Torque

Hello!.... My Nano Brompton has developed a problem regards its speed. The bike only has a thumb throttle, no LCD, and I noticed it had no real speed to the motor only about 7mph on throttle alone whist on board , so I’ve investigated the electrics so far by firstly cleaning the contacts on the Brompton bag copper strips that Nano fit to give power to the motor via the front Luggage Block and fully charged the bosch 36v battery + swapped it for another also ( checked batt connector unit was ok, no probs there ) but no improvement. So today had another ride and it appeared to be worse, checked and found one bag copper electrical contact bent,probably did that today putting bag back on— so I straightened that but no change, now down to 4mph on throttle alone whilst sat on bike. Standing beside bike all power LED’s on on/off switch light up and stay on, power comes in strong when throttle worked and bike leaps forward on the ground but the no load speed with the wheel now raised in the air the motor speed tails off rapidly after initial good start? . Brake cut off ( only one) connecting/disconnecting fine . Suspect I’ve done more damage running bike with copper strips bent interfering with power delivery. Any ideas what else to check or change please? Bikes been fine last 5 yrs .. oh well, any help appreciated. Thanks T

Perfect!!!..... thanks for giving me th extra info VFR, it’s much appreciated ....Ta T ..... Thanks for fixing giving the extra info VFR, much appreciated!!! :-) T

Ok✅ .... so Battery level LED’s state of charge redundant. I run this ebike on Bosch drill battery’s so I can monitor the state of charge on their inbuilt batt level gauge. So I take it that your saying that the 48v thumb throttle will work ok in all regards on my 36v ebike apart from the loss of accuracy of the battery level state of charge LED’s ? Got to say thanks a lot for the prompt insightful ( as ever!) reply VFR .......Ta T

Hi chaps! My problem is regarding a thumb throttle with 3 LED’s . Basically my ebike is a Brompton ( Nano kit) and I only have a thumb throttle on it instead of PAS + Display . I wish to change the throttle as the Power on Red button is not staying in reliably and the clear plastic covers to LED’s are missing. I have another identical type of one marked 48volt on the side, can I still use this on my 36 volt system, will it work well ? Or could it damage the controller? Wiring should be the same as the old one ( not with bike at the moment) photos of replacement 48 volt throttle . Any help much appreciated ..... Ta T :-)

Well the current Hub.. presume you mean MOTOR? FRONT drive on mine ( 27.5 inch wheel) which is the latest Swytch motor of this type ( Nov 2020 I got it) says 100SX -5XX-36H-B. Let me know if you find a link to this motor for purchase please. This motor works well with the small pro power pack from Swytch, seems to be smooth and fast no complaints. I’ve mounted mine onto a small rack just over the front wheel- adapted battery bracket to fit the rack. Just to say thanks here to VFR for taking the time to offer up his knowledge ... a great help on this forum .....as always :-)

Errr.... do you mean can you just plug in the 9 pin male lead that exits the new AKM Motor into the 9 pin ( female) lead that goes to the handlebar block that your battery slides onto? If so then yes it’s a straight exchange. That’s the set up on my other 20 inch wheel kit is ( same type battery pack/controller handlebar connector block and leads on it ) so just unplug Xiondga motor and plug in AKM Motor . As you say the smaller AKM is a better comparison weight wise which I like. I did buy from somewhere else the AKM 100 motor and that’s a fair bit heavier.yes they did state is was a easy freewheeling motor in their initial ad blurb .., proved not to be the case with the Xiondga early doors motor.

Ive also got the Xiondga front motor ( 2 of them actually) with the first batch kit from SWYTCH..... I’ve got exactly the same problems as you too much resistance when pedalling off power to the extent it’s off putting also means I’m loathe to run under power at a low level of assistance. I also have the AKM motor in a smaller 20 inch size ( again batch1) same battery pack the large tour size and controller, absolutely no problems with it as it runs much quieter and smoothly than the Xiondga and freewheels much better off power at least to an extent that it’s exceptable. Have you mentioned your problems to Swytch? If so what was their reply?

Why was the Cummings loophole that came early in the lockdown not more widely broadcasted to benefit others subsequently?

Hi all....Just like to say thanks for the help from VFR 400 for the advise regards manipulating the Brompton forks and that they should be ok, reassuring to get that knowledge from him and also Kristin who advised me to contact Brompton as they’re very helpful, so I did via their Zendesk and they did tell me the 1997 forks mk2 Brommie would fit a 2002 mk3 Brommie...maybe a very small change to the rake that wouldn’t effect handling a great deal but length of blade and head tube diameter 11/8 in ...the same. So I bought a used one for £17, apparently now if you buy new forks from Brompton dealers they have to fit them. Cheers again for the help!!

I’m also a bit inexperienced in the thread posting...apologies! #1 Hi all!....wondering if anybody knows what were the dates that Brompton changed there front fork specifications and what exactly were they esp regards Steerer tube,offset, fork blade length or anything else I know they went from 1” to 11/8” early on but at what date and whether there where any other changes of any consequence. My Brompton is an early one from 2005 with a stretched to 100mm fork for the Nano motor.... need to narrow it down now to possibly install a SWYTCH kit of 75 mm across drop outs. Presume it’s best to go with another set of original sized forks?Looking to buy them used if possible. Any help appreciated. Thanks T

Hi all!....wondering if anybody knows what were the dates that Brompton changed there front fork specifications and what exactly were they esp regards Steerer tube,offset, fork blade length or anything else I know they went from 1” to 11/8” early on but at what date and whether there where any other changes of any consequence. My Brompton is an early one from 2005 with a stretched to 100mm fork for the Nano motor.... need to narrow it down now to possibly install a SWYTCH kit of 75 mm across drop outs. Presume it’s best to go with another set of original sized forks?Looking to buy them used if possible. Any help appreciated. Thanks T

Also another typo E- Biking I mean

Yup your right Trex edit.

Yup your right tried-- 350 watt bpm seems to fill the credentials that I need but motor seems to heavy and too large a diameter for me esp for the front---- as I live in the centre of London however I can't take any chances regards the law and have to err on the correct side of the law to a fair degree---- damit! Phoned the whoosh site--- if I fit the kit as I wish to they won't honour to the warranty--- I've got a Brompton that I've just had professionally ( best course in my opinion as it folds)fitted, this one I wish to do myself as I consider is in the spirit of Pedelecs to at least attempt a kit built to show a commitment to e-king---just my opinion. Thanks for your link to BPM and their up and coming motors and maybe keen to order from there-- it may have been covered no doubt but what would the customs duty be to import a kit or motor or other parts currently? I do currently have a 250 watt motor fwc kit on order

Thanks for the latest reply Craiggor, Peter and Shannock it all helps---- encourages me to go for the 250 watt Front motor, I just have triple chainring derailleur gears, your Nuvinci and rohloffs far superior to my set up--was thinking of rear hub drive motor as well and not sure if 250 watt motor good enough but you all seem to think it's adequate so that helps----as its a MTB Tandem I'm converting with Alumimium Susp forks I'm thinking of putting torque arms on-- maybe you think they're not needed at 250 watt power?--- but if fitting them which is best the short ones that Cycleezee sell ( they probably sell the others too) where the end bolts onto the mudguard stay screw holes ( I have V brakes) to anchor it or the longer types that are strapped at their ends via jubilee clips to the fork legs to resist the torque plus what thickness plate and material ie stainless--- probably a kit comes with torque washers but fancy using one of these options as a back up --- usage wise just be riding trails at the roughest extreme. Thanks T.

Thanks to all those that took the time to reply and suspect I will go down the route you advise, interesting the tandem posted by flecc-- looked at some past posts and saw that members cwah and drsolly expressed some interest in these Xiondga kits in 2014 and was also hoping for their input.

Thanks for the prompt replies Flecc and Nealh--- suspect your right about the pawls but a shame as I was quite keen on it, difficult fix?, regards the weight of the bike and 2 people will a 250 watt motor be enough( Or best to spec up?)--- even from the regarded Bpm and Ezee obviously don't mind the peddling but sometimes I will be out on the tandem with my wife ( under 11 stone) and err not so keen.

Hi all, I'm trying to make up my mind which conversion kit what be suitable for a 21 speed derailleur MTB tandem (susp forks) approx weight both riders about 11-12 stone max. Was thinking of the Xiongda kit 250 watt 48 volt version, Panda bikes have these -- for reasons of small size/weight, legality( are tandems allowed more power?) Dual terrain settings for power and speed, I will be only trail riding off-road. Would prefer a rear drive, rack battery set up so not so obvious--- not keen on very large diameter 500 watt rear motors as it may attract too much attention. Does anybody have any idea of the long term reliability of these motors and whether they'll suit my purpose or should I stick to a more traditional set up. Thanks for any replies chaps.

Great to hear your getting good service all round from your Brompton and hopefully I expect the same. Thanks for posting!

Yes I think your absolutely correct, giving it assistance especially from standing start on hills and continued assistance after that--- luckily I dont mind pedalling only want the strain relieved at times like going to work at 5am--yawn.Thanks for the reassurance. T

Thanks a lot for answering my post and for the link--- It highlights the points I wanted to know about but I'm surprised as a lot of bikes must have this motor installed therefore I would have expected more complaints of unreliability on the site? Are there any other recent owners that are pleased with the good service they've had from these motors?

Fitted to a Brompton.

----------------------------------- Mmmm not good reading as I've just had the latest Nano kit fitted! Thought I'd done enough research but obviously not-- any chance of explaining where exactly the fragility is in the motor and any warning signs to take note of please.