Cheap Brompton Conversion Kit?

[jerrysimon]

Yep they do it in both sizes as they did with the Nano. From memory I think like these the smaller of the two is rated at 180W over the 200W of the larger one.

I prefer the smaller Goldant one for the Brompton but as yet its untested by those of us here that have been using them. I have about 100 miles on mine as opposed to 4000 miles on my larger Nano. For this reason I would continue to recommend the Nano until we know that the Goldant ones will work well long term.

They only became available recently and with the stock controller are limited to pedelec only. The now do a throttle version but it still has pedelec priority which makes it less useful. However if you read my other new thread it appears that they work well with throttle priority using a Lyen controller.

Jerry

 

[patpatbut]

Thanks Jerry

It seems choosing the Tongxin nano for my conversion would be ideal.Also, I do think the lighter of the bike, the easier I pedal it.

I probably risk it having more power to this nano motor to gain more speed. Do you know what is the max mph it can do with ease?

One more thing, I am still waiting for Cici's email. I emailed her again yesterday but no reply.

Thinking what to do next...

Pat

 

[jerrysimon]

Pat some people do successfully over volt the Tongxin motors though I am content with the 15mph assist.

If I recall Cici is at a ebike show at the moment in Europe so may not be picking up her email. That said, I have had others pick up and respond to her email before.

Regards

Jerry

 

[Deleted member 4366]

Don't forget that the Togxin Nano is 14mph max!

 

[jerrysimon]

Dave hence why I think some overvolt them which from my understanding is ok as long as you limit the current to 10-12amps.

Regards

Jerry

 

[patpatbut]

Dave hence why I think some overvolt them which from my understanding is ok as long as you limit the current to 10-12amps.

Regards

Jerry

Hmm...this leads to think about what BMS battery should I get...

I intend to do 14mph with throttle and 15mph assisted. Can you advise me?

Any recommended controller that works with Tongxin quite well with this setup?

Thanks.
Pat

 

[benjy_a]

Hmm...this leads to think about what BMS battery should I get...

I intend to do 14mph with throttle and 15mph assisted. Can you advise me?

Any recommended controller that works with Tongxin quite well with this setup?

Thanks.
Pat

I would stay at 36v, look at the BMS lifepo4 batteries they are made with high quality headway cells which have a great life expectancy.

I'd buy a Lyen programmable or E-Crazyman programmable controller. You can adjust the speed and max current, both controllers will allow you to go up to 115% speed if you so wish.

 

[shemozzle999]

As the original kit was not available to suit a Brompton I have looked elsewhere and found this Company on Aliexpress.
Although they cannot supply a complete kit looking at their site they do have a motor suitable for a Brompton, also a handlebar display and matching controller.
You would have to get the throttle and battery elsewhere.

Aliexpress.com : Buy 16 to 28 inch electric bike BLDC hub motor MWB from Reliable rear hub motor suppliers on MW motor

 

[Deleted member 4366]

That's a Bafang SWXB - if the one in the picture is the one that you get.

 

[shemozzle999]

Looks like it d8veh.

Only $127 delivered ( cheaper than BMSBattery ) plus duty if your unlucky.

It may be old technology but the motor is nearly symmetrical about the centre line ( no wheel dishing required ) and the 7mm boss on either side should help gain the fork clearance required for the Brompton with the addition of a torque washer.

 

[superDove]

Newb question alert!

If the tongxin is 80mm wide and the Q85 83mm wide, is it possible to use a 36V battery and place the controller in a S/C bag frame like here

That way you could swop the front wheel (I'm guessing the Tongxin would need spacers) and have option as to how you want use the Brommie. Less assist, less drag or better hill climbing, less range.

Is this a possibility?

I was wondering because I'm in the same situation, having tried neither motors I thought maybe you could get one now and then the other later on when finances allow. After trying them you could sell one if you know you're not going to use it. Compared to an off the shelf conversion kit, it seems like you would still be quids in if you went the DIY route (even after buying spares of everything!) and of course you would be in a better position to service the bike yourself.

(braced ready for someone to pop my idea-balloon)

James

 

[jerrysimon]

shemozzle999 did you get my pm/email earlier this week ?

Regards

Jerry

 

[jerrysimon]

Newb question alert!

If the tongxin is 80mm wide and the Q85 83mm wide, is it possible to use a 36V battery and place the controller in a S/C bag frame like here

That way you could swop the front wheel (I'm guessing the Tongxin would need spacers) and have option as to how you want use the Brommie. Less assist, less drag or better hill climbing, less range.

Like this

Everything controller and battery is in my bag connected via an umbilical chord to the motor and throttle which are just on the bike

Umbilical parks on a dummy connector on the bike when not in use.

This DIY thread details the whole build from a bare motor wheel build to building a small battery from single power drill cells.

PS doing it yourself as you say does have the advantage of being able to fix it your self and you can buy two of everything as spares and still have a lot of money left over compared to buying a kit.

Regards

Jerry

 

[superDove]

shemozzle999 did you get my pm/email earlier this week ?

Regards

Jerry

shemozzle999
just tried sending a PM (very slow reply, apologies!) and it said your inbox full.
James

 

[superDove]

I've read your thread several times Jerry! and your minimalist eMoulton! and the Goldant Brommie! I like the way you think! (hmm now how can I justify a Moulton to SWMBO)
Thank you for sharing your work.

Did you see the pic in my previous link with the controller attached to the bag frame?
Is yours like that or is it in the bag pocket?

James

 

[jerrysimon]

Yes James, but I didn't see it till I looked through all the pics. Its a nice alternative and one I have not considered or thought about before.

Much as I love my Moulton for longer rides, the Brommie is still my bike of choice for city riding most days.

Regards

Jerry

 

[Deleted member 4366]

That way you could swop the front wheel (I'm guessing the Tongxin would need spacers) and have option as to how you want use the Brommie. Less assist, less drag or better hill climbing, less range.

I haven't yet tried the Q85, but it appears to be a narrower version of the Q100. When the Q100 motor is going less speed than the bike, the clutch disengages completely, so only the drum rotates - no motor and no gears need to turn when it's free-wheeling, so this makes it very low drag - suitable for small-wheeled bikes.

 

[shemozzle999]

QUOTE=James Duffin;150007]shemozzle999
just tried sending a PM (very slow reply, apologies!) and it said your inbox full.
James[/QUOTE]

Hi James,

I have cleared down some of my messages, it should be OK now.

I now have your old Bafang kit running on my other Brompton; it successfully completed a few laps at Blenheim.
It needed a new wheel rim as the old one was slightly buckled, and the freewheel was sticking occasionally but if you bang the tyre with your hand in the forward rotating direction from a stopped condition it releases it and the hub washers needed slight filing to remove unwanted radii to ensure a tight fit on the forks.
The judges are still out on the frog battery I cannot be certain whether it is failing early because of a cell going down or the controller/bms is kicking in at too high a minimum voltage.
I will run it down on your system and then transfer it over to my other Brompton to see if it will still run.

Time to offer belated thanks to Catsnapper for the spoke order and Cyclezee for the thumb throttle whose usual rapid response made the build possible in time for Blenheim - thanks guys.

One of the reasons for starting this thread was to try and find a set of products for cheap Brompton conversion as we discussed at the hand over of your old kit - I am still working on it.

I have ordered a motor from MW motors, see earlier post, and will let you know how I get on.

Another couple of contenders on the motor front:

250w electric bike kit front drive brushless hub motor QB02-A / http://www.aliexpress.com/store/product/24v-250w-mini-front-hub-motor-for-electric-bicycle/209533_511203609.html

E-BIKE BRUSHLESS MOTOR 250W 36V FRONT MOTEUR AVANT | eBay / Chang zhou hua yu xin feng meachanical&electronic co.,ltd

 

[patpatbut]

Thanks everyone

I have checked the electric bike transport and they have Brompton Sparticle kit with V6 version

By looking at its specs and it can be a very powerful setup if required

Performance
Min Range 20 to 30 miles at full power
Max Power 960 watts
Nominal Power 250watts
Hill Climbing up to 25.00%
Max Motor Speed 13-26 mph
Average Charge time 2 to 4 hours

How could it run up to 26mph? have the soldered the shunt of the controller to achieve this?
It would be good if I know the made of this motor.

Pat

 

[jerrysimon]

I am not sure that would be possible without overvolting it.

This has been discussed often in that do you really want to do 26mph unassisted on a 16" wheeled bike lol

Regards

Jerry