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TRS posted:

Hi folks,

Back in the late 1980's in Australia, someone, somehow, imported 200 C5's and sold them through a bike store in the Sydney suburb of Granville. A family friend bought one of them, and as a kid I had the privilege of riding around in it a bunch of times.

I think this particular C5 was about a year old (I'd say this was around 1988/1989?) when someone took a right hand turn quite fast and tipped the poor C5 onto its side. I'm told this caused the original battery to fall out, and lead acid leaked out all over the place, etc, etc... Long story short, the C5 was put into storage, and that was that. (oh, and the battery, cover plate, and charger are long gone!)

Fast forward a few decades, I'm now living in Singapore, and seeing said C5 owning friend once or twice a year... Each time I see him, I've been hassling him about his C5. I had fond memories of riding around in it, and decided it was time to bring it back to life. I've spent at least six years twisting his arm, and patiently waiting and waiting. Earlier this year, over a huge pot of Singapore Chilli crab, he finally, relented and said I could have it. Result!

Anyway, once back in Aus, here's what he delivered:

Not great, but not bad either. No tyres or tubes, no battery or cover plate, but otherwise intact. It also looks better now, after a wash :)

(here's one for the 'trainspotters' who want to know which batch were imported to Australia. It has a dark grey boot.)

Now, onto business. First of all, the chain tensioner was a disaster, so I've sourced a new one, and a new spring.
I also managed to get one of those battery wiring kits from c5alive all the way to Sydney, and with my brother being the arms and legs, and me in the background on Skype video with some wiring diagrams handy, we fitted it and attached a battery.

No dice.

After checking around with a multi meter to test the fundamentals, and discovering that the motor switch wasn't really getting any voltage, this was discovered:


Oops. Given the electronics on the board look fairly straightforward, with components that can still be obtained, we'll just get this looked at by someone who is handy with a PCB and a soldering iron :) Though, I've found other examples of D1 blowing, but none of them have been so 'violent'! Hopefully the PCB isn't damaged and we can salvage it.

So, while getting that looked at, I do have a question... What's the best way to test the motor in a C5? We disconnected the motor from the Control Box and applied 12v directly to it, but nothing happened. Any advice on how I can validate the state of the motor independent of the rest of the C5?

posted on: 14/06/2014 09:45:14

Dan posted:

Hi and Welcome to the Website.  Thanks for sharing the story its always fascinating to read about C5's and how they managed to make it out of the UK Regarding the motor, yes, putting it straight to the battery should make it work.  I'd check the brushes aren't stuck.  Area51 and Chas are the motor experts I'm sure they will have some tips.
posted on: 14/06/2014 10:40:40

Area51 posted:

Hi there make sure the motor turns free
Then look at the brush end of the motor
Look through the holes and see if it looks relatively
Clean then see if you can pull up the brush
Braiding to make sure both brush move
Freely in the boxes they maybe stuck
Try not to damage the braiding as this
Carrys the current through the brush and
Not the spring if the braiding is damaged or Brocken
Then the current will go through the spring
Heat the spring up and you will loose
Spring tension if it still doesn't work you
May have to polish the commutator

As for spare brushes watch what you use
Washing Machine brushes are 230 volt and
Low current which you may get away with
At 12 volt there seems to be 2 types in the
C5 carbon and high content copper if you can
Always use high content copper with thick
Braiding as these will run cooler dew to the
Low resistance of copper any low voltage high
Currant motor uses high content copper brushes like a car starter motor
Carbon is slightly resistive and the current won't
Flow aswell and this will cause heat

I don't think there will be anything wrong with the
Armature I think it is just a brush problem
Give it a try and let us know how you get on

posted on: 14/06/2014 14:31:41

TRS posted:

Thanks for the replies!
Good news, the motor works fine now. All it took was a bit of 'percussive maintenance' (i.e. apply power to the motor, then give the drive pulley a tap/spin)

I've ordered a replacement D1 diode, as well as a relay, and LM358 IC, as I expect the latter two will likely have failed based on what I have been reading. Hopefully that sorts the control box out and we will be in business :)
posted on: 18/06/2014 02:49:08


Hi well done keep us informed bye Chas
posted on: 18/06/2014 13:31:54

TRS posted:

While waiting for the control box parts to be delivered, I have a question about batteries.

I'm keen to use a LiPo battery instead of a car/leisure battery, as the car/leisure batteries are just so heavy in comparison. (and yep, I know all about what happens to LiPo batteries when they go flat, I have R/C cars )

A friend who builds electric bikes can make me up either:

*A 3 cell lipo pack that will be 12.6v off the charge and 10v when flat. Most of it's discharge will be spent around 11.5v so on the road it's actually a touch slower than the original Oldham (Lead Acid) battery which hovers in the lower 12s the whole time.

*A 4 cell LiPo pack, however hot off the charge this will output 16.8v, and 13v when flat. This will make it faster but if there's low tolerance parts inside (some capacitors and other components are rated at 15v) then it could blow something in the control box or pod.

The 3 cell option seems very safe, but it will be a touch slow, I believe.

While the 4 cell option seems like a better idea, I know 24V breaks the pod, requires a cooling fan on the motor, and some other electronic controls, etc. Can anyone tell me if battery with a peak voltage of almost 17V is something that will break things like the control box or the pod?
posted on: 20/06/2014 04:45:09

Dan posted:

I think you will have problems in both control box and POD when putting 17v through it  I cant say for sure as I do not run on a pod/CB. You may be better running the motor straight from a relay or Porter 10 motor controller and have a volt/amp meter to show you whats going on. Running the motor at 17V shouldn't generate too much excess heat but you would probably need a cooling fan. I have cooling fans at 12V.  I think it will put a lot of stress on the gearbox when using a relay and you might destroy the cogs in the gearbox.
posted on: 27/06/2014 19:31:32

TRS posted:

Thanks Dan, I think I'll stick with a 12V battery for now.

As per this thread our control box woes are over, and the motor spins when the throttle is pressed. A great result.

Still more restoration work to do like replacing the chain tensioner, and cleaning and re-greasing the gearbox, but once done we should then have our C5 on the road again.
posted on: 02/07/2014 11:49:27

TRS posted:

Last night my brother rode our C5 to the next suburb to a pizza joint, to get dinner

It needed a lot of pedal assistance as there were hills, but overall he was pleased with it.

Thanks to everyone for their assistance.
posted on: 23/07/2014 05:34:43