My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar

Show off your E-bike creation here.
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Re: My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar

Post by philf » Jul 20 2018 7:26am

Well, Justin, I hope you guys aren't feeling any disappointment for not having made your (geographical) goal. Time is everybody's enemy - but considering that even the design of your vehicle was just an idea in your mind just a few months ago, and all that has gone into getting to this point, I think you should be really pleased. That last few hundred kilometers doesn't really mean much in the overall context of this feat.

And you guys haven't killed each other. There is that :-). (I imagined an inner dialogue within An-So's head, were the trike to keep breaking down. "Who the @#*! designed this thing? Oh.")

So, CONGRATULATIONS, I say!

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Re: My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar

Post by wturber » Jul 20 2018 10:13am

I got up this morning to check Google Earth as I've been doing for a few weeks now. The little icon hadn't moved. Oh no. Read the post and thought, "bummer."

But, of course, Philf has it right. Even though you didn't quite make your final goal, the trip was obviously wildly successful. As they say, it isn't the destination, its the journey. And that's a simple truth, not a tired cliche.
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Iron Horse 3.0 hardtail - 48V / 1000W / 470rpm generic Chinese DD Hub motor (ebay)
8 x 36v 4.3ah 10s 2P battery packs - 1500W 30A DC Boost Converter delivers 54v and about 1000 watts peak
53T/42T Sakae Road cranks - 30mph+ on flats
viewtopic.php?f=2&t=90369

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Re: My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar

Post by Perfesser » Jul 20 2018 11:52am

Congratulations you guys !

I've been lurking, watching your great success.
In a few weeks, I should be back in Vancouver .
I'm looking forward to being home & seeing you again.

Hugs all around.
-Karl
Modified KMX chassis, 7 speed, oversized chain ring, 48V 8AH Ni-Cad pack, 404 Crystalyte motor on a 20" wheel, Cycle-Analyst.
65 Kph is rather thrilling when your buttocks are 3 inches off the ground.

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Re: My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar

Post by Warren » Jul 20 2018 3:26pm

What an experience. You two will have amazing memories of your "honeymoon."

Looking forward to more stories and pix.

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Re: My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar

Post by wturber » Jul 20 2018 3:39pm

Warren wrote:
Jul 20 2018 3:26pm
What an experience. You two will have amazing memories of your "honeymoon."
I think all couples should do that before getting married. It's a good way to test a relationship.

... and I'm only half-joking. :^)
"Commuter - DC Booster"
Iron Horse 3.0 hardtail - 48V / 1000W / 470rpm generic Chinese DD Hub motor (ebay)
8 x 36v 4.3ah 10s 2P battery packs - 1500W 30A DC Boost Converter delivers 54v and about 1000 watts peak
53T/42T Sakae Road cranks - 30mph+ on flats
viewtopic.php?f=2&t=90369

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Tehran

Post by justin_le » Jul 23 2018 5:12pm

Yehoo! We managed after all to get a postponed flight and so have had a few days to actually chill out and do touristy stuff for a nice change while we're here in Tehran.
Tourists.jpg
It also gave us a chance to ride around this massive city on the trike for a bit and do one last photo-op and media interview. We kept doing circles and circles around the Azadi tower while they followed us in cars and motorcycles filming to the point of dizzyness. Here's the last selfie photo of total friendly strangers with the trike
AzadiFinalSelfie.jpg
And at some point today or tomorrow we'll be on Iranian TV.
FinalMediaInterview.jpg
While we saw some number of bicycles in smaller towns on the way here, inside Tehran there hasn't been any. The expressions we've heard several times is that everyone think's they're Michael Shumacher on the road, more on a fluid racetrack than a city with intersections and traffic controls, and most people said it'd be suicide to ride I bike. But after this trip I felt oddly comfortable riding like that too.

We were really fortunate to have been hooked up with a small collection of people operating from a research institute who are attempting to do ebike and electric vehicle development work inside Iran. It's not an easy country logistically and politically to work from doing tech development like this. Plus the actual market situation is far from ideal with cheap gas, a depressed economy, and very little actual bike culture to launch from. But it's also the kind of place that could benefit so much from adopting ebikes in terms of pollution and congestion levels, and so I really admire the efforts here and wish them the best success.
IranTrikeExplain.jpg
Workshop Gathering.jpg

Inside, you can see some of the collection of ebikes and scooters that they have built and prototyped over the years. The yellow sports car in the back was a student project that they made 10 years ago as part of an electric car competition that was held in Italy, and it was still in running condition. Probably more relevant to them though is the electric motorcycle that I'm sitting on here.
TehranWorkshop.jpg

While there isn't much of a bicycle culture, there is a huge contingent of gas 2 wheelers on the road so that is something that could see more immediate adoption. This prototype was built using a cluster of series/paralleled ebike batteries to provide a 72V nominal ~40Ah battery pack, running a 5kW motor. They have a 2nd one similar to this that is currently being field tested by one of the many motorcycle based delivery companies here.
IranMotorcycle.jpg

It rides really well and I'm hoping they can materialize it into a production item. This is a project that is partly the brainchild of Ali, the owner of a conversion kit shop in Canada (https://ebikebc.com/) who helped connect us to this group.
philf wrote:
Jul 20 2018 7:26am
Well, Justin, I hope you guys aren't feeling any disappointment for not having made your (geographical) goal.
Ha, there was like 2 minutes of that, and then it turned into pure elation when we realized we could be done and didn't actually have to keep riding until 4am with just 50 watts of assist! The trip for us had always been more about the adventure/touring side and experiencing the viability of solar bikes for that, rather than hitting a specific distance target. I mean it was fun to have daily goals and see where we were at vis-a-vis other suntrip racers, but that was never the reason we set out.

So, CONGRATULATIONS, I say!
Thank you, and to everyone else too who had been giving us good wishes right to the end. Both the solar trike and our relationship stayed largely in tact through all the ordeals, and the future for solar charged ebike touring is pretty bright.
Previously competed in the Suntrip race on a back to back tandem solar powered row/cycle trike. 550 watt solar roof, dual Grin All Axle hub motors, dual Phaserunner controllers, 12 LiGo batteries, and a whole wack of gear.

Now back in Vancouver learning to be a dad with my Big Dummy Frame (yes This One, thanks ES!) with GMAC 10T rear hub motor, Phaserunner controller, and 52V 19Ah EM3EV pack
My website: http://www.ebikes.ca
Please contact via email, info@ebikes.ca, rather than PMs, which are disabled

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Re: My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar

Post by tomjasz » Jul 23 2018 11:34pm

Go Canada! Best vicarious trip in years! Thanks.
Thanks Justin_le we're here thanks to you. All the best to the mods for their tireless work keeping it on an even keel.

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Re: My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar

Post by panurge » Jul 25 2018 5:43am

Hey Justin

What a fantastic trip! Sure an epic personal experience other than technical for you and Anne-Sophie.

Sadly I was not in Italy when you experienced the fantastic "ai pioppi" restaurant-park, I know Bruno and his works and would have been perfect to meet you again and re-visit "ai pioppi" at the same time.

Would like to set-up a vehicle for one of the next edition...maybe the 2019 alpine ring....

Thanks for sharing your tech and life experiences about solar biking, I'm sure this solar trip edition will be a milestone for the community.
JulesL.


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Re: My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar

Post by Michel » Jul 26 2018 12:28am

the snow missed you I presume. Thanks for sharing so much about your trip.

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Re: My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar

Post by Miles » Jul 29 2018 4:40am

Awesome adventure Justin! Thanks for sharing the experience, all the way from conception.

Can't wait to see your hybrid rowing boat! Rowing generator; pedals; batteries; solar panelled roof/sail; propellor............ 8)

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Re: My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar

Post by StuRat » Jul 29 2018 5:37am

Well done you two.

Inspiring.

In so many ways.

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Re: My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar

Post by justin_le » Jul 29 2018 5:02pm

panurge wrote:
Jul 25 2018 5:43am
Hey Justin

What a fantastic trip! Sure an epic personal experience other than technical for you and Anne-Sophie.
Sadly I was not in Italy when you experienced the fantastic "ai pioppi" restaurant-park, I know Bruno and his works and would have been perfect to meet you again and re-visit "ai pioppi" at the same time.
That indeed would have been so fun. Me and AnSo were talking about trying to connect with you while going through Italy but assumed you were much further south. Bruno was such an amazing character and it's nice to see that he's been widely appreciated too. We have some good video footage of the visit and now that we're back in Canada it should be faster to get these edited and live for others to see.

Anyways I'm back in Canada now, recovering from jetleg, the entire body is still a little stiff from all that exercise and inadequate stretching. Gained 3 pounds compared to when we left, which I'm hoping is mostly muscle weight :-)
Miles wrote:
Jul 29 2018 4:40am
Can't wait to see your hybrid rowing boat! Rowing generator; pedals; batteries; solar panelled roof/sail; propellor............
You sure know what's coming next on my project list Miles! Before that though, for our upcoming wedding in 2 weeks, I'm thinking of building the worlds most inefficient electric boat. Imagine a wood-burning hottub, floating in the ocean, with a couple peltier devices between the furnace and the cold ocean water to power a small electric propeller and scoot around the bay at 1-2 knots :D

For any Farsi speakers, we finally got a link to the final interview piece inside Tehran from just before we wrapped things up and disassembled the trike:

and there is a fair bit of the raw footage available from the Associated Press site:
http://www.aparchive.com/metadata/MEEX- ... b94fd5d34f
Previously competed in the Suntrip race on a back to back tandem solar powered row/cycle trike. 550 watt solar roof, dual Grin All Axle hub motors, dual Phaserunner controllers, 12 LiGo batteries, and a whole wack of gear.

Now back in Vancouver learning to be a dad with my Big Dummy Frame (yes This One, thanks ES!) with GMAC 10T rear hub motor, Phaserunner controller, and 52V 19Ah EM3EV pack
My website: http://www.ebikes.ca
Please contact via email, info@ebikes.ca, rather than PMs, which are disabled

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Re: My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar

Post by maitilupas » Jul 29 2018 5:26pm

really nice , and now your famous in Iran!

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Re: My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar

Post by fechter » Jul 29 2018 6:51pm

Can't wait to see the wood powered boat.

So what are you going to do with the solar trike now? It should probably go in the ebike museum somewhere. But it takes up a lot of space, so I could imagine keeping it disassembled.
"One test is worth a thousand opinions"

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Re: My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar

Post by eCue » Aug 04 2018 11:59am

a BIG Congratulations :D happy everyone is safe and the Trip was a success SWEET you guys were IMO in some scary territory :arrow:
Solar charge station on wheels join the Revolution

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Day 1, the other perfect day

Post by justin_le » Aug 05 2018 3:01pm

Cephalotus wrote:
Jul 04 2018 8:47am
Thanks a lot for the data on your "perfect day". Highly appreciated.
I hope that someday after the trip there will be data available for every day and every vehicle involved.
So I've not got all my raw data available for anyone who wants to look at it here:
https://www.dropbox.com/s/kt8in0sfmvdd5 ... g.zip?dl=0

The start and stop point of the files isn't exactly at the start of each day depending on when I remembered to reset the databox logging device, but most of them are reasonably close. This is just raw log data, we're working on some web tools that will do automatic day by day summaries of all the stats and enhancements to the trip analyzer page so that it can handle and display way larger data files without chocking.
Can you show data from a day with rainy or overcast weather, too if you find some time to do so?
Still coming soon! But I'm going to start with another near perfect day which was the first day of the race. Conditions in the week before the Suntrip gathering were terrible (lots of people pedaled their rigs to Lyon in endless downpour), and then improved during the June 14th-19th preamble from Lyon to Chamonix, and finally on the race start day it couldn't have been better, with bright skies, clean air, and tailwinds. It was like everything was going to fall into place.

We left from France at 10am, went over two 1500m peaks, rode through a flat valley in Switzerland, and then climbed up and over a 2000m pass. Descended from there into Italy having covered 199km, pretty much spot on our initial daily target. If you look at the graph data, we were doing 30-35 kph on the flat valley, hovered above 20kph for most of the hill climbs while consuming 1400-1600 watts, and clamped our speeds to 40-50kph on the descents with regen.
SuntripRace_June19_Graph.jpg
On the solar, it shows a total of 4kWhr, but that's because I hadn't reset the logger from the previous day, so when we started it was already at 1200 Wh giving us a total of 2.8 KWhr. Since the battery was charged in the morning before the 10am departure we didn't collect anything from the sunrise to 10am point.
SuntripRace_June19_Solar.jpg
Because there was so much mountain climbing this was a perfect leg to showcase the benefits of DD hub with regen, though it also became apparent that we didn't have our setup quite as dialed as would be ideal. I had configured each Phaserunner controller to do a max of 12 amps of regen (so 900 watts net from both controllers) in order to keep the combined solar+regen charge current to just a little over 1C on the LiGo batteries to keep the cells happy.

However, what that meant is that if the hill was steep enough that 900 watts regen was not sufficient to keep the speed clamped, then the bike would continue to accelerate, and the faster down you went the LESS regen torque you would have on the motor because at a higher RPM fewer Nm are needed for a given braking power and regen wattage. We would only get more than 900 watts of regen once the speed of the bike had reached a point where the back-emf voltage of the motors was above the pack voltage which would be at +45 kph, and then suddenly the regen would increase again since the controller has no way to limit it.

This resulted in a situation where if our goal was to maximize the amount of battery charge recovered on the downhill, it was often advantageous to still use the mechanical brakes to keep our speed at say 30 kph. If we didn't use mechanical brakes, the speed might increase to 45 kph; we'd still be getting just 900 watts into the battery but the descent would be over that much sooner so the total amp-hours recovered would be less, with a much larger share of our potential energy would have gone into wind drag losses. It also meant that pedaling on the steep downhills like this was similarly counter productive, it would just mean going downhill faster less time spent getting this fixed regen into the battery.

Here's a link to just the data from the 2nd hill pass.
http://www.ebikes.ca/tools/trip-analyze ... rip=nbc8ZL

You can see that we get 42% regen range extension, with some sections where we were going above 50 kph and having more like 1200-1400 watts of regen from back-emf, but mostly we stayed slower using the brakes to keep it in the 900 watts regime.
SuntripRace_June19_Regen.jpg
Ideally, we would have had a setup with either higher C rated cells that can be charged at 2-3C, or a larger battery pack, that could take full advantage of absorbing the potential regen energy from the motors and Phaserunners. In that scenario with the phaserunners not having a max regen curren tlimit, we could have set a speed on the descent of say 30 kph, rowed and pedaled on the downhill sections too, probably had 1500+ watts going into the battery and likely doubled the amount of regen energy captured. Not that 42% regen is bad, but it doesn't represent the true potential in this scenario.

Another thing that this first day was very useful for was giving us an idea of how many Watt-hours we needed for a given elevation climb. Here is the data on this pass at 100m elevation steps.
Watthrs per 100m.jpg
Watthrs per 100m.jpg (27.93 KiB) Viewed 3819 times
As a good ballpark we could see that we were averaging about 100 watt-hours consumed for each 100m of elevation gain, and that became a really useful rule of thumb for budgeting our battery reserves on future hill climbs during the entire trip. If we knew that there was a 500m elevation climb ahead, we'd aim to ensure we had at least 500 watt-hours in the battery, or about half full, so that even if we lost sun while climbing there would still be enough in reserve to make it to the top. Once at the top, a flat battery is no issue since it's all regen going down, but if you run flat while climbing a hill then moving a behemoth of an ebike like this with no motor assist is a real grind.
SuntripRace_June19_LVC.jpg
You can see that on this 2000m pass, we dialed it pretty well. We took two breaks on the climb to allow some solar charging while the motors would cool, and only just hit the system's low voltage rollback right at the top of the mountain. The CA's LVC was set to 29V, but that includes the voltage drop along the long lead from the battery to the two motor controllers. The actual voltage as seen by the datalogger directly connected to the packs was a bit higher at 30.3V.
Previously competed in the Suntrip race on a back to back tandem solar powered row/cycle trike. 550 watt solar roof, dual Grin All Axle hub motors, dual Phaserunner controllers, 12 LiGo batteries, and a whole wack of gear.

Now back in Vancouver learning to be a dad with my Big Dummy Frame (yes This One, thanks ES!) with GMAC 10T rear hub motor, Phaserunner controller, and 52V 19Ah EM3EV pack
My website: http://www.ebikes.ca
Please contact via email, info@ebikes.ca, rather than PMs, which are disabled

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Race Day 1 Trip Video

Post by justin_le » Aug 05 2018 3:11pm

And for those who want to see a video of this first day of the Suntrip race, Aaron here at Grin has finished editing a bunch of the gopro footage that we took on the first day. We wanted to see most of the other riders for one last time before everyone went their own way at their own pace.



I tried to have this ready like a month ago but too much logistics challenge dealing with large video files and restricted internet access while on the road. So now we're publishing the trip video of the first day right after one of the riders has already completed the entire 12K+ km and finished the race in Guangzhou!

https://www.thesuntrip.com/raf-van-hull ... ou-canton/
https://www.thesuntrip.com/raf-van-hulle-interview/

More to come...
Previously competed in the Suntrip race on a back to back tandem solar powered row/cycle trike. 550 watt solar roof, dual Grin All Axle hub motors, dual Phaserunner controllers, 12 LiGo batteries, and a whole wack of gear.

Now back in Vancouver learning to be a dad with my Big Dummy Frame (yes This One, thanks ES!) with GMAC 10T rear hub motor, Phaserunner controller, and 52V 19Ah EM3EV pack
My website: http://www.ebikes.ca
Please contact via email, info@ebikes.ca, rather than PMs, which are disabled

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Re: My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar

Post by philf » Aug 05 2018 3:54pm

Speaking of "Perfect Days"... When exactly is yours, Justin? This coming weekend? (Apologies if it appears elsewhere - you guys have been all over the various media, but everything I've read merely alludes to the month). I don't think I have the power to will every day in August to be perfect for you and Anne-Sophie, but I'll try :-).

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Re: My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar

Post by wturber » Aug 05 2018 4:25pm

philf wrote:
Aug 05 2018 3:54pm
Speaking of "Perfect Days"... When exactly is yours, Justin? This coming weekend? (Apologies if it appears elsewhere - you guys have been all over the various media, but everything I've read merely alludes to the month). I don't think I have the power to will every day in August to be perfect for you and Anne-Sophie, but I'll try :-).
Yeah that was my thot. What's he doing compiling ride data? Doesn't he have a wedding to prepare for? Oh wait!! This is Justin. Last minute prep is his standard. ;^)

Great video BTW.
"Commuter - DC Booster"
Iron Horse 3.0 hardtail - 48V / 1000W / 470rpm generic Chinese DD Hub motor (ebay)
8 x 36v 4.3ah 10s 2P battery packs - 1500W 30A DC Boost Converter delivers 54v and about 1000 watts peak
53T/42T Sakae Road cranks - 30mph+ on flats
viewtopic.php?f=2&t=90369

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Re: Day 1, the other perfect day

Post by solarEbike » Aug 06 2018 5:27pm

Now we're getting to the good stuff! Thanks for posting this analysis and the sample logs. Zooming in on the longer regen segments helped me better understanding what's going on.
justin_le wrote:
Aug 05 2018 3:01pm
...and the faster down you went the LESS regen torque you would have on the motor because at a higher RPM fewer Nm are needed for a given braking power and regen wattage. We would only get more than 900 watts of regen once the speed of the bike had reached a point where the back-emf voltage of the motors was above the pack voltage which would be at +45 kph, and then suddenly the regen would increase again since the controller has no way to limit it.
:shock: :idea: Well, this would seem to explain some of the unexpected behavior I've been seeing on long and/or steep descents like increase/decrease in braking power around the 45 kph mark and more/less regen amps than my max regen amps setting on the PR. When comparing to your example speeds, it helps that I'm using the same motor (Grin 5T DD), wheel size (20") and battery (36V). Maybe if I re-read the definition of back-emf for the 11th time it will eventually sink in...
justin_le wrote:
Aug 05 2018 3:01pm
...it was often advantageous to still use the mechanical brakes to keep our speed at say 30 kph. If we didn't use mechanical brakes, the speed might increase to 45 kph; we'd still be getting just 900 watts into the battery but the descent would be over that much sooner so the total amp-hours recovered would be less
Now I get why I saw ~40% regen on an extra-slow ride I took a few weeks back when the same hilly loop usually gets me 20-25%. I was descending the same hills at around 20 mph (32 kph) instead of the usual 30 mph (48 kph) or so. I knew the potential energy from the top to the bottom of the hill hadn't changed but it wasn't clear to me why I was getting so much more regen. (I also used less battery energy on the ascent.)
justin_le wrote:
Aug 05 2018 3:01pm
As a good ballpark we could see that we were averaging about 100 watt-hours consumed for each 100m of elevation gain, and that became a really useful rule of thumb for budgeting our battery reserves on future hill climbs during the entire trip.
Excellent. I've been struggling with this aspect of on-the-fly range estimation. Now that I have the GPS Analogger working with the solar firmware, I'll have to figure out my Wh per 100m number.
justin_le wrote:
Aug 05 2018 3:01pm
The CA's LVC was set to 29V, but that includes the voltage drop along the long lead from the battery to the two motor controllers. The actual voltage as seen by the datalogger directly connected to the packs was a bit higher at 30.3V.
So over 4% voltage drop? Was this a deliberate design decision or the result of something else like not having a larger gauge wire size on hand at the last minute? For residential PV design, I was taught to keep voltage drop under 1% on the AC side and under 2% on the DC side. I've been trying to keep it around 1-2% on my bike (both charging and discharging) but 2-3 meters of of 10 AWG (5.3 mm^2) wire adds up to some significant weight.
Current setup: SWB recumbent, Grin v1 5t DD hub w/ Statorade, Phaserunner, 6x LiGo battery, 238 watt sun-tracking solar trailer and 76 watt solar roof with 3 Genasun MPPT boost controllers, CA3 w/ solar FW & GPS Analogger, Rohloff hub. Solar ebike build, Website, Instagram

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Re: My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar

Post by FredTheSwede » Aug 09 2018 2:55pm

Great fun to read, my french in not so up to date so I have some teams I always check first ;-) before using translation services.

Thanks for the data will download in a second.
Is the data for others available somewhere, and should be default be handed out, or is it owned by each team or by the "Suntrip" team?
(Would be nice to run some scripts and compare designs with performance).

/Fred

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Re: My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar

Post by rachdatu » Aug 10 2018 4:54am

Fantastic race. Congrat for the report and the data.
Good to know that you were in Switzerland, in Valais (flat valley) and then up to one of these "legendary" Swiss pass (Simplon pass).
Switzerland is a nice country to test ebikes, don't need to go far to find all kind of profiles.

A bit of tourism: https://www.valais.ch/en/touren/road-an ... ain-passes

By the way, I did not know you were speaking French as well. Next time I send you an email, you know in which language it will be :-)

Walter

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Re: My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar

Post by StuRat » Aug 10 2018 5:01am

No french-speaking girl would ever marry a man that cannot.
But I'd say it came easy. The French. It's second language in canada.


What happened to the bike??

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usertogo   100 W

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Re: My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar

Post by usertogo » Aug 15 2018 7:37am

Generated footage...
I bet Justin&Anso has backed up some of the potential Video treasure... How long it appears for everybody else till TheSunTrip makes their 'big' documentary like they did 2013 and 2015 mainly for the french speaking and did it even have subtitles? Anyhow the world wants to learn everything about design choices and real world roads...

What interests most is for example that mysterious wrong road, that long time second place Bertrand Stephan took in China which cost him many positions and who knows what else...
I had done little exploration in Germany and my GPS would have made me take forest trails that could be given variable weather fully impossible or at least 'stuck in the fractal' and not making distance, but that a region exists that is so fully disconnected from major routes that one would have to backtrack a days worth of travel?

I would like to propose that pro quick charging consciousness a new Solar Muscle Electric 'Tribrid' Race - with larger battery capacity and Quick Charge stops allowed - would be interesting!
I also favour taking a stronger position on peoples rights,that given proper tires and brakes - for example speeds >45km/h need to be defended in such a race!

I have been thinkering for years (since 2013 when I found out about the Suntrip) and been developing prototypes Hoping to eventually visualize the optimal _anti gravity Solar ape cage_ that could win such a race 12000km and more :mrgreen:

billvon   1 GW

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Re: Day 1, the other perfect day

Post by billvon » Aug 15 2018 11:23am

Hey Justin thanks for the updates! You said something that struck a chord for me -
justin_le wrote:
Aug 05 2018 3:01pm
However, what that meant is that if the hill was steep enough that 900 watts regen was not sufficient to keep the speed clamped, then the bike would continue to accelerate, and the faster down you went the LESS regen torque you would have on the motor because at a higher RPM fewer Nm are needed for a given braking power and regen wattage. We would only get more than 900 watts of regen once the speed of the bike had reached a point where the back-emf voltage of the motors was above the pack voltage which would be at +45 kph, and then suddenly the regen would increase again since the controller has no way to limit it.

This resulted in a situation where if our goal was to maximize the amount of battery charge recovered on the downhill, it was often advantageous to still use the mechanical brakes to keep our speed at say 30 kph. If we didn't use mechanical brakes, the speed might increase to 45 kph; we'd still be getting just 900 watts into the battery but the descent would be over that much sooner so the total amp-hours recovered would be less, with a much larger share of our potential energy would have gone into wind drag losses. It also meant that pedaling on the steep downhills like this was similarly counter productive, it would just mean going downhill faster less time spent getting this fixed regen into the battery.
This is something I've noticed in my own riding, and it was very counter-intuitive to me at first.

When you are climbing a hill, a given throttle setting (on a torque-throttle setup) gives you a steady climb. If the bike sees a transient acceleration (i.e. you pedal or something) then it starts climbing faster. This requires more power (since you are increasing elevation at a faster rate) but torque hasn't changed - so you slow back down to the speed you were at before. Same thing happens if there's a transient slowdown - you speed back up to the speed you were at before.

At low speeds where drag isn't much of a factor this should be pretty simple to figure out - you climb at the speed where power = weight * (height/time.)

At first I thought going downhill with regen should be similar. After all, on my bike (as on most bikes) regen gives you a fixed torque resisting your descent - so you should descend at a constant speed, with regen "holding" you at that speed.

But what I found was the opposite. Because while the same formula holds (p=w*h/t) it's not stable. On a downhill, if you transiently speed up a little, then the "power" from the descent available (which is w*h/t) goes up - and the braking torque goes down as you describe. (same power, more RPM = less torque.) So you accelerate. Now you have more available power from gravity, since your h/t is going up, but braking torque is dropping, so you accelerate even more rapidly, until you hit the terminal velocity caused by increasing aero drag. When you transiently slow down a little, then the power available from gravity (w*h/t) goes down but braking torque goes UP, so you slow down even more. And you keep slowing down until you hit the limit of the regen, and then you creep down hill at some low regen point, usually a few kph.

One of the games I play during a long descent now is to try to find the magic point where the two (regen and descent 'power') balance out, both to maximize regen and for something to do. The one thing I don't like about this is it effectively requires me to 'pulse' the regen on and off (via the brake handle) to maintain this, and that's somewhat jarring. Someday I may find a two-way throttle (spring loaded return to 'zero' so you can twist one way for power, other for regen) so I have more control over regen, which would make the above a lot easier - and perhaps harvest a little more available power on a given descent.

An alternative, I guess, would be to have a speed-hold mode to keep you from exceeding X kph, and using regen to hold it there. Ironically one of my first ebikes (an EMS E+) did exactly that; when you were coasting downhill and the speed of the motor started exceeding base speed, the controller body diodes would start conducing power back to the battery and hold you at that speed. As I went to higher and higher battery voltages that stopped happening.

Thanks again for all the updates.
--bill von

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