How to limit a bike to 20MPH

[Mouert]

Kinda the opposite of what most people want. I want to limit a 2024 bike to 20mph so that its considered a class 1. I will remove the throttle as well. This will let my kid get to school legally (I'm in California) and when he gets experience and years on him we can adjust.

So what would the process/parts be like to make a bike's top speed be 20MPH. MANY THANKS for any guidance!!

Let's say its an RX series if that matters.

 

[offGridDownUnder]

Depends on the controller. Mine has settings I can change. I don't now what 'RX' means - can you provide links, or a picture of the controller?

If you can't set it in the controller, then it's another problem, and we can ask about that.

 

[Nix Liou]

If it's a hub motor you would need to find how to adjust the controller settings probably. Some have adjustable speed limits, some might let you change the tire radius, where increasing it would make it think its faster than it is.
For a mid drive motor, you could do the above, or change the gearing, and decrease the ratio.

What RX series? s73?

 

[amberwolf]

Kinda the opposite of what most people want. I want to limit a 2024 bike to 20mph so that its considered a class 1. I will remove the throttle as well. This will let my kid get to school legally (I'm in California) and when he gets experience and years on him we can adjust.

So what would the process/parts be like to make a bike's top speed be 20MPH. MANY THANKS for any guidance!!

Let's say its an RX series if that matters.

Not knowing what an RX series is, or which specific bike, brand, model, etc., and all the details of what comes on the bike and what controller / display it has, and thus what options it might have available, we can't give you any specifics about how to modify it to do what you want.

But in general, you can do one of these:
--change speed limit settings in it's menu, if it has any
--buy something like the Cycle Analyst from ebikes.ca (and tune all of it's settings to match your system and needs)
--replace your controller / display with a new one that has speed limit settings and all other features you want in the system
--build and code a small MCU (arduino, pic, esp, etc) board to read your speed sensor and then apply ebrake if speed exceeds 20mph (if you were using throttle it would be able to directly control the speed, but if you're using PAS via the controlelr it can't--you'd have to have it also read the PAS and then send a throttle to the controller instead, which is what the CA does).

 

[E-HP]

Kinda the opposite of what most people want. I want to limit a 2024 bike to 20mph so that its considered a class 1. I will remove the throttle as well. This will let my kid get to school legally (I'm in California) and when he gets experience and years on him we can adjust.

So what would the process/parts be like to make a bike's top speed be 20MPH. MANY THANKS for any guidance!!

Let's say it’s an RX series if that matters.

Does he agree with your approach? Do you ban him from the internet?
He’s going to figure out how to unlock it in less time than it takes you to lock it, because he’s probably better at finding that out on the net than you are already. You control the wallet, not the technology. Buy a slower bike.

 

[wturber]

Does he agree with your approach? Do you ban him from the internet?
He’s going to figure out how to unlock it in less time than it takes you to lock it, because he’s probably better at finding that out on the net than you are already. You control the wallet, not the technology. Buy a slower bike.

Maybe he would. Maybe he wouldn't. Depends on the kid I guess. My inclination would be to explain the reasons - namely that it is the law and that there are liability/safety concerns. If he re-engineers the bike back to Class 3. Then no more ebike. Simple.

Of course, buying a slower bike might be sensible. But the same logic applies. Some kids will find a way to boost the slower bike. But again, let the kid face the consequences. And depending on how parent feels about the reasonableness of the laws, he may choose to just let the school and or legal system impose the consequences (if any). My concern as a parent would be mixed between the kid's safety and personal/family liability. If safety was a big question mark with this kid, I'd probably never get the ebike to begin with. The fact that he has it at all carries with it some degree of trust.

 

[E-HP]

Maybe he would. Maybe he wouldn't. Depends on the kid I guess. My inclination would be to explain the reasons - namely that it is the law and that there are liability/safety concerns. If he re-engineers the bike back to Class 3. Then no more ebike. Simple.

Of course, buying a slower bike might be sensible. But the same logic applies. Some kids will find a way to boost the slower bike. But again, let the kid face the consequences. And depending on how parent feels about the reasonableness of the laws, he may choose to just let the school and or legal system impose the consequences (if any). My concern as a parent would be mixed between the kid's safety and personal/family liability. If safety was a big question mark with this kid, I'd probably never get the ebike to begin with. The fact that he has it at all carries with it some degree of trust.

With those kind of ninja parenting skills you should be able to just tell the kid to keep it under 20 and do nothing to the bike. Too bad you're fighting hormones and peer pressure too, I mean if johnnys dad doesn’t limit his bike, I guess my dad doesn’t trust me like his cool dad does. Even the best kids can succumb to peer pressure, and I barely ever see them riding alone, which they will be, if they can’t keep up.
Which message do you convey? I trust you so much that I’m not locking down your bike, or I trust you enough to understand that I don’t trust you enough to make good decisions so I’m locking down your bike. But, I do trust you enough not to unlock it. Or, you just buy the slower ebike and say you get what you get, don’t get upset. That way dad’s not stupid, he’s just cheap.
I’ve seen waves of these groups of kids on e-bikes over the last two summers, and they all ride responsibly, in their parents imagination.

 

[wturber]

With those kind of ninja parenting skills you should be able to just tell the kid to keep it under 20 and do nothing to the bike. Too bad you're fighting hormones and peer pressure too, I mean if johnnys dad doesn’t limit his bike, I guess my dad doesn’t trust me like his cool dad does. Even the best kids can succumb to peer pressure, and I barely ever see them riding alone, which they will be, if they can’t keep up.
Which message do you convey? I trust you so much that I’m not locking down your bike, or I trust you enough to understand that I don’t trust you enough to make good decisions so I’m locking down your bike. But, I do trust you enough not to unlock it. Or, you just buy the slower ebike and say you get what you get, don’t get upset. That way dad’s not stupid, he’s just cheap.
I’ve seen waves of these groups of kids on e-bikes over the last two summers, and they all ride responsibly, in their parents imagination.

Cheap dad wouldn't be buying a new bike. He'd be using the old bike. Now you are imagining the boy is stupid?

As for trust, as I said, dad is just trying to be compliant with the law. The message doesn't have to be communicated as a matter of trust at all. You can hide behind the law as easily as you can hide behind being cheap in this case.

Having been a young boy, it would have been easier for me to restrain myself from modifying a bike than it would have been to restrain myself from simply using what was immediately at hand to go faster. The 28 mph bike in the hands of a boy is, IMO, more of an attractive nuisance than one that has been modified/reconfigured. Trust isn't binary. But as I said, these kinds of decisions depend greatly on the particular kid.

 

[2old]

Since it has a throttle, it's almost certainly not a major OEM, so configurable. Probably it has a 25+ amp controller, and replacing it with a 12 - 15 amp will limit the speed to Class 1. Also, some of those bikes have a system whereby connecting (or disconnecting) a wire system will impact the PAS system by removing a couple of levels (I have a DIY hub bike with that feature; you can lock out Levels 4 & 5 of a five PAS system).

 

[E-HP]

Cheap dad wouldn't be buying a new bike. He'd be using the old bike. Now you are imagining the boy is stupid?

As for trust, as I said, dad is just trying to be compliant with the law. The message doesn't have to be communicated as a matter of trust at all. You can hide behind the law as easily as you can hide behind being cheap in this case.

Having been a young boy, it would have been easier for me to restrain myself from modifying a bike than it would have been to restrain myself from simply using what was immediately at hand to go faster. The 28 mph bike in the hands of a boy is, IMO, more of an attractive nuisance than one that has been modified/reconfigured. Trust isn't binary. But as I said, these kinds of decisions depend greatly on the particular kid.

Never implied any kids being stupid. What message is conveyed when you adjust the bike to be compliant with the law, but then add “and when he gets experience and years on him we can adjust.”? Does that mean you can break the law once you are older and experienced enough? How does hiding behind the law work then?
I was riding dirt bikes at a young age. You see examples of that on this forum. Always wear a helmet and don’t ride around cars are the main rules a kid can follow and the most important for staying alive. That and don’t hang out with the wrong crowd.
If you control the wallet, then you take care of the speed element, unless the kid wants to get a job and pay for upgrades, which wouldn’t really be a bad thing, since he will be demonstrating the kind responsibility that dads are looking for.

 

[offGridDownUnder]

Does that mean you can break the law once you are older and experienced enough?

Well, is that actually the case here?

I read that the OP wants to limit the ebike to 'class 1' or such while the child is younger. 'Older and experienced' could coincide with 'adult'.

Your question stands on it's own, just noting that the OP is looking for a short-term fix.


Irrelevant to the rest of this post, but my solution is that no one operates a motor-powered vehicle in public spaces without a driver's license - and we focus on refining and enforcing licenses rather than wasting resources coming up with fanciful schemes for a myriad of special cases. We don't need to - it's all the same problem.

A driver's license is about maturity, so already answers the question. If no other children are operating motor-powered vehicles, then the peer-group aspect goes away, and we need not worry about the maturity question - except about enforcing it for people over the age to receive a driver's license. That's what we lack - an honest approach to dealing with driver licensing.

Children benefit form using their bodies, and not doing this while growing can't be completely corrected later - 'acoustic' bikes are quite enough - they won't excel more at school if they don't pedal. If anything, I would expect the opposite.

If there aren't any dicks of any age on ebikes, then we have an easy answer to the problem of irrational laws about ebikes. That is the real problem and the real solution. As well, if we don't tolerate dicks in cars, then we can avoid the problems of dicks in cars. It's a win-win.

Pointing out the real problem and being consistent about pointing it out will help penetrate the bullshit hand-waving that is used to avoid solving the problem.

 

[wturber]

Never implied any kids being stupid. What message is conveyed when you adjust the bike to be compliant with the law, but then add “and when he gets experience and years on him we can adjust.”?

I assumed it meant when he was of legal age to ride a Class 3.

 

[wturber]

Irrelevant to the rest of this post, but my solution is that no one operates a powered vehicle in public spaces without a driver's license - and we focus on refining and enforcing licenses rather than wasting resources coming up with fanciful schemes for a myriad of special cases. We don't need to - it's all the same problem.

You mean a motor powered vehicle? Keep in mind that a bicycle is a powered vehicle, but it is human power, not motor power. Why should a human powered vehicle be OK while a motor powered one is not? There is nothing fanciful about these schemes in general. The general attempt is to recognize like vehicles. A slow and/or lower powered ebike is very much like a human powered bicycle. They are far more like a bicycle than what has been traditionally considered to be a motor vehicle. So it makes sense that - within limits - they be treated the same or similarly and not be treated like cars, trucks and motorcycles that are many times the ebikes weight and that travel at multiples of their speeds. The problem is largely isolated on two factors, speed and weight. Regulation should focus on those two things not simplistic notions of "powered" or not.

 

[E-HP]

I assumed it meant when he was of legal age to ride a Class 3.

Maybe, but a lot kids would already have their learner's permit or would be bugging their parents to let them practice driving or to take driver's ed (do they still do driver's ed in high school?) by that age.

 

[offGridDownUnder]

You mean a motor powered vehicle?

I agree that my writing was poor in this case.

 

[offGridDownUnder]

Regulation should focus on those two things not simplistic notions of "powered" or not.

My point is that regulation should focus on the issues of maturity and responsibility.

This leads to a social environment that routinely puts people on notice that they are living with others, and will not be excused from acting like they are.

I accept that various vehicles may need variances in their other licensing terms - consider the vehicles we permit disabled (and elderly disabled) people to use.

I don't agree in relying only on prescriptive attempts to 'prevent' people from admitting their participation in society and avoiding calling them out on it. The physical parameter approach should not substitute for this. People are not (only) animals, which must be trained - we should expect adult behaviour and insist on it - that should always be the foundation. It should be in everyone's face every time they go out into public.

Prescriptive approaches invite argument about the terms because people see (or pretend to see) them as arbitrary. Responsibility to others is very difficult to argue with if every adult is held responsible - it immediately presents as selfishness, because it is.

The majority always gets their way. Sometimes it is necessary to remove some criminals who are attempting to force their desires on the majority, but it always breaks down. There is no reason not to notice the real problem and work towards it, and the observation that it takes longer this time than this other time is only a reason to get started sooner.

And yes, we can have this. When enough people admit it, we'll put it in place. I think this is a foundation of a working system - reality based.