A third day of 40°+ and the rest of the week isn’t looking any cooler. According to the forecast it will drop to the high 30’s late next week. Only mad dogs; Englishmen and those who have to work will be outside!
With nothing else to do I decided to press on with the ebike project. But not before bring the bike inside where the three air conditioners are earning their expense.
When the lithium battery arrived I noticed it had a usb outlet.
Yes Pip…. You are in luck… more red arrows today!
My initial thought was “I can charge my mobile phone whilst riding!” Immediately I realised I could also use the phone as a satnav. To save money I haven’t activated mobile data on the phone. But that doesn’t matter because the OSMAND satnav app doesn’t require internet access. The maps are downloaded to the phone.
A quick search on eBay identified a 90deg usb plug for a couple of dollars. It arrived today.
And is a perfect fit
Then another idea popped into my head. If I used a usb splitter I could power both the phone and a usb red tail light. Another couple of dollars and a suitable cable has been ordered from Aliexpress.
The pedal were removed and carefully labelled as they are specifically left and right. Then the cranks were removed from the hub. Up until this point the going wasn’t too hard. However removing the centre hub took some serious effort. Hercules must have tightened it!
With the hub removed I could fit the Bafang motor and gearbox. The design of the frame prevented me from swinging the motor up higher but I think there is still sufficient ground clearance. I don’t plan to go mountain biking
The motor is held in place by a large nut on the end of the hub and a plate that presses against the face of the hub socket. The plate is held by two bolts which were too short. There was also a gap between the plate and the hub.
This was resolved with the purchase of two longer M6 bolts and six washers which were used as packers in the gap.
The next step was to fit the speed detector sensor. A small magnet is attached to a suitable wheel spoke and the sensor was glued and tied to the lower wheel bracket.
That’s it for today! Tidy the wiring tomorrow.
4 comments :
You said "The next step was to fit the speed detector sensor" and show it mounted to detect motion of the wheel.
I don't know what you will be using that for but in Britain (if I understand the law correctly) the sensor has to detect the pedals are being turned (not the wheel) before allowing power to the motor. I assume that is to minimise the risk of a bike motoring off without a person properly sitting on the bike and in control of it.
It also ensures the speed fed to the motor controller doesn't vary with what gear you are in.
Your law might be different and your motor controller might be different so your work might be fine for your needs.
Hi Paul
I believe the law in the UK, Oz & NZ is the same for ebikes ridden in public roads. The size of the motor can't exceed 250W and the motor must cut out at 25km/h.
I have yet to configure the wheel size in the controller but I assume this; in combination with the speed sensor; controls the maximum assisted speed. The motor does come with a manual throttle which means there is no requirement to pedal but that will obviously increase battery consumption. I'll know more when I start doing some test rides.
After further research into UK Law (although your law might be different) I still think you need to detect that the bike is being actively pedalled by a human to be counted as a "bike" and not a "motor bike" and avoid the need for type approval, insurance, tax etc.
For example:
https://www.gov.uk/electric-bike-rules
https://www.cyclinguk.org/article/electric-bikes-and-law-what-you-need-know
https://www.sustrans.org.uk/our-blog/get-active/2021/everyday-walking-and-cycling/where-to-start-with-electric-bikes-all-you-need-to-know/#ukrules
Paul after another test ride I can confirm the motor only activates when the pedals are rotating.
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