Be careful with your #VanMoof Electrified S

by Volker Weber

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Last week I came across a broken Electrified S made by the dutch startup VanMoof. This is a rather simple ebike that gets lots of rave reviews from gadget sites. It's dragged by a front motor, the battery is in the down tube, the electronics are in the top tube. This is a design first construction with the lights at both ends of the top tube.

The particular bike had a very peculiar problem: no steering, but the handle bar was still attached to the bike and the wheel did not come off. So I removed the screw through the top of the stem, and it was unusually long. As soon as I removed this screw, the handle bar came right off with the top of the fork.

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What is interesting here is that the shaft of the fork broke inside the steering tube, and not below, where the largest forces occur. And it was immediately clear why this happened: the shaft was milled to make room for the wire that runs from the electronics down the shaft and through the fork to the front motor.

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That is the root of the problem because the shaft is made from an aluminium alloy and is usually polished with no holes whatsoever. Aluminium is very brittle and this fork developed a stress fracture from the vibrations it was subjected to. Components made from aluminium lose their fatigue strength if they are subject to a notch effect.

I posted on Twitter and VanMoof was quick to contact me, once they figured out my email address:

I hope you’re doing well. First of all, we’re really sorry to see what happened to your bike. This is a known issue which affects a specific batch of 2016 Electrified bikes. We designed and manufactured a new fork component which prevents this from happening, and contacted every rider of this model directly to assist them with the install.

Please know that we have updated our fork design for all bikes produced after 2016 to ensure this issue does not recur. We’re also happy to report that there have been no instances of front fork damage in 2016 Electrified bikes with the new fork component installed.

I asked VanMoof two additional questions. These are their anwers:

Q: Did you replace the fork in those 2016 bikes or are you referring to the long screw that runs through the middle of the assembly to the bottom of the steering tube?

A: We replaced any forks which were damaged. We also shipped/fitted in person a strengthening bolt that indeed runs through the steer tube. This provides extra rigidity and reduces vibrations. In the unlikely event that a fracture does still occur (we’ve had no reported cases), the bolt means the rider can still control the bike and stop safely.

Q: Can you tell me how the new fork looks like?

A: The front fork was completely redesigned for later Electrified models. The necessary holes for cables have been made smaller and moved to a different point on the stem to minimize potential stress. All of our bikes and components have been externally tested for safety and exceed industry standards. I’ve attached a photo of the new fork design.

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Photo VanMoof

I gather that VanMoof did not put new forks into the 2016 bikes that already shipped. Instead they advised owners to fit the long screw through the middle of the front assembly. I do not agree that this measure reduces vibrations but it does prevent the front wheel from coming off which would mean your face hits the ground about one second later. You still lose steering and the outcome depends on where you will find yourself when that happens.

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I am very confident that all of those forks will break with sufficient load cycles. If VanMoof has not heard of any, they simply are not old enough.

On a personal note, I am unlikely to buy any of their bikes. They do look nice in an effort to hide the battery and the motor. But the industry has more or less settled on the mid-motor design with a transmission and better components than VanMoof provides.

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Comments

Hi Volker,
this post came with the right timing, because i was just in the middle of the buying process for an Electrified S. I really like the desgin, but i don't like, what you have found out. Any other recommendation ? Kind regards, Rüdiger

Ruediger L. Thomas, 2020-02-04

You will not be buying an Electrified S but the Electrified S2, which is a completely different bike. Continue if you still like the bike.

Did you ride one? You have to. It's a very different experience from other bikes. Like all aluminium bikes it is very rigid and it has zero suspension. You feel every little bump of the road in your joints. Since there is only one size of frame it is also too large for me to add a suspension to the saddle.

I already have a bike, but if I needed one, I would buy this: https://www.r-m.de/models/charger3/

Volker Weber, 2020-02-04

Almost biking my whole life (but not with the engineering background of Volker) I would also not go for a VanMoof.
Motor in the front wheel will make the bike be difficult to ride in "slippery" situations (e.g. Ice, water and mud,... combined with turns). The power of the front motor will almost every time lead to falling of the bike. Therefore the concept of the middle motor is superior to this.
Volker already mentioned that the alloy frame is very rigid and from what I see this cannot be compensated by bigger wheels, that would provide some suspension.
Now the information with the design of the fork (I would say a nono) to make the "clean" design possible. (and on a personal note: I doubt that the new design - see pic above - will last).
I like "reduced" designs, but first of all form should follow function.

Markus Sperzel, 2020-02-04

Some (like Stromer) have the motor placed at the back wheel. What's the opinion about that?
Thanks.

Ludwig Deruyck, 2020-02-04

The original idea was to build a city bike that withstands any vandalism. There were no lights to break off, no generator, essentially no loose parts at all. And it was quite inexpensive with roller brakes and other rather simple parts. There was a variant with a bike chain inside the frame. At the time I wanted to buy one, it had a 2 gear rear hub, which would have been enough for city riding around here.

But there were trade-offs. The lights would charge with embedded solar panels, or better, they would never charge when you kept your bike inside.

Some things changed with the Electrified and the Smart Bike, basically an Electrified without the front motor and with a smaller battery. Now the bikes have disc brakes. But some things did not. The bike components are still rather cheap. The grips are foam, the saddle is very simple, the brakes are not hydraulic.

And there are tradeoffs again. You can't remove the battery to charge it, so you have to drag the bike up to your flat, unless you have a shed where you could charge it. The founder and CEO is also very tall which might explain why the frame is so large. For smaller people VanMoof came out with the X and then X2, with a significanly lower top tube. This bike looks rather odd, but it can retain the same down tube, which houses the battery.

For me the biggest drawback is the front motor. There was no way to run power to this motor without compromising the front assemby or giving up on the idea of building a vandalism-safe bike.

What I am very, very curious about is the internal lock that blocks the rear wheel with a kick to the rear axle. What could possibly go wrong?

Volker Weber, 2020-02-04

Ludwig, if you have the motor in the back wheel, that's a bit better than a front motor. It's the only sensible way to retrofit a bike that was designed with a standard frame. Its main advantage is the power does not need to go through the chain or carbon belt.

Pinion has an interesting concept where the transmission is in front where the mid-motor usually sits and the actual motor goes to the back. That feels very natural to me: https://pinion.eu/e-bike/

Volker Weber, 2020-02-04

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