Battery Vehicle Society

Anyone else seen this ? A c5alive forum member spotted this update on the Sinclair Research website;
http://www.sinclairzx.com/


...even though it's far from perfect I still want one !!

I spotted it from a link on the ES forum a day or two ago. The bodywork looks OK, but I wonder what on earth Sinclair were thinking of by giving it tiny 16" wheels and no suspension. On anything other than nice smooth roads (not a lot of those about where I live......) the ride will be dreadful, all the more so because it's a recumbent - all the shock loads will go straight up your back, with no leg 'flex' to take out the worst.

The wimpy little motor (why didn't they use the full 250 watts allowed?) is another minus point, as is the inefficient 24V supply. It's almost as if Sinclair are now strong on the aesthetic design but have lost all their technical know-how. Pretty much anyone who's played with small EVs will quickly realise how easy it would have been to improve the efficiency of this thing, a higher battery voltage (for lower I²R losses), bigger wheels (for a better ride and lower rolling resistance), the full 250W legal power limit etc. The manufacturing cost difference would be small to have got it right.

Mind you, if they were to sell just the body work then I might be interested. I think it has the potential to be turned into something both practical and efficient.

At least they learned the need for visibility lesson from the C5..................

Jeremy

I think Cedric has another date with the courts.

Do you think Clive might have seen Cedric on one of his London commutes?

Please expand re "Cedric" and "Courts" and "another".................
Has Cedric been reported by some ##### ?
(a ##### whose opinion of "The Law" may become baseless custom and practice, in a worst case?)
OR
Do you mean Clive is, possibly, "Inspired" by Cedric's personal transport?
I'm certainly inspired by the idea of a sustainably-powered, highly-visible, ultra-light vehicle
One NOT requiring pseudo-Samurai clothing, nor grimy, noxious, maintenance sessions and by-products
When I finally get on the Highway with something like this, I will advertise Cedric's inspiration

As to the "Modern C5", how efficient is the body?
My brief test-runs in a couple of "roofed-scooters" left me convinced the openings produced a net 'aero' loss
I would love to hear from anyone who can clarify? (Terry....?)
All the best
Ed

Down at the speeds this thing is designed for (sub-15mph) the aerodynamics, as such, would be more concerned with the effect of cross winds I'd have thought. Having the sides open might be essential to stop the thing being blown sideways into oncoming traffic............

The openings would certainly increase the Cd by a bit, but not, perhaps, by as much as you might think. I've flown with the doors on and off in the same, approximately 70mph cruise, light aircraft and the extra power doors off was only around 10% or so (it was a bit windy in the cockpit, mind..............).

I'm pretty sure that Sinclair's objective isn't aerodynamics but providing a modicum of weather protection in city traffic. I doubt it's that effective. A friend (well, the instructor I did my seaplane rating with) is currently pedalling across America in an enclosed/partially enclosed trike (http://breenmachineworldtour.blogspot.com/). He can at least roll down side covers in really bad weather, plus he's made an effort to get the drag when fully enclosed down a bit. Here's a photo:



Gerry can get away with side screens because his creation is a trike, but if you want to build a fully enclosed two wheeler, like Cedric's, then you need more area at the rear than the Sinclair things got, to move the lateral centre of pressure back so that it's more in line with the centre of gravity. That way, when it gets hit by a side wind it won't tend to turn either away from the wind (lateral C of P forward of the C of G) or into the wind (lateral C of P aft of the C of G).

Jeremy

ex925 wrote:Please expand re "Cedric" and "Courts" and "another".................
Has Cedric been reported by some ##### ?
(a ##### whose opinion of "The Law" may become baseless custom and practice, in a worst case?)
Ed

Oooops, I should explain that I was only referring to Cedric's past experience being ripped off by big business as described by himself on the Agni site.

I think he built that design years before Sinclair and uses it for daily transport very successfully.

My bad, (my paranoia?)
I am wary of the creeping acceptance of assumption eroding legitimate liberty
(re-reads the above, thinks "Must get out more".....)
All the best
Ed

Jeremy wrote: The bodywork looks OK, but I wonder what on earth Sinclair were thinking of by giving it tiny 16" wheels and no suspension. The ride will be dreadful, all the more so because it's a recumbent - all the shock loads will go straight up your back, with no leg 'flex' to take out the worst.

The wimpy little motor (why didn't they use the full 250 watts allowed?) is another minus point, as is the inefficient 24V supply. It's almost as if Sinclair are now strong on the aesthetic design but have lost all their technical know-how.
A higher battery voltage (for lower I²R losses), bigger wheels (for a better ride and lower rolling resistance), the full 250W legal power limit etc. The manufacturing cost difference would be small to have got it right.

At least they learned the need for visibility lesson from the C5..................

Jeremy

Too right Jeremy, 24v hmm, upping it to 36v would give the 250 watts (and bit more )
Wonder if Clive has this in mind as an no doubt, expensive upgrade

Those small wheels = everything smaller = everything cheaper

The A bike is the same, tiny wheels, at 90 PSI Don't see how that can smooth out the ride.
Doh - silly me, it's a Light Goods Bike (HGVs run tyre pressures around 110 PSI)

No variability in the gears either. "Twin Chain Drive" is it overdriven e.g. 1:0.5 = example only.

Deker