Test / E-Performance: With the Pendix, we took a close look at an e-bike retrofit drive made in Germany. The easy-to-assemble drive, which costs almost €1.500, convinces with a well thought-out concept and only shows a few small weaknesses in practical tests. Nevertheless, the Pendix is not a drive for everyone.
Pendix: The concept
E-bikes are slowly but surely conquering the market - that is evident at every trade fair, as shown by the sales figures or simply by looking at the street or the cycle path. Despite the e-bike boom, retrofit solutions are still exotic and hidden in a niche market. The need is certainly there: After all, there are quite a few cyclists who invested a lot of money in a new bike not too long ago, but which is now gathering dust in the cellar or garage due to lack of fitness or injuries. For many of these cyclists, the thought of an e-bike is quite tempting - but again a major investment? And what to do with the old, new bike? This is exactly where retrofit solutions are an extremely attractive option to kill several birds with one stone.
But the problem with many retrofit kits was that they could only be fitted with great effort, that they could only be fitted on selected bikes, or even both. With these existing problems in mind, the minds behind German manufacturer Pendix sat down to develop a better, universal aftermarket drive. These thoughts gave rise to the Pendix drive of the same name - it can be assembled in less than an hour, is compatible with almost all common bicycles and, from a technical point of view, is state-of-the-art.
Despite the simple installation, Pendix decided against direct sales to end customers - for reasons of liability. The specialist dealer not only takes on the assembly of the drive, but also checks whether the wheel is technically suitable for the installation. By the way, the Pendix costs €1.490 – depending on the effort involved, a little more has to be calculated for the installation.
Pendix: What is behind it?
Basically, the Pendix consists of two components: The motor integrated in the crank and the battery including control electronics and control unit. The latter is an optically quite successful, black cylinder that is simply mounted on the threads for the bottle holder and connected to the motor or crank with a cable. The motor sits in a round plastic housing that sits between the bottom bracket and the left crank arm. It may take some getting used to at first glance, but it has two decisive advantages: it is comparatively easy to install and can be fitted to almost any bike. The only requirement is a frame with BSA thread for the bottom bracket. There are no space problems with the engine, as there is usually more than enough space on the left side of the frame.
The drive itself puts 250 watts and 50Nm on the road - quite respectable for a retrofit drive! The energy comes from the black cylinder, which contains a 300Wh battery. Incidentally, a more powerful model with more endurance has just been announced for the Eurobike, which starts in two weeks. In addition to the energy cells, the housing also contains the controller and the display for the charge level. The Pendix can be regulated in three support levels - Eco, Smart and Sport. The selection is made via a rotary wheel on the top of the battery that is easily accessible and easy to use while driving. There is also a stylish light ring here, the LEDs of which indicate the charging status and are easily recognizable even in bright daylight.
The smart bottom bracket in conjunction with pedal and speed sensors ensures that the support is controlled. The Pendix should offer a similarly harmonious support as modern e-bikes.
Pendix: This is how the retrofit drive performs in practice
It all sounds good in theory, but what matters is practice. We sit on our test bike and start riding without the drive activated: It works surprisingly well, which is partly due to the only slight additional weight of 6,5 kg, but above all to the motor, which is completely inconspicuous when switched off and does not have any effect while pedaling resists. For example, the drive can be easily switched off while driving if you don't need it for a long time.
But after all, we want to test the drive here, so a quick flick of the wrist to the battery, press the big button in the middle and you're good to go. The support is already clearly noticeable in Eco mode and puts a lot of pressure on. It gets even sportier in the Smart and Sport modes, although the highest level of support was almost a bit too much of a good thing for us and also seemed a bit inharmonious at times. Setting the different levels is quick and thanks to clearly noticeable clicks in the easily accessible rotary wheel, you always know which level you are on. We were really surprised by the almost non-existent background noise of the Pendix: The drive is one of the quietest that we have tested in this area so far.
We noticed the system's clearly noticeable after-run as a negative. If you stop pedaling, the motor 'pushes' along for a short moment before stopping. You get used to it quickly and in most cases this can also be neglected, but this unfortunately disqualifies the Pendix for sporty use on the E-MTB - during technical passages, pushing the bike for a short time could end badly.
As already mentioned elsewhere, the Pendix comes with a battery with 300Wh: Compared to the batteries of 'real' e-bikes, this is not too lavish - 400Wh or even 500Wh are usually used here. The slightly smaller capacity is also reflected in the range: Depending on the support level, terrain and your own performance, you can cover up to 70 km - but on long climbs and little personal effort, it can be over after 25 km. The battery can be removed very easily with one hand for charging. To protect the valuable cylinder from thieves, it has a pull-out metal strap through which a standard lock can be threaded.
Pendix: Conclusion on the e-bike retrofit kit
The Pendix is an extremely interesting e-bike drive. Interesting because it is not only light, but also almost noiseless, easy to retrofit and compatible with the majority of commercially available bikes. In the practical test, too, it clearly showed more light than shadow: It is an excellent choice for touring riders who also like to be on the road without support from time to time. We found the clear pushing along somewhat annoying, which is why we would only recommend the drive for off-road use to a limited extent. The range is somewhat limited with the 300Wh battery - but the new model with a higher capacity, which will be released in a few weeks, will be able to remedy the situation.
Andi says
That's exactly what I'm looking for. I choose my bike independently of the e-bike offer and then an uncomplicated, practical motor. You have more fun and range over long distances of more than 100 km.
snipping koetter says
Looking for a dealer who installs Pendix. Area Gladbeck, Essen, Bottrop radius 50km
olo says
Just look at the provider's website (pending.de). There are several dealers in the Gladbeck/Bottrop/Marl area
Falko says
http://Www.pendix.de store locator
Uli says
Karsten Poesken
Poststreitweg 124
45145 Essen
installed the drive for me, very satisfied
Jürg says
A bike that keeps its characteristics. It reacts like without a motor, but you can feel the support. Speeds over 25km/h are easily possible, without e-support but without additional pedaling resistance from the motor. It rides in a headwind as if you had a tailwind. The best thing about it is the absolutely quiet motor. (no whirring like with the Bosch motor)
John says
Stumbled upon this site by accident and need to express my opinion.
I drove the Pendix for a whole year and then gave it back with thanks.
It neither pulls the butter off the bread, nor does it have enough charging capacity and the new, large battery looks like a fire extinguisher, only in black and green.
I was very disappointed as the handling was a horror. In the mountains I tried to change the support and because of the awkward grip on the down tube I almost ended up in oncoming traffic.
The only good thing about this system is the optics, but otherwise I would stay away from it.
Kicking it back is really dangerous!
If you want something useful, then please a Bionix or the Binova flow. These are 2 systems that are really good and make sense.
Klaus says
So I can't quite confirm your description of the Pendix. I test drove the drive and was able to determine the after-run. With normal driving, however, this is not a problem at all. Only when you start and then want to stop again immediately does it push you noticeably. I think, as described in the article, it is not so good for pure off-road driving, but a real recommendation for touring drivers. The various modes can also be easily adjusted while driving. I will definitely order it this week and let it grow!
Axel Heyl says
I had the Pendix drive installed in September 2017. I drive daily tours that are about 50-70 km long, mostly in eco mode. I think the support is great, but I'm a bit disappointed with the performance of my 500 Wh battery.
When fully charged, I get about 65-72 km (tested with a day counter) and find this performance too little even in winter. The bike is in the garage at night at about 8 degrees Celsius, so the battery doesn't cool down extremely. The performance of the 500 Wh battery is specified as 95-160 km, unfortunately I'm far from that.
Can anyone give me any tips that will help?
Jochen says
Hello, lithium batteries are temperature sensitive. Try to keep the battery at 20°C until you start your journey, and then insulate it against the outside temperatures with a sweater (wool, bubble wrap, etc.). Then the range should be better.
Uwe says
I can confirm that. The promises made in the manual are never achieved. I have kept accurate records and achieve a maximum of approx. 55% of the promised information with the 500Wh battery. I have treated the battery with care, never stored it below 15°C and never drove it in temperatures below freezing.
Sabine Eck says
It is not clear to me why the "re-kicking" should only be problematic off-road. As an everyday cyclist, I am confronted with careless drivers every day and have to be able to brake reliably. When I imagine my bike giving an extra push at such a moment, I get the creeps!
I find that extremely unfortunate, because otherwise I really like the fact that there is little or no noise and that the ride is unaffected even without support.
Unfortunately, my bike (Pegasus) is also one of those that do not make conversion possible.
Fränkie says
I test drove the Pendix drive. Drive power and driving characteristics are super good, the engine works silently. The power levels can be conveniently set on the battery.
The barely perceptible after-running of the engine doesn't bother me and has no effect on driving safety.
When the assistance is switched off, there is no pedaling resistance.
The conversion kit consists of only a few parts (no tangle of cables as with the other kits), installation is simple and problem-free and almost all bicycles can be converted with it without much effort.
The drive is also visually appealing and the bike does not look "tinkered".
Conclusion: A good alternative to a new pedelec
Sebastian Bop says
I have a Ghost Square with toothed belt drive from Cates, can I retrofit it?
Hamed.kinderknecht@gmail.com says
I am also very disappointed, I had it installed for about 1800 euros with the large 2018 battery. The battery is empty after 17 km on Sport with a child trailer. He just can't pull a child trailer over long distances. But since I'm a commuter, it was important to me. Optics are awesome. Motor quiet but price-performance a disaster. I'm still talking to my bike dealer. Unfortunately, I didn't listen to the advice and bought a new bike with the money and everything was already assembled. I have to honestly say that before I tested it, I bought a used e-bike on eBay for 350 euros, which pulled like a donkey with a bicycle trailer. The engine was loud, yes, but unfortunately I couldn't get used to the look and sold it again. Conclusion: I would never have this system installed again.
E Weeger says
There are two problems with these direct drives: on the one hand, the torque to speed ratio, and on the other hand, the weight required to be able to achieve the required power with thick coils and an enlarged diameter at the low speeds. Unfortunately, this is pure physics, the power is simply torque times speed. With a compact design and decent efficiency, it doesn't work without a gearbox. Especially not when the drive is on the low-revving bottom bracket. Every start-up process and every little acceleration costs a lot of electricity, which explains the short driving distances achieved in practice. The Pendix system looks good at first glance, but unfortunately this technology is not well suited for most applications. There is nothing like the classic drives with high motor speeds and reduction gears. They are also significantly less critical thermally, and with a good design they do not require a thermal shutdown. Quiet does not also mean good efficiency, which is also particularly low with a direct drive on the bottom bracket due to the low speed.
Ralph Opitz says
Never again Pendix - catastrophic - I feel cheated!!!
€1500,00 loss – just because I absolutely wanted to keep my old bike and had trusted the full-bodied Pendix manufacturer promises.
I had the system installed in the specialist workshop in Dresden Pillnitz. They were always friendly there and always tried to get my bike working again. Unfortunately, nothing could be done about the fundamental problems.
I drove with Pendix for over 1 year - if it wasn't just for repairs. Constant system failures - sometimes only for 1 - 2 minutes but often total failures.
A Pendix employee was even present during the last repair. Some parts have been swapped again. Then it worked, but the utopian range specifications in the device description for the 300 Wh battery were usually not even half achievable.
The battery has been checked at Pendix (after almost a year of use). Result according to the test report = everything is fine - no defect!
Since my driving conditions are usually at least average, I assumed that I would achieve at least half of the maximum range (“Sport” mode = 45 km, “Smart” = 72 km, “Eco” = 105 km).
My results were in good driving conditions - mode "Sport" = 21,3 km, "Smart" = 25,5 km and "Eco" = 50,0 km. That's cheating!!!
You shouldn't try to see the causes of incorrect driving or shifting behavior, panniers that are always overfull, a neglected (unoiled gearshift) bike and 1 year of constant headwind and yes, on my daily commute to work (Elbradweg from Radebeul - Dresden) there are actually some easy ones Gradients - but in the afternoon it's downhill again at these points.
I have kept everything for presentation - purchase receipts, repair and test reports and driving records.
I also complain about the long loading time. At the end of the charging time, the control lamp will flash irregularly (2 – 3 x green and then 1 x red). According to the description, this does not exist, but Pendix says by phone = everything is OK!
That ridiculous battery safety bracket fits right in with all the other problems.
I've been driving a "Riese and Müller Cruser" for 8 months now = everything is OK!!!
I haven't changed my driving style, the panniers are just as full or empty and I haven't "lost weight".
I find Pendix's nomination for the business award "Saxony's Entrepreneur of the Year" 2018/19 interesting. This award is an initiative of, among others, "Volkswagen Sachsen" (see SZ article from Monday, January 28.01.19th, 23, page XNUMX). No wonder for me - VW is well versed in number manipulation and how to leave customers out in the cold with impunity.
Kind regards Ralf Opitz.
Flesh says
Anyone know anything about the controls? Is the torque generated by the driver measured (what is meant by "pedal sensor"?) and is the motor switched on proportionally?