Nice write up! I am also fiddling with my bike and have just figured how to pull the binary from the main M4 soc. Perhaps you could share your work with https://github.com/Bernardus/openmoof
(Not my repo but has a lot of good info, I plan to share the binary as well once I made some progress in reversing it)
The VanMoof e-shifter is awful: Every shift comes as an interruptive surprise which makes for a very uncomfortable ride. The test ride was the reason I did not get one.
Cowboy bikes are much better, but mine broke on the second day. I sent it back.
Now I got big legs thanks to those brittle novelty iPhone e-bikes failing me.
Can the second analyzer software not do the same measurement as the first? Coming from a point of ignorance here: I lucked into some higher and DLAs (though not 5v compatible so they wouldn't directly help here) and their softwares allow both decode and measurements
Yes, but only in hindsight - and you have to take the "part 1" into account too.
An oscilloscope is able to show analog values. If you have no clue what a signal is, it is your best bet to start with. In this case it turned out to be a simple digital serial signal, but it could've just as well been a 0V-5V analog one or perhaps an open drain bus with pullups like i2c.
Logic analyzers only really work for binary values. You are able to set a single threshold: everything above becomes a 1, everything below becomes a 0. Great if you've got a purely digital signal, useless if it has analog components.
In the first part the author had to start with an oscilloscope to begin exploring. They could've probably switched to the logic analyzer before the first step of part two, but there isn't really a strong reason to do so - and there would still be a nonzero chance of analog components playing a role. Seeing that it was a simple digital "one wire TX, one wire RX" probably gave enough confidence to assume it was something like serial uart and move on.
Maybe I wasn't clear enough, I meant cutting out the gtkwave step. Oscilloscope is great, pulseview great, but what's gtkwave doing here that the others can't?
> The reliability of this e-shifter in the X3 and S3 has been argued as the cause of the failure and eventual bankruptcy of VanMoof
I always wondered what exactly the problem e-shifters were trying to solve was. Is it the "ugliness" of shifting cables? Route them through the frame...
I've got Shimano Di2 shifters on my road bike and they're very luxurious to use.
Advantages:
The controls are simply electronic switches, so you don't need much finger strength to operate them (reputedly these make them useful for people with hand strength issues such as arthritis) and also this means that you can reconfigure them (e.g. a one-armed cyclist can move the relevant controls to just one side) or even add extra controls such as sprinter buttons.
If you've got double/triple chainrings, then the gear change can incorporate the switch-over point so you can just change up or down a gear and let the electronics handle when the chainring shift should occur (this can be changed in the software too according to your preferences).
Also, with regards to the chainrings, the shifting system can adjust the front derailleur to accommodate the chainline better i.e. the front derailleur may need to be a mm or two further over for the smallest or biggest rear cog to prevent the chain rubbing. That's commonly referred to as "trim" and can usually be done manually on a manual gear system.
Probably the biggest benefit is highly reliable shifting - once set up, it will perform perfect shifts every single time, whereas traditional gears will need adjusting as the gear cable inner stretches over time.
As to disadvantages, the biggest issue is the price and the next problem would be that you need to keep the battery charged up or otherwise you're not going to be able to change gear. Typically, a single charge will last for thousands of shifts or a few months. I've also had the battery fail and unfortunately, they're very expensive to replace as the battery component also houses the main electronics for the system (e.g. the brain).
I’ve never used the Shimano system, but I have used the Bosch/Rohloff system. I would much prefer a mechanical shifter.
Pros of electronic controls: it will try to delay shifting until the minimum pedal torque part of the cycle (kinda cool, but I can do this myself just fine without even thinking about it), it will reduce motor torque (useful, but see before — if I pause pedaling for a split second, that will pause motor torque too), and it will automatically downshift when stopped (this is conceptually nice but so problematic that I turned it off).
Cons: you can’t shift large amounts quickly. And, critically, if the Bosch assist system craps out for any reason except low-but-not-quite-dead battery, the shifter will crap out along with it. This turns an oh-well-I-have-no-assist situation into a there’s-no-way-I’m-getting-this-bike-back-home situation.
The Rohloff system is a hub shifter, so all the fancy front derailleur management benefits don’t apply at all.
That sounds quite different. The Shimano Di2 is for manually propelled bikes and it has no way to determine the torque/pedal position. However, derailleur systems are designed to shift under torque, so it doesn't make much odds with most shifts, unless you're doing front chainring shift at the same time as that can make a big change in the pedal resistance which you would want to anticipate.
On all derailleur bikes I’ve ridden, I try to back off the torque a bit while shifting, and this at least seems to reduce nasty noises and any occasional tendency to feel like the chain slipped one link. But I’ve also never ridden a bike with a top-of-the-line derailleur and chainring set from any of the major manufacturers.
Backing off a bit should only really be needed by either worn or misadjusted derailleurs. Modern derailleurs work really well and there's not a huge difference between top and bottom ranges for the major manufacturers. Most of the difference is lighter weight, better manufacturing tolerances and often the number of gears. Misadjustment is more common for the cheaper ranges as the bikes will often not be as well maintained as the expensive ones.
An indexed shifter can also perform perfect shifts for thousands of times, and after that time you don't need to change out a battery you just need to maybe turn the barrel adjuster a few mm. The chainring thing is cool but front-gearing is also sort-of on the way out in favor of 1x groupsets.
One of the greatest things about bikes, IMO, is how elegantly simple they are and how that translates into reliability and ease of maintenance. The push to using electrical components feels like a step in the wrong direction in this regard.
I've got nothing against non-electronic index-shifters, but they do require more adjustment than Di2 systems (not a big deal - usually just use the barrel adjuster). There's also the need to replace the inner cable which most people don't bother doing (I had one snap in the brifter head which seemed to be a fault with that particular brifter model).
You can take my double-chainring when you can pry it out of my cold dead hands.
I do agree about the simplicity and maintenance benefits of manual shifters (I do most of my own bike maintenance, so have worked on both systems) and if I were planning a cross-continent bike ride, I think mechanical shifters would be beneficial as it may not be easy to source electronic shifting components (e.g. hitting a rear derailleur on a rock and requiring a replacement).
However, the sheer pleasure of using electronic shifting (a slight press and then a satisfying click-whirr to change gear) means that most people who have experienced it are unlikely to go back to mechanical.
By the way, you usually just charge up the Di2 system rather than replacing the battery. Battery replacement is only for when something has gone wrong or you require features not supported on the older versions (e.g. synchro-shifting wasn't supported on the older external battery compared to the seat-post battery versions).
I doubt it's about the cabling. It's convenient not to have to think about shifting, like an automatic transmission in a car. I sometimes wish my bike had it.
With a derailleur, no amount of e-shifting magic can shift while stopped. And even with a hub shifter, most “automatic” systems I’ve used have an annoying failure in which you slow or stop briefly, try to start pedaling again, and discover that the system has chosen that moment to downshift several steps and you actually can’t go anywhere until it’s done.
Regular shifter cables can and are also routed through the frame.
Expensive road bikes (as well as the ones professionals ride) use e-shifters without any problems. These are made by companies that have some expertise in manufacturing shifters. They’re very expensive, though, as they’re made for road racing, not for regular bikes like the ones VanMoof made.
VanMoof wanted to do everything themselves and found out the hard way that was a bad idea.
Trek Lime had an automatic 3-speed, circa mid-2000's. A friend of mine had one. I don't think there were ever widespread reliability issues. Sram had a 2-speed automatic that was fully mechanical.
Intriguing stuff here from a geek perspective, as I have an X2 and am only plagued by a lack of gears. I would expect e-shifters to have been made reliable by the time the 3 series came out, I didn't realize they were that bad, especially as I would love to see them everywhere. Having to adjust my son's bike shows how tough shifting gears can be, and the cable is constantly stretching. Plus, the whole getup freezes in winter.
Nice write up! I am also fiddling with my bike and have just figured how to pull the binary from the main M4 soc. Perhaps you could share your work with https://github.com/Bernardus/openmoof
(Not my repo but has a lot of good info, I plan to share the binary as well once I made some progress in reversing it)
The VanMoof e-shifter is awful: Every shift comes as an interruptive surprise which makes for a very uncomfortable ride. The test ride was the reason I did not get one.
Cowboy bikes are much better, but mine broke on the second day. I sent it back.
Now I got big legs thanks to those brittle novelty iPhone e-bikes failing me.
Can the second analyzer software not do the same measurement as the first? Coming from a point of ignorance here: I lucked into some higher and DLAs (though not 5v compatible so they wouldn't directly help here) and their softwares allow both decode and measurements
Yes, but only in hindsight - and you have to take the "part 1" into account too.
An oscilloscope is able to show analog values. If you have no clue what a signal is, it is your best bet to start with. In this case it turned out to be a simple digital serial signal, but it could've just as well been a 0V-5V analog one or perhaps an open drain bus with pullups like i2c.
Logic analyzers only really work for binary values. You are able to set a single threshold: everything above becomes a 1, everything below becomes a 0. Great if you've got a purely digital signal, useless if it has analog components.
In the first part the author had to start with an oscilloscope to begin exploring. They could've probably switched to the logic analyzer before the first step of part two, but there isn't really a strong reason to do so - and there would still be a nonzero chance of analog components playing a role. Seeing that it was a simple digital "one wire TX, one wire RX" probably gave enough confidence to assume it was something like serial uart and move on.
Maybe I wasn't clear enough, I meant cutting out the gtkwave step. Oscilloscope is great, pulseview great, but what's gtkwave doing here that the others can't?
> The reliability of this e-shifter in the X3 and S3 has been argued as the cause of the failure and eventual bankruptcy of VanMoof
I always wondered what exactly the problem e-shifters were trying to solve was. Is it the "ugliness" of shifting cables? Route them through the frame...
I've got Shimano Di2 shifters on my road bike and they're very luxurious to use.
Advantages:
The controls are simply electronic switches, so you don't need much finger strength to operate them (reputedly these make them useful for people with hand strength issues such as arthritis) and also this means that you can reconfigure them (e.g. a one-armed cyclist can move the relevant controls to just one side) or even add extra controls such as sprinter buttons.
If you've got double/triple chainrings, then the gear change can incorporate the switch-over point so you can just change up or down a gear and let the electronics handle when the chainring shift should occur (this can be changed in the software too according to your preferences).
Also, with regards to the chainrings, the shifting system can adjust the front derailleur to accommodate the chainline better i.e. the front derailleur may need to be a mm or two further over for the smallest or biggest rear cog to prevent the chain rubbing. That's commonly referred to as "trim" and can usually be done manually on a manual gear system.
Probably the biggest benefit is highly reliable shifting - once set up, it will perform perfect shifts every single time, whereas traditional gears will need adjusting as the gear cable inner stretches over time.
As to disadvantages, the biggest issue is the price and the next problem would be that you need to keep the battery charged up or otherwise you're not going to be able to change gear. Typically, a single charge will last for thousands of shifts or a few months. I've also had the battery fail and unfortunately, they're very expensive to replace as the battery component also houses the main electronics for the system (e.g. the brain).
I’ve never used the Shimano system, but I have used the Bosch/Rohloff system. I would much prefer a mechanical shifter.
Pros of electronic controls: it will try to delay shifting until the minimum pedal torque part of the cycle (kinda cool, but I can do this myself just fine without even thinking about it), it will reduce motor torque (useful, but see before — if I pause pedaling for a split second, that will pause motor torque too), and it will automatically downshift when stopped (this is conceptually nice but so problematic that I turned it off).
Cons: you can’t shift large amounts quickly. And, critically, if the Bosch assist system craps out for any reason except low-but-not-quite-dead battery, the shifter will crap out along with it. This turns an oh-well-I-have-no-assist situation into a there’s-no-way-I’m-getting-this-bike-back-home situation.
The Rohloff system is a hub shifter, so all the fancy front derailleur management benefits don’t apply at all.
That sounds quite different. The Shimano Di2 is for manually propelled bikes and it has no way to determine the torque/pedal position. However, derailleur systems are designed to shift under torque, so it doesn't make much odds with most shifts, unless you're doing front chainring shift at the same time as that can make a big change in the pedal resistance which you would want to anticipate.
On all derailleur bikes I’ve ridden, I try to back off the torque a bit while shifting, and this at least seems to reduce nasty noises and any occasional tendency to feel like the chain slipped one link. But I’ve also never ridden a bike with a top-of-the-line derailleur and chainring set from any of the major manufacturers.
Backing off a bit should only really be needed by either worn or misadjusted derailleurs. Modern derailleurs work really well and there's not a huge difference between top and bottom ranges for the major manufacturers. Most of the difference is lighter weight, better manufacturing tolerances and often the number of gears. Misadjustment is more common for the cheaper ranges as the bikes will often not be as well maintained as the expensive ones.
An indexed shifter can also perform perfect shifts for thousands of times, and after that time you don't need to change out a battery you just need to maybe turn the barrel adjuster a few mm. The chainring thing is cool but front-gearing is also sort-of on the way out in favor of 1x groupsets.
One of the greatest things about bikes, IMO, is how elegantly simple they are and how that translates into reliability and ease of maintenance. The push to using electrical components feels like a step in the wrong direction in this regard.
I've got nothing against non-electronic index-shifters, but they do require more adjustment than Di2 systems (not a big deal - usually just use the barrel adjuster). There's also the need to replace the inner cable which most people don't bother doing (I had one snap in the brifter head which seemed to be a fault with that particular brifter model).
You can take my double-chainring when you can pry it out of my cold dead hands.
I do agree about the simplicity and maintenance benefits of manual shifters (I do most of my own bike maintenance, so have worked on both systems) and if I were planning a cross-continent bike ride, I think mechanical shifters would be beneficial as it may not be easy to source electronic shifting components (e.g. hitting a rear derailleur on a rock and requiring a replacement).
However, the sheer pleasure of using electronic shifting (a slight press and then a satisfying click-whirr to change gear) means that most people who have experienced it are unlikely to go back to mechanical.
By the way, you usually just charge up the Di2 system rather than replacing the battery. Battery replacement is only for when something has gone wrong or you require features not supported on the older versions (e.g. synchro-shifting wasn't supported on the older external battery compared to the seat-post battery versions).
Note that the VanMoof was an e-bike with a lot of built-in features, so it wasn't intended to attract a minimalist market in the first place.
The point is, it's an everything bike, in a stylish package.
I doubt it's about the cabling. It's convenient not to have to think about shifting, like an automatic transmission in a car. I sometimes wish my bike had it.
Good luck.
With a derailleur, no amount of e-shifting magic can shift while stopped. And even with a hub shifter, most “automatic” systems I’ve used have an annoying failure in which you slow or stop briefly, try to start pedaling again, and discover that the system has chosen that moment to downshift several steps and you actually can’t go anywhere until it’s done.
Yeah, I'm not holding my breath.
Regular shifter cables can and are also routed through the frame.
Expensive road bikes (as well as the ones professionals ride) use e-shifters without any problems. These are made by companies that have some expertise in manufacturing shifters. They’re very expensive, though, as they’re made for road racing, not for regular bikes like the ones VanMoof made.
VanMoof wanted to do everything themselves and found out the hard way that was a bad idea.
Trek Lime had an automatic 3-speed, circa mid-2000's. A friend of mine had one. I don't think there were ever widespread reliability issues. Sram had a 2-speed automatic that was fully mechanical.
My wife struggles with shifting gears so an automatic shifter would make things easier for her.
Intriguing stuff here from a geek perspective, as I have an X2 and am only plagued by a lack of gears. I would expect e-shifters to have been made reliable by the time the 3 series came out, I didn't realize they were that bad, especially as I would love to see them everywhere. Having to adjust my son's bike shows how tough shifting gears can be, and the cable is constantly stretching. Plus, the whole getup freezes in winter.