Kit options for a Brompton

[Chris Maluszynski]

Hi,

I have owned a Wisper 905 for some years and become addticted to this bike.
I recently moved London and left my ebike in Norway. Last night my manual folding bike was stolen, and I am now looking to buy a new bike, and considering my options.

I am leaning towards buying a used Brompton, and hopefully also fitting it with an electric conversion.

I use the bike to haul my kids to preschool in a double bike trailer, uphill. That task was easy enough with the Wisper (considerably harder with the manual folder). But will it be possible with an electrified Brompton? (Hill is not very steep btw).

I don't need speed. But I do want decent torque.
Also, I'd preferrably not go broke in the process.

I understand there are two main kits: Sparticle and Nano? Also, I know NYCewheels in New York sell a popular kit with a Crystalyte motor - not sure if this is availble in the UK? Also heard of German alternatives like Heinzmann?

My questions to all you knowledgeable and helpful folks here on the forum are:

Of the available kits:

-Which have the torque needed for the job (all? none?)
-Which offer the best value for money?
-Where should I buy them?
-How hard are they to install?

Is DYI an alternative? Meaning, buying a motor, battery, controller etc off Ebay or from China. And if so - what to look for, and where to look for it?

Thanks for any advice!

Chris

 

[trex]

if you don't want to spend a lot of money, and a lot of torque, an electrified Brompton is neither. The woosh Zephyr-B has good torque and folds:
http://wooshbikes.co.uk/?zephyr-b

 

[RobF]

I have a Brompton Nano and I like it.

But it actively does not meet your spec.

As trex says, it's expensive and the motor is comparatively weedy.

 

[Chris Maluszynski]

Ok, maybe I should rephrase that. I do not need the bike to actually take me up the hill, as I am perfectly capable of pedalling myself, but of the available options for the Brompton - which gives the most torque (for the best price)?

 

[RobF]

A high torque motor in the front of a Brommie is not a good prospect.

The dropouts need to be filed to fit any motor, thus weakening them, and I expect wheelspin might be a problem.

The bike shop C H White specialise in folding ebikes, and last time I was in, they were working on their own higher power rear drive Brompton.

Worth giving them a ring.

Details on the contact page of their folding bikes site.

http://www.foldingbikes.biz/

 

[patpatbut]

I am riding my ebrompton for more than 2500miles without problem. The torque is better than my 28 inch ebike.

I converted it by myself with the help of the memebers here. As RobF mentioned, you need to file and strengthen the dropout. You can ask TETS for the specially made brompton torque washer.

Pat

 

[Deleted member 4366]

I've seen a Brompton running a Bafang SWX motor at 48v in the front, so I can't see the strength of the forks as a problem as long as you use some sort of torque arm. Traction would be a problem on very steep hills, and you'd get a bit of wheel-spin each time you start if you're not gentle on the throttle, which would wear the tire fairly quickly. If you're not too bothered about going fast, say 12mph, a 250rpm 36v motor should be enough. I wouldn't bother with a narrow motor. It doesn't take much to stretch the forks, so a 260 rpm Q100H kit from BMSBattery should do the job nicely.

 

[Chris Maluszynski]

d8veh: Is it this one you mean?

https://bmsbattery.com/ebike-kit/576-q100-36v350w-front-e-bike-whole-kit-ebike-kit.html#/display-lcd/rpm-328

It seems to be 328rpm? Does that make a difference?
Have you ordered from this site before? How does shipping and customs work?

Also patpatbut: Who is TETS? (re the torque washer)

Is front drive the only option for the above kit on a Brompton btw?

Thanks everyone!

c

 

[RobF]

Chris,

I can't help with your kit question, but you seem keen on a Brompton.

Having told you a Nano lacks the grunt for your needs, if you happen to try one and find it suitable, my excellent condition example might be available for an appropriate consideration.

Just sayin' like.

 

[Chris Maluszynski]

RobF, not sure I'm getting that right, but do you have one for sale? A kit or a bike with the kit?

 

[RobF]

RobF, not sure I'm getting that right, but do you have one for sale? A kit or a bike with the kit?

I have a 2009 six speed Brompton with a 2012 Nano kit installed by Nano.

It was my first ebike, and while I'm not actively trying to sell it, I have two other ebikes - and another one on loan - so I would sell it, particularly in circumstances such as this where I don't have to go through the faff of advertising.

The bike is in as good a condition as it could be, everything works, recent new Marathon tyre on the rear after a puncture.

 

[patpatbut]

d8veh: Is it this one you mean?

https://bmsbattery.com/ebike-kit/576-q100-36v350w-front-e-bike-whole-kit-ebike-kit.html#/display-lcd/rpm-328

It seems to be 328rpm? Does that make a difference?
Have you ordered from this site before? How does shipping and customs work?

Also patpatbut: Who is TETS? (re the torque washer)

Is front drive the only option for the above kit on a Brompton btw?

Thanks everyone!

c

Hi Chris

The kit from BMSB is not good as the rim they supply is not the 349mm. You need to get something like Sun CR18 with 36h however it is pain to put the tyre on.

I have ordered from BMSB 5 times and they all went very well. However, all orders were caught with customs fees around £25

My SWB clone motor is running at 340rpm 36v that is about 15.3mph max on load.


TETS is the link below
http://www.electricbikesales.co.uk/

If you can connect Eddie I am sure he can supply it to you

If you need anything else, just let me know

Pat

 

[Deleted member 4366]

The kit from BMSB is not good as the rim they supply is not the 349mm. You need to get something like Sun CR18 with 36h however it is pain to put the tyre on.

Good point. You have to buy the bare motor and build your own wheel with the right rim. The kit linked above is the cooking Q100. The Q100H can handle more power. It would probably be best to get an uncased battery and stick it in the front bag because there aren't many places to mount a battery on a Brompton.

IMHO, the kits offered specially for Bromptons are very over-priced and/or short on power.

 

[patpatbut]

Maybe you can ask Morphix for the kit. Follow the thread below

http://www.pedelecs.co.uk/forum/threads/cyclecharge-anyone-need-e-bike-motor-kit-or-battery.19698/#post-245218

 

[Chris Maluszynski]

Thanks for the link to Morphix thread. But agh! looks like it's too late for his order.

Ok, then. Let's go back to the BMSB site and build our own high torque Brompton conversion kit, shall we? Help me out, those of you who know more than me (that is anything):

Motor: Q100H (260rpm?)

https://bmsbattery.com/ebike-kit/630-q100h-36v350w-front-driving-ebike-hub-motor-ebike-kit.html?search_query=q100h&results=5

Rim:

And this can then be manually fitted to a rim that I have to buy separately?
(or could the original Brompton rim be fitted with it?)

Spokes:

How do I know lenght and number?

https://bmsbattery.com/ebike-parts/458-1-pcs-12g-stainless-steel-spoke-with-a-brass-nipple-parts.html

Controller:

Should I follow the BMSB suggestion for controller? Which one? S06P or S06S? I don't understand the difference. Also it says the motor is 350W but those controllers are for 250W?

Battery (for Brompton bag):

When you say uncased battery, do you mean this one?

https://bmsbattery.com/ebike-battery/183-36v10ah-lithium-ion-electric-bicycle-battery-pack-battery.html

Does a battery like that withstand some rough handling (dropping bag, travel etc?)

Also, is there a battery that you can (legally) check in as luggage on an airplane? I belive NYCewheels sells an 8ah battery that divides into two smaller ones somehow, and those are then technically legal to bring on an airplane.

Brake sensors?

https://bmsbattery.com/ebike-parts/459-hwbs-hidden-wire-brake-sensor-1pcs-parts.html?search_query=in+line&results=1

Do these go into any controller?

LCD?
(is this necessary?)

https://bmsbattery.com/ebike-kit/548-s-lcd1-e-bike-lcd-meter-ebike-kit.html

Throttle?

https://bmsbattery.com/ebike-parts/395-half-twist-throttle-parts.html?search_query=half+twist+throttle&results=40

Pedal sensor?
(is it necessary?)

Is that it? Did I forget something?

Wiring?


Maybe we can actually make this list complete for future reference?

And is BMSB the place to get all this stuff? (If Morphix can't assist)

Thanks and sorry for the newbie-questions.

Chris

 

[Deleted member 4366]

If you search back, this list comes up a lot. The problem is knowing what to search for. There's never an exact answer to what components to choose, but we can make a good go at it

36v 260 rpm Q100H front motor
S06S controller
S-LCD1 or 3. Controller doesn't work without it.
Wheel speed sensor
Plain thumb throttle
PAS sensor - the more magnets the better, but they all work OK.
A pair of hidden wire brake sensors. You only need one on the back brake. It'll plug into the controller.
Spoke key
36v 10ah shrink-tube battery (like you indicated)

You then need from somewhere else the rim indicated in a previous post and spokes. You have to calculate the spoke length using an online spoke calculator. You also will probably need some 14g silicone wire to join the battery to the controller and some connectors. I use the red "T" connectors that you can get from BMSB. You can find the wire on Ebay.

The S06S is a sinewave controller that gives smoother motor operation. The Q100s don't like to run without hall sensors, which eliminates the S06P, which is for sensorless motors. The KU63/65 controller will also work and it's a bit cheaper, but you don't get as many features. You need the optional LED display to go with it.

You can't take any batteries on an aeroplane. I think 100wh is the maximum, which would be 2.5ah at 36v.

 

[patpatbut]

This rim will do

http://www.sjscycles.co.uk/sun-cr18-16-x-1-3-8-(349)-abt-alloy-rim-silver-36-hole-prod8542/

Putting Marathon Plus tyre on is a pain in the axx...better to get your LBS to do it.

 

[Chris Maluszynski]

Thanks d8veh!

Just some follow up questions.

36v 260 rpm Q100H front motor
S06S controller
S-LCD1 or 3. Controller doesn't work without it.

Is there any difference in the lcds other than the buttons being separate from the lcd on the 3? (=more wires)

Wheel speed sensor

This one: https://bmsbattery.com/ebike-kit/550-speed-sensor-ebike-kit.html ?

Plain thumb throttle

Is this preferable to the half twist throttle for some reason?

PAS sensor - the more magnets the better, but they all work OK.

This seems to have a longer wire and 10 magnets:

https://bmsbattery.com/ebike-kit/579-ten-poles-pas-pulse-padel-assistant-sensor-ebike-kit.html?search_query=PAS+sensor&results=59

This is more expensive (better?) and has 12 magnets:

https://bmsbattery.com/ebike-parts/504-pas-pulse-padel-assistant-sensor-with-12-pcs-magnets-parts.html?search_query=PAS+sensor&results=59

A pair of hidden wire brake sensors. You only need one on the back brake. It'll plug into the controller.

A pair or just one?

Spoke key

36v 10ah shrink-tube battery (like you indicated)

I'm thinking: This battery will be in the bag of the brompton and cannot be locked (?) That means I will have to carry it every time I park the bike. The battery above weighs 3kg. Not ideal running around with that. Is there an option of locking such a battery to the bike? The bottle batteries BMSB sells, that are lockable cannot be attached to the Brompton I gather? Are there smaller batteries that would be lighter, but still usable for say a 10km ride?

You then need from somewhere else the rim indicated in a previous post and spokes. You have to calculate the spoke length using an online spoke calculator.

It seems BMSB sells spokes made to the right lenght. Is it worth trying those and getting the rim elsewhere?

You also will probably need some 14g silicone wire to join the battery to the controller and some connectors. I use the red "T" connectors that you can get from BMSB. You can find the wire on Ebay.

The 75 amp ones here?

https://bmsbattery.com/ebike-parts/57-single-pole-connector-parts.html?search_query=t-connector&results=112&

You can't take any batteries on an aeroplane. I think 100wh is the maximum, which would be 2.5ah at 36v.

It would be an extracurricular activity, but maybe there would be a way to make a pack of 4x 2.5ah batteries…?

And speaking of batteries, I understand that some of the conversions for Bromptons put a battery connector on the carrier block and bag. Has anyone achieved this themselves using a standard block and bag?
If not this solution, then what kind of connector do you use to connect the battery?

Thanks again everyone.
Chris

 

[patpatbut]

As D8veh is on this case I do not think I can get better advice

I could answer some brompton related quesiton.

The problem is the handle bar of brompton is too short of half twist throttle. It is possible but not very good for handling.

For the rim, if you can find a rim that is 349mm with 36 holes that would be fine. However, you doubt you can find it apart from CR18

For battery connection, the controller/battery connection is mounted on the stem which does not foul the fold. I am using Anderson connector to connect the battery and the controller.

 

[Deleted member 4366]

The LCD3 is bigger than the LCD1. They both work. I'm not sure that you can get all the advanced functions from the LCD1. You'd have to download the manuals to find out - otherwise the LCD1 should be PK. It might be easier to mount.

They're the right speed sensor and PAS 10 or 12 magnets makes little difference.

A half twist throttle might be OK. As they don't cost much, get both, then you can see which is easiest to fit. You'll be able to sell the spare one on Ebay for a profit.

For the battery, you're only limited by your imagination and DIY skills. Bromptons are the hardest bikes to fit a battery to because it can affect the folding mechanism. There's all sorts of front racks and bags for Bromptons. You just have to find the right one. I'd mount the controller in a a project box clamped to the frame somewhere so you can disconnect the battery and take it away. The connectors you indicated are not the ones I use. I use Deans connectors, also called "T" connectors when they're not genuine Deans. They're very quick and easy to connect/disconnect and easy to solder onto the wires too.

HWBS used to come in pairs. You can buy the singly now, so get one.