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Comment by cunidev | Hacker News Reader

Similarly, some models suggested have overpowered (or "illegal") engines, as subtly admitted. Going that fast on a bike is by no means safe, if anything because of tyres.

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Pedal bikes will get up to speeds well over 20mph(30kph) going downhill and their tires are still safe.

I mean......based on what? Like don't get me wrong, I used to do a lot of mountain cycling on a road bike, and going downhill I'd approach 60mph(100km/h) easily.....but I was never under any illusion that it's "safe" to do, or that the manufacturer even tested the tyres up to that speed. They just happened to work when we did it.

Road bike tyres are clearly expected to hold at speeds like 50-60kph... that’s not even fast for a descent.

And commuter bike tyres are usually substantially beefier.

Lawyers.

What would you expect to happen to the tyres at high speed? I assume at some speed they’ll fall apart or something but that surely must be at more than 100kph. The things are already holding in air at 100psi+ — why would rolling quickly be an issue?

Of course, at 100kph you might have other issues, like stopping in time, but I wouldn’t expect my tyres to fall apart under me. If you have any further information on this topic I’d love to see it!

Look up "tire speed rating" for answers to your questions.

You only have to look at pro racing to know it’s not common that tyres explode at high speed. Other bad things happen! But tyres only really go on descents when rim brakes melt carbon rims. That’s why many riders used alloy rims in mountains until relatively recently .. when high temp epoxies became more widely available.

Why should cars not have governors, but ebikes should?

Because you can't drive a car on public roads without mandatory training and passing an exam - so the assumption is that you know and understand the standing speed limits and obey them, but you ride a bike/ebike anywhere without any training or licences so the barrier to entry is lower .

Same way how(at least over here) anyone can ride a 50cc motorbike without any training whatsoever, but to ride something more powerful you need a proper motorcycle licence. I'd be happy with some sort of process where you can only ride a 250W ebike with no self-drive without a licence, but more powerful motors are available after passing a licence and with mandatory insurance.

Before we go hog wild with regulations, let's wait until there's a database of vertifed major injuries to innocent people with these rascals on their electric bikes.

(I am not a fan of overregulation. In the USA we have made practically everything illegial.)

Just so I get this straight - you're saying let's wait until people get injured and only then regulate this?

That's right. Not just minor injuries, but major injuries. And not just to guilty people, but innocent people. Then once we have a database (definitely a heavy duty one like Oracle with lots of consultants to nurse it), we'll need a consortium of independent auditors to verify that all those injuries were major, and all the injured people were innocent. Only then will we be able to embark on developing a standard VerifiedInnocentPersonMajorInjuryRecord interchange format, and begin the debates about whether it should be based on CORBA, XML, YAML, JSON, or CSV, and if we can't come to an agreement on that, then we'll have to develop converters between all the different data formats. Because the free market trumps government regulations every time. For some definition of "Trump".

The "mandatory training and exam" are an utter joke in the US. The reality is that of course cars should have speed governors, but we have turned cars into luxury goods so now peoples fragile ego centers around how big and fast their transportation is. Reasonable people want to simulate a PID controller for hours as much as they want to shift manually - not at all.

Cars typically have speed limiters. Not sure why people think they don’t.

Not at a meaningful speed for safety.

Many (most? all?) cars absolutely have governors from the factory. And they're often related to the rating of the tires factory-installed.

You definitely should be able to (and can!) have e-bikes without governors, however, an unlimited e-bike is (and should be) legally treated as the equivalent of a moped/motorcycle, not as the equivalent of a bicycle.

Eh?

I take it you've never seen the Tour de France then?

I mean, severe crashes do happen, and Tour riders are also professional vehicle operators.

Not because tyres explode tho

But not because the (incredibly lightweight and skinny) tires failed due to speed.

I was thinking the failure condition there is that the compounds in the tire were insufficiently grippy to hold the surface of the road in a corner. That’s certainly my biggest worry on a motorcycle. (Edit: it’s also where a great deal of engineering work goes into motorcycle tires)

Why do the tyres matter regarding safety?

Tyres for any vehicle are usually rated for speed. There are probably many more informed people here, but I assume the material and the patterns are designed on a scale according to assumed speed.

The same applies with bikes, just that it's not legally required to advertise so most manufacturers don't really care. Schwalbe is the only company that I know of which actually tests and advertises compatible speeds on their e-bike tyres.

I had no idea. Thanks!

The tires define the distance you need to break the vehicle.

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