Bionic Tandem Part 2

Our First Big Ride with the Heinzmann Pedelec Kit

Castell Dinas 2
The Black Mountains, photo thanks to the welldigger blog

Having got the ‘Direct Power’ kit working apart from the regenerative braking, and the installation more or less tidied it up, it was time for a proper test. In a week’s time we are riding the Way of the Roses coast to coast route with Cycle Sheffield, a five day trip, carrying our own luggage, across some very hilly country.

So we needed to assure ourselves that we and the bike were up to the task, especially as Isobel has not ridden further than a fairly easy 15 miles since she had her new knee less than 5 months ago.

Luckily our friends Jane Barnes and Rob Green, who run the excellent Bicycle Beano cycling holidays, had been asked to organise a one day ‘Lakes & Mountains’ ride as part of the Hay-on-Wye Bike Fest. As Isobel and I had first met on a Bicycle Beano holiday 30 years ago in that same area it seemed a perfect opportunity. In fact the small group on the ride were all Bicycle Beano regulars so it was a very nice social event as well as a beautiful ride with some big hills.

My aim for this ride was to work out how far we could ride on this sort of terrain with the electric kit and how to manage the setup for the best results. The main plan was to keep the power assist switched off except when we were climbing, so on the level and on small or gentle uphills we relied on our own efforts.

Heinzmann Display
Heinzmann Display screen sitting neatly under the Pino Riser Bar

The Direct Power kit provides a large display screen which shows you how much ‘Assist’ you have selected (1, 2 or 3 bars showing the three power levels) and how much ‘Battery’ charge you have left (up to 6 bars). It also shows your speed and distance travelled in Km but I was relying on our Garmin eTrex GPS unit for more precise information about our progress.

The eTrex not only recorded the route we had followed but acts as a trip computer, for this ride I set it to display the total distance covered in miles and the total amount of climbing we had done in metres. During the ride, as the battery indicator dropped down I was able to see what sort of distance and climb we had done for the battery power used.

The Route started out with a fairly easy undulating section from Hay to Talgarth where there was a great coffee stop at Talgarth Mill, a working Flour Mill and bakery with really excellent pastries, Jane reported the “best cheese scone I have ever had”. 

From Talgarth we started to climb and the little road just went up and up through a beautiful narrow valley, passing a nature reserve and a traditional telephone box converted into a tourist information centre. The weather was mixed with some nasty squalls of rain but as the day progressed it became drier and brighter so we felt we had done well to press on with the ride despite an unpromising forecast.

Once we started to climb I turned on the lowest level (one bar) of power assist. There’s a little control pad by my thumb with three buttons. The middle one turns the whole system on or off at the start and end of the ride. An up button increases the power and a down button reduces it. If the regenerative braking had been working there would be 7 different settings: three levels of power assist, neutral and three levels of drag brake.

Heinzmann Display & Control pad
The display screen and the three-button control pad, at the end of the handlebar under the rider’s thumb

The help was quite appreciable. It was easy to gauge how much assistance there was just by turning it off for a few seconds. We were able to maintain a higher speed than usual, in a higher gear, but also it felt more relaxed so I wasn’t breathing quite so hard or feeling so hot (I tend to get pretty hot). It was still good work and we were still breathing heavily when we paused for a break but there was never a point when it felt like a strain. There were a few short stretches which were steeper and I just gave it two bars for as long as it took.

In a group which included a couple of very fit cyclists, it felt like we could keep up pretty well, in fact we stopped a couple of times to wait for friends who were finding it harder work.

The toughest day on the Way of the Roses ride will have 942m of climb (and 34 miles) so as the battery level dropped down I was pleased to see that we were on target to complete over 1000m of climb on a full charge. Of course we were not carrying our luggage for 5 days and no doubt later in the ride we would need more help as our strength ebbed.

On the other hand we didn’t have the regenerative braking, and there were some lovely long downhills that would have been ideal for that. We also had around 2 hours of cafe and pub stops when it would have been possible to plug our battery in for a topup (the charger is light enough to carry). It takes 6 hours to charge the battery so two hours of cafe/pub breaks could add 30% to our battery capacity for a day. It’s tough work sitting around eating cakes but we are prepared to make that sacrifice.

In the end the ride was 35.7 miles and a total climb of 653m, with more than 1/3 of the charge left. At the point when the battery dropped to 50% charge we had climbed 538m so allowing for a bit of fatigue in the second half, 942m  climb and 34 miles on a single charge looks quite possible.

And we didn’t feel the kind of strain we might expect after a ride like that. Normally I would be not enjoying the last few miles and my muscles would be complaining a lot. We were both very tired but the last stretch felt no problem and if somebody had said “another 5 miles” it would have been OK. We were both tired and aching after the ride but we slept well and next day we both felt fine. This was particularly important for Isobel as some forms of exercise can leave her knee quite stiff and painful for several days.

The rest of the ride was more beautiful scenery, uphills and downhills and patches of sunshine. We had a good lunch by the log fire in the Castle Inn at Pengenffordd, rode down to Llangorse Lake where a fierce wind across the open water made it very wild and a huge number of swans were sheltering in the little dock area where summer visitors hire rowing boats and visit the replica of a Saxon Crannog. Then we pedalled back over the hills to Talgarth where the mill cafe was closed but the very enjoyable Strand Cafe gave us tea and home made cake under walls lined with bookshelves.

The last section was generally downhill so the battery wasn’t troubled and I gave the bike 3-bars of power as we rode into our campsite, whoosh!

So a Successful Trial. Today (Monday) I packed up the control unit and sent it off to Andreas Schroeer to have the regenerative braking switched on and we can start packing for our big adventure next week feeling confident that the Bionic Tandem is working (nearly) as well as we had hoped and seems to make a big ride manageable despite one of us being convalescent and both of us feeling our age. Thanks are due to Andreas Schroeer at Twike UK, to Joerg Heydt at Hase and Ruth and John at JD Tandems for helping us get the show on the road. Here’s the schedule for next week:

Monday 28 miles 431m climb (Morecambe to Austwick)
Tuesday 34 miles 942m climb (Austwick to Pateley Bridge)
Wednesday 47 miles 449m climb (Pateley Bridge to York)
Thursday 38 miles 360m climb (York to Hutton Cranswick)
Friday 24 miles 186m climb (Hutton Cranswick to Bridlington)

(some hardy souls are doing those last two legs as one on the Thursday, so that’s 62 miles and 542m but past experience says that on the fourth day you can get pretty tired)

Next post will be about the big test on our 5-day Way of the Roses Ride

PS. Having uploaded the route to Ride With GPS, the mapping software there says we climbed 873m, not 653. On the one hand that’s the same mapping software that says Tuesday’s ride is 942m so that could be a like with like comparison, and the eTrex was using barometric pressure which is a bit unreliable. On the other hand I’d rather stick with the more conservative number. We’ll see how it goes next week.

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6 Responses to “Bionic Tandem Part 2”

  1. Jeff Frost Says:

    Glad to hear it is working out well for you. We retrofitted a Bionx system on the wife’s Belinky viewpoint. Our experience has been, we made a mistake and should have purchased the larger system. We picked up one that is set for about 40km of assistance, and tends to top out at 28kph. That said it has been a big help. My wife rode last summer with both children ( one on a WeeHoo tag-a-long) and was able to zip around town including lots of hills…we live in a slightly hilly town. Last year we did a 300+km ride over 7 days that showed how well it helps.

    While no day’s ride ever exceeded 60km we always had enough power to complete the ride and she found it very comfortable. It made such a difference that she didn’t even notice that her bottom bracket was seizing up. The Bionx has 4 settings, level one offsets the having the extra 15 lbs on the bike and big drag created by the motor. Level 2 gives that lil boost of a weak tail wind, 3 will drain the battery a little quicker but smooths out slight slopes and 4 when fully charged give a big push up the hill.

    One really great aspect of the system is the regeneration settings functions as a excellent drag brake. That was the more important function to the regen, dropping into a long hill the regen can keep the bike from easily exceeding 50kph. That might seem counter intuitive to want to slow down, but having a 6 year old on the bike, you want more control than speed. Raising the saddle we made a made dash for home just my spouse and I, leaving the children to fend for themselves in a cottage with their grandparents.

    My wife was unable to leave until 4 pm on the Saturday, meaning our 170+ ride would have to be over 2 days. We managed to hit 86 kms finishing after twilight and averaging 31 kph with the assist. The motor is not really enough to help push two fat out of shape cyclists on a heavy frame up a steep hill, but it is enough to help keep us from toppling over because we are going so slow. The second days ride was not as easy, but we still kept the average speed in the mid 20’s.

    This year has seen a few rides, again adult with two kids, kid and parent, and two adults, and since having replaced the bottom bracket, it seems much easier to travel. It does help level out the hills, but has a negligible effect on average speed. We find it actually slows you down slightly on flats and down hills due to the increased resistance from the motor, it makes a significant help on the uphill, and also really helps in stop and go city riding. we are still young enough to see that we can ride as well without it, it just means much slower climbs on the hills, but is very helpful when riding with kids and lot of lugage.

  2. chrisrust Says:

    Hi Jeff, that’s very interesting. What’s the maximum power and speed allowed in Canada? In Britain we are restricted to 250watts and 25kph (15mph). For the UK, Bionx list their smaller 300WH battery as good for 80km and the 423WH Battery (a bit bigger than our Heinzmann at 400) at 105km. I was wondering if your lower range figure of 40km was because of higher power rating or a smaller battery. Obviously these figures are pretty meaningless in practice but they give a basis for comparison as each of us will use it differently.

    Also, when you say “big drag from the motor” how does that feel when you spin the wheel? With ours there’s a very slight drag, maybe like a brake making the tiniest contact but I wouldn’t call it “big”. But it’s all a matter of opinion. It would be interesting to put the two motors side by side.

    I was trying the tandem today, riding solo. With the maximum power setting on a level road and normal pedalling it would accelerate very rapidly up to 25 kph above which the motor cuts out anyway so it feels like there is not much case for us using the drive except uphill. If your regs allow a higher powered speed then it might make more sense to use it on the flat. Is yours a pedelec or a throttle?

    Of course having the motor in a 20″ wheel might be making quite a lot of difference for us on hills, as it’s effectively in a lower gear.

  3. gingerbeard Says:

    I’m not sure about the max power, i think it is 500W, but the max speed is somewhat varied. Federally it is 50 kph, in Ontario, our province, it is 32kph. As roads are provincially regulated every province is different, same with helmet requirements.

    We did go with the smaller battery and motor, a mistake, had we gone with the larger one we’d have more range and top out at 32, but I’m a bit of a weight weenie, and didn’t want too much extra weight. as for the drag, the wheel has a lot more resistance because of the motor, you may not notice because it is on the front wheel, but ours is on the drive train, so it is apparent, it is about 1-2 gears harder, like a very slight incline.

  4. chrisrust Says:

    We are getting a little drag. You can detect it if you spin the front wheel – it does about two turns and feels a little less free. On a level road we don’t seem to require more effort or a lower gear but I’ll keep an eye on that.

    So at present we are only using assist uphill. On the level we usually get above 25kph so it would not cut in anyway. Tomorrow is the start of the big test – how will it feel after a couple of days of fairly tough riding?

  5. gingerbeard Says:

    With my wife and I on the tandem, we can keep it up around 30 or more on the flats, even on slight inclines, but its different with the kids, so the battery gets used more, really it is one adult on a 50 lb tandem with a 40-70 passenger that might help.
    If you end up on this side of the pond you’re welcome to drop in for a visit and we can compare rigs and share a good long ride.

  6. Chandra Says:

    What a pretty picture! While I don’t know how hard it would be climb, I do appreciate the sense of adventure and simply how breathtaking the place is.

    Peace :)

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