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The wheels move exactly as the driver wants in any vehicle with a mechanical steering rack. It's not a problem. Lag due to poor drive-by-wire implementation how

The wheels move exactly as the driver wants in any vehicle with a mechanical steering rack. It's not a problem. Lag due to poor drive-by-wire implementation however is most definitely a problem and not a small one, it's a significant safety hazard.

smallmancontrov 3y ago
> The wheels move exactly as the driver wants If I try to turn the front wheel of my bike too far left or right it does not let me. Further, this is accomplished by a rubber bumper that continues to push for a short time after I let up, but it would be absurd to call this "lag." Normal operation of the bicycle never gets close to those limits. The question is whether this video is showing typical system lag -- in which case, yeah, I agree, it's a problem -- or whether it is showing limiting behavior in which case getting upset about it makes as much sense as getting upset over the rubber bumpers on my bike.
- throwaway81348 3y ago
  I am not upset by a bike behavior because I know exactly what my wheels are doing just by holding the bars. Same in a mechanical steering rack. This here seems more like a guessing game
- zettabomb 3y ago
  >If I try to turn the front wheel of my bike too far left or right it does not let me. Not sure what you're referring to here - I've got multiple bicycles and the headset bearing allows them to spin around 360 degrees, the only thing preventing them from going further is the cables and hydraulic hoses. >Further, this is accomplished by a rubber bumper that continues to push for a short time after I let up What bumper do you mean? Your handlebars, stem, and fork should be moving as a solid unit, with minimal deformation under any reasonable conditions. There's very little elasticity in the system, perhaps the biggest source is just the spokes (or the grips if they're quite thick). The behavior exhibited in the video is way more than any properly operating bicycle.
  - smallmancontrov 3y ago
    Your bike is different than mine. Shrug. It is not beyond my imagination to imagine the free-spinning mechanism you have described, so I cannot imagine that it is beyond yours to imagine a bumper. Try, and you will succeed.
    - zettabomb 3y ago
      I seriously have no idea where such a bumper would even go, let alone what it would look like. And it's not my bike, it's dozens of ones that I have owned or seen. It's also far easier to imagine the lack of something rather than the existence of something you've never even heard of. A simple link to a photo would be quite helpful.
  - defrost 3y ago
    If you ditch the cables altogether it's a blast: https://www.youtube.com/watch?v=lqCyTM1bF6Q https://www.youtube.com/watch?v=lqCyTM1bF6Q
itishappy 3y ago
> The wheels move exactly as the driver wants in any vehicle with a mechanical steering rack. Your rims might, your tires don't. Check out about halfway down this page: https://ciechanow.ski/bicycle/ https://ciechanow.ski/bicycle/
- lloeki 3y ago
  Yes there's a bit of slack and elasticity all the way including in metal parts, not just in tires. Still, even though the tire tread doesn't move right away the moving rims are immediately exerting force on the tire interior, and thus there's an instant converse force from the tire interior which resists the movement. In any case, this vehicle has rims and tires; what's being discussed here only adds lag to the existing system, which appears to be several orders of magnitude higher than the above physical process. But what's apparently worse here is that there's no link (whether physical or digital): the video shows the driver has moved the steering device all the way to lock yet the wheels are only halfway through and then continue moving towards lock in spite of the steering device being completely still.
- zettabomb 3y ago
  >Your rims might If they don't something is broken. >your tires don't. I did say "wheels", which generally speaking means the rim. Yes, I'm well aware of tire deformation and contact patch mechanics, but that's not the issue here - the rims on the truck are not moving in sync with the wheel. It's just not acceptable.
  - itishappy 3y ago
    > If they don't something is broken. The speed of sound in steel and roughly 1m of steering column put the theoretical minimum latency at 0.2ms. Manufacturing tolerances and material strain put minimum bounds on accuracy as well. Your entire suspension, down to the rigidity of the individual linkages, influences the steering of your vehicle. > Yes, I'm well aware of tire deformation and contact patch mechanics, but that's not the issue here... I think it's very relevant to know that cars already take the direction of the tires/rims/wheel as more of a suggestion. The "tightness" of the steering and the suspension varies drastically between vehicles. So what is the issue here? How it drives. I don't have one, but a common comment I've found in reviews is that it's "too sensitive." I think this is an imagined problem.
deleted 3y ago
[deleted]

smallmancontrov 3y ago

> The wheels move exactly as the driver wants If I try to turn the front wheel of my bike too far left or right it does not let me. Further, this is accomplished by a rubber bumper that continues to push for a short time after I let up, but it would be absurd to call this "lag." Normal operation of the bicycle never gets close to those limits. The question is whether this video is showing typical system lag -- in which case, yeah, I agree, it's a problem -- or whether it is showing limiting behavior in which case getting upset about it makes as much sense as getting upset over the rubber bumpers on my bike.

throwaway81348 3y ago
I am not upset by a bike behavior because I know exactly what my wheels are doing just by holding the bars. Same in a mechanical steering rack. This here seems more like a guessing game
zettabomb 3y ago
>If I try to turn the front wheel of my bike too far left or right it does not let me. Not sure what you're referring to here - I've got multiple bicycles and the headset bearing allows them to spin around 360 degrees, the only thing preventing them from going further is the cables and hydraulic hoses. >Further, this is accomplished by a rubber bumper that continues to push for a short time after I let up What bumper do you mean? Your handlebars, stem, and fork should be moving as a solid unit, with minimal deformation under any reasonable conditions. There's very little elasticity in the system, perhaps the biggest source is just the spokes (or the grips if they're quite thick). The behavior exhibited in the video is way more than any properly operating bicycle.
- smallmancontrov 3y ago
  Your bike is different than mine. Shrug. It is not beyond my imagination to imagine the free-spinning mechanism you have described, so I cannot imagine that it is beyond yours to imagine a bumper. Try, and you will succeed.
  - zettabomb 3y ago
    I seriously have no idea where such a bumper would even go, let alone what it would look like. And it's not my bike, it's dozens of ones that I have owned or seen. It's also far easier to imagine the lack of something rather than the existence of something you've never even heard of. A simple link to a photo would be quite helpful.
- defrost 3y ago
  If you ditch the cables altogether it's a blast: https://www.youtube.com/watch?v=lqCyTM1bF6Q https://www.youtube.com/watch?v=lqCyTM1bF6Q

itishappy 3y ago

> The wheels move exactly as the driver wants in any vehicle with a mechanical steering rack. Your rims might, your tires don't. Check out about halfway down this page: https://ciechanow.ski/bicycle/ https://ciechanow.ski/bicycle/

lloeki 3y ago
Yes there's a bit of slack and elasticity all the way including in metal parts, not just in tires. Still, even though the tire tread doesn't move right away the moving rims are immediately exerting force on the tire interior, and thus there's an instant converse force from the tire interior which resists the movement. In any case, this vehicle has rims and tires; what's being discussed here only adds lag to the existing system, which appears to be several orders of magnitude higher than the above physical process. But what's apparently worse here is that there's no link (whether physical or digital): the video shows the driver has moved the steering device all the way to lock yet the wheels are only halfway through and then continue moving towards lock in spite of the steering device being completely still.
zettabomb 3y ago
>Your rims might If they don't something is broken. >your tires don't. I did say "wheels", which generally speaking means the rim. Yes, I'm well aware of tire deformation and contact patch mechanics, but that's not the issue here - the rims on the truck are not moving in sync with the wheel. It's just not acceptable.
- itishappy 3y ago
  > If they don't something is broken. The speed of sound in steel and roughly 1m of steering column put the theoretical minimum latency at 0.2ms. Manufacturing tolerances and material strain put minimum bounds on accuracy as well. Your entire suspension, down to the rigidity of the individual linkages, influences the steering of your vehicle. > Yes, I'm well aware of tire deformation and contact patch mechanics, but that's not the issue here... I think it's very relevant to know that cars already take the direction of the tires/rims/wheel as more of a suggestion. The "tightness" of the steering and the suspension varies drastically between vehicles. So what is the issue here? How it drives. I don't have one, but a common comment I've found in reviews is that it's "too sensitive." I think this is an imagined problem.

deleted 3y ago

[deleted]