50% of the electricity you started with, when you could work the lights directly from the battery and get 100% of it.

 

[Tony1951]

It doesn't make sense to use a dynamo on an electric bike. You're using the power in the battery to drive the bike, which turns the wheel to generate electricity to work the lights. That means that there are two low efficiency conversions, which probably lose more than 50% of the electricity you started with, when you could work the lights directly from the battery and get 100% of it.

Especially bad to use a low efficiency friction drive to provide for the dynamo. The hub motor sollution is vastly better.

 

[StuartsProjects]

So I'm looking at finding out more on thr Qiroll friction drive.

To quote their website;

"Do I have to pedaling anyway?

You can operate the motor at full power without pedaling"

So not legal ?

 

[StuartsProjects]

On my non-folding eBike, I use lights powered from the main eBike battery, obvious chice reallly.

But as others have said using a dynamo on an eBike seems a bit odd.

I recall from days gone past that with dynamos the 'lights went out' when you stopped. Hiding stationary in the dark does not make sense to me these days.

 

[Kneebiker]

Thanks for your input all.

Usually I would agree, lose the front dyno hub wheel and replace with hub motor. However, I have to carry the bike quite a bit on my multi mode commute . I simply won't be able to carry the brompton with a hub motor conversion on. This is my primary reason for keeping the front wheel rather than lighting

 

[Kneebiker]

On my non-folding eBike, I use lights powered from the main eBike battery, obvious chice reallly.

But as others have said using a dynamo on an eBike seems a bit odd.

I recall from days gone past that with dynamos the 'lights went out' when you stopped. Hiding stationary in the dark does not make sense to me these days.

They stay on for about 5 minutes after stopping cycling

 

[Kneebiker]

To quote their website;

"Do I have to pedaling anyway?

You can operate the motor at full power without pedaling"

So not legal ?

I can see that the motor won't kick in until the wheel speed hits a certain level.

But as there is no pas sensor I suspect you are correct. Once the initial startup speed is met its a self full filling feedback loop

 

[jamesporritt]

Do rear wheel KT hub motor kits for Bromptons exist?

 

[Woosh]

Do rear wheel KT hub motor kits for Bromptons exist?

not that I know of. You have the hub gears at the rear wheel.
It's possible to replace the rear wheel with a hub motor like my DWG2NC but you would lose the gears, reducing what we call gear inches by about 25%-35%, imagine you are pedalling with the gear stuck in gear 1.
Front hub kits are the only practical solutions.

 

[Kneebiker]

not that I know of. You have the hub gears at the rear wheel.
It's possible to replace the rear wheel with a hub motor like my DWG2NC but you would lose the gears, reducing what we call gear inches by about 25%-35%, imagine you are pedalling with the gear stuck in gear 1.
Front hub kits are the only practical solutions.

I'm aware of this one coming

Boost your Brompton with the lightest e-motor upgrade system

Boost is the lightest, most discrete way to make your Brompton electric

boostbike.uk

But untested and very expensive. And only works with 2 speed derailleur verison of a brommie. Not a IGH version like my m3l