DIY Mechanical Dongle

Gringo

Esteemed Pedelecer
Jun 18, 2013
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Some folks appear to have missed the point of my experiment.
I just wanted to see if it was possible to have my display show kph but actually be doing mph, simply out of curiosity and nothing more.
I didn’t intend to raise the “legality “ issue, just thought some may find it interesting from an engineering / mechanical angle.
I wish I’d never bothered starting this thread now.
 
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D C

Esteemed Pedelecer
Apr 25, 2013
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It is illegal to possess any fitted method under the rider's control that can increase the assist speed above 25 kph (15.5 mph), whether used or not.

Such a machine is no longer an EAPC (Electric Assist Pedal Cycle) in law. It becomes a motor vehicle with all that implies.
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I don't wish to derail this interesting thread but does that mean that the King Meter supplied with my Woosh kit could be construed as illegal as it's possible to change the maximum speed. I've never done this nor have any wish to do so but from the manuals it appears it can easily be done.
Dave.
 

Benjahmin

Esteemed Pedelecer
Nov 10, 2014
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I understand - I do. It's an engineering/maths challenge. One up for garden shed engineering, long may it continue, lest we get to the point that motorcycles seem to have arrived at. It's virtually impossible to alter or even service these highly developed machines without a mechanics degree and a full workshop kitted out with oodles of specialist tools all having one specific job on one specific machine.
Keep tinkering chap!:p
 
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flecc

Member
Oct 25, 2006
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I don't wish to derail this interesting thread but does that mean that the King Meter supplied with my Woosh kit could be construed as illegal as it's possible to change the maximum speed. I've never done this nor have any wish to do so but from the manuals it appears it can easily be done.
Dave.
Yes, it's a daft situation that manufacturers are in with rider alterable LCDs, but it does make their pedelecs technically illegal, no longer qualifying for exemption from being motor vehicles.

The DfT use the term "Off road button" to describe any method of speed alteration by the rider. Note the words strictly forbidden in the following DfT sentence:

"The use of an "Off Road Button" however is strictly forbidden now and is specifically mentioned in documents appertaining to new and existing guidelines."

Obviously they mean it. Of course in practice no-one is going to be bothered by this technicality if the facility is not used, but if it is used the situation is entirely changed as the DfT makes very clear in saying "the use of".
.
 
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flecc

Member
Oct 25, 2006
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Some folks appear to have missed the point of my experiment.
I just wanted to see if it was possible to have my display show kph but actually be doing mph, simply out of curiosity and nothing more.
I didn’t intend to raise the “legality “ issue, just thought some may find it interesting from an engineering / mechanical angle.
I wish I’d never bothered starting this thread now.
It's inevitable that legality will always be raised, even with an interesting and excellent experiment like yours. Many are genuinely interested in what the law actually is and whether they could enjoy such options.
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vfr400

Esteemed Pedelecer
Jun 12, 2011
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It is illegal to possess any fitted method under the rider's control that can increase the assist speed above 25 kph (15.5 mph), whether used or not.

Such a machine is no longer an EAPC (Electric Assist Pedal Cycle) in law. It becomes a motor vehicle with all that implies.
If you have the right knowhow and equipment, you can change the assist speed by software of just about any electric bike, including bikes with systems from Bosch, Shimano, Yamaha, Bafang, Wisper, Gocycle, etc. The question is what "under the rider's control" means. A simple on/off button is fairly clearly outlawed, but when you do it by settings, how many button presses is the limit?

Another point is how anyone would know. If you've made a change that deceives the software by changing the speed signal device to wrongly represent the speed. The cut-off will still be apparent at the displayed 25 km/h, so no more questions.
 
D

Deleted member 25121

Guest
Another point is how anyone would know. If you've made a change that deceives the software by changing the speed signal device to wrongly represent the speed. The cut-off will still be apparent at the displayed 25 km/h, so no more questions.
By riding the bike over 15mph?
 
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soundwave

Esteemed Pedelecer
May 23, 2015
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been riding my bike with a dongle for the last 5 years and no one gives a toss not even plod lol ;)
 

flecc

Member
Oct 25, 2006
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The question is what "under the rider's control" means. A simple on/off button is fairly clearly outlawed, but when you do it by settings, how many button presses is the limit?
There's no question and no limit to button presses. These are not modifications, they are controls available to the rider, just like brake levers or light switches.

As the DfT makes clear "strictly forbidden", that's quite emphatic.

In any case, what's the point of arguing? Motor assisted over 15.5 mph is illegal, making an e-bike a motor vehicle in law.
.
 
D

Deleted member 25121

Guest
How will they know what the speed is? It'll show 10mph at a true 15 mph and cut off power when the display shows 15 mph.
I very much doubt that they'd rely on the displayed speed. There are lots of ways of measuring speed, my iPhone has an app that tells me my speed for example.

Having said that I can't see many police wanting to cycle along checking maximum assisted speeds of ebikes but that doesn't make these dongles acceptable. I know of people who've been drink driving for the last few decades and they'y got away with it, that doesn't make drink driving acceptable does is?
 

flecc

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Oct 25, 2006
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How will they know what the speed is? It'll show 10mph at a true 15 mph and cut off power when the display shows 15 mph.
The vehicle inspectorate's simple time over distance check. 25 instead of 15.5 mph will be very easy to detect.
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Amoto65

Esteemed Pedelecer
Jul 2, 2017
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Well personally I think it is a very clever mod and we should be praising the fact there are still people who like to tinker and discover things like this as this is how advancement in technology is made. We all know the legalities of 15.5mph so don't need too jump on soap boxes.
 

flecc

Member
Oct 25, 2006
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We all know the legalities of 15.5mph so don't need too jump on soap boxes.
If only that was true. Unfortunately a very large number in here don't know the law, only today I've had to correct two false interpretations from experienced members. Hence the many inquiries, including in this thread, and answering them is not jumping on soap boxes.

I really don't care what the authorities set to the law to, and I don't care whether anyone breaks the law or not. But if a question on it is asked I'll answer it and if someone posts false information on it I'll correct that.

That's because everyone in here has the right to know what the EAPC law really is.
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egroover

Esteemed Pedelecer
Aug 12, 2016
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Whilst I contributed to misunderstanding the motive for such engineering wizardry, I do admire the technical solution. And well done for finding 2 pulley wheels the exact ratio to convert km to miles
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
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Basildon
Unfortunately a very large number in here don't know the law, only today I've had to correct two false interpretations from experienced members.
Just because you expressed an opinion, it doesn't mean that you corrected anyone. If what you said is true, just about every single ebike that you can buy in shops is illegal, since you can change the speed setting on any of them. They all have a back door into the speed setting if you know how to use it. So what is it, are they all illegal or not?
 
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flecc

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Oct 25, 2006
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Just because you expressed an opinion, it doesn't mean that you corrected anyone. If what you said is true, just about every single ebike that you can buy in shops is illegal, since you can change the speed setting on any of them. They all have a back door into the speed setting if you know how to use it. So what is it, are they all illegal or not?
I've already answered, they are illegal for the reason mentioned. I'm well aware what can be done in e-bike software and am more versed in pedelec law than anyone else in this forum. When I correct someone on this law it is not an opinion and I post the legal details why that is so.

May I remind you that almost all the e-bikes sold in Great Britain from 10th November 2003 to 6th April 2015 were also illegal, not complying with the law, often in even more ways. So this new technical illegality is not at all unusual.

Our pedelecs operate under an exemption from being considered motor vehicles and that exemption has certain requirements. One is that its motor must not be capable of propelling the machine at or above 25 kph. Here is the copy and pasted exemption (h) from the Two and Three Wheeled Type Approval Regulation 168/2013:

"Pedal cycles with pedal assistance which are equipped with an auxiliary electric motor having a maximum continuous rated power of less than or equal to 250 W, where the output of the motor is cut off when the cyclist stops pedalling and is otherwise progressively reduced and finally cut off before the vehicle speed reaches 25 km/h"

Add to that clear law the DfT statement that any use of what they call an "off road button" to defeat the regulation is "strictly forbidden" and the legal position is abundantly clear.
In the joint meeting when that was spelled out, the DfT were adamant that any method of defeating the assist speed limit is illegal. Since the DfT create all pedelec law for Great Britain I'm happy to take their word for it.

Challenges like yours annoy me since they cause nothing but trouble, causing the uncertainty among members that leads to constantly repeated requests for clarification. Whether you like the law or not isn't relevant, it's very clear what the law is.
.
 
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soundwave

Esteemed Pedelecer
May 23, 2015
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go on ebay and find a diy kit you cant adjust the software ;)