dahon v brompton

[stevieb]

HI,
I have had a Brompton and a Dahon 20inch wheel folding bike for a few years

I am thinking about putting a kit on one of them but cannot decide which bike to do it on.

i feel that maybe using the brompton may turn it into something its not meant to be, but it is a much more user friendly bike as far as folding and unfolding is concerned.

The dahon is not as easy to fold /unfold but there are probably more kit options out there and it may be more suitable for conversion .

The bike will be used from my campervan for transport / shopping when i am parked up on a campsite.

A range of 20 to 30 miles would be useful .

it would be great to hear from someone who has tried both types of bike in electric form

thanks

 

[vfr400]

I've converted both. You've summed it up pretty well. The problem with the Brompton is to get the wires around the folding points. Wires don't like to be frequently bent in different directions. It's six and half a dozen which one you convert. Rather than fold them completely, I'd just drop the bars and seat, then fold the pedals to make them flat. That makes things much easier when it comes to wire routing.

The best motor for the Brompton is probably the Q85 from BMSBattery. The Dahon can use any rear motor,so more options.

 

[stevieb]

Thanks for that

That is a very good point about the wires and folding points

The dahon looks the favorite at the moment

 

[patpatbut]

For easy option you could try swytch kit for Brompton. I am happy with it so far and I have done a review here

 

[stevieb]

I have checked out recent reviews of the swytch kit

it does look easy to fit ,but there does seem to have been some issues with it.

Noises coming from front wheel .

communications with the company also seemed to be an issue , although to be fair they did come on this forum and try to resolve problems.

I cannot find out if the problems did get resolved

 

[vfr400]

The battery weight on the handlebars has a profound effect on a bike's handling. I wouldn't put a battery there unless there was no alternative.

 

[Jonah]

I have a Swytch kit on my Brompton.
Pretty pleased with it but couldn’t fit the PAS on my older bike. Later Bromptons with the new BB and cranks are OK I believe. They have more room for the magnet ring. Folds without a problem ( but then I don’t have the PAS cable to worry about!).

I previously used a much heavier and more powerful Sparticle kit and the lightness of the new kit suits the Brompton better. Power is enough.

 

[jarob10]

Dahon with bbs01 fitted.

PAS only, running displayless so no wires at the fold

The kit was taken from my first ever conversion of a 26” wheel mtb - modifying the pannier to suit the 20” dahon wheel took most of the time

 

[stevieb]

The battery weight on the handlebars has a profound effect on a bike's handling. I wouldn't put a battery there unless there was no alternative.

that is a very valid point and i think it would make the front end handling a bit dodgy

 

[stevieb]

I have a Swytch kit on my Brompton.
Pretty pleased with it but couldn’t fit the PAS on my older bike. Later Bromptons with the new BB and cranks are OK I believe. They have more room for the magnet ring. Folds without a problem ( but then I don’t have the PAS cable to worry about!).

my brompton is an older model so the swytch kit for it is not looking like an option

 

[stevieb]

View attachment 31862

Dahon with bbs01 fitted.

PAS only, running displayless so no wires at the fold

The kit was taken from my first ever conversion of a 26” wheel mtb - modifying the pannier to suit the 20” dahon wheel took most of the time

this looks interesting

no wires at the fold is a good idea

 

[Woosh]

no wires at the fold is a good idea

you still have the wire from the pedal sensor to the controller.

 

[stevieb]

Oh well
Never mind
Another obstacle, Ha ha

On the plus side I have been playing about with both my folding bikes to see which I prefer in readiness for conversion and have discovered that they are both not too bad as they are.

I’m not saying that I won’t bother converting them , just that I can take my time as this may prove to be a bit of a minefield

I converted a bike years ago with an Alien kit and it was easy

Infact it has been the most reliable ebike I have owned

Thought converting a folder would be equally straightforward forward,but maybe not

 

[Woosh]

I converted a bike years ago with an Alien kit and it was easy

the biggest problem with 20" or 16" folders is where you fit the battery.
If I had to choose, I'll choose the Dahon any day. It's much easier to convert.
If you need a reasonable torque and range, you really need 13AH battery for BBS01 or XF07/XF08 and it's heavy and bulky. I think I remember vfr400's old Dahon D7 with a bottle battery on the main beam. He had to make a battery mount adapter with fiberglass.

 

[vfr400]

Jimmy (ebikebatteries,co.uk) will make you a custom battery in an under-saddle tool-bag. I think he does several sizes. On a light folding bike, I'd use a 20 cell battery for 6Ah and about 20 miles range. 30 cells will give 9Ah and 30 miles. He can also make you a battery any shape you want. He made my 30 cell Brompton one in a slightly curved shape to match the frame.

 

[stevieb]

That is all good info thanks

I will now check it out

 

[Paul Kay]

that is a very valid point and i think it would make the front end handling a bit dodgy

May I suggest that if you get a chance you try one out. I believe that, from my experience, you will be pleasantly surprised. Especially compared to those Bromptons with 'ginormous front hanging bags on them! Which must be like steering a ballpoint through treacle on a winter's eve.

 

[vfr400]

May I suggest that if you get a chance you try one out. I believe that, from my experience, you will be pleasantly surprised.

Hmmm! I tried one, and I was unpleasantly surprised. Sure, you can still ride the bike, so it's still possible as a solution, but compared with a rear motor and battery mounted in the middle of the bike, which is unnoticeable concerning a bike's handling, you have to ask yourself why you'd want to spoil your bike's handling with a kit like that. Anybody that's fitted a normal front motor kit can notice how it makes the handling a bit weird, but when you fit a battery to the steering, the difference is massive.

As I said, it doesn't make the bike unrideable, and I'm sure that owners are riding around on their bikes happy with the power assist. It's a bit like using a 35 cwt Transit for your weekly Tesco shopping. It works and it's better than walking, but it's a solution that will only suit some people.

For anybody that's not sure what I mean, all you need to do is put a house brick in a plastic carrier bag and hang it close over the front of your handlebars, ride your bike, then ask yourself whether you preferred it with or without the brick. The Swytch kit is actually worse than that because of the addition weight in the front wheel. Try two house bricks maybe for equivalent effect.

 

[Paul Kay]

Try two house bricks maybe for equivalent effect.

A good analogy, since a UK house brick weighs approx 3.5kg, about the same as the 25 mile Swytch power pack. So 2 bricks would be perhaps just slightly more than the front motor plus power pack. I agree, I also have an ebike with a rear wheel motor and frame enclosed central battery pack and the handling is completely different. However I'm a Swytch advocate because they are so simple to install in most cases, and, as in the name, are fast to switch to alternative bikes. Plus they are quick to remove the most expensive part, the battery pack, when leaving your bike for a while. It's really a simple 2 part solution, wheel + power pack, rather than the mishmash of wheel + battery pack + controller pack + display pack that other kits offer, and they also do a rear wheel motor version, if you want to move some of the weight there. Horses for Courses, I guess, I usually don't notice any handling problems... 'til I'm already embedded in the hedge And... Stop the presses, this week Swytch have announced their Version 2 power pack which will be 70% smaller and 50% lighter than their initial version. A true game-changer and fully backward compatible. So Go Swytch and be ready for the next generation power pack.

 

[Woosh]

Anybody that's fitted a normal front motor kit can notice how it makes the handling a bit weird, but when you fit a battery to the steering, the difference is massive.

the gyration effect is much more noticeable on smaller wheels.
For something like the 16" Brompton, I would have thought the best way is to put the motor to the rear, and do away with the hub gear. If gears are absolutely wanted, then fit a double chain ring.
The battery and controller can go into a leather bag under the saddle.