giant-lafree-comfort-st-power-consumption

Giant Lafree Comfort ST

Giant Lafree Comfort ST Electric BikeA little under three years ago, Giant revealed the Lafree Lite, raising the stakes in the electric bicycle world overnight.This quietly understated machine was quite simply Light Years ahead of the opposition. At 22.2kg, it was lighter than almost everything else, yet it was well equipped, and offered a reasonable 20-mile range. Crucially, it was also a really nice bicycle to ride, either assisted or with the motor turned off. A year later, the Lite was joined by the Comfort – £200 more expensive, but complete with decent brakes, automatic halogen lights, front suspension forks and a suspension seatpost.

…it seems Giant didn’t so much choose the 5-speed option as jump ship…

We were less complimentary about the Comfort, principally because it weighed an extra 3.1kg.Those reservations didn’t stop us buying one, though, and 3,000 miles later, we’re still delighted with our load-carrier, winter school run transport and shopper.The bike continues to do well and – incidentally – has run almost entirely on solar power since early March (see A to B 36 and 37).

One mild criticism has involved the gearing: 3-speed Nexus hub on the Lite and 4- speed Nexus on the Comfort. Both hubs have the same 184% range, giving a bottom gear of about 45″. In practice, that’s low enough to climb most gradients and haul some impressive loads, but we’ve been defeated once or twice. Long 16% (1 in 6) slogs are just manageable, but not with a trailer in tow.

Enter the 5-speed

Giant Lafree Comfort ST Electric Bike - SRAM 5-speed hub

SRAM 5-speed hub. Note the all-enveloping chaincase and the gear adjustment can be checked through the little perspex dome

It seems Giant didn’t so much choose the 5- speed option, as jump ship for one of the few suitable replacements, as Shimano has given notice that production of the 4-speed Nexus hub is to cease.We have mixed feelings about this – the 4- speed was a heavy and rather unsophisticated lump, but it forgave all selector ‘click box’. Gear sorts of abuse and was particularly well suited to electric drives, which can put out a lot of power, sometimes whilst you’re in mid gearchange…

There are two suitable replacements; the recently back-in-production Sturmey Archer 5-speed, and SRAM’s P5, latest version of the elderly Pentasport. In the event, Giant went for the German hub rather than the home product (like most Giant bikes, Sturmeys are now made in Taiwan), perhaps because the SRAM offers a whopping 251% range, against the Sturmey 5-speed’s 225%.That’s much broader than the 184% of the Nexus 4-speed, and the SRAM weighs a whopping half a kilogram less as well.

…the clunky change can make the Lafree slower in town than the old model…

We’ll get straight to the downside – like the Sturmey, the SRAM is a fine piece of engineering, but it can’t deal with the rider pedalling, or motoring, through changes. Against the relatively slick Nexus shifting, the SRAM is ponderous and slow. It rarely misses a gear, but you can’t start pedalling until you hear a click from the back wheel signifying a complete change, and this takes an age.The pause is longer changing down through the gears, but still evident with upward changes. If you rush it, the hub simply refuses to do the business. First gear is a particular problem, especially when a steep gradient takes you by surprise – in other words, just when you need a low gear in a hurry. By the way, Giant claims that the change improves with use…

Giant Lafree Comfort ST Chainguard

The new frame is both lower and more rigid than the old design.These chainguard/motor/battery mouldings are more difficult to refit than they look

The clunky change can make the new Lafree slower in town than the old model, but we soon got used to treating it as a wide-ratio 3-speed, using gears 5, 3 and 2, which saves a bit of time. In hilly country, things are very different. On really steep hills, where the 3- or 4-speed bikes would be struggling, the 5-speed has a ratio and a bit left in reserve. How useful this is depends on where you live, and how you expect to ride the bike. As with the Honda Compo, but more so, there really is no practical limit to the hill climbing ability of the 5- speed Lafree.

Top gear is a shade low, at 79″, against 80″ for the Lite variant and 83″ for the 4-speed Comfort. Heading down, the ratios are 64″, 50″, 39″ and 32″, which would be reasonably low on a conventional bike. Overall, that’s slightly undergeared, so we’d be tempted to reduce the size of the hub gear sprocket by a one tooth, giving a top ratio of 83″.You could go further and give the ST a nice fast ‘overdrive’ top, but that would be illegal so, of course, we wouldn’t dream of recommending it…

If all this talk of percentages, ratios, inches and sprockets sounds confusing, all you really need to know is that the 5-speed Lafree offers unsurpassed efficiency. Compare the power consumption graph on page 18 with that for the Honda on page 28, and it’s immediately obvious that the Lafree’s Panasonic drive is not only fundamentally more efficient, but the extra two gears help it to run closer to peak efficiency for more of the time.The system also cuts out when you pass a preset pedal cadence, so there’s no need to turn the motor off when riding above 15mph.The SRAM hub feels efficient too, helping to make the ST one of the most pleasant electric machines to ride unassisted.

Adjustment is probably the easiest we’ve seen on any hub or derailleur system. Thanks to a little transparent window on top of the ‘clickbox’, you just twiddle the cable adjuster in Gear 3 until two cross-hairs are in alignment. Other manufacturers please note.

Other changes

An occasional criticism of the Lafree was the relative flexibility of the step-thru ladies frame, although frame flex is less important on an electric bike than a conventional bike, because you’re less likely to be heaving on the handlebars.The new 5-speed addresses the problem with a beefier 6cm mainframe tube in place of the older 4cm x 51/2cm oval design.The bike certainly feels a lot stiffer, but there’s a 300g weight penalty, even after the lighter gearbox has been taken into account.

For the time being, the 3- and 4-speed Lafree will continue in production in both ladies ‘step-thru’ style, or gents, with a traditional top tube, but the 5-speed will only be available in this step-thru form. Bad news for gentlemen is that when stocks of the 4- speed hub have been exhausted, only the base 3-speed model will be available with a full frame. However, the new design is probably just as stiff, and there’s no top tube to get your leg over. At 40cm, the step-thru height is unusually low, against nearly 47cm on the old model.

Giant has also added a few grams by fitting a full chainguard, but it’s hard to understand why.The old guard was light, simple and must have done a reasonable job, because our chain is in fair condition after 3,000 miles.The new one is made from four plastic mouldings, bolted, screwed and clipped together in the most confusing manner imaginable.The bits don’t fit together very well, and ours rubbed on the wheel on arrival – it took five minutes to fix the problem and an hour to reassemble the bits.The chain will last for ever, but you’ll need a modest tool kit, an even temper and plenty of time to get the wheel off by the roadside.That’s a shame, because one of the Lafree’s primary selling points was easy wheel removal, compared to other electric bikes.

Another small, but significant change, is to the automatic lights, where the duplicate Nexus sensor has been omitted.When we tested the Comfort (see A to B 31), we found it interfered with the light sensor in the Lumotec front light.This odd mismatch has now been cured, leaving a front light that goes on and off according to ambient light levels as intended. If you ride through a tunnel, or into a glade of trees at dusk, the lights will come on.We’d rather it happened in brighter conditions, but it is a superb system nonetheless.

Range

giant-lafree-comfort-st-power-consumption

The Lafree sips fuel where others slurp - note the low peak consumption and the very small amount (the grey area) wasted by the machine’s control systems

Just to recap, all the electric bikes we test (or at least, those that are up to it) are ridden on our long established course across the hills into Dorset, given a brief (and usually insufficient) two- hour charge and sent home again. Back in 2001, the Lafree Lite managed 20 miles at a rather leisurely 12.8mph. The following year, the slightly higher geared 4-speed Comfort managed only 18.5 miles, but at a much more impressive 14mph.

…It’s the most efficient electric vehicle we’ve seen, and the best hill climber..

With marginally the lowest gearing of the three, and five well spread ratios, it seemed logical that the ST would do better, but we were still surprised to achieve 20.1 miles before the ‘low fuel’ warning light began to flash, and a total mileage of 22.9 at a reasonable 13.2mph. In terms of fuel efficiency, that’s easily the best we’ve seen – 6.8 watt/hours per mile based on the nominal battery capacity, or more realistically, 10.8 Wh/mile if charging losses are taken into account.

giant-lafree-comfort-stIf you think 23 miles isn’t far, remember we’re riding fast in hilly country. On a more leisurely 30 mile jaunt with Alexander in the child seat, the ST came home with two ‘fuel’ lights still glowing out of five. On the ‘ECO’ setting, we’d say 40 miles would be quite within reach with care.

Charging rate is better than most; our two-hour top-up providing a 52% charge, giving (in this case) a range of 9.9 miles at 13.3 mph.The charger is the same light, compact unit provided with Lafree bikes since their introduction, and the total charge time of 3 hours and 50 minutes is unchanged.

Running costs come out at 7.9p per mile, which is the same as the 4-speed Comfort, the £50 extra purchase cost being offset by the improved running efficiency. Incidentally, we’re assuming a replacement battery cost of £195, but Giant tell us dealer prices may vary, so it could be worth shopping around. An up-to-date running cost comparison chart can be found on our website.

Conclusion

The Lafree ST is the heaviest Lafree yet and, at £1,149, the most expensive, none of which sounds very good. But it’s only marginally heavier, and it only costs fifty quid more than the 4-speed Comfort. In the credit column, it’s the most fuel-efficient electric vehicle we’ve seen, and the best hill-climber, which is quite a rare feat. Our only real doubt is over the gearbox – we’d certainly recommend trying it against the cheaper 3- or 4-speed bikes before making a decision. But gearbox and chainguard niggles apart, the rigid frame, smooth looks and overall efficiency make this one of the best electric bike yet to reach these shores. It’s one of the most expensive, but we think most users would consider it a price worth paying. (For more background on the Lafree, See A to B 27 & 31)

Specification

Lafree Comfort ST £1,149
Weight Bicycle 21.7kg (48lb) Battery 3.9kg (8lb) Total 25.6kg (56lb)
Gear system SRAM P5 hub
Ratios 32″ 39″ 50″ 64″ 79″
Batteries Nickel metal-hydride
Nominal capacity 156Wh
Maximum range 22.9 miles
Two-hour range 9.9 miles
Fuel consumption 10.8Wh/mile
Full charge 3hr 50m
Test Duration 200 miles
Running costs 7.9p per mile
UK distributor Giant UK tel 0115 977 5900 mail info@giant-uk.demon.co.uk

Loading