Saturday 1 March 2014

Reviving the Synergie

I have a 20 inch wheel folding bike that I haven't used for a long time. Instead, I've been using the 26 inch wheel bikes, based on a Haro folder.

The  Synergie (which I plan to name bike.4) had two problems. The first problem was that the pedals got very wobbly. I decided that this was caused by worn bearings in the bottom bracket, and my local bike shop said the wouldn't be able to fix it, because it used a custom bottom bracket. I believed them, but after several months, I was looking in Ebay for a bottom bracket for one of the Haros, also because of wear. And I found that bottom brackets come in all sizes, and are quite cheap, about £9. So I bought one that I thought would fit bike.4, and blow me, it worked a treat. So, first problem fixed.

The second problem was more severe. I couldn't see any way to put a rear carrier on the bike, so carrying spare batteries, water etc was a major problem. I could only use a backpack, and that can be a lot of weight on my back. But very recently, I looked at bike.3, which doesn't have eyelets for a carrier, and reaslised that the carrier that I had on that, would very likely work on bike.4.

So I got one from Ebay, £15, and yesterday I fitted it, and it looks good!

This means that I can remove the rear battery carrier shelf (the battery will go in a pannier), and while I'm about it, I can replace the bike motor controller with something a lot better - an Infineon.

So I removed the battery carrier, and unwound the curly-wurly cable tidy, took off the cables, and looked at what I had. The first thing I saw was the reason why the front light wasn't working - the wire had broken. I also found that the microswitch on one of the brakes (it's to cut the motor when you brake, in case you forgot to) wasn't working.

So, I stripped off all the wiring, put on a new pair of brakes with working switches, put on the three-way switch that will change power levels from 50%-75%-100%, repurposed the light switch as an ignition cutoff switch, put on a thumb throttle to replace the twist throttle (I've gotten used to a thumb throttle now, and a twist throttle would confuse me), programmed the Infineon controller to match the bike, and got everything wired up.

Testing will follow ...

Update ...

The light switch didn't work, so I took it to bits and had a look. The problem was the wire, so I unsoldered that, and looked around for a suitable wire - I wanted something thin and light (this isn't carrying many milliamps of current). I chose a cable I've had for ages, it came with a UPS, and I don't link UPSes to my computers (you can tell the computer to shut itself down when the UPS signals that power is out). It looked like a serial cable, but it didn't behave like one. So it's been sitting in a box for many years. I cut it open, and to my delight I found four multi-strand wires inside. So two of them will go to the light switch (now my power-on and power-off switch, like the ignition switch on a car) and the other two will go to my voltmeter. So I attached the voltmeter to the ignition switch, and it looks very neat. All the electric bikes I've seen use a blog system. Five blobs means full, and it stays at five for a long time, then rapidly moves down to 4, 3, 2 at which point, you're empty. Not very useful. Another system is even worse, you get green-amber-red. Again, it stays on green for ages, then you get amber for a very short time, then red. So you have really no idea how much battery you have with either of those.

But the voltmeter (which cost about £1, plobably less than the blobmeter) tells you exactly how many volts you've got, to one decimal place, which is exactly what I want.

So now I was ready to roll. I put the bike on a bike stand, hooked up one of my old batteries (they have a 10 amp fuse, which I like the thought of in case of catastrophe), Ignition on, apply throttle ... nothing.


I tested the Halls - OK. I tested the motor windings - OK. I reprogrammed the controller to be happy at only 25 volts, tried it again ... nothing. I tried my Hobbyking Lipo batteries, nothing. I removed the brake cutouts, in case one of them was stuck on ... nothing. I unplugged the three-way level switch ... nothing.

I won't go down the list of all the things I tried; I'll cut to the finish. I had the throttle wired backwards. Duh. That's because I couldn't use a proper socket for putting the throttle plug into - I've ordered a bunch of suitable 6, 3 and 2-way plugs and sockets for this sort of thing so I shouldn't have this problem in future.

So the motor turned the wheel. But switching beteween level 1, 2 and 3 did nothing. Again, the cause turned out to be stupidity; in my thrashing around to fix the "it doesn't work" problem, I'd disconnected the three-way switch. As soon as I reconnected that, the motor turned, it responded nicely to the throttle, and the three levels worked - 50%, 75% and 100%.

By that time is was 11:30 pm, too late in the day to take the bike out for a spin. Plus, that bike doesn't have a speedometer (I've ordered one, £3, I cannot believe how cheap all this stuff is).
And I need to go round the bike tightening up all the things I loosened, I need to make it so that the wiring doesn't just hang down to the ground (cable ties are my friends) and I need to balance the rear wheel (I've noticed some of the spokes aren't taut, and the wheel isn't running true). But this is all straightforward stuff. At this point, I know that this bike is going to work!

And I weighed it. It's 13 pounds lighter than bike.1 (44 pounds compared to 57) and that can be a big blessing when you're lifting a bike over a five bar gate that should have been left unlocked but which has been chained and bolted. For example.

Tomorrow, I go to London again. I'll be going in from the West (my two previous forays came from the North and then the East. And I'm hoping to finally finish off London Invasion.

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