Tandem

[geejay]

Any suggestions for a suitable kit for a tandem.
It must be: reliable, good after sales service, light, effective on hills, fitted with pedelec sensor, will accept existing disc brakes.

I mainly want it to provide a bit extra on the bigger hills, but not so heavy that it defeats the object on lesser gradients or the flat. We have 27 gears and I don't see any point in one which reduces 3 chainwheels to one.

Any ideas gratefully received up to about £2k.

 

[peerjay56]

Cytronex do a conversion for tandem, but price is on application!.
Alien Ocean feature a tandem conversion on their website about halfway down the page. No idea which kit was used, but I'm sure they would tell you.
All up weight is usually an issue depending on the motor/controller utilised, but maybe that is mitigated by two people supplying power as opposed to one?
Good luck whatever you choose to do.

 

[banbury frank]

Hi our Baby kit will do the job see the link below price with 48 volt 20aH battery £1395 we offer a fitting service for £200


Commuter Baby

We have a demo bike in banbury please come for a test ride we are open 7 days a week

Frank

 

[Deleted member 4366]

You haven't really given us enough to narrow down a choice. All the kits do what you want. You should have a word with Cyclezee because he has the largest range of kits with lots of different battery installation options. Ezee kits have high torque, which might suit the weight of a tandem better.

 

[geejay]

Thanks for the replies.

I thought I had given quite a bit of information: I ruled out hub conversions as they do away with 2 chainwheels; I said light and some are certainly not light; I said I wanted to use it on hills and some are not suitable for very hilly terrain and I don't want to use it on the flat or more gentle slopes - I'm thinking of the kind of hills we get up here in Scotland or Yorkshire. Finally, reliable and good after sales. I realise that's very subjective, but like Trip Advisor, it can be useful to read other's opinions based on actual experience.

My initial preference was for the BionX but I've read some bad reviews online. However, their European agent says they are aware of their shortcomings and things are improving.

Anyway, thanks for your thoughts - I'll do more research.

 

[Deleted member 4366]

This causes me to worry a bit. What inspired you to think about the Bionx kit? It doesn't fit with the criteria you stated.

 

[geejay]

This causes me to worry a bit. What inspired you to think about the Bionx kit? It doesn't fit with the criteria you stated.

That's why I posted on here - to get the views of people who know more about it than me. Reading their website the Bionx seems to fit quite a few of the criteria - it's a reasonable weight, adequate power, good mileage, cuts in when needed, I can get it built into a tandem specific wheel. However, it has had some mixed reviews. Am I missing something?

I've also looked at Cyclezee which looks impressive.

 

[Deleted member 4366]

Everything is relative. The Bionx is relatively heavy compared with what a lot of people on this forum have; it's direct drive, so doesn't free-wheel as well as a geared motor with a clutch; and it's not a particularly good hill-climber, however, there's different versions of it, all of which are relatively sophisticated and expensive, but the main difference is the power.

Different people have different criteria, and, for some, sophistication and expensiveness are important, while as others are only interested in something that does the job. This is what I was trying to explore, so perhaps you could clarify. Are you going to fit the kit yourself or do you want the kit supplier to do it?

 

[geejay]

Thanks, I see what you mean about the Bionx. I want something that works, is reliable and will help on the hills (where tandems aren't so good) and will cope with the kind of rides we do of between 30 and 50 miles or so and maybe 2.5k - 4k feet ascent. I'm not interested in sophistication, and therefore expense, for its own sake. I can fit the kit myself, assuming it doesn't need any specialist tools or knowledge.

 

[Deleted member 4366]

It sounds like the Ezee kit will be a good choice if you want UK support and plug-and-play. If you don't nind a bit more DIY, you can buy the stuff from China and save a lot of money. The money you save covers anything that goes wrong, but it's rare that anything ever does.

Another question is how legal you want it to be, bearing in mind that hardly any ebikes in the UK are strictly legal? There's a 40kg weight limit in the regulations. Do you know the weight of your tandem? Can we see photos to judge the best type of motor?

 

[geejay]

I think it must weigh about 40lbs.

 

[RobF]

The Cytronex link refers to a front wheel conversion.

I would caution against this, braking forces at the front of a tandem are much higher than an ordinary bicycle.

The forks and headtube should be stronger to reflect this, but I wouldn't take the front end of a tandem away from standard.

Also keep an eye on all-up weight - tandems tend to run closer to the maximum safe payload which means there's not as much wiggle room as there is with an ordinary bike.

 

[geejay]

Thanks for your comment. I take your points about the front wheel and weight. I believe the Ezee can be fitted to the rear wheel.

 

[RobF]

You are clearly an experienced tandem rider and will know better than me, but I understand the main risk to the front end is braking down hill.

This risk can be reduced by using more of a rear wheel braking bias than you would on an ordinary bike.

Your tandem also looks like a good one - you can draw on that extra quality for the conversion project.

All hub conversions put extra strain on spokes.

Thicker ones will deal with that.

Ezee are well thought of on here, so they should provide you with sensible advice.

 

[geejay]

At least with a tandem there's little danger of applying the front brake and going over the handlebars, but yes, I do use the rear brake more to adjust speed on downhills and use the front in combination with the back when I need extra braking.

Wheel strength is a concern and I'll follow that up the dealer when I decide to go ahead.

Thanks for your comments.

 

[Deleted member 4366]

You need to measure the distance between the front drop-outs. The forks look a bit narrower than the standard 100mm. Also, the tapering inwards might be a problem for motor clearance. I think a rear motor will be a better solution anyway. The problem with rear motors is that most use crappy free-wheel gears that will mess up your nice bike a bit. There's various options for expensive motors with cassette splines. Cyclezee have a couple of options, but not Ezee kits (AFAIK). Frank has a Xipi kit also that has a cassette motor. If you want to save a lot of money, you can get very nice cassette motor kits from MXUS. You have to e-mail them direct and ask for a kit with the MX01A motor, or buy direct from Xofo, or you can get the Bafang CST kits from BMSBattery.com. If you take these options, you have to do some extra things like dishing the wheel to get the rim in the middle of your frame. The complete kits with battery should be £500 to £600. Also, bear in mind that cable lengths might not be right depending on where you want the motor, throttle, battery and controller.

I think you should check out all the options, then plan out what battery you want and how you're going to install it. You'll need a high torque motor capable of running with 20 amps or more, which means a high discharge battery able to provide that current.

 

[geejay]

Lots to think about here. Many thanks.

 

[los monty]

Just came across this page and it appears you can go to 60kg on a tandem or tricycle.

https://www.gov.uk/electric-bike-rules

 

[ElectricBikeConversions]

We recently fitted a front hub Cyclotricity kit to a tandem (different model than yours but the principles are the same). The fact that it was front drive didn’t cause any real issues and the customer hasn’t reported any problems associated with this.

The main thing that I wanted to point out is that most kits, the Cyclotricity one included, are designed for standard bikes and the cable lengths are measured to suit. Hence it takes a fair bit of planning to make sure that you can run all the cables from the battery, handlebars, motor, PAS sensor etc to the controller. You have to find a position for the controller such that all of the cables will reach. We just about managed to find a suitable position on the underside of the frame and the only non-standard thing that we had to do was to make a new extended battery cable. Otherwise you’re in to making new cables for the components which is more of a fiddle.

I would have posted a few photos but stupidly forgot to take any before handing the bike back to the customer…..

 

[Cyclezee]

You need to measure the distance between the front drop-outs. The forks look a bit narrower than the standard 100mm. Also, the tapering inwards might be a problem for motor clearance. I think a rear motor will be a better solution anyway. The problem with rear motors is that most use crappy free-wheel gears that will mess up your nice bike a bit. There's various options for expensive motors with cassette splines. Cyclezee have a couple of options, but not Ezee kits (AFAIK). Frank has a Xipi kit also that has a cassette motor. If you want to save a lot of money, you can get very nice cassette motor kits from MXUS. You have to e-mail them direct and ask for a kit with the MX01A motor, or buy direct from Xofo, or you can get the Bafang CST kits from BMSBattery.com. If you take these options, you have to do some extra things like dishing the wheel to get the rim in the middle of your frame. The complete kits with battery should be £500 to £600. Also, bear in mind that cable lengths might not be right depending on where you want the motor, throttle, battery and controller.

I think you should check out all the options, then plan out what battery you want and how you're going to install it. You'll need a high torque motor capable of running with 20 amps or more, which means a high discharge battery able to provide that current.

Cyclezee have converted several tandems with front or rear eZee motor wheel kits, the DNP or Sunrace Freewheels that we also supply for rear motor wheels are good quality with no reported failures.

We also have available front or rear Ansmann and Heinzmann kits, their rear kits both accept cassettes, Falco rear kits and the 8Fun BBS-01 centre or crank drive.