Tandem bike---suitable E motor

[Torque]

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.

 

[flecc]

Tandems aren't allowed more power, they are restricted to the same 250 watt rating. For reliability with good power and climb ability I think a BPM-CST or eZee motor would be a good choice. Neither are particularly large diameter and eZee have a choice of battery systems with rear racks to suit.
.

 

[Nealh]

If you want legal then 250w on any bike.
Xiongda is reported as having very good torque and speed but reliability has proven to be a bit of an Achilles heel with the clutch pawls failing I believe.Two other options are a BBS or a Q128 48v in 500 or 800w but the same size as a Xiongda

 

[Alan Quay]

Tandems aren't allowed more power, they are restricted to the same 250 watt rating. For reliability with good power and climb ability I think a BPM-CST or eZee motor would be a good choice. Neither are particularly large diameter and eZee have a choice of battery systems with rear racks to suit.
.

Second that. I have a CST and use it to tow my son on his bike, so pretty much an articulated tandem. Together, I estimate our combined weight at 22 stone.

It still pulls like a tractor. (Here in the West Country that's a good thing!)

 

[Torque]

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.

 

[flecc]

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.

These two are substantially more powerful than the average 250 wat hub motors, and their additional torque is very noticeable. The only ways of coping better or differently are either an illegal hub motor or a legal crank motor. The latter would allow slower increased climb ability through the motor's use of the gears.

BikeTec use a front crank Panasonic motor on their Flyer tandem, though a kit one could equally be in the rear BB:

 

[Torque]

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.

 

[craiggor]

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.

Mine still going 1464 miles in 10 months.Don't know the exact problem with the freewheel clutch or if they have sorted yet.It does not wear out,it seems to stick and if you roll it backwards it makes a clicking sound.I think to many clicks and you can break the plastic gear or the metal gear bousing.If I hear one click I roll forward an inch and it rolls back.I dont think i have read a post saying mine doesn't stick. There is grease on it,i have herd of a thing called grease slap this may be the cause of the noise.I went for it because it is cheap.I have big hills to get up with shopping. Flat and less hilly roads and I don't use the low gear.loads of threads on here and endless sphere.Fantastic service and spares direct from the factory in China.I think it was said somewhere that they had changed the plastic in the gears.Don't know about the few that have Burnt the motors,overvolting ? I have no experience of the alternatives.

 

[Peter_Tandem]

Hi
Last year I converted my tandem to electric to make life easy on the hill. The 250W motor is fine. We are both around the 10 stone mark, and the motor pulls us comfortably up steep inclines with a bit of assistance. The bike isn't particularly light either with loaded panniers, battery etc.
I bought a front wheel conversion kit, and have the battery mounted behind. I have an nuvinci n360 gearbox on the rear hub, so had no option but for a front wheel conversion. Be prepared to solder cables together for extra length since standard cables are too short. We don't have pedal assist, and only use the throttle for the hills (or when feeling lazy). The electric motor makes starts particularly easy since you no longer have to synchronise pedals to pull away which makes cycling in traffic a breeze.
For a whole day cycling in the breacon Beacons, or up in the Cotswolds I still haven't run the battery totally flat yet.
Would definitely recommend.

 

[Shannock]

Hi, We have a tandem equipped with Rohloff rear gears. Use an Ezee 250w 14amp carrier battery, front wheel drive.You can easily covert to 350w power,
( up from Hay on Wye on the Longtown road pedelling as well). We cycle tour in France pulling a Yak Bob trailer and its great for assistance.
Suggest you speak to John at Milton Keynes, he advertises here

 

[Torque]

Hi, We have a tandem equipped with Rohloff rear gears. Use an Ezee 250w 14amp carrier battery, front wheel drive.You can easily covert to 350w power,
( up from Hay on Wye on the Longtown road pedelling as well). We cycle tour in France pulling a Yak Bob trailer and its great for assistance.
Suggest you speak to John at Milton Keynes, he advertises here

 

[Torque]

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.

 

[trex]

you have to fit torque arms with front BPM 350W or Ezee motor. These geared hub motors have immense torque that can wreck your fork on starting up when fitted without torque arms.
This is one fitted with woosh BPM front kit:

 

[Torque]

you have to fit torque arms with front BPM 350W or Ezee motor. These geared hub motors have immense torque that can wreck your fork on starting up when fitted without torque arms.
This is one fitted with woosh BPM front kit:

 

[Torque]

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

 

[Torque]

Yup your right Trex edit.

 

[Torque]

Yup your right Trex edit.

Also another typo E- Biking I mean