DubT

For several years I have been fascinated by electric motors for tandems. I recently saw a Calfee that had a Bionx system installed at the factory.

I sent an email to Calfee and received a response from Rob Baird, he actually built that bike and has also installed electric motors on his own bike plus his fathers and others. Craig is a big support of electric drive.

He leans more towards Mid Drive motors rather than hub motors. After his explanation and encouragement I was hooked. Per his instructions and with his complete support I ordered the Bafang BBSHD kit from Luna Cycles.

The kit was a complete bolt on with the exception of having to carefully remove a little material from the center/bottom of the rear bottom bracket.

We are extremely happy with the results. We go further and faster than ever before and do not have any concerns about which way the wind is blowing. We can go out with the wind and come back into it with no problems.

Does the motor defeat the whole purpose of riding, NO, it is a major enhancement! We still get a great work out.

The motor can produce up to 1500 watts and has 9 levels of assist, we usually run on level 2. The system we have is a PAS (Pedal Assist System) and does require that you pedal, it does have a throttle that allows an immediate power increase if needed.

Pictures upon request. They are now difficult for me to post.

Ludkeh

We're going on our third year with a motorized DaVinci tandem and WE LOVE IT! I purchased a front hub kit consisting of a 500 watt free wheeling front hub motor and a 48 volt lithium Ion battery that stores at the front down tube bottle location. The controller and wiring are stored in a front handlebar bag. The motor is controlled by a handlebar throttle and I have a cruise control button if I choose to use it. The motor has three speeds, low gives me 12 mph, Medium around 18 mph and high around 22 mph.

My wife and I are both 69. I've been a life long cyclist, but my wife hasn't been, she was an occasional recreational rider. Over the years, our riding dynamics on a tandem were becoming less enjoyable for me. On longer rides, as she tired, I was working harder and harder! Terrain that was easy riding on the outward loop became exceedingly difficult on the return leg. We still wanted to ride the tandem, but I was enjoying it less and less. Sooo I started looking for a solution.

I decided to give the electric motor a try. What did I have to loose, I could return the bike to it's original condition in less than 15 minutes. The only loss would be to my wallet so it was worth the risk.

So how has it been working for you? It's made riding fun again!! We usually ride with the motor on the low setting (12 mph). I can use the motor as little or as much as I choose. On the flats, we ride as we always did, going thru the gears ect. ( Central New York is very hilly) When we encounter rollers I just goose the motor and it helps us over the top. If we're peddling faster then the motors top speed setting the hub is just free wheeling. Long uphills, I set the motor on cruise control and we gear down to be able to contribute as much as possible to the motors efforts. The more we contribute the less the motor strains and the greater our range. Steep hills that we previously had to try and go around, we now go over.

In town, the motor works great at stop lights and such, where I've got one leg down waiting for the light to change. Light turns green,we start as usual, I goose the throttle and we've off, clip back in and we're cruising. No drama, and much safer! Did I tell you that we love riding our tandem again?

This past weekend we were out riding and got caught in a rain storm. From what we could see it was going to get worse, not better and we were still 5 miles from home. I set the hub motor in it's high setting and we started buggying home at 22-23 mph peddling for all we're worth. We got home QUICKLY before the heavy rains set in.

So what are the negatives and our limitations? First the kit cost around $1200 with shipping. It adds 15 lbs to an already heavy bike. (500 watts easily compensates) I haven't tested or come close to the limits of the battery yet. Range is based on how much I use the throttle, and which speed setting I'm using. But from experience and monitoring Watt Hour usage I suspect we could go around 25 miles using only the motor and not peddling at all. Probably 35-40 miles with the motor set on low and us peddling like we always do. Recharge time is usually 2-3 hours.

Last year I had a severe health crisis. This time last year I was in a wheel chair and wondering if I would or could ever get back on a bike. I'm slowly recovering and life looks good again. If it weren't for the electric motor on our tandem it would be sitting in our garage collection dust! But we're out enjoying life. Purists will scoff, but if it gets us back riding again and enjoying ourselves what more can one ask for!

Regards

waynesulak

What brand of system are you using?

Ludkeh

I purchased the kit from EM3ev.com. If you follow the electric bike forum Endless-sphere.com, you'll find that EM3ev is a well established dealer and well regarded. They give you a wide range of options. You can essentially build a custom ebike to meet your needs and get as fancy as you please. Me setup is relatively simple.

My focus was not on speed but instead torque. Therefore I picked the Mac motor with 12T winding and a higher power controller. I added two front fork torque arms which are essential, especially for a heavy tandem. I purchased the ebrake setup but never installed it. Realized after the fact that I didn't want to mess up my Campagnolo Record shifters. I've also have front and rear disk brakes that have incredible stopping power and didn't want to screw that up!

Hope that helps and have fun with you research.

Regards

DubT

You asked how is it working out for you.

We have had the system on for a week and absolutely love it! It is hard to describe how much we enjoy the experience, we have always enjoyed riding tandem but this truly enhances the experience.

I wanted speed and power which is what we have, our average speed has gone up 4-5 mph and going into the wind is no longer an issue. We used to ride low gears and spin into the wind so that we did not wear out, now we go where we want to go with out regard to wind direction. It is like we always have a tailwind. We would always ride harder with a tailwind and that is what we are experiencing. I asked my stoker her opinion on our ride yesterday, on a scale of 1-10 with 10 being the best, she thought a minute and said, there is nothing she does not like so she gave it a 10.

Ludkeh

TOTALLY AGREE! Completely transformed our riding experience. Like you, I had my bike set up with very low gearing so that we could grind thru the wind or up hills. Always making sure that we would not bonk before we got home. No longer! And yes, it feels like we have a perpetual tail wind!

Enjoy

zonatandem

We've been long time tandemistas (42+ years) and are now on tandem #5 that currently is nearing the 50,000 mile mark


We are now ages 84 and 82 . . . and yes, we still ride regularly. Not as fast, not as far and no longer 6 days a week.
But we still enjoy riding TWOgether and without a power assist.
We live near Tucson and, yes, there are elevation changes (from hills to 8,000+ ft mountain climbs). We no longer do the hard stuff; we still have fun and stay fit.
A power assist system is a definite advantage. Have seen a local bent tandem using the Bionix system on uphills. and yes, they passed us . . . but we caught them on the downhill!
Pedal on!
Rudy and Kay/zonatandem

twocicle

Now you can go set some local Strava KOMs

DubT

We already have something like 20 without the motor.

Dean V

But now you can start getting the uphill ones .

Artmo 

During our annual, 3-4 month visits to the UK we have found it increasingly difficult to climb the hills on our T2000, even with 24X32 gearing, so this year we decided to buy a Circe Helios STEPS from Cyclecentric, near Cambridge, UK. We have had the bike about 3 weeks and done about 120 miles. Our experience has been very similar to those described above - simply amazing! It is powered by the Shimano STEPS-assist, with three assist levels. In Europe, the max speed is 15.5 mph with 250W before it is classed as a motor vehicle requiring a license, but we have not found this limit to be a problem. The range on the ECO setting is about 58 miles, which comes down to nearer 30 if HIGH is used continuously. The tandem can be separated and packed into two cases.

twocicle

I don't recall seeing you previously mention going to same side drive. Did you do SSD for this motor install and also change out the captain cranks to what? What sort of gearing did you opt for?

https://lunacycle.com/bafang-bbshd-1000w-mid-drive-kit/

"
Regarding the BBSHD and Legal Street Use

"Our drives come programmed for 750w. You can choose to have us program it with our hot rod settings if its for off road use on private property such as for a hunting vehicle or pit bike.
This drive is capable of 1500 watts in the right power settings.
If you do choose 1500 watt model, we suggest you also buy a programming cable so that you can change the firmware back to make it legal for street use."

Have you messed with programming yet?

DubT

I worked extremely closely with Rob Baird at Calfee and SSD was a solution to a problem. I am using simple fixie cranks front and rear. If I used a standard crank on the LH side of the motor the crank arm would hit the motor. So his recommendation was to go with 2 fixie cranks, one up front and one at the rear. It works perfect. I did have to back to the chain as there is about 10 mm of misalignment. The rear Q factor is wider than before.

I bought the Hot Rod off road only package, it was preprogrammed for up to 1500 watts.

I bought the nice Luna Eclipse chainring with 48 teeth, the rear cassette is an 11-28 Ten speed, I am running 1X10 with absolutely "0" issues. The bike will easily go 30+ MPH at level 2 of 9 settings.

After our ride today, another windy day on the prairie, I asked my stoker if she would want to go back to riding without the motor and she did not even have to think about her answer "NO", that just about says it all.

We still get a good work out but the wind is no longer a factor and the few hills that we have are a non issue.

DubT

Since the 14th of July we have ridden our tandem with the PAS over 600 miles and can say that we are extremely happy with the conversion.

I at one time considered myself a "purists" and would not consider a motor assist but even ex crit racers can change.

We no longer are concerned about the wind direction, I ask my stoker where she wants to go and that is where we go, no longer do we have to take wind direction into account. It makes riding much more enjoyable for us. We live in Illinois on the prairie and have plenty of wind.

Our conversion is not governed, we are not limited to a 20mph max speed, in fact we will now typically average 19/20 mph. Our longest ride has been 50 miles and it was very windy coming home so I set the assist level at 4 (I normally run at level 2) by the time we arrived home the battery was down to the 10 percent level. I had to drop down to level 1 for the last few miles.

1tandem

Were you able to install right sync crank onto the Bafang unit without modifying the crank or the 48 tooth chain ring?
What size sync rings are you using?

JM

DubT

The Bafang unit came with a 46 tooth steel chainring, I upgraded to the Luna Eclipse and the crank with the sync chain ring fits perfectly on the inside of the spider. I am using 40 tooth sync rings. I do however have a Phil Wood bottom bracket on order that will allow me to go back to belt drive on the RH side.

twocicle

I'm waiting for the photos in lieu of reading a 1000 words. After 50 or so my OCD kicks in and then

DubT

I have lots of pictures but with the policy change at photobucket I could not post them. I just found a new way to post pictures and will work on getting some posted.

DubT

Pictures:

twocicle

Ah, didn't realize you had gone with a 1x setup for this. Obviously you have a lot of torque now. Should be interesting to see how that holds up for whatever hills you eventually do on this rig.

The stoker crank/spider shape is an interesting solution to spanning the drive ring's mounting bolts.

Here's my inevitable question (and I do understand it has no bearing for your setup needs)... what is the stoker's Q-factor here?

DubT

The rear "Q" factor is wide, it is right at 195mm.

Hills are on problem, we don't have any big hills here on the prairie but we do have some that I have had to shift from the big ring tot he middle ring and use the 39/30 to climb. With the motor we still have to work but the speed is much higher and I have the option of applying the throttle or increasing the boost level, we normally run at level 2 and i recently boosted it up to a 4 for one particular hill, stoker was not happy with the speed at the crest. We have up to 1500 watts of power at our disposal. Hills and wind are no longer an issue.

twocicle

Well, full on 1500 watts (motor) plus whatever your bodies add, will be as much as a pro level sprinter in full hammer mode. Since you now only have a single big drive chain ring, you have lost mechanical advantage in lieu of riding essentially in the big ring full time. That puts a ton of torque load on your drivetrain which was the point I raised. I would anticipate your drive chain, cogs and freehub not lasting long if not outright shredding engagement splines on rear hubs not designed for e-bike torque.

Sure right now you have almost no hills, but should you ever want to venture elsewhere... you are kind of stuck within the range limits of this setup. These are important system limitations for others on this Forum to be aware of. Caveat emptor.

DubT

Chains cogs and cassette bodies can take a beating, using the gear sensor to momentarily turn off the motor and pausing between shifts (soft shifting) especially from a big cog to a small cog is supposed to help drive train life. I have been monitoring it very closely and so far at 750 miles everything looks great. I do carry a spare chain.

As far as gearing goes, Rob suggested an 11/40 cassette with a mountain bike RD, so far we do not need lower gears. We were spinning out in the original 46/12 so I am now running a 48/11 and that is enough gear for us. If we were to ride in hillier areas I could go with the 11/40 cassette and a 42 tooth chain ring.

We ride in Illinois, Indiana, Oklahoma and Florida and so far I am not aware of anyplace there that will require a gear change.

As for components not being designed for an ebike, they are not designed for tandems, yet they seem to hold up very well for some pretty good size teams.

Time will tell on the components. I am certainly not concerned, when they wear out I will replace them.

pdlpsher

Is the air horn for dogs or to warn other cyclists that a freight train is coming, or both

DubT

Both, but primarily for runners and dog walkers who wear headphones on a bike trail that we ride to get out of town. I have a bell and if that gets their attention then great but if not then stoker sounds the air horn, it gets their attention.

She will also use it when a car appears to be getting ready to pull out in front of us.