May 12, 20233 yr All my electronics go in one back pocket of the Brompton bag and the battery in the other (it just fits). This keeps everything light, the main bag empty.and means you can carry Brompton in one hand and bag in another We had all the same issues you have found buying ready made up wheel sets re tyres so in the end build our own wheels PS therer are newer versions of mowers and hence batteries around now.
May 12, 20233 yr Author We had all the same issues you have found buying ready made up wheel sets re tyres so in the end build our own wheels Interesting to know. I will end up with a 'spare' Motor wheel from the Swytch kit, so at some point in the future I might just buy a proper Brompton rim and teach myself wheel building. And thanks for the pictures, there are hoverboard batteries around at 4Ahr - 5Ahr, £50 to £75 that come in a plastic case too. Might be worth buying one just to see how long its lasts.
May 12, 20233 yr Meant to add in Cambridge (very flat) I get between 10-15 miles depending on wind. If I go further I just carry a spare. The motor is only 180w so not power hungry, draws less than 5-6amps max and mostly when I am pedaling less than a couple of amps. The solution would not meet requiments of people in much more hillier places!
May 12, 20233 yr Interesting to know. I will end up with a 'spare' Motor wheel from the Swytch kit, so at some point in the future I might just buy a proper Brompton rim and teach myself wheel building. And thanks for the pictures, there are hoverboard batteries around at 4Ahr - 5Ahr, £50 to £75 that come in a plastic case too. Might be worth buying one just to see how long its lasts. Probably Lithium Polymer which I used a lot in RC Flight (super light) but prefer safer Li-Ion cells on an ebike. Mine are built into both the older and newer Brompton rims which is not difficult for radial builds, as long as you get the spoke length correct
May 12, 20233 yr Author Probably Lithium Polymer which I used a lot in RC Flight (super light) but prefer safer Li-Ion cells on an ebike. No, they are 18650 Lithium Ion. Although given that they are for sale at £50 (delivered) in the UK, one might imagine they are made of no-name cells in the far East. as long as you get the spoke length correct If the ERD is the same, maybe the old spokes will fit. Edited May 12, 20233 yr by StuartsProjects
May 13, 20233 yr No, they are 18650 Lithium Ion. Although given that they are for sale at £50 (delivered) in the UK, one might imagine they are made of no-name cells in the far East. If the ERD is the same, maybe the old spokes will fit. The eletric hub will be much larger than the stock one, so very unlikely.
May 13, 20233 yr Author The eletric hub will be much larger than the stock one, so very unlikely. The wheel with the not fully compatible rim on it, is the front motor wheel. Spokes are around 147mm on a standard wheel, and about 112mm on the wheel I would re-rim.
May 13, 20233 yr Yes on my 100mm hubs from memory, I think they are around 118mm. Radial builds are quite easy just lace up, bring up to tension and then work round keeping the rim straight and circular as you can. Loads of youtube videos show you how Edited May 13, 20233 yr by jerrysimon
May 14, 20233 yr Author Radial builds are quite easy just lace up, bring up to tension and then work round keeping the rim straight and circular as you can. Loads of youtube videos show you how Do you know if there is anything special about the rim for one of these motor wheels ? Looking at the spoke holes on the TBK 74AD Motor wheel and my Swytch motor wheel they do not look like they have been drilled to accomodate the more outward angle of the spokes.
May 15, 20233 yr Do you know if there is anything special about the rim for one of these motor wheels ? Looking at the spoke holes on the TBK 74AD Motor wheel and my Swytch motor wheel they do not look like they have been drilled to accomodate the more outward angle of the spokes. All I recall (is was 13 years ago) the ones provided ready built from China use to have a generic 16" rim that had an ETRO of 305 whereas the Brompton rims are ETRO 349. The other challenge back then was the motors only came with 36h so could not be laced into a standard Brompton rim which was 28h. That changed later when they made us motors with 28h. As long as your motor is 28h you should be able to relace it up easiy in a stock Brompton rim Again with the angles of the radial lacing somtimes we use to put copper washers on the spoke head (on the hub flange) to help seat them properly. The countersink on the hub flages were not machined very well. I suspect things are better now in terms of the hole drilling and counter sink on the flanges. Edited May 15, 20233 yr by jerrysimon
May 15, 20233 yr When we first built them we use to lace them up 1X but soon realised that radial lacing was sufficient (strength wise) for such small wheels. This also made the spoke angle and building more managable/simple As you can see on the wheel in the front of the picture (black Brompton) this was a 36H motor hub. Back then we managed to get the last few 16" ETRO 349 wheels that were drilled 36h. That was one of the first wheels I ever built, but as I said later we got motors with 28H which made everything much easier. Edited May 15, 20233 yr by jerrysimon
May 15, 20233 yr Last post today We use to use these which are single walled but obviously now you can get better double walled ones for the Brompton. Back then all Brompton rim holes were drilled straight whereas now, for the rear at least, I think they are drilled at an angle. https://www.sjscycles.co.uk/rims-tape/16-x-1-38-349-standard-drilled-single-wall-rim-silver-28-hole/
May 15, 20233 yr While seeking wide rims for 1.75" tyres for my 20" wheeled folding Dahon, I found these made by Litepro. I read somewhere on these forums that Litepro manufacture frames and parts for Brompton. But again, too narrow, and it's the same story for Litepro's 20" rims. https://www.aliexpress.com/item/1005002909682333.html
May 16, 20233 yr Looking again at SJSCycles it appears some Brompton rims are only suited for rear/hub builds and as the spokes are crossed I guess that is why the angles are more and thus the holes drilled at an angle. They specifically say not for front wheels/two speed rear wheels or radial built wheels. As I said as long as the spokes on the electric motor hub are built radial, straight drilled holes would be fine. I guess you could use the double rim Brompton front wheel rim shown below, but to be honest all mine are single walled and have lasted years. https://www.sjscycles.co.uk/rims-tape/brompton-16-x-1-38-349-standard-drilled-double-wall-rim-silver-28-hole/ We did also use the Sun CR18 double walled rims but they were a nightmare to get Marathon Plus tyres on! Edited May 16, 20233 yr by jerrysimon
May 16, 20233 yr Author Looking again at SJSCycles it appears some Brompton rims are only suited for rear/hub builds and as the spokes are crossed I guess that is why the angles are more and thus the holes drilled at an angle. They specifically say not for front wheels/two speed rear wheels or radial built wheels. As I said as long as the spokes on the electric motor hub are built radial, straight drilled holes would be fine. I guess you could use the double rim Brompton front wheel rim shown below, but to be honest all mine are single walled and have lasted years. https://www.sjscycles.co.uk/rims-tape/brompton-16-x-1-38-349-standard-drilled-double-wall-rim-silver-28-hole/ We did also use the Sun CR18 double walled rims but they were a nightmare to get Marathon Plus tyres on! Thanks for the info, very useful. I saw the 'not for rear wheels' comments. And the Brompton electric rim but that uses cross over spokes. I think a standard double wall will do. The single wall is stupid cheap (£12), but given the number and size of potholes that have become the norm on roads these days, the stronger rim is probably a good idea.
May 16, 20233 yr We did also use the Sun CR18 double walled rims but they were a nightmare to get Marathon Plus tyres on! I find tight reusable zipties either side of the final bulge, hold that in place for pushing in. We did also use the Sun CR18 double walled rims but they were a nightmare to get Marathon Plus tyres on! I looked at those, but as I have no experience of wheel building, and would have paid my lbs to make them, I bought a pair of compatible entire Tern wheels for less than twice the price of those rims. Worked out cheaper overall because of the lbs's wheel building service price, a bonus being two old hubs which I can use in future. Edited May 16, 20233 yr by guerney
May 16, 20233 yr I find tight reusable zipties either side of the final bulge, hold that in place for pushing in. I looked at those, but as I have no experience of wheel building, and would have paid my lbs to make them, I bought a pair of compatible entire Tern wheels for less than twice the price of those rims. Worked out cheaper overall because of the lbs's wheel building service price. If you want to learn how to build wheels then 16/20" is the place to start. Plenty of youtube howtos and info on line. Small wheel builds are easy. I had to learn as 13 years ago it was impossible to get anyone to do electric hub builds for Brompton/small wheels. Radial makes it even easier. Years ago we did posts on here about how we learnt. I can now do large wheels including rear wheels/dishing etc. I am not an expert, but have built loads for my various bikes which have performed perfectly well. Here is a few builds I have done on the Brompton wheels. From left to right SRAM auto change 2 speed which was on my Brompton for a while. Two speed rear Brompton wheel and a radial front on a double walled Brompton rim.
May 16, 20233 yr I 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. 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 ? 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. Edited May 16, 20233 yr by jerrysimon
May 16, 20233 yr Author Just over 2.1Kg, maybe new ones are much lighter now ? Looks like, I dont have the weights for just the motors, but the weights for the complete wheel, no tyre, tube or tape are; Swytch front motor wheel 2.01Kg TBK-74AD front motor wheel 1.906g
May 16, 20233 yr Looks like, I dont have the weights for just the motors, but the weights for the complete wheel, no tyre, tube or tape are; Swytch front motor wheel 2.01Kg TBK-74AD front motor wheel 1.906g This is my wheel. On the TopBikeKit website it says their motor is 1.6kg which is impressive. Are they quiet ?
May 16, 20233 yr Author Are they quiet ? You can hear the TBK-74AD, but its not noisey and the Swytch motor is quieter.
May 16, 20233 yr If you want to learn how to build wheels then 16/20" is the place to start. Plenty of youtube howtos and info on line. Small wheel builds are easy. I had to learn as 13 years ago it was impossible to get anyone to do electric hub builds for Brompton/small wheels. Radial makes it even easier. Years ago we did posts on here about how we learnt. I can now do large wheels including rear wheels/dishing etc. I am not an expert, but have built loads for my various bikes which have performed perfectly well. Here is a few builds I have done on the Brompton wheels. [ATTACH=full]51673[/ATTACH] From left to right SRAM auto change 2 speed which was on my Brompton for a while. Two speed rear Brompton wheel and a radial front on a double walled Brompton rim. Thanks for the encouragement. Given their increasing rarity, the day will come when I will have to build my own wheels. I've seen very interesting Youtube videos about wheel building. Looks like you live in a straight gravity area. It's another postcode lottery I suppose. That's my excuse and I'm sticking to it. Edited May 16, 20233 yr by guerney
May 17, 20232 yr So good for the eBrompton motor wheel I thought, but I was disappointed, they wont stay on the motor wheel rim, when the tyre gets up to pressure it tries to escape the rim, see picture. I spotted these... long wait for delivery, and they might turn out to be rubbish or otherwise unsuitable, but: https://www.aliexpress.com/item/1005003767350512.html Edited May 17, 20232 yr by guerney
May 17, 20232 yr [mention=3847]saneagle[/mention] found these cheaper and with faster delivery - there may be rims on AliExpress with the right number of holes of the same brand: https://www.aliexpress.com/item/1005005201841822.html
May 18, 20232 yr 28H, 36H. Although rim width sizes aren't mentioned (in English at least), Google lens is translating text in the chart below as 30mm height and 25mm width ... best have a chat with the seller. AliExpress Standard delivery speed, which seems to be about 2 weeks in my experience. https://www.aliexpress.com/i/32951467441.html Edited May 18, 20232 yr by guerney
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