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BionX Miele Tivoli

A new breed of power-assisted bike

Price:
£1,000 approx
Rating:
3
On 01/12/2004
Last modified:23/11/2012

Summary:

It's a low-key, low-torque machine, but if you commute through rolling hills and you want a conventional bike with a subtle boost, this Rolls-Royce system could be for you.


bionx miele tivoli 295x447 BionX Miele TivoliThe Canadian-made EPS power system was introduced as long ago as 1998, but has only just arrived here in Europe. If it looks familiar, yes, it is the same system shown in A to B once or twice on a bike called the Amigo.The manufacturer is now called Bionx EPS (Energy & Propulsion System, if you hadn’t guessed), but the technology is exactly the same, either in kit form, or fitted to a proprietory bicycle, in this case a Miele Tivoli.

Beneath the surface, the bike is seething with technology, but you would never know, because it’s a more or less conventional- looking machine: the rear hub is slightly larger than normal, there’s a discrete streamlined battery box in the frame, and an instrument pod, but no obvious stray wires or switches.

If you’re one of the many readers totally averse to electric bikes, you really should read on.We’re not suggesting this sort of machine will suit every rider in every eventuality, but if you regularly grind your way up a nagging gradient, only to blow away all that hard-won effort braking down the other side, you might be interested, because this is a regenerative system.Yes, you really can recharge the battery by pedalling if you wish, and you can also recharge it by putting the brakes on. In other words, an EPS-equipped bike will recycle some of the energy you put into accelerating and climbing hills.There are a few complications, both good and bad, but more of that later. Meanwhile, we’ll use the Giant Lafree as a reference point, because the Bionx is the first bike that can seriously claim to be a natural competitor. Price is expected to be around £1,000.

Miele Tivoli

We don’t see many conventional bicycles at A to B, so it’s all rather exotic to us. It may be to you too, because these Canadian bikes are quite rare in Britain. An unusual brand, perhaps, but the Tivoli is the sort of hybrid-style, suspended bicycle that most commuters will recognise. It has an alloy frame, 3 x 7 Shimano Acera gear set, straight handlebars, Suntour CR870 suspension forks, suspended seatpost, mudguards and (to us) enormous 28-inch wheels.

The gear range starts with a nice 28″ ‘near Granny’ gear, and extends to a reasonably high cruise of 96″ – dead conventional in other words. It may be our fault, but we found the Acera change rather noisy and crude. Adjustment is critical, and we were unable to completely tune out the odd grunt and bang from both the front and rear mechanicals. Otherwise, there’s little to report.The frame is rigid, the riding position good, the narrowish 700 x 38C tyres cover ground quite well, and the suspension does a workmanlike job of ironing out the bumps. Rather better than the Lafree Comfort, in fact.

The only thing slightly out of the ordinary is weight.Without the battery, the Bionx- equipped Tivoli tips the scales at 19.7kg, which is a bit heavy for a suspension hybrid, but one of the lightest electric bikes we’ve come across. Only the three-speed Lafree Lite weighs less, but a fairer comparison is the 5-speed Lafree Comfort, which has suspension and more gears, and weighs a couple of kilograms more than the Tivoli.Add batteries (3.9kg for the Lafree, and 4.4kg for the Tivoli) and you hit gross weights of 25.6kg and 24.1kg respectively, so Round One goes to the Canadians.

Power system

bionx hub motor 295x312 BionX Miele Tivoli

The direct-drive motor is 221/2cm in diameter, but only 51/2cm wide

As usual these days, energy comes from a nickel metal-hydride battery, with a claimed capacity, in this case, of 192Wh. At the business end, the hub motor is unusually narrow and large in diameter. Its also a bit special.

If you were to delve inside most electric hubs, you’d find a fast running direct current motor (or its more efficient cousin, the brushless ‘Hall Effect’ motor), driving the hub through gears and a freewheel.The helical gears tend to be noisy and inefficient, but they’re needed to bring the motor speed down to a practical level.The freewheel allows the bicycle to be pedalled normally without pointlessly spinning the motor – some are quiet, but cheaper units can make quite a racket.

…we have a simpler, lighter, quieter and more efficient system…

The Bionx has a Hall Effect motor, but it has been configured to run very slowly, which has allowed the engineers to eliminate those noisy gears and drive the wheel direct.With no gears or brushes, there’s no friction, so the freewheel can go too. With no freewheel, the motor can be programmed to run as a generator, putting power back just as easily as it takes it out.

All brilliant news so far – we have a simpler, lighter, quieter and more efficient system. However, as Professor Pivot likes to point out, the opportunities for regenerating power on a bicycle are rather limited, because most of the power consumed in climbing and accelerating is lost through wind and rolling resistance.The other small problem is that electric motors are never really comfortable running slowly, and when you’re inching up a hill with a system like this, the bicycle wheel (and thus the motor) is revolving very slowly indeed. Anyway, that’s the theory, plus some cautionary small print to stop you getting too excited. How does the Bionx actually perform on the road?

bionx miele tivoli 2 295x357 BionX Miele TivoliThere are four buttons in the handlebar-mounted pod: an on-off switch, another for setting the odometer and other things, and the two power controls: ‘+A’ and ‘-G’.There are four power steps and four regeneration steps, with a neutral position in the middle. Prod the +A button and power increases, press -G and it reduces, or starts to regenerate if you go far enough.The liquid crystal display includes a speedometer (only in kilometres, the swine), a resettable odometer, and a regenerate/power meter. There’s also a very effective backlight and an alarm. Being a pedelec, the Bionx doesn’t have a throttle control, because power comes in only when sensors register pedal effort. Quite right too.

Ever since we began grinding, whining and occasionally smouldering up hills on these machines, we’ve grappled with describing power-assist sensations. In this case, you start to pedal and – without a sound – there’s a gentle push, rather like sitting behind a powerful but silent locomotive.The power meter confirms that something is going on, as the onboard computer matches the assistance to your pedal effort. Just once in a while, it changes it’s mind, and you feel a gentle nudge. Otherwise, you’re only really aware that the ground is moving by more rapidly than normal. In heavy traffic, it’s impossible to tell that the motor is doing its stuff without checking the meter, but on a quiet road, those with excellent hearing may detect a tiny hum at full power. Subtle stuff.

bionx battery 295x260 BionX Miele Tivoli

Clever stuff. A metal plate screws to the bottle cage braze- ons, providing a quick release base for the battery, which is locked in place. It can either be charged in situ or removed

On the flat, or gentle gradients up to about 7% (1:15), the bike glides effortlessly up to a maximum of 20mph with just a whisper of power assistance (rate 1 or 2). On steeper hills you need full power (rate 4).This is a useful 480 watts, but you still have to make good use of the gears because the motor is only really chirpy above 12mph, and rapidly wilts below 6mph.Thus a 12% (1:8) hill might need the 2nd chainring, and 17% (1:6) will probably need the 1st. At very low speeds, there’s a gentle vibration from the motor, but it’s still near silent.

Obviously steep hills are not its forte, but to be fair, our test bike is a US/Canadian model, electrically ‘geared’ to give a top speed of 20mph (don’t they have hills?). European production bikes will be reconfigured to assist below 15mph, which should boost hill-climbing torque by nearly a third. Either way, the Lafree’s crank motor wins on gradients.

Regeneration

Stop pedalling, and after a decent interval, the computer silently turns the motor off. If you so wish, you can now turn the motor into a brake by setting one of the four regeneration levels with the -G button, or by touching the front brake lever, which gives a higher braking force. Actually it should be the back brake lever, but we’ve dutifully reversed the cables for British use – the levers will have to be reversed for production. The effect is slightly noisier than power – a gentle vibration, rather like poorly set brake blocks rubbing on the tyre.With a bit of experience, you learn to (for example) dial in a low background braking level on a long descent, then gently touch the brake lever for extra stopping force on the corners.The trick is to avoid using the conventional brakes, and if you enjoy playing these sort of games, ‘driving’ the Bionx is very satisfying. If you don’t, just preset a power level, ride as normal, and the computer will do its best to smooth your progress.With eight buttons and levers to play with, it’s more like piloting a space shuttle than riding a bicycle, but that’s progress. And we should point out that power-assist involves only two buttons… it’s the derailleur that gets us really confused.

Watching power funnel back into the battery is very satisfying, although really high rates tend to be short-lived. Plummet down a 17% gradient with the electric brake full on, and speed will stabilise at about 20mph, at which “…don’t get too point you will be generating 200 watts or more. excited about the perpetual Sadly, 100 watts is more realistic during a typical  stop, and at low speed, even though the braking effect might feel quite fierce, the output is actually pitifully low. Don’t get too  motion idea. Results depend on the territory, and getting the best from the system is quite an art.You’ll be lucky to salvage 25% of the outgoing power, even under ideal conditions. Still, it’s better than a poke in the eye with a blunt stick.

…don’t get too excited about the perpetual motion idea…

If you’re feeling really enthusiastic, you can keep the electronic brake lightly engaged on the flat and recharge the battery with your muscles.Why on earth would you want to do that? Bionx craftily claims that this gives your body a better work out, which is true enough if you’re looking for a workout, and more sensible than loading the bike down with weights.We tended to regenerate and pedal on those long, gradual descents that are too shallow to get up any real speed.You know the sort of thing. On the flat, even a modest 50 watts is quite hard work, but serious athletes will no doubt be pounding round the block, putting away enough energy to run the telly for the rest of the evening.

One rather unlikely side effect of this system is that you hardly ever use the brakes, except when coming to a halt in traffic. If you suffer from rim wear and smouldering brake blocks, this characteristic alone might sway you.True, there isn’t enough oomph in the battery to power all the way up that alpine pass, but you won’t need to touch the brakes going down the other side, and the battery will be nearly full again at the bottom.

How are we doing against the Lafree? Well, the Giant has a very efficient motor, but it doesn’t regenerate on descents, so it’s Bionx again.

Range & charging

With so many variables at work, range can be pretty much whatever you want it to be, depending on the level of power, and the amount you’re able (or willing) to regenerate.We’re usually quite brutal in our testing regime, but the Bionx responds best to a gentle touch. so we opted for power rate 1 or 2 where the undulations were generally upward, and regeneration rate 1 or 2 where the going was easier. Hills of 10% and above demand full power to keep momentum up.

As you ride, the power gauge moves down the scale with alarming speed, but the motor continues to run for long after the gauge has given up and gone home. It’s hard to put a precise figure on the range because downhill runs keep restoring the status quo, and the computer gradually turns down the gas, rather than cutting the motor off.

Blast along on full power without a care in the world, and range can be as little as ten miles, but 15 miles is easy with a bit of care, and if you work hard at your regeneration, 22 miles is possible. Obviously, the battery will last all day if you don’t use it much (Bionx claim up to 50 miles), but then you wouldn’t be averaging 14.3mph in hilly country – a respectable rather than blistering pace.

The detuned European model will certainly go further, although quite how much further is hard to judge.We’d hazard a guess that 25 miles should be within reach on our hilly test route, but you might do better.

Charging is satisfactory rather than exciting.Weighing less than 400g, the little charger is almost pocket-size, but still manages to fill the battery in five hours, turning off thereafter, so there’s no point in leaving it connected.

At 7.2p per mile, running costs are almost identical to the Lafree, but we can’t say for sure until the price of the bike and spare batteries has been fixed. Range is about the same, but speed (from this US model at least) is quite a bit higher. Charging time is slowish, but the charger is more portable. Sounds like a draw.

…the prospect of everlasting wheel rims might be tempting too…

Conclusion

We tend to use electric bikes for slogging up steep hills with trailer-fulls of rubbish, so we’d be less likely to opt for a low-key, low-torque machine like the Bionx. On the other hand, if you commute through rolling hills and you want a conventional bike with a subtle boost, this Rolls-Royce system could be for you.The prospect of everlasting wheel rims might be tempting too.

There’s no need to buy the Tivoli, as the Bionx will also be available as a kit, but you’ll need a donor bike with plenty of derailleur gears, because hub gears are incompatible with the motor.There’s no price yet, but we’d guess at around £700, which would put the Bionx kit at the top end of Heinzmann territory. It’s not as powerful, but it’s much, much more sophisticated.

Does it outclass the Lafree? That all depends where you live and how you ride.We only had a chance to show the Bionx to one dedicated Lafree enthusiast, but she was absolutely delighted with the riding position and the quiet, effortless power.There is no distributor in the UK as yet, but the company is open to offers from aspiring importers, and hopes to have direct and/or dealer sales established very soon.

Specification

BionX Miele Tivoli £1,000 approx .Weight Bike 19.7kg Battery 4.4kg Total 24.1kg (53lb) . Gears Shimano Acera 3×7 . Ratios 28″ – 96″ . Batteries NiMH . Capacity192Wh . Range 22 miles Full charge 5 hours . Fuel consumption Overall 12.5Wh/mile . Running costs 7.2p per mile Manufacturer BionX (EPS Inc) www.bionx.ca mailr.guimond@bionx.ca fax +1 819 879 0084 tel +1 819 879 0041 ext. 235