Cheap Brompton Conversion Kit?

[Deleted member 4366]

They used to say things like that about honda motorbikes when their engines revved twice as fast as a BSA. OK, you clearly have something against them. That's your choice and I respect that, but you have to be careful what you say because other people ase less informed and need something on which to base their decisions.

From my own experiments with the Q100 at 20 amps and 48v, I'd say that there's nothing unrobust about these lovely little motors. I now prefer them to the Bafangs that I used brfore - and still do, but that's my opinion.

 

[NRG]

I like them, I don't think running the stator twice as fast is going to be a long term issue plus the freewheel design is a good step forward and enough of a positive to buy rather than the Bafang....IMHO

 

[shemozzle999]

Nothing against them d8veh but when I inquired, see start of this thread, they were not available @ 340rpm for a Brompton, hence my alternative suggestions.

From one of my previous postings:

gspace » Blog Archive » Cute 85 BLDC Motor Disassembled

 

[Deleted member 4366]

Just in case you want to give one a try, they're available now. I just bought four of them from Greenbikekit.com.
I have one in my Dahon, and it gives about 18mph at 36v. Mine's a 24v one, which is slightly different, and probably the same as the high speed 36v one in that it doesn't have those two-stage reduction gears. Maybe that's how they get the speed difference rather than with the windings. You should get about 16.5mph in a Bromton (16" wheels).

 

[jerrysimon]

So they don't do this in 36v ?

electric motor, hub motor, 24V250W front engine for electric bicycle online store for electric bicycle components-GreenBikeKit.com

I assume you get the 201RPM one for 24v ? I been meaning to try one for a while. Which is better sensored or sensorless ?

I have do have a spare sensor ecrazyman controller

I prefer sensorless given its less wires for my umbilical cord arrangement.

Regards

Jerry

 

[Deleted member 4366]

You can get both 201 rpm and 328 rpm in 24v and 36v. What I'm saying is that the 201 rpm 24v might be the same as a 36v 328 rpm one.

 

[jerrysimon]

Thanks Dave.

Jerry

 

[shemozzle999]

New member Jane111008 of MW Motors has emailed me regarding being unable to make a post in the forum - she does not appear in the member list yet - help and advice to solve this please.

 

[shemozzle999]

Motor shell replacement update.

Through her contacts Jane at MW Motors has managed to source a couple of the hard to find high speed SWXU motors for me. So I am now awaiting delivery of the replacement hub shell for the transit damaged SWXB together with 2 SWXU front wheel motors one 24v (290rpm) and one 36v (340rpm).

I might also have some future news regarding 36H look a like Brompton rims.

 

[shemozzle999]

Motors now shipped and should be here in a couple of weeks. They wont be advertised on the website as they were a special order direct from 8fun but anyone interested should contact Jane direct.



I have also managed to buy a small batch of Brompton type rims with 36H using the profile shown below, but I think they wont be delivered before the end of the month.

 

[shemozzle999]

Update.

The SWXU motors and replacement SWXB shell have arrived intact this time.

The rims have been manufactured, checked out OK for size and are now being prepared for shipping.

 

[jerrysimon]

Rims look interesting

All my Tongxins for 16" wheels will now be specified and purchased with 28h.

Jerry

 

[shemozzle999]

Better buy a few now Jerry, those new double walled rims for 2013 look like they will give the same tyre problems as the Sun CR's.

Brompton 2013 component upgrades and accessories | road.cc | Road cycling news, Bike reviews, Commuting, Leisure riding, Sportives and more

 

[shemozzle999]

Just noticed that MWMotors have added a range of MXUS based wheel kits with several battery options:

ebike kit - Shop Cheap ebike kit from China ebike kit Suppliers at MW motor on Aliexpress.com

 

[shemozzle999]

The rims have arrived they look ok, they are already drilled to accept standard inner tubes so no changes required.

Using the method quoted by the spoke calculator guide it appears that the effective rim diameter (ERD) for this rim is 338mm, that together with the motor dimensions should be enough to determine the spoke lengths required.

I will now pass this information over to catsnapper and see what he advises and then I can get on with the system testing.

Measuring the ERD using spokes of a known length and then measuring the gap in between:

 

[jerrysimon]

Interesting. So are they single or double walled and how deep is the well ?

Regards

Jerry

 

[shemozzle999]

Their profile is shown in post #110, the same as the Brompton, but the 19mm dimension is in fact 21mm their next size up rim.

The well depth is just a tad over 14mm.

 

[jerrysimon]

Ah I was being lazy thanks

PS if they work well, then there should be a demand for them for those who find fitting tires to the Sun rims difficult. What do you expect them to retail at ?

Regards

Jerry

 

[shemozzle999]

I do not run a business Jerry, I have only purchased a small sample batch although I will have a few spares available if they prove to be up to the job.

 

[shemozzle999]

It looks like the days of the self build are coming to a close.
It is a shame.
I will complete this project, just because I have started it, but will not be planning to do any more.
I bow my head to the powers that be and have to accept that the future will be limited to the major players' offerings.
I am glad I managed to snap up the Wisper that was up for sale as it will be the only retrospectively legal ebike that I own.