What, how and why. Test bikes and test procedure. Ride testing. Lessons learned and potential for developments in the cargo pedelec market. Special demands on the drive system. Motor position and gears. Steering, and handling in general. Special components for cargo pedelecs.
You might call cargo pedelecs the “Yes, we can” generation in cycling. Whenever a conventional cycle just isn’t enough, either in load capacity or to cover the distances required, that’s when the cargo pedelec fun begins: in no other sector of cycling does electrification make so much sense. So it’s no wonder that this product group has become a rising star in the media. And the diversity of models on offer is rising rapidly: whether it’s for families, deliveries or for trades people: there are suitable two or three wheeled cargo pedelecs for near-countless applications. The advantages are self evident: transport by cargo pedelec is cheap, fast and environmentally friendly.
The potential is also huge. Depending on the model, there can be room in a cargo pedelec for one to four children, plus shopping. For commercial use there are numerous cargo modules, and heavy haulers to carry up to 300 kg on a Europallet. According to one study for the EU-supported “Cyclelogistics” project, cities could displace over half of all motorised transportation trips to cycles with the help of cargo pedelecs. Cargo pedelecs can also be attractive in the countryside, too: with a pedelec 45 version even 15 km to the supermarket and back with a week’s shopping becomes an enjoyable ride.
All of this was more than enough to convince ExtraEnergy to organise this special Cargo Pedelecs Test 2016, with the support of Arne Behrensen (cargobike.jetzt) and Wasilis von Rauch (e-Rad Hafen).
The overriding aim of the test is to give you, dear reader, well founded advice on selecting a suitable cargo pedelec. Additionally, we aim to contribute to the optimisation of these products, and to make it a positive learning experience for manufacturers. Working with our test riders, all with cargo pedelec expertise, we identified numerous areas for improvement on the cycles, discussed these with the manufacturers and in many cases these were implemented. And last but not least: this tri-lingual test report, published to appear at EUROBIKE, additional partner publications and media reports on the test (e.g. in the Süddeutschen Zeitung, the Deutschen Handwerks Zeitung and in BIKE BILD) will raise awareness of cargo pedelecs and give the market an additional, noticeable boost. ExtraEnergy estimates there is the potential for cargo pedelecs in Germany to be every fifth pedelec. In just a few years this could add up to around a million units, because ExtraEnergy views the German market, with around 5 million units sold annually, as mature. For 2016 ExtraEnergy estimates another 900,000 to one million unit sales in Germany, and worldwide around 36 million units, with the Chinese market dominating. 10 cargo pedelecs from this ExtraEnergy Test took part after the test in testing for BIKE BILD, whose first edition also appeared at EUROBIKE 2016.
Test bikes and test procedure
With 13 bikes on test, we have almost doubled the count from the first ExtraEnergy cargo pedelec test in Autumn 2013, in which we tested seven machines. There has never before been a cargo pedelec test the size of the current test. The cycles tested offer a very good overview of the current diversity of products for two-wheeled cargo pedelecs. One pedelec with trailer, one multi-track child transporter and a postal bike for heavy transport, also multi-track, extend the diversity on test.
To get to grips with the huge range of functional forms these bikes represent, we have defined three product groups, each with a minimum payload capacity of 50 kg (in addition to the rider):
“Family” (main purpose: child transportation)
“Performance” (main purpose: fast and good range)
“Commercial” (main purpose: commercial transport)
A fourth product group was also defined for especially heavy duty commercial transportation as “Commercial – 120+”. These vehicles must be able to transport at least 120 kg rather than just 50 kg.
Customer wishes profiles were then allocated against each of these four product groups. Particular factors such as range, speed, power assist level and price were given varying weightings, depending on which characteristic is particularly important for each specific application. A single test bike can in principle be evaluated in multiple product groups, as long as it meets the relevant minimum requirements. Two more things: at least three entries are needed for analysis of the product group. In the “Performance” product group only two pedelec 45 test bikes were present, the “Load” from Riese & Müller and the “Rapid” from Radkutsche. That’s why unfortunately we could not crown a test winner in this product group, and we gave out no test awards. There were also just two single-track cargo pedelecs, the Urban Arrow “Family” and the trioBike “Cargo-E” in the “Commercial 120kg+” product group, but these could compete with the multi-track CDS E-Trike VS 3E for the test win and awards.
ExtraEnergy is treading new ground with this definition of four product groups for cargo pedelecs, and their customer wishes profiles, minimum requirements and exclusion criteria. We are dealing here with a first attempt to get to grips with the broad spectrum of cargo pedelecs and their applications. Over the course of the tests questions have already arisen, and these will be discussed at the next meeting of the panel of experts who set weightings and exclusion criteria for the product groups. Current questions include e.g.: should cargo pedelecs 45 compete in the ‘family’ and ‘commercial’ product groups, or should they always be evaluated in ‘performance’ because of the need for a permit and the ban on using cycle paths? Is the minimum payload of 120 kg the right value for heavy commercial cargo? Should there be separate product groups for single-track and multi-track cargo pedelecs? How can the quality and versatility of add-on modules be better presented in the test reports, as against the quality of the assist systems?
Seven test riders rode the bikes on the well-proven 14.7 km long ExtraEnergy test circuit – once loaded and once unloaded. For the load, 50 kg of wood briquettes were used, and in one case (the Kranich test bike from Utopia) these were loaded onto a trailer. For one other test bike (“Get 2s plus” from Gobax), “only” 30 kg were loaded into the carrier rack box, as was appropriate to the intended use of the bike and the rating of the carrier rack. When coupled up to our test trailer, with over-run brakes, it could have transported 50 kg or more.
During the rides, speed, rider power output and electrical usage by the drive were measured. From these figures, specific values could be determined for each bike for range, the power assist factor and for the average speeds over the three different sections (tour, hills and city). These values are given in the test reports for every bike.
We are pleased to report that all of the bikes managed the test circuit, with its gradients of up to 17%, loaded with 50 kg, without problems, and without reaching the limits of their e-assist systems. The multi-track post carrier, the CDS E-Trike VS 3E, was also tested loaded up with 100 kg, as befits its payload rating. In contrast to the 2013 test, there were neither e-assist system failures nor unpleasant surprises. The range from the batteries, and the power assist levels from the drives, were significantly improved on the latest test bikes. Clearly electric assist systems on cargo pedelecs have moved forwards in quality in leaps and bounds.
Improvement were however needed in some of the components fitted. On one test bike, a disk brake rotor mount broke. This unsatisfactory mounting was then improved via a recall process for all bikes produced. On another bike, the arrangement of the controls on the handlebars was impractical, and was changed.
In the ergonomics test, which was carried out separately, the everyday usability of the bikes was evaluated. We also took note of add-on modules for private and commercial use, and make reference to any relevant aspects in the test reports. Furthermore, we have written specific pieces on the themes of child transport and cargo transport.
The test cannot deliver any verdict on the durability of the bikes or their components. Also, braking performance and frame strength were not tested, because for this it is necessary to run tests in a technical test lab. That said, after this test was complete, braking and ride stability tests were conducted for BIKE BILD at velotech.de, and these prompted numerous modifications.
Lessons learned and potential for developments in the cargo pedelec market
Overall, cargo pedelecs are at the very beginning of their development. The potential for future development is therefore great. At the same time, the increased weight of cargo pedelecs places tough, specific demands on all components.
Special demands on the drive system
This test has shown that to achieve optimal electric assist for cargo pedelecs, software profiles specific to cargo pedelec use should be used in the motor controller. Standard profiles for use on normal pedelecs showed weaknesses on test. On two of the test bikes, new firmware was installed which called up more performance from the motor, after analysis of the measured values. In one case the issue was a lack of assistance under peak loads, and in another it was the need for a blanket increase in performance in all riding conditions. And when it comes to the motor itself, there are good reasons to use special-purpose solutions, especially in the Commercial 120+ cargo pedelec product group, because these “HGVs” of the cargo pedelec world are the furthest away from the loads and demands placed on standard pedelecs. The CDS Etrike VS 3E does use a motor specially designed for heavy cargo use, the ERZMO from EMGR, and with this it achieved good results even with a payload of 100 kg.
Motor position and gears
The question of which motor position and gearing type is best is a complex one.
Mid motors dominated the test field. In general they offer the advantage that the motor can also benefit from the effect of the gears, just as much as the rider. This can have a positive effect on the efficiency of the drive system. However, the drivetrain is then loaded particularly heavily, because it must transmit the power of the electric motor alongside the rider’s own muscle power. Gearing systems popular on the market today typically reach their limits quite quickly under this double loading, and this shows up in much higher levels of wear or in a significantly reduced service life. This effect is especially pronounced on cargo pedelecs because of their higher total weight. The combination of mid motor and derailleur gearing gives especially high wear rates, so that replacement of chain and sprockets may be needed every 2,000 km or so. If hub gears are fitted then more robust chain or belt drives, with longer service lives, can be used. But hub gears, taken from ranges intended for standard bicycles, also quickly reach their limits and wear out faster when used with mid motors in cargo pedelecs. One way out is to use especially robust and generally high priced hub gearing systems such as Rohloff or NuVinci. The company CDS Bike from Sömmerda has found another completely different solution: they use the ERZMO mid motor, especially developed for use in cargo pedelecs, with an integrated gearbox. This approach promises excellent reliability.
Hub motors in the front or rear wheel don’t load up the drivetrain, because the motor power works directly on the wheel. Silent direct drive motors in the rear wheel (on test: the BionX on the trioBike and the GoSwiss Drive on Hartje and Gobax) are powerful. But because of the low rotation rate, direct drive motors can drop into an unfavourable regime for efficiency when under high load, for example on hill starts or for extended climbing when loaded, and this can lead to increased energy consumption (= reduced range) or in the worst case to throttling back of the motor power. The direct drives on test had derailleur gears for the rider’s efforts. The combination of rear wheel hub motor and hub gears is also available on the market, but not currently in a performance class appropriate for a cargo pedelec.
More compact geared hub motors have a high rate of rotation even on slow hill-climbs, and hence a higher electrical efficiency, but as a rule they are significantly louder, and they are only seldom equipped with torque sensors which deliver a smooth riding sensation.
On single-track cargo pedelecs front motors have the advantage that the front wheel is usually smaller, and hence the lever effect is favourable for the motor (examples on test are the “Rapid” from Radkutsche and the “Long Harry” from Pedalpower). The Rapid from Radkutsche combines a Rohloff hub gear with a very powerful front hub motor which is controlled via a twist throttle, rather than though a responsive torque sensor. It takes a little time to get used to co-ordinating pedalling and the throttle properly. Because of the motor’s torque the front wheel can slip sometimes on not-so-grippy surfaces, and when only little payload is on board. But the motor does obey the direct commands of its controller.
The all wheel drive assist from Marquardt was very interesting to test, and it is available commercially for the first time in the Pedalpower cargo bike. The ride performance figures show that on cargo bikes hub motors, especially with all wheel drive, have many convincing advantages over the popular mid motor systems. One additional advantage of front motor systems, which test riders really enjoyed, is increased stability when riding: the driven front wheel is more stable tracking out of turns, runs straight ahead better, and is less inclined to shimmy compared to other set-forwards front wheels on cargo pedelecs with mid or rear motors.
Steering, and handling in general
One technical challenge for single-track cargo bikes of the “Long John” type concerns the forks and steering linkage for the front wheel, which is placed far out in front. Steering is usually handled via a push rod or a Bowden cable (as on the “eHarry” and “Long Harry” from Pedalpower in this test). But if the chosen design permits even a little play, the steering will become ‘floppy’. Manoeuvring these long bikes in confined spaces becomes significantly easier if the steering angle is not limited – although it’s then impossible to rule out over-steering as you ride. Another widespread problem on single-track cargo bikes is steering shimmy at higher speeds, usually triggered by a bump. The front wheel can then flutter alarmingly. On some test bikes that happened even before passing above 30 km/h, although it was significantly later than that on most. This would make the issue mostly irrelevant for everyday use. Nonetheless, manufacturers should inform their customers about this phenomenon.
Note: ExtraEnergy selected 10 normal pedelecs and 10 cargo pedelecs from the bikes in the Spring 2016 test and had them tested for wheel shimmy by velotech.de. There was a similar number of machines with a tendency to shimmy among the 10 normal pedelecs as among the 10 cargo pedelecs. So the shimmy phenomenon affects all categories of pedelec. It should be considered even more intensively in development and test phases, and it’s a very relevant issue for cargo pedelecs. Indeed, some of the cargo bike manufacturers have taken this ExtraEnergy testing to heart and further optimised their steering systems.
Some manufacturers have already overcome problems at higher speeds, using a variety of steering dampers, guides for the steering linkage and optimisation of the fork design – in some cases, however, at the cost of the lightness of the steering and the overall agility of the bike.
Multi-track cargo bikes are valued for their stability, and with electric assist they become much less hard going. Models with a cargo box in front, for example the Urban Wheelz in this test, usually have a centre pivot steering system, although sometimes stub axle steering is used. Steering dampers ensure that they track easily straight ahead. But three-wheeled front loaders are not really intended for higher speeds and thrilling acceleration. Also, there’s the danger of overturning, especially on uneven surfaces and in corners. Now, though, the first manufacturers have developed front loading trikes with sophisticated leaning technology, which allows fast riding through corners just as with two-wheeled models.
Special components for cargo pedelecs
One thing came up more and more often in the test, and it also came into sharp focus at the meeting of all participants in the ExtraEnergy special cargo pedelecs test: manufacturers of cargo pedelecs would love significantly more components which are designed for the specific needs and greater loadings of cargo pedelecs from the major component makers. This starts with the electric assist systems and brakes, and goes through to the wheels and tyres, which especially on multi-track cargo pedelecs in the heavy load category can have to endure very heavy shear forces.
When it comes to the drive systems, this current test could provide some significant inspiration. Another hopeful sign is that in December 2015, the ContiTech company announced a variant of its CDS belt drive system specially for cargo pedelecs. Other manufacturers, too, are working on special components for cargo pedelecs, for example tyres.
The pedelecs described here in the test are already very capable and innovative. They offer versatile and effective transport options for both private and commercial users, in the city and, for cargo pedelecs 45, also for longer journeys in the countryside. It was noteworthy that the participating manufacturers took a keen interest in the test process, and were very interested in opportunities to optimise their products. This resulted in numerous positive developments.
Nonetheless: the perfect pedelec – or rather, the components necessary for it – are still largely yet to be developed. There is still huge potential for improvement of handling and safety for cargo pedelecs in the areas of leaning technology, damping and suspension. Even active, electronically-controlled structures, which adjust themselves to the payload, are conceivable. As more and more models come onto the market, and with growing sales figures, such developments will be worthwhile for ever more manufacturers.
In any case, development is already underway. As Victor Hugo said “Nothing is more powerful than an idea whose time has come.”
So be part of it, enjoy the ride and help shape the future!
Rad all test results and further background inormation on the ExtraEnergy Test in the ExtraEnergy Magazine:
Copy: Arne Behrensen, Hannes Neupert, Wasilis von Rauch
Picture: Moritz Grünke
Online Publication: Angela Budde
10 October 2016