Saturday, May 14, 2011 7.00am
By Cycling Plus
First impressions of the A2B are good, as its tidy, uncluttered design looks clean and simple. Cabling is mostly internal and the battery seems to hover unsupported by any fussy rack above the powered rear wheel.
Considering the lithium ion battery alone weighs 5.4kg and the upper rear arm must also carry the weight of the rider, it’s clear this has to be seriously strong – which goes some way to explaining the noticeable heft of the bike, which weighs just over 29kg (63.9lb), despite the lighter potential of a 6061 aluminium frame.
In use, the A2B is quick and efficient round city streets, accelerating swiftly from junction to junction – if maximum range isn’t an issue, then it’s easily powerful enough to leave in a big gear all the time. For longer journeys, it was very good for spinning on the flat – we found buzzing along an ex-railway bikepath, with the motor tickling in and out to keep a constant 15.5mph, a breeze.
It also won the closed circuit time-trial race held as part of our testing. “Surely that’s derestricted,” was one comment afterwards. Apparently not – according to Ultra Motor’s Mark Loveridge, the A2B is UK compliant, with its 250W motor delivering the legal limit of 15.5mph. If you notice anything more, it’s the “perfectly legal extra 10 percent tolerance".
The only place the A2B didn’t perform as hoped was on a seriously steep hill, where the assistance failed to make up for the limitations of the seven-speed SRAM gearing – the result meant harder work than we’d hope from a pedal-assisted bike. Coming down the same 1-in-4 hill didn’t cause any problems though, with the excellent Avid BB5 disc brakes front and rear doing their job admirably.
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