On this page, I'm going to comment trips and experiences I make with the caravan or changes and updates I make to it. The main focus will be on the technical part. The page will be in english only.
04/09/17 - 08/09/17: On the road again ...
Welcome back for some updates about „el Patu“! The caravan is two years old now and in the meantime has gotten some scratches here and there. I also had to send the inverter back to Votronic (it didn't work any more - but it still was under garanty, so they repaired it for free and now it works fine again). But apart from that, the caravan is still in excellent shape and was waiting for it's third mission away from home ...
Welcome back for some updates about „el Patu“! The caravan is two years old now and in the meantime has gotten some scratches here and there. I also had to send the inverter back to Votronic (it didn't work any more - but it still was under garanty, so they repaired it for free and now it works fine again). But apart from that, the caravan is still in excellent shape and was waiting for it's third mission away from home ...
The goal this time was to make a longer tour – ideally 1-2 weeks. But unfortunately the weather was bad ... Of course, you can go out cycling when it's raining (and you are certainly better in a caravan than in a tent), but personally I think that this is not really a pleasure. I mean: one or two days of rain are ok, but this time they announced rain the whole week without interruption. So I ended up travelling during 5 days only in which I made 279 km. And again: I managed to make the whole tour without external charging of the e-bike, so only solar power was used!
Tour
Tour
I was again following the lakes but pushing the tour further to the east (Laupen and Wohlensee) and the south (Lausanne and lake of Geneva):
Day 1: Fribourg, Lac de Schiffenen, Laupen, Mühleberg, Aarberg, Erlach (72 km) Day 2: Erlach, St-Blaise, Neuchâtel, St-Aubin, Yverdon-les-Bains (64 km) Day 3: Yverdon-les-Bains, Orbe, La Sarraz, Cossonay, Ecublens, Lausanne (53 km) Day 4: Lausanne, Cheseaux-sur-Lausanne, Vuarrens, Yverdon-les-Bains, Estavayer-le-Lac (59 km) Day 5: Estavayer-le-Lac, Payerne, Cousset, Léchelles, Belfaux, Fribourg (33 km) Total: 279 km Avg: 55.8 km |
Climbings
Of course, I tried to avoid steep climbings - and the whole tour was between 350 meters (lowest point) and 690 meters (highest point) - but some climbings were inevitable:
Of course, I tried to avoid steep climbings - and the whole tour was between 350 meters (lowest point) and 690 meters (highest point) - but some climbings were inevitable:
Two examples and experiences:
(1) From Wohlen to Salvisberg (about 80m): extremely steep climbing (18%). I switched to „power mode“ and tried to overcome it pedaling as much as I could, but no chance: the motor overheated in less than 3 minutes (20 minutes to let it cool down again ...)! Conclusion: there is only one solution for such climbings – push your bike (and caravan ...)! (2) From Lausanne (350 meters) to Cheseaux (about 620 meters): rather steep at the beginning (but less then the first example), but I could do everything in „eco mode“ and finally was surprised how easy it was! |
Solar power
The conditions were not as ideal as on my last tour: especially in the morning the sky was cloudy and I couldn't get full sun.
The conditions were not as ideal as on my last tour: especially in the morning the sky was cloudy and I couldn't get full sun.
Day 1: 258 Wh
Day 2: 287 Wh Day 3: 447 Wh Day 4: 320 Wh Day 5: 356 Wh |
Total: 1668 Wh
Avg: 333 Wh |
As a comparison: this is only 74% of what I got in 4 days on my last
tour! Day 3 is higher because I decided to stop at midday and position
the solar panel directly towards the sun. I stayed there for two hours
with at more or less 100W from the solar panel (so 200 Wh in 2 hours).
This method is absolutely recommendable since you can get 1/3 – 1/2 of
the daily production (when you are cycling normally) in just 2 hours!
Consumption
This time, I tried to got the electrical consumption even further down by pedaling without assistance on flat terrain and using the motor only for climbings or in cities (in order to be more „reactive“ in the traffic). The estimated power consumption (counting also the accumulators of the bike and the caravan that were charged to the maximum before the trip) was 2491Wh for 279 km or approximately 9 Wh / km (which in my opinion is just fantastic*:).
(*) That's half of what I used on my first tour, so you can more or less just double the values I published then ... !!! ;)
Speed
Of course, since I was pedaling quite often without any assistance, the average speed was lower than the last time: 13.9 km h.
Obstacles
This time, I tried to got the electrical consumption even further down by pedaling without assistance on flat terrain and using the motor only for climbings or in cities (in order to be more „reactive“ in the traffic). The estimated power consumption (counting also the accumulators of the bike and the caravan that were charged to the maximum before the trip) was 2491Wh for 279 km or approximately 9 Wh / km (which in my opinion is just fantastic*:).
(*) That's half of what I used on my first tour, so you can more or less just double the values I published then ... !!! ;)
Speed
Of course, since I was pedaling quite often without any assistance, the average speed was lower than the last time: 13.9 km h.
Obstacles
There are many obstacles you can find on your trip: narrow bridges or barriers ... stairs (that are non indicated on the map because normal bikes can use a „rail“ overcome them – which unfortunately is not possible with a caravan). In general I didn't have many problems with that (a width of 80 cm most of the time is narrow enough to pass through), but in two occasions the planned route was a dead end (stairs) and I had to turn around ...
Hitch
Hitch
Well ... and finally the bad news: on day 4, driving on a non asphalted road with lots of bumps and stones (between Cheyres and Estavayer-le-Lac), I noticed that the adapter for the coupling system (Weber) was moving. After inspection I quickly noticed what the problem was: the official adapter is attached to the hitch with only one screw (which forms an ideal leverage point ...)! In my opinion this is just poor design: the part of the adapter that goes into the hitch should be longer and there should be two screws to fix it! Anyway: I used some tape to fix it (attaching the leg of the foldable part of the caravan on the side). But this, in the end, was the reason why I headed home directly on day 5 (making only 33 km and with around 150 Wh of power left unused in the batteries ...)
Conclusions
Solar power: Again, I come to the conclusion, that the solar system really does a good job! 120W doesn't look like much power, but if you use it efficiently – and are willing to pedal without assistance in the flat parts – you can easily reach 60 km per day with solar power only! If you accept to charge the Stromer at your destination (in the evening) you easily reach 100 km – which means that with the caravan you can travel the same distances as you would with a tent.
Coupling system: Another (annoying) problem with the coupling system ... First it was the adapter plate on the bike, now it's the adapter for the Weber coupling. Sorry guys (or should I say: dear ingeniers): why can't you just do that right?! I mean: it's all based on offical products you sell - and in the end it doesn't work ... !
So I know two things for sure:
Anyway, I'm sure I can fix that ... !
Solar power: Again, I come to the conclusion, that the solar system really does a good job! 120W doesn't look like much power, but if you use it efficiently – and are willing to pedal without assistance in the flat parts – you can easily reach 60 km per day with solar power only! If you accept to charge the Stromer at your destination (in the evening) you easily reach 100 km – which means that with the caravan you can travel the same distances as you would with a tent.
Coupling system: Another (annoying) problem with the coupling system ... First it was the adapter plate on the bike, now it's the adapter for the Weber coupling. Sorry guys (or should I say: dear ingeniers): why can't you just do that right?! I mean: it's all based on offical products you sell - and in the end it doesn't work ... !
So I know two things for sure:
- Next time I wont use any adapter parts any more! Everything that's on the coupling system should be in one piece so that you can be sure that everything is tight and that there are no moving parts!
- I'm not sure any more that making a caravan that short is a good idea. A longer caravan means a longer distance between the coupling point and the axle of the caravan, which results in less stress on the hitch! I think that the next caravan I build (if I have time to build one (..)) will be 2 meters long!
Anyway, I'm sure I can fix that ... !
24/08/16 - 27/08/16: Three lakes and four hot summer days ...
After a long period of inactivity, el Patu is finally back on the road! At the end of august, I had some days off and the meteorologists announced the «hottest weekend of the whole year» in Switzerland (with temperatures from 25°–35°). These were ideal conditions to test the caravan with special regard to the following technical aspects:
- Coupling system: Stromer (the manufacturer of my E-Bike ST1) had a look at the problem and found a solution by fixing two of the three screws from both sides and putting «lock tight» to all the screws (I must admit that I didn't do that and that's why most probably the screw got lose on my last trip ...). Would these changings be enough to secure the adapter plate?
- Solar panel: The idea was to make this tour with solar power only (so «no charging, nowhere»). How much energy would it be possible to harvest in these ideal (!) conditions during a normal cycling day? How many kilometers can you drive with solar energy only, especially using the "eco-mode"?
The tour
Mostly flat in the region of «three lakes», i.e. lakes of Neuchâtel, Bienne and Morat (see photo for a rough overview). Just small climbings, one steeper climbing in the middle and especially in the end (to get back to Fribourg):
- Day 1: Fribourg – Estavayer-le-lac – Portalban (54 km) - Day 2: Portalban – Avenches – north of lake of Morat – Pont-de-Tielle/Zielbrücke – following la Thielle – Erlach (58 km) - Day 3: Erlach – Nidau – Büren an der Aare – passing over a hill to Aarberg – Lyss – Kerzers – Muntelier/Loewenberg (80 km) - Day 4: Muntelier/Loewenberg – Domdidier – Corcelles-près-Payerne – Fribourg (40 km) Total distance: 232 km |
Coupling system
Seems to work this time (all screws tight from the beginning to the end). I still am little bit sceptical because I still think that the design of the adapter plate is not ideal and the steel plate of the Weber itselfs moves too much in my opinion. But ok: my expectations for a good coupling systems are maybe a quite high (in general, I prefer constructions that are a little bit heavier, but strong and 100% reliable).
Foto - Two screws secured from both sides - "Lock-tight" applied to all screws |
Solar energy
The panel has 120 Wp and I mesured a maximum of 110 W. I noticed that partial shadow makes the efficiency drop drastically: if you cover just the upper 4 solar cells (out of the 40 cells in total = 10%) you lose 50% of power! So, for optimal results it is important that the panel gets full sun, especially when the caravan is standing still. I estimate that when driving around (when the orientation of the panel is not always ideal), you get around 70-80 W in average. Of course, all other rules for solar panels apply: In the morning / evening, when the sun is very low (1-2 hours after sunrise / before sunset), you wont get much energy.
The panel has 120 Wp and I mesured a maximum of 110 W. I noticed that partial shadow makes the efficiency drop drastically: if you cover just the upper 4 solar cells (out of the 40 cells in total = 10%) you lose 50% of power! So, for optimal results it is important that the panel gets full sun, especially when the caravan is standing still. I estimate that when driving around (when the orientation of the panel is not always ideal), you get around 70-80 W in average. Of course, all other rules for solar panels apply: In the morning / evening, when the sun is very low (1-2 hours after sunrise / before sunset), you wont get much energy.
Results
- Day 1: 618 Wh
- Day 2: 547 Wh
- Day 3: 513 Wh
- Day 4: 554 Wh
Total: 2232 Wh
Average: 558 Wh
Foto:
Charging on the parking (with Brompton)
Power consumption
It is difficult to make a exact calculation for the power consumption of the Stromer since the accumulator only indicates percentages. The most reliable mesurement is the charger of the solar panel (which shows 2437 Wh). Adding the power used from the accu of the Stromer (which was at 37% when I got home = 2/3 of 522 Wh), this gives us a rough estimation of around 2790 Wh for 232 km or an average consumption of 12 Wh / km. This is much less than in my last tour (where it was around 18 Wh) and the differences come from:
- Eco-mode: The Stromer has 4 assistance modes (eco-city-tour-power). Last time I always used power-mode. This time I used eco-mode whenever possible and I only switched to higher modes during steeper climings trying no to fall below 10 km/h (most of the time using city- or tour-mode was enough). This also reduces / eliminates vibrations of the motor (that I experience especially in power-mode the last time).
- Flat terrain: This time, there where only a few climbings, so that the power of the solar panel and the charger was enough to compensate the consumption (accu of Stromer was at 100% most of the time). Climbings instead take a lot of energy: going from Corcelles to Fribourg (16 km, 300 m climbing) took about 42% (220 Wh) of the accu.
- Day 1: 618 Wh
- Day 2: 547 Wh
- Day 3: 513 Wh
- Day 4: 554 Wh
Total: 2232 Wh
Average: 558 Wh
Foto:
Charging on the parking (with Brompton)
Power consumption
It is difficult to make a exact calculation for the power consumption of the Stromer since the accumulator only indicates percentages. The most reliable mesurement is the charger of the solar panel (which shows 2437 Wh). Adding the power used from the accu of the Stromer (which was at 37% when I got home = 2/3 of 522 Wh), this gives us a rough estimation of around 2790 Wh for 232 km or an average consumption of 12 Wh / km. This is much less than in my last tour (where it was around 18 Wh) and the differences come from:
- Eco-mode: The Stromer has 4 assistance modes (eco-city-tour-power). Last time I always used power-mode. This time I used eco-mode whenever possible and I only switched to higher modes during steeper climings trying no to fall below 10 km/h (most of the time using city- or tour-mode was enough). This also reduces / eliminates vibrations of the motor (that I experience especially in power-mode the last time).
- Flat terrain: This time, there where only a few climbings, so that the power of the solar panel and the charger was enough to compensate the consumption (accu of Stromer was at 100% most of the time). Climbings instead take a lot of energy: going from Corcelles to Fribourg (16 km, 300 m climbing) took about 42% (220 Wh) of the accu.
Conclusions
So, how many kilometers can you make with el Patu based on those values?
- Solar power only: you should be able to make 42-52 km / day (513–618 Wh).
- Bike accu: If you start with a full bike-accu (522 Wh) and later charge it from a power supply from time to time, you can add 42 km which makes 84-94 km in total.
- Caravan accu: If you also use the accu of the caravan (nominal value = 360 Wh, but with the inverter you can probably use around 300 Wh) for driving, you can again add 25 km, bringing it to a total of 109-119 km.
- Pedaling: If you want to go even further, you can completely cut electrical assistance on flat terrain: it is possible to pull the trailer with muscle power only (you can go at 10-15 km/h), but quite tiring ...
- Another accu: Of course, there's also the possibility to take a second bike accu with you (so that distances up to 150 km / day should be in reach).
23/10/15 - 25/10/15: The moment of truth ...
Yes, one day all theory comes to an end and an invention must proof that it works! So, I had to go out and test "El Patu". Of course, I was a bit nervous ... but in the end, everything worked fine - well, more or less ... ;-)
Program
For my first experience, I didn't want to go too far away (so that it would be easy to turn around and come back if anything failed), so I chose to spend one night at home and the go from Fribourg to Portalban:
For my first experience, I didn't want to go too far away (so that it would be easy to turn around and come back if anything failed), so I chose to spend one night at home and the go from Fribourg to Portalban:
- 23/10/15: Packing & first night in the caravan (in front of our house)
- 24/10/15: Fribourg - Portalban (28.1 km / +220m / -420m), night at camping
- 25/10/15: Portalban - Fribourg (27.3 km / +420m / -220m)
Climbings
No problem on the first day. In average climbings (< 10%) you generally can keep a good speed (>15 km/h). What's not nice is that the motor produces a lot of noise and vibration around 15-17 km/h. In climbings near to 10% or above you get very slow (around 10 km/h) and of course the motor doesn't work at best efficiency (this is true for all climbings > 5% I'd say).
On the second day, I got the message "HEAT" after 1 hour of cycling and a steap climbing. The motor went of and I had to wait about 40 min to let it cool down. I made all climbings at maximum power. I tried to do some climbings with less power (for example in "City"-Mode, but the caravan is too heavy and the Stromer gets very slow). A big disadvantage of the Stromer: it doesn't have small gears to do climbings without electrical assistance (so practically, you have no other choice than use the "Power Mode")
No problem on the first day. In average climbings (< 10%) you generally can keep a good speed (>15 km/h). What's not nice is that the motor produces a lot of noise and vibration around 15-17 km/h. In climbings near to 10% or above you get very slow (around 10 km/h) and of course the motor doesn't work at best efficiency (this is true for all climbings > 5% I'd say).
On the second day, I got the message "HEAT" after 1 hour of cycling and a steap climbing. The motor went of and I had to wait about 40 min to let it cool down. I made all climbings at maximum power. I tried to do some climbings with less power (for example in "City"-Mode, but the caravan is too heavy and the Stromer gets very slow). A big disadvantage of the Stromer: it doesn't have small gears to do climbings without electrical assistance (so practically, you have no other choice than use the "Power Mode")
Roads
You feel EVERY (and I mean EVERY!) bump and have to drive carefully. Asphalted roads are best, but I also tried some roads with gravel (if it's small gravel and your going slow - around 10 km/h - it's ok, but really not the best choice). Sleeping Both nights I slept quite well. Tree sleeping positions possible: on the back, on the side (with or without folded legs) or on the stomach. I used my winter sleeping bag with a fleece inlet and wasn't cold at all. Light The "Morphea"-lamp is really, really nice! Makes you feel very "homy" and with such a nice light it's definitely better to be in a caravan than in a tent! ;-) Speed You can go fast (easily 30 km/h in the flat), but most of the time you won't because of bumps. My average speed on both days was 17.3 km/h. |
Humidity
The camping in Portalban is near the lake, so the humidity was very high. With the low temperatures during the night, everything outside got really wet. Inside the caravan, the wood really did it's job: no problems at all with humidity!!! The only thing that got really wet, where the two windows (but no problem: in the morning I could dry them with a towel).
The camping in Portalban is near the lake, so the humidity was very high. With the low temperatures during the night, everything outside got really wet. Inside the caravan, the wood really did it's job: no problems at all with humidity!!! The only thing that got really wet, where the two windows (but no problem: in the morning I could dry them with a towel).
Coupling system
The coupling system: very, very bad!!! For the Weber ES, that Stromer needs a special plate which is fixed to the body of the bike with 3 screws. On both days, one of those screws got loose! Very, very bad and dangerous!!! Weber ES: I was surprised that the metal plate moves a lot! I'm not sure that this is good and I cannot imagine that this coupling system is specified for 100 kg!!! It really seems impossibly to me. I really need some time to think about that: both the plate and the Weber ES are a big deception to me!!! Marks: - above: the screw that got lose twice (why?) - below: movement of the Weber EL (is this normal?!?) |
Electricity
(*) The Stromer went out at 13% (first time) and at 18% (second time) which brings me to the conclusion that due to the constant charging/discharging during the ride, the percentage is not very accurate (but anyway - I got home with the last ampères at 18%:-).
- 0 - 16.6 km: only with power of Stromer accu (522 Wh, 100% - 66%)
- 16.6 - 28.1 km: Stromer accu charged from caravan during the ride (the Stromer accu oscillated between 60% - 70%, at the arrival at Portalban it was at 68%)
- 28.1 - 46.8 km: Stromer accu charged from caravan accu during the ride (the Stromer accu went slowly down from 68% - 26% during the climbings since the charging was less than the consumption).
- 46.8 - 50.9 km: at 46.8 km the inverter went out (= solar accu empty) and I continued with the Stromer accu only (which than dropped from 26 - 13% and went out (*))
- 50.9 - 55.4 km: without any energy left, I had to wait 2 hours in order to get some energy from the solar pannels to make the last 4.5 km (fortunately, the sun was shining ... :-). Charged the Stromer up to 31% and it was at 18% when I arrived in Fribourg. (*).
(*) The Stromer went out at 13% (first time) and at 18% (second time) which brings me to the conclusion that due to the constant charging/discharging during the ride, the percentage is not very accurate (but anyway - I got home with the last ampères at 18%:-).
Solar power
From the morning of the 24th to the evening of the 25th, the solar pannel accumulated a total of 265 Wh. The weather was mostly cloudy with some moments of blue sky (especially the 25th in the afternoon). In Portalban the caravan was standing in the shadow (giving a maximum of 7-8W of power). During the day, I could get 30-50W with partially clouded sky and 70-80W with blue sky.
From the morning of the 24th to the evening of the 25th, the solar pannel accumulated a total of 265 Wh. The weather was mostly cloudy with some moments of blue sky (especially the 25th in the afternoon). In Portalban the caravan was standing in the shadow (giving a maximum of 7-8W of power). During the day, I could get 30-50W with partially clouded sky and 70-80W with blue sky.
Energy
The above data (accumulators of Stromer and caravan and power of solar pannel) allow us to calculate / estimate more or less the consumption of the bike with the caravan: Stromer: 522 Wh Caravan: 300 Wh (*) Solar: 225 Wh (**) Total energy: 1027 Wh Total distance: 55.4 km Average consumption: 18.54 Wh / km (*) Estimated, real capacity is 380Wh but the inverter shuts itself down at 10.9V which is probably 80% of the nominal capacity. (**) Only the amount charged to the Stromer battery is calculated. Ranges Stromer accu: 28 km Caravan accu: 16 km Solar energy: 12 km (14 km in total for both days) |
My personal conclusion
- The caravan: It basically works! It is very heavy and therefore not appropriated for steep and long climbings because the motor of the Stromer can overheat. Normal and short climbings are ok. Ideal travelling speed is 15-20 km/h.
- Coupling system: It's completely useless!!! Don't have a solution for the moment, but for me it's clear that the plate and Weber EL as it is now, don't work! As I wrote above: this is a big deception. Both the Stromer and the caravan and the Stromer work well, so it's a pitty that the coupling system in the middle is the weak point!
- Range: The range of 28 km for the onboard accumulator of the Stromer seems poor, but since there were some climbings and the Stromer used maximum power all the time, it's the minimum you should achieve. You should get better range on flat terrain and pedaling more by yourself. Maybe it would be good to adapt the standard gears of the Stromer in order to have lower gear for climbings.
- Solar power: Here also, 265 Wh seem poor at first sight. But you shouldn't forget that it was cloudy, that the caravan was standing half of the second day in the shadow and that we're at the end of octobre. For me the important value are the 80W achieved today with blue sky and the octobre sun. For me that means, that in summer, the pannel will easily reach the 80W (it actually has 120Wp). Since the days in summer are longer, you should get 6-7 hours of sun without any problem. So, that means 480-560 Wh in a very pessimistic calculation, which corresponds to 26-30 additional kilometers / day. So, distances of 54-58 km (70 - 74 km with accu of the caravan, if you need it) per day with full assistance and climbings should be possible.