May 10, 20233 yr Author Shame those didn't work out. They are nice tyres. When eBrompton is finished, I intend to remove the Swytch electric kit from my old Brompton, so I have a much lighter bike for local stuff that will force a bit more exersize. The tyres on that are Marathon plus, the Continentals do run better, slightly narrower and lighter. The Marathons are around 3 years old and as there is someone on eBay selling the Continentals for £17, I ordered some to replace the Marathons.
May 10, 20233 yr I think you'll find that it's the rim's diameter that's different. Some tyres don't like to be re-fitted, especially if you have a bad technique and use unnecessary force to lever them over the rims, which can stretch the wire in the bead.
May 10, 20233 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. If those tyres are safe on those rims.... and I'm probably telling a granny how to shuck eggs but... did you use diluted washing up liquid so they slither about on the rims easily; make sure the tyres hooked in all the way around, when partly inflated? Edited May 10, 20233 yr by guerney
May 10, 20233 yr Author I think you'll find that it's the rim's diameter that's different. Some tyres don't like to be re-fitted, especially if you have a bad technique and use unnecessary force to lever them over the rims, which can stretch the wire in the bead. The rim is circa 2mm less diameter. The Continentals are easy to fit by hand, no levers needed, so no 'unnecessary force' needed either.
May 10, 20233 yr They are nice tyres. Big weight saving if you can find high quality rims! With Firefox, it's easy to disable CSS on AliExpress to look closely at photos posted by reviewers, otherwise only shrunk photos are displayed, and burrs etc. can be seen. So far, I haven't found any there I'd buy for my bike. I wouldn't be surprised if a lot of third party rims were splayed in places.
May 10, 20233 yr Author If those tyres are safe on those rims.... I'm probably telling a granny how to shuck eggs but... did you use washing up liquid so they slither about on the rims easily; make sure the tyres hooked in all the way around? I dont use washing up liquid, but for sure I make sure the tyre bead is pushed down and hooked in all the way round. Not a Granny, but I have been for 50+ years fitting tyres to cycles such as Moulton, Raliegh RSW 16, Bikerton and for the last 20 years a Brompton. I will give it another go when the new Continentals arrive, but it does appear to be a black and white issue, the Continental tyre fits well in the normal straight forward way on a Brompton rim but if voodoo and special chants are needed in a workshop to fit the tyre on the smaller motor wheel rim its a non-starter going out for a ride on it, just in case you do get a puncture.
May 10, 20233 yr voodoo and special chants are needed in a workshop to fit the tyre on the smaller motor wheel rim its a non-starter going out for a ride on it Sometimes I'm happy being a satanist, as making pentagrams using salt aound the bike, is much more convenient than carrying live chickens to sacrifice for voodoo... but rum is good, the requisite mumbling for either must be easier to do when drunk. Edited May 10, 20233 yr by guerney
May 11, 20233 yr Author Putting it all together – the first time I first needed to connect the conversion kit bits together to check it all works. Once I have done that, and given the bike a test ride, I can review and test the battery options and then can I finally work out which bag to use to store the battery controller and cables. The conversion kit had a handle bar bag designated for the install and it could take a 10Ahr or 15Ahr battery, the bag itself weighed 182g. Using this bag and the kit as is would be the heaviest option. I put the bag on the handlebars, facing backwards so the Brompton would fold. I had got hold of a hover board battery, which was 10S2P of 18650 inside the plastic, supposedly fireproof case they use, for testing the setup and it should be representative of the weight of a 10S2P of 18650 battery made of quality cells that would have a capacity of up to 6.7Ahr. I put thehover board battery in the handlebar bag. I added the controller to the bag, plugged in the 1 to 4 cable and the display, the throttle, connected up the motor wheel and turned eBrompton on. It powered up OK so I checked the wheel size was 16” and set it for mph. The wheel did spin the right way using the throttle as a tester so I plugged in the PAS and rotating the cranks did make the front wheel go. I tidied up the cables, with all the cable slack being coiled up inside the bag. I then went for a ride. It performs much the same as my Swytch Brompton. Only having two gears was not a problem, with the electric assist you can stay in one gear most of the time. Maybe the high gear could go up a bit, possibly change the front chain ring from 47 to 50 or 52, something to look at later. The total weight this working eBrompton was 11.8Kg. So that looks promising, a better quality battery which would be smaller and lighter would need a smaller lighter bag. Then tiding up the cables and getting rid of all the slack will save a bit, so the finished weight should creep under 11.5Kg, or 10.75Kg plus battery. Who needs Titanium ? The stem catcher is what holds the handlebars in place when the Brompton is folded, a knob on the steer tube fits inside the catcher. When I bought the bike, the standard Brompton stem catcher had been replaced with a H&H Titanium stem catcher. They cost around £30+. However it did not really hold the handlebars firm enough, so I gave the arms a little squeeze, like you do. The catcher snapped, oh dear. So I put the standard Brompton stem catcher on and the weight of the bike increased by a massive 16g, not good enough. So I ordered an Aluminium one costing as much as £6.25 from China. Fits just fine, hold the bars very securely. Its lighter that the titanium one.
May 12, 20233 yr Author Brake levers and sensors The brake levers with built in switches as supplied with the TOPBIKEKIT could be used. But for me that would be as a last resort. The conversion kit was only about £5 more expensive with the levers, so I thought they might be useful as spares. What I would much prefer is to keep the Aceoffix levers I had already fitted to the Brompton. The above lever weighs 112g, the Aceoffix levers are 78g lighter. There are inline brake sensors that fit on the brake cable itself as on the Swytch kits. The 1 to 4 cable has 2 pin red Julet connectors for the brake sensors, so I bought one of the inline sensors with a 2 pin JST-SM plug. I was not sure how the two wire brake sensors worked so I built some Julet to crocodile clip adapters so I could check. If the brake lever switch was just that, a simple switch, you would expect the resistance measured between the two wires with a multimeter to be the same when the multimeter leads were swapped around. If there was semiconductors involved in the switch\sensor then you would expect the resistance to change when you swapped the leads around. The resistance across the two wires of the brake lever plug on the TOPBIKEKIT levers when the brake was applied was around 10ohm, and infinity when the brake lever was not active. The readings when the levers were the same when the connections were reversed. This suggests a mechanical switch. I fitted the in-line 2 wire sensor (with the JST-SM connector on the end) to the front brake lever and carried out the same test. To fit the sensor you just pull back the brake outer at the lever and slip the sensor over the inner, so easy to fit (If they work). The similar 3 pin ones work well on my Swytchified Brompton. The test results suggested the in-line sensor was a mechanical switch also. I cut the JST-SM connector off the in-line sensor and used one of the Julet to crocodile clip adapters I had made to connect the in-line sensor to the controller and the display did indicate brake when the lever was activated, success. I cut the JST-SM connector off soldered on a 2 pin Julet connector. I now have a fully working eBrompton at 11.8Kg and there are still weight savings to make. The next decision is what battery to use. If a 10S1P 21700 5Ahr battery proves up to the job, that would be my preferred option, but it is likely going to be a couple of weeks before I get hold of one. The next option would be a 10S2P 18650 6Ahr which would be slightly bigger and heavier.
May 12, 20233 yr I now have a fully working eBrompton at 11.8Kg That's very light! Do you find that's now light enough for you to easily carry as intended? My Dahon folding conversion with 19.2Ah battery, loads of lights, Oxford side lollipops, horn etc. etc. weighs 22.4kg, and at my current level of health it's luggable up stairs up flights of stairs at train stations, but only if I carry the battery in my rucksack. Do have to stop and catch my breath though. I recall easily springing up those same stairs carrying my racer in the 80's... Edited May 12, 20233 yr by guerney
May 12, 20233 yr Aswell as it's very low weight, I particularly like the hi-viz harlequin colours. Edited May 12, 20233 yr by guerney
May 12, 20233 yr Author Do you find that's now light enough for you to easily carry as intended? When folded, its definetly much easier to pick up and carry, very definetly. Easy peasy to lift into a car with the battery attached. When I have the right battery in it, I should be able to move all the battery\controller into a much smaller bag. When that stage is finished I will actually be adding a bit of weight to give it shopping trolley mode, by fitting a much lighter rear rack and decent wheels. Then of course you dont have to carry it so much in the first place. Edited May 12, 20233 yr by StuartsProjects
May 12, 20233 yr When that stage is finished I will actually be adding a bit of weight to give it shopping trolley mode, If price was no object, and if this "134.1g/138.1g" Titanium + Carbon rear rack even fits? https://www.fantastic4toys.com/en-gb/products/ti-parts-workshop-titanium-carbon-rear-rack-for-brompton-bicycle Edited May 12, 20233 yr by guerney
May 12, 20233 yr Author As well as it's very low weight, I particularly like the hi-viz harlequin colours. I did origionally colour the grips and brake cables in appropriate colours, just in case I forgot my right and left, which is important for cycling on the road as you know. So the right side is Red for right and the left side is Lemon for left. But I may change the brake cables to black so the electric cables blend in a bit more and are not so obvious.
May 12, 20233 yr Author https://www.fantastic4toys.com/en-gb/products/ti-parts-workshop-titanium-carbon-rear-rack-for-brompton-bicycle If its for a Brompton it will most likely fit. I have got a cheap alloy one here to try, its a bit shorter than that one above, and does weigh 161g versus 134g, but it was only about £20 versus the £250+ the carbon titanium ones can cost. As long as the rack I have is long enough for shopping trolley mode, then thats OK. I dont need a full length rack for putting stuff on.
May 12, 20233 yr But I may change the brake cables to black so the electric cables blend in a bit more and are not so obvious. I like your colour scheme. Hi-viz is preferable to the current general public's obsession with dark coloured bikes. I might go with yellow or red for the Espresso, was thinking silver to match the silver aluminium frame. Once thing's for sure, my cables won't be stealth black! https://www.ebay.co.uk/itm/393639952946 Edited May 12, 20233 yr by guerney
May 12, 20233 yr I have got a cheap alloy one here to try, its a bit shorter than that one above, and does weigh 161g versus 134g, but it was only about £20 versus the £250+ the carbon titanium ones can cost. £8.51+ per gram! Deffo stick with the alloy.
May 12, 20233 yr Author my cables won't be stealth black! I think mine will be, and I have a few other ideas for eBrompton stealth mode. I could have had the motor in black but its not that big and in silver looks less like an eMotor wheel.
May 12, 20233 yr I think mine will be, and I have a few other ideas for eBrompton stealth mode. Don't do this, it'll only add weight:
May 12, 20233 yr Author How to save 13.2g The metal ring that you would normally use to hold the PAS disk together on a heavyweight eBike, weighs 13.3g. The PAS disk halves seem stiff enough when pushed together and to keep the halves together without the heavy ring, I used a bit of spectra cord.
May 12, 20233 yr Years since I posted here but nice to see people still converting Bromptons. I was one of the first on here using a lightweight Tongxin (almost silent) motor sourced and shipped from China in 2010. I'm retired now but the steel one is still going strong. I now use prebuilt 4Ah 36v lawn mower batteries (have quality/safe cells in them and no sag with my setup) which you can pick up from ebay for around £40 and just make a connector to fit the battery. Back then we use to build our own batteries and I did that to keep them light and as I live in Cambridge (its very flat) I didn't need to carry a massive 10-12Ah one. I also converted a Ti Brompton in 2012 with a very lightweight but subsequentally unreliable motor. Here are some pics of both bikes. I deconverted and sold the Ti years ago. This is my original steel brompton now 13 years old (upgraded with lots of newer Brompton parts). All the electronics and battery are in the front bag connected to the bike with an umbilical wire/plug. Back then we could legally use just a thumb throttle which kept it all simple. The Ti which I think was around 11-12kg excl battery ? PS if you want more info I will post details of battery and connector. Edited May 12, 20233 yr by jerrysimon
May 12, 20233 yr Author 4Ah 36v lawn mower batteries Could be interested, are they Lithium ? And did you find the 4Ahr lasting long enough for local shopping trips etc. Retired here too.
May 12, 20233 yr There you go Good quality/safe Li-Ion Samsung Cells with a BMS built in. You'll need a charger and make some kind of connector (mine is also fused) as shown. Made by Spear & Jackson. These are from an older model lawnmower sold by Argos. I have four purchased off ebay as lots of the lawn mowers are returned and ebay sellers buy up old/unused stock and sell bits on ebay.
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