Below are the current (March 2024) rules for UK EAPCs (electrically assisted pedal cycles).
What counts as an EAPC (Government site)
- An EAPC must have pedals that can be used to propel it.
- It must show either:
The power output – Bafang motors come with visible labels stating the output.
The manufacturer of the motor – ‘Bafang’ is embossed into the motor casing.- It must also show either:
The battery’s maximum voltage – both batteries are labelled by the manufacturer.
The maximum speed of the bike – not marked anywhere.- Its electric motor:
Must have a maximum power output of 250 watts.
Should not be able to propel the bike when it’s travelling at more than 15.5mph.- EAPCs may have more than two wheels (eg. a tricycle).
This last point troubled me a little. More recently, on social media, I have seen that the Police have targeted e-bikes to check the maximum speed. OK, their focus may have been on Deliveroo and Uber Eats riders but there’s still a slim chance of the bike being checked, especially if we were involved in an incident/accident. The last thing I want is to have the bike confiscated due to a (in my opinion) minor but illegal feature.
While it’s handy being able to apply the throttle and boost the speed a little (up to about 20mph in favourable conditions), it’s not essential, so I decided to see if I could reduce the top speed of the throttle to the legal 15.5mph limit.
A little searching on the web and I found a pretty good video showing all I needed to know…
I ordered the necessary cable from eBay.
Online version of programming software for Macs (use Google Chrome browser).
Download Windows version of programming software here.
Borrowing Karon’s MacBook Air, I loaded the URL for the software, put the battery into the bike and turned it on then connected the cable, as per the video. I ignored the upper sections of the settings as I was only interested in the throttle section and there I changed the maximum speed from 40kph to 25kph (15.5mph). The ‘write’ was instant. After disconnecting the programming cable then reconnecting the cables on the bike I lifted the back wheel, set the power level to 9 (maximum) and pressed the throttle. The rear wheel initially went above 15.5mph as it was rotating freely without any load, but crucially, the power cut once above that speed and then settled to around a constant 15mph. Job done 🙂
There’s Government talk of increasing the legal limit of power of motors and possibly the top speed, but now I have all the necessary bits and links, I can make changes should the rules be relaxed in any way.