ELECTRIC BIKE KITS
bargain basement bikes – as is the case with the vast majority of cheaper hub motors which are fitted on many of the cheapest E-bikes available in the UK. Rather, it’s meant as a lightweight, subtle addition for a quality lightweight bike. Most importantly, the small but very positive surge of power which it delivers is available throughout the very wide gear range of the PDQ, converting it into an excellent hill climber. The advantages are many – it’s the second lightest motor here and the integral motor and controller mean it has a lovely clean appearance with the minimum of cable runs. The efficient application of power for just long enough between pedal strokes will be familiar to all those Giant Lafree lovers out there – that bike works in a similar fashion. This feature means any bike fitted with a Sunstar will retain its essential pedalling and riding characteristics – whereas bikes fitted with hub motors start to take on moped-like qualities. Small DIP switches, housed within the tiny handlebar on/off switch, can be set to make the motor power anything with wheels from 12" to 28" inches according to the manual. In practice I found the best power came when all of the switches were simply turned off. In terms of pure efficiency at converting battery power to hill climbing ability the Sunstar is probably the best kit I’ve tested yet.
Who would use it? My earlier carping about lack of power amounts to criticizing a gazelle for not being a rhino. The Sunstar is the gazelle of retrofit kits and has proved a hillclimbing boon on the PDQ, which previously
struggled in cramp-inducing fashion up steeper inclines. If you are looking for a lightweight ‘power supplement’ for a bike which is already quick this is certainly worth considering. It would also combine well with a lightweight folder. Zone Cyclable use it on a number of lightweight Dahon-style folders which they sell as complete bikes. My only real criticism was the tiny capacity and high price of the batteries. I’d like to use it as a long-distance tourer but this problem has so far limited me to local leisure rides (around 20 miles maximum, including use of a spare battery). I’ve experimented with NiMH batteries from an old Lafree: this works OK but the range still isn’t really satisfactory, so I’m still searching for a company capable of fitting a suitably large capacity Li-Ion battery. If I can manage that I’m convinced that an almost effortless 100 miles or more a day for fully loaded touring is easily achievable.
Specifications Motor and integral controller weight: 3.2 kg Battery weight: 870 g Battery capacity: Approx 80 Wh Charger weight/recharge time: 425 g/1.5 hours Replacement battery cost: 250 Euros Total retro-fitted bike weight: 21.6 kg Bike requirements: BB shell width of 68–70 mm and correct thread (check with retailers). Frame size where motor mounted no less than 180 mm. Guarantee: 2 years all parts, including battery RRP: 899 Euros
VELOVISION ISSUE 32 DECEMBER 2008
BIONX I’ve tried this very sophisticated Canadian made pedelec style hub motor system a couple of times and it’s smooth quiet power is pretty impressive. The motor gearing on the BionX-equipped Airnimal I tried was designed to assist at speed rather than for torque, but it made for a very acceptable long distance commuting or touring system (see Issue 26 for a full review of the Airnimal Joey Move with BionX – Ed]. The BionX system itself has been around for a number of years and has a proven track record, especially in its home country of Canada. It consists of a large-diameter but thin hub motor, groovily-shaped frame-mounted battery and a small handlebar mounted LCD console which allows you to control the various power settings. It’s unique – as far as I know – in being the only regenerative kit on the market. That is, it uses the motor to feed power back into the battery whilst descending or braking. This regeneration is controlled by power settings which are set via the console on the bars, so you can set the system for anything from a real hill-climbing boost to regeneration mode – with enough braking from the motor that you don’t have to touch the brakes on all but the steepest of descents. How much regenerated power this provides in practice is a moot question however. I consistently managed to get over 30 km on a single NiMH battery in moderately hilly country, so more recent Li-Ion battery options should give a very impressive range.
Who would use it? For me the BionX would be an ideal touring or commuting system, especially for those looking for quality and reliability above brute power. Undoubtedly you are paying a premium for the Li-Ion version – but if you want unique technology, a truly unique riding experience and a piece of bicycle history then BionX stands out. It’s highly unusual in being a true pedelec to ride but with a hub rather than crank motor – needless to say this involves some fairly complex electronics. If you are aiming for really steep climbs though, it’s best to look at other options.