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Butt-kicking battery bike has attitude to spare

Bikes, Quads & karts

Brisbane, California - There streets are full of naked bikes, enduro-styled beetle-crushers and gnarly motocross bikes with semi-slick tarmac rubber called supermotards because they were invented in France and that’s how the French speak Bike.

But it you wanted to tool around the urban jungle on a street-legal flat tracker, you either had to build it yourself or pay somebody to build it for you. Until now: what you see here is the Alta Motors Redshift ST concept - a fully functioning, very nearly street-legal prototype flat tracker. And here’s the kicker - it’s electric.

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Alta Motors is an electric motorcycle company started by three biker friends who were smart enough to to figure out that there was one arena where a battery bike could not only compete with combustion-powered machines, it could spank them.

Motocross races are short - 20 minutes plus one lap - so range is not an issue. The best motocross bikes are not necessarily the fastest; a flat torque curve and centralised masses are just as important, and these are areas where electric beats petrol hands down.

Then Derek Dorresteyn, Mark Fenigstein and Jeff Sand got really smart. The heaviest component of any electric vehicle is the battery - that’s unavoidable. But the heaviest component of a conventional bike is the engine - so they put their home-made, high energy density lithium-ion battery, which weighs about 40kg and has a capacity rating of 5.8kWh, where the engine of a conventional motocrosser would be.

Then they installed their own water-cooled 14 000rpm electric motor at the input end of a 3.5:1 reduction gearcase they called the bulkhead, with the output sprocket at the bottom end, where the gearbox of a petrol-powered bike would be.

The rest was a matter of fabricating an aluminium frame and die-cast swing-arm, and buying the best running gear off the shelves - including WP suspension and Brembo brakes. The result is a 114kg motocross machine that can deliver 29kW and 49Nm from zero revs, flat out for 20 minutes and one lap, with amps to spare.

At $14 995 (R203 000) the Alta Redshift MX is expensive - although less so when you consider that only maintenance it needs from one season to the next is a wash and a squirt of chain lube - but it does what it says on the tin, which is to compete on level terms with comparable petrol-powered machines in regional racing, and that’s a first.

That first model was followed by the $15 495 Redshift SM, a street-legal version with 17 inch motard rims and superbike tyres. Its performance is awe-inspiring - 0-100km/h in 3.3 seconds and 105km/h flat out less than a second later - but, of course, in a tarmac context, range becomes a problem; 80km is about the best you can expect.

But the boys from Brisbane reckon the battery will take a full charge from flat in four hours from an American-standard 110 volt domestic outlet, or two and a half hours on 220 volts.

Bigger, faster, more dangerous

Another discipline where the Redshift can kick petrol-powered butt is flat track, the bigger, faster, more dangerous American version of speedway - and in fact Alta is fielding a factory-supported team in the appropriate class of California regional series, using a slimmed down chassis with not even a dummy fuel tank, a lightened rear subframe and the barest minimum of furniture.

That, in its turn, spawned the ‘street tracker’ Redshift ST concept you see here, mechanically similar to the established MX and SM models, with lights but no indicators, its twistgrip circuitry tuned for enormous midrange and running on 19 inch South African-made BST carbon-fibre rims and special flat-track tyres.

Dorresteyn, Fenigstein and Sand say if the demand is there they’ll built the ST for sale - with indicators as per the SM but without the $4000 (R54 000) rims - starting in the first quarter of 2018. And a battery scoot with this much attitude - that can outdrag a litre-class superbike from one red light to the next - might just be worth it.

IOL Motoring

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