The Electric Vehicles Of EMF Camp: A Sinclair C5, (Almost) As It Should Have Been

Most Hackaday readers will have heard of [Clive Sinclair], the British inventor and serial entrepreneur whose name appeared on some of the most fondly-recalled 8-bit home computers. If you aren’t either a Sinclair enthusiast or a Brit of a Certain Age though, you may not also be aware that he dabbled for a while in the world of electric vehicles. In early 1985 he launched the C5, a sleek three-wheeler designed to take advantage of new laws governing electrically assisted bicycles.

The C5 was a commercial failure because it placed the rider in a vulnerable position almost at road level, but in the decades since its launch it has become something of a cult item. [Rob] fell for the C5 when he had a ride in one belonging to a friend, and decided he had to have one of his own. The story of his upgrading it and the mishaps that befell it along the way are the subject of his most recent blog post, and it’s not a tale that’s over by any means.

The C5 was flawed not only in its riding position, the trademark Sinclair economy in manufacture manifested itself in a minimalist motor drive to one rear wheel only, and a front wheel braking system that saw bicycle calipers unleashed on a plastic wheel rim. The latter was sorted with an upgrade to a disc brake, but the former required a bit more work. A first-generation motor and gearbox had an unusual plywood housing, and the C5 even made it peripherally into our review of EMF Camp 2016, but it didn’t quite have the power to start the machine without pedaling. Something with more grunt was called for, and it came in the form of a better gearbox which once fitted allowed the machine to power its way to the Tindie Cambridge meetup back in April. Your scribe had a ride, but all was not well. After a hard manual pedal back across Cambridge to the Makespace it was revealed that the much-vaunted Lotus chassis had lived up to the Sinclair reputation for under-engineering, and bent. Repairs are under way for the upcoming EMF Camp 2018, where we hope we’ll even see it entering the Hacky Racers competition.

40 thoughts on “The Electric Vehicles Of EMF Camp: A Sinclair C5, (Almost) As It Should Have Been

    1. Unfortunately correct. I thought one of the reasons the C5 had pedals was to exploit the e-trike permissions, as without pedals it would be considered a mobility scooter and only for use by those with a medical need.
      Bicycles are a little worse off as the legal limit for pedal-assist is just 200W. One of the reasons Segways are illegal for public use in the UK; they’re massively overpowered to be considered a bicycle, but not capable of being licensed for road use.

      Personally i’d like to see the whole set of rules replaced with one dictating a power to weight ratio. The lighter a vehicle is, the faster it’s permitted to go as long as it’s potential impact energy remains under a set limit. There’d be a graph and you’d just need to stay under the red line while loaded & in motion.

      1. I agree, the current rules were a mush mash installed to prevent the Segway from taking off when it was introduced. The rules on pedal powered cars make no sense in reality and highlight the Flintstone aspect of the regulations.

        1. The current rules weren’t put in place to block the Segway. They were “updated” in 2015, but that was just amendments. The 200/250w, 15mph, limits have been law in the UK since 1983 (The Electrically Assisted Pedal Cycles Regulations 1983 ).

          The matter is enforcement. It’s not universal. Segways were too public and there was a nice big corporation the government could go after. There’s also laws stating all electric vehicles must be in direct physical control of a driver and no remote control vehicle can be operated outside of line of sight. Those companies trying out delivery drones in the UK are breaking the law, but are relying on startup momentum to get them to cashing out before the law catches up. Likewise those ride-in electric cars kids play with are illegal to use on public land.

          A few years back there was a case where a milkman lost his job because of these laws. He had an electric power-assist hand-cart he delivered milk with in a small rural town. It’s an electric vehicle. It moves at walking pace. Legally he should have had a drivers licence for it because it’s a “motor vehicle”. But his eyesight was too poor for a licence. So he lost his job. Somewhere an officer decided it was more than their job was worth to overlook this unique situation and a disabled man lost his job as a result.

          The law by definition does not accommodate anything outside its existing scope.

          1. Only thing about this anecdote (may be different in other countries) is the obligations of the employer as it relates to the handicapped. That hand-cart falls under that.

    2. Oh the last time I looked at the regulations I could have sworn it was 20 mph, but your link does say 15.5 mph, so that’s an 11.5 mph difference. Awesome!

      That’s 3.2kW as manufacturer rated, it’s unlikely to be able to sustain 3.2kW for any length of time. It is of course limited in the speed controller firmware…

      1. To be honest, given Cambridge traffic, I’d be impressed if you can get up to 5mph, let alone exceed 15! (and out of town, other than the mis-guided busway, I think there are enough pot-holes around that I’d be nervous about taking a C5, with its limited ground visibility in front, too fast).

        1. Good luck getting a C5 on the misguided busway- the central front wheel might not have a great time. I’ve ridden my racing bike on the busway before it was operational, that was fun but hypnotising after a while.

          1. I was thinking of the pathway alongside rather than the ‘road’ track the busses go in (purely to avoid any issues with the busses that never speed on it) – although given the extra girth of the C5, I can see that it may have problems on a lot of cycle-paths

        2. Plenty of ground viability in front, the trick is to aim for the pot holes, then only the front wheel goes in, aim to miss them like you do in a bike and one of the rear wheels gets them and boy do you feel it!

          The 27 mph was hit between The Royal Cambridge hotel and The Fitzwilliam Museum on Trumpington Street.

          Traffic’s rarely been a problem, but I don’t really go out in rush hour so I’m largely missing it.

        1. ACK.
          Manual, lat. manus = hand –> by hand
          Pedal, lat. pedem = feet –> foot lever (like on a piano, in a car…)

          So Missie List the HAD scribe hand cranked the pedals of the C5 on her way back. PICS OR IT DIDN’T HAPPEN.

          Hackery of natural languages?

  1. Hot damn, that is one lucky person winning 26 spares/repairs ebike batteries for £125 in reasonable capacities. If only half of them worked and those that worked had 50% of their rated capacity and we go off the lowest ratings that’s 2.3kWh of battery right there. Meanwhile it’s £400 or so for 700Wh buying new (from a brief look). That’s at 52V, maybe you can get luckier with the lower voltage packs.

    1. I was thrilled when I won the auction. And stunned when they all largely seemed to be okay. I’ve been discharging them through some massive load resistors and they seem to typically have between 80 and 110% of rated capacity. Still got quite a few left.

      1. I’d slap all the good cells together and make an ultra long-range ebike. If you bent the law more than a little to make a 30mph ebike with a few kWh of battery capacity you could do crazy things like go to Warsaw in 4 days on less than £5 of electricity. Beat that electric cars.

  2. “The C5 was a commercial failure because it placed the rider in a vulnerable position almost at road level”

    Jenny, you’re a Brit, you honestly going to tell us you’ve never hooned around in a Moke???
    When they first came out the usual supects went on and on about “people won’t want to be this exposed”, Mokes sold like hot cakes.

    I’ve driven quite a few, ok it is a “tad” exciting in traffic with trucks or on the highway, on country roads they are great!

    but, hey, it’s not fun unless it’s a little bit dangerous!!!

      1. seriously??

        they were made by Mini and then Leyland

        I thought they were another of the ubiquitous British imports here in Oz!

        Morris Minors, Morris Majors, Marinas, Leyland P76, which was way ahead of it’s time

        I took it as an article of faith they were common there as well

        1. Only about a third of them were made in the UK, and an open top vehicle with no real weather protection costing more than the hardshell versoin of hte same car is a hard sell in a country which mostly gets rain and when it’s not raining it’s snow or hail. They sold rather better in other places they were made such as Australia or Portugal.

          Most Brits have only seen one in episodes of The Prisoner where they’re zooming around Port Meirion (The Village).

          There’s a guy near me has 2 of them and despite loving them deeply, even he won’t take them out in most of the weather we get here.

  3. One of the drawbacks of the C5 was that it was not adaptable for different person lengths. i’ almost 1,96 and the pedals are way too close to the seat for me to be conforable. My dad bought one when i was a kid and i remember driving it to school, but after the battery (nicd) died, the thing went dormant. If you look closely at the underside, you see that it actually is made very bad. it alsmost looks like a prototype. the chassis is very flimsy, no gears on the pedals and some of the main drive are made of plastic. also the plastic wheels with metal cups for the roller bearings is a weak point.
    I would suggest just using the grey shell and completely rebuild the chassis and power train is the best option. there is room for a 7 speed hub and you could try to make the pedals a little bit adjustable.

    1. Yeah, that’s definitely a problem with the design and the plastic wheels scare me!

      That is my eventual goal, a completely new, modern, chassis with the original plastic body on top. However rather than attempt all that at once I figured I go slow and improve it bit by bit. This way I get a working vehicle throughout most of the process and most importantly I should never get overwhelmed with the scale of the task.

  4. Sometimes I use a Segway for transportation and once I was next to a C5 and we pulled up together when the traffic-light turned green. When we went downhill into a tunnel, the Segway kept its maximum speed of 20kmH while the C5 picked up speed and overtook me, but when we left the tunnel going uphill, the Segway kept running at 20kmH while the C5 considerately lost speed so in the end, I (the Segway) won this little competition.

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