Legal speed restrictions on electric bikes

General cycling advice ( NOT technical ! )
rogerzilla
Posts: 2876
Joined: 9 Jun 2008, 8:06pm

Re: Legal speed restrictions on electric bikes

Post by rogerzilla »

I remember them all coming in together and parking up at the touchline at football matches. You could have any colour you liked as long as it was pale blue.
djnotts
Posts: 3024
Joined: 26 May 2008, 12:51pm
Location: Nottingham

Re: Legal speed restrictions on electric bikes

Post by djnotts »

rogerzilla wrote: 12 Aug 2022, 9:40pm I remember them all coming in together and parking up at the touchline at football matches. You could have any colour you liked as long as it was pale blue.
Memory jogger, I'd forgotten that. The blue ones were I think one of a few makes/models. There's a detailed history on wiki!
hemo
Posts: 1438
Joined: 16 Nov 2017, 5:40pm
Location: West Sussex

Re: Legal speed restrictions on electric bikes

Post by hemo »

andrew_s wrote: 12 Aug 2022, 6:28pm
st599_uk wrote: 11 Aug 2022, 10:42am Presumably they can still be subject to a stop for Wanton or Furious Cycling
If the police ever stop a derestricted ebike, there's a whole raft of charges they can use, since it's a motor vehicle.
No tax, no insurance, no motorbike helmet, no licence, no MoT, no type approval for the vehicle, etc etc.
The guy in Dalstom who went to court after he and woman collided ( she sadly died of her injuries) and he was riding an illegal bike with a 1000w motor and never got a sniff of any motoring offences.
User avatar
Chris Jeggo
Posts: 571
Joined: 3 Jul 2010, 9:44am
Location: Woking, Surrey

Re: Legal speed restrictions on electric bikes

Post by Chris Jeggo »

MikeF wrote: 12 Aug 2022, 8:57pm ..... Someone near me has "mobility aid" and he proudly tells me its range is 28 miles, before the next charge is needed.
I think 8mph is the legal maximum but on roads (carriageways).
One day last year, cycling along the canal towpath, I caught up with a mobility scooter. I kept station behind him, keeping a close watch on my well calibrated cycle computer. When the path widened I came alongside, saying "Hello! Your scooter does a good speed, seven and a half miles an hour". He just glared at me. "Eight!" he snapped.
MikeF
Posts: 4336
Joined: 11 Nov 2012, 9:24am
Location: On the borders of the four South East Counties

Re: Legal speed restrictions on electric bikes

Post by MikeF »

hemo wrote: 12 Aug 2022, 11:33pm
andrew_s wrote: 12 Aug 2022, 6:28pm
st599_uk wrote: 11 Aug 2022, 10:42am Presumably they can still be subject to a stop for Wanton or Furious Cycling
If the police ever stop a derestricted ebike, there's a whole raft of charges they can use, since it's a motor vehicle.
No tax, no insurance, no motorbike helmet, no licence, no MoT, no type approval for the vehicle, etc etc.
The guy in Dalstom who went to court after he and woman collided ( she sadly died of her injuries) and he was riding an illegal bike with a 1000w motor and never got a sniff of any motoring offences.
More info here
https://www.thesun.co.uk/news/7136632/c ... ike-crash/
and
here https://www.bbc.co.uk/news/uk-england-london-51647068
I think there is a public misconception that electric bikes are limited to 15.5mph, and not the assistance is limited to that speed.
To the vast majority of the public anyone cycling over 15mph is riding carelessly/dangerously. It's beyond their comprehension unfortunately.
"It takes a genius to spot the obvious" - my old physics master.
I don't peddle bikes.
MikeF
Posts: 4336
Joined: 11 Nov 2012, 9:24am
Location: On the borders of the four South East Counties

Re: Legal speed restrictions on electric bikes

Post by MikeF »

Chris Jeggo wrote: 13 Aug 2022, 12:17am
MikeF wrote: 12 Aug 2022, 8:57pm ..... Someone near me has "mobility aid" and he proudly tells me its range is 28 miles, before the next charge is needed.
I think 8mph is the legal maximum but on roads (carriageways).
One day last year, cycling along the canal towpath, I caught up with a mobility scooter. I kept station behind him, keeping a close watch on my well calibrated cycle computer. When the path widened I came alongside, saying "Hello! Your scooter does a good speed, seven and a half miles an hour". He just glared at me. "Eight!" he snapped.
:lol:
"It takes a genius to spot the obvious" - my old physics master.
I don't peddle bikes.
User avatar
CyberKnight
Posts: 913
Joined: 18 Dec 2009, 4:44pm
Location: Derbyshire

Re: Legal speed restrictions on electric bikes

Post by CyberKnight »

the ones that can do 8 mph are not allowed to do so on the pavement, max speed is 4 mph legally
John Wayne: "I won't be wronged, I won't be insulted, and I won't be laid a hand on... I don't do these things to other people, and I require the same from them."
pete75
Posts: 16356
Joined: 24 Jul 2007, 2:37pm

Re: Legal speed restrictions on electric bikes

Post by pete75 »

tatanab wrote: 12 Aug 2022, 6:33am As you say, battery size is simply the size of a fuel tank as it were, nothing to do with speed or power.
The battery contains all the power on an ebike. The motor doesn't produce power it, converts battery power into motion.
Last edited by pete75 on 15 Aug 2022, 12:20pm, edited 1 time in total.
'Give me my bike, a bit of sunshine - and a stop-off for a lunchtime pint - and I'm a happy man.' - Reg Baker
pete75
Posts: 16356
Joined: 24 Jul 2007, 2:37pm

Re: Legal speed restrictions on electric bikes

Post by pete75 »

hemo wrote: 12 Aug 2022, 11:33pm
andrew_s wrote: 12 Aug 2022, 6:28pm
st599_uk wrote: 11 Aug 2022, 10:42am Presumably they can still be subject to a stop for Wanton or Furious Cycling
If the police ever stop a derestricted ebike, there's a whole raft of charges they can use, since it's a motor vehicle.
No tax, no insurance, no motorbike helmet, no licence, no MoT, no type approval for the vehicle, etc etc.
The guy in Dalstom who went to court after he and woman collided ( she sadly died of her injuries) and he was riding an illegal bike with a 1000w motor and never got a sniff of any motoring offences.
It seems like he was but was found not guilty

"Jurors retired to deliberate on the trial just after lunch today and returned within just over an hour to acquit him of causing death by dangerous driving and driving without a licence and without insurance."
https://www.hackneygazette.co.uk/news/c ... an-3652146
'Give me my bike, a bit of sunshine - and a stop-off for a lunchtime pint - and I'm a happy man.' - Reg Baker
User avatar
simonineaston
Posts: 7993
Joined: 9 May 2007, 1:06pm
Location: ...at a cricket ground

Re: Legal speed restrictions on electric bikes

Post by simonineaston »

I doubt the police are particularly bothered with illegal ebikes.
Much to my amusement / despair the only person I've seen being talked to by a bobby or a pcso has been a little old lady who lives nearby, who doesn't drive and suffers from the old arthurs. For her, a modest 'leccy scooter was a real god-send, changing her mobility picture much for the better overnight. So there's an irony there, when she got the ticking off, when the same paths & vicinity are used by guys from a very different demographic, riding various 'leccy vehicles that are super-fast and not always that well maintained - not that plod stands any reasonable chance of catching them, that is !!
S
(on the look out for Armageddon, on board a Brompton nano & ever-changing Moultons)
thirdcrank
Posts: 36764
Joined: 9 Jan 2007, 2:44pm

Re: Legal speed restrictions on electric bikes

Post by thirdcrank »

I presume this is the case which was at court over 2 years ago

E-bike rider Thomas Hanlon weeps as he is cleared of death by careless driving

https://www.standard.co.uk/news/crime/t ... 76446.html

My reading of that article is that he was tried for offences involving riding a motorbike rather than an ebike and was cleared by the jury.
djnotts
Posts: 3024
Joined: 26 May 2008, 12:51pm
Location: Nottingham

Re: Legal speed restrictions on electric bikes

Post by djnotts »

" there's an irony there, when she got the ticking off, when the same paths & vicinity are used by guys from a very different demographic, riding various 'leccy vehicles that are super-fast and not always that well maintained - ...."

Coppers always prefer opponents who are unlikely to fight back or even argue. Much easier to assault children or the elderly.
rogerzilla
Posts: 2876
Joined: 9 Jun 2008, 8:06pm

Re: Legal speed restrictions on electric bikes

Post by rogerzilla »

pete75 wrote: 15 Aug 2022, 12:12pm
tatanab wrote: 12 Aug 2022, 6:33am As you say, battery size is simply the size of a fuel tank as it were, nothing to do with speed or power.
The battery contains all the power on an ebike. The motor doesn't produce power it, converts battery power into motion.
Power = energy (or work)/time.

The battery contains energy, not power. The motor develops power from the energy stored in the battery.
pete75
Posts: 16356
Joined: 24 Jul 2007, 2:37pm

Re: Legal speed restrictions on electric bikes

Post by pete75 »

rogerzilla wrote: 16 Aug 2022, 6:56am
pete75 wrote: 15 Aug 2022, 12:12pm
tatanab wrote: 12 Aug 2022, 6:33am As you say, battery size is simply the size of a fuel tank as it were, nothing to do with speed or power.
The battery contains all the power on an ebike. The motor doesn't produce power it, converts battery power into motion.
Power = energy (or work)/time.

The battery contains energy, not power. The motor develops power from the energy stored in the battery.
Is a watt not a unit of power then?
'Give me my bike, a bit of sunshine - and a stop-off for a lunchtime pint - and I'm a happy man.' - Reg Baker
User avatar
Cugel
Posts: 5430
Joined: 13 Nov 2017, 11:14am

Re: Legal speed restrictions on electric bikes

Post by Cugel »

pete75 wrote: 16 Aug 2022, 7:58am
rogerzilla wrote: 16 Aug 2022, 6:56am
pete75 wrote: 15 Aug 2022, 12:12pm

The battery contains all the power on an ebike. The motor doesn't produce power it, converts battery power into motion.
Power = energy (or work)/time.

The battery contains energy, not power. The motor develops power from the energy stored in the battery.
Is a watt not a unit of power then?
Wot's this? A confusion over power? Well, we do tend to use the terms for energy use and storage rather loosely at times. In common-speak:

Battery capacity (it's maximum stored energy) is measured in watt-hours - the quantity of power stored. The power usage rate is the time taken to use the energy in the battery - an hour of power at a usage rate of 250 watts if a battery capacity is 250 watt-hours, say.

Therefore, the rate of power delivered & used from the battery determines how long a battery of a particular capacity will last until fully discharged. For example, two hours if the power usage rate is a constant 125 watts.

Power usage rates from a battery are limited by a) the ability of the consuming thing to turn battery-watts into another form of power (such as the moment of an electric motor at its maximum power consumption rate; and b) the maximum practical discharge rate of the battery if it's energy is to be safely and efficiently used.

E-bike motors are (legally) limited to an average usage rate of 250 watts. In practice they seem to vary in their momentary maximum power output, with some able to operate at short periods of many more watts than 250. Generally they get used at lower powers; and sporadically, not continuously. A more practical measurement seems to be the torque an e-motor can produce - although it's not clear whether that's usually expressed as an average or a maximum ( usually in Newton-meters).

The e-bike battery is managed by circuits designed to optimise various behavioural factors, such as maximum/minimum storage amount allowed (less than the absolute maximum and more than the absolute minimum) to prevent battery damage. Charging and discharging rates also seem to get managed, to the same intent of preventing damage. So it's never quite clear what the real capacity and maximum discharge rate of a battery are, since it would be damaging to rely on those values in use.

************
Incidentally, the legal speed limit for electric bikes (that 25kph) is allowed a variance of 10% in practice, or so I read. Presumably this is because the power-limiting software governing the e-motor employs a single assumed wheel size? Putting a fat tyre on a wheel will make it's wheel circumference significantly longer, so your bike will go further per wheel revolution than the assumed circumference-value used by the speed limiting software to cut off motor power. You'll be able to go a bit faster than 25kph before the motor cuts out.

Cugel, now waiting to be corrected. :-)
“Practical men who believe themselves to be quite exempt from any intellectual influence are usually the slaves of some defunct economist”.
John Maynard Keynes
Post Reply