Hello @jerrysimonI hope I am not hijacking this thread just say
I use to post several times every day on this forum for years when I was learning this stuff.
If you are interested here are my Tongxin 36v, 180w, 260RPM, 28h motors. Not sure if you can still get them. They are only three wire not hall sensored. The beauty is they have steel roller bearings inside not gears so are vertually silent when running. I use to purchase them in pairs as it was cheaper direct from China for shipping. No Paypal back then, so we paid up front directly into accounts and often waited 6 weeks for delivery with no guarantees!
The Chinese to English transulation often ended up confused hence we ended up with motors with roller brakes on them, wrong number of holes etc etc. It got better and the sellers always delivered and were honest. It really was an act of faith sending them money.
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They were 80mm widebetween shaft bearings, 120mm diam and needed spacers to stop the forks fowling, so the Brompton forks needed to be spread about 8-10mm and fork cutouts widened for the larger motor shafts!
Just over 2.1Kg, maybe new ones are much lighter now ?
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PS just re-read thread and looks like the ones you are using now are a little bit lighter. When we fitted these they were at least 0.5kg lighter than the equivalent traditional geared motors. Maybe the ones now are also higher than powered ?
These draw about 2 amps when you pedal assisting on the flat and a max of about 6-7amps (set) when you are going up a hill. There's only one in Cambridge!
With the controllers back then we could re-program it to ensure we kept the current down and stopped them slipping on their clutches etc.
I still use my e-Brompton which I home-made well over a decade ago. My build adventure was largely inspired by original DYI-ers such as yourself. I documented the process on this forum but I think the pictures have since vanished.
By the way, after I cross-laced my two 16" e-wheels for my two different hub motors, I never laced a wheel again
I guess it's one of these "skills" that ends up being put into use only once in a lifetime I have kept my Brompton as a M6R+: M-style handlebar, 6 gears (2 derailleur + 3 hub), rear rack and dynamo lights. It's a 2005 model if I remember correctly, but I upgraded the usual replaceable parts.
A while back I sold my 8-Fun / Bafang wheel (quite heavy noisy motor, despite its plastic planetary gears), as I didn't mind the less powerful (180W) less fast (200rpm) Tongxin motor which suits my local hills. I like its virtually silent operation, as well as the smooth free-wheeling.
I am still using the 10amps programmable controller, and an early version of the Cycle Analyst display. My 10Ah 36V LifePO4 battery pack was dismantled to remove a couple of dead pouch cells, but since then I have only ever been riding short distances so my small A123 battery packs have been sufficient (no BMS, I continue to balance the 6 cylindrical cells of each sub-pack via a cheap Turnigy charger).
I am now embarking on a full nuts-and-bolts restoration, which will give me the opportunity to re-route the electrics wiring, relocate the detachable controller and position the battery just ahead of the seat post (less weight at the front, fewer vibrations too).
I finished desmantling the Brompton. The stem wedge that holds the handlebar post into the top of the fork had seized ... I had a fun time dislodging it! I
This is a deep renovation / cleanup / re-grease project, all the way into internals such as the 3-speed hub gear!PS: I have several old Makita 18V battery packs (garden and garage tools) which can easily be linked together in series using cheap fused adapters from eBay (£9 for a pair). I will be trying this for short rides (2/3/4/5Ah capacities so quite similar to my A123 packs but with a lesser C discharge rate I imagine).
