Untitled

Giant's Electric-Assist Bicycle: A Review

I have a biking nemesis: During my regular rides around thesix-mile outer loop of New York’s Central Park, the big hillat the north (uptown) end of the park invariably sucks the verylife out of my aging legs. Yesterday, however, pedaling up the bigincline was another story altogether. It was as easy as climbing asmall rise. My new-found prowess had nothing to do with anyimproved fitness, of course; it was the bike I was riding, theTwist Freedom DX from Taiwan’s

Giant Bicycle, Inc. which augments every pedal stroke with a finely timed electricboost..The Twist Freedom DX incorporates a battery-powered electric motorin the front wheel that relatively seamlessly supplements your legmuscles to “smooth out” your ride. This means you canmaintain a nearly steady pace no matter what road you take. Theoverall effect is to give you “light feet,” as if youset a stationary gym bike to a low resistance level--one thatenables you to just pedal away with abandon. The power boost isespecially noticeable when you start out; the electric-assist makesit effortless.Giant’s Hybrid Cycling Technology is based on a torque sensorin the pedal crank that measures how much pressure the rider exertswith each stroke. Some rather sophisticated software algorithms inthe I2 Driver Unit’s computer located just aft of theseat tube takes this force data and converts it on the fly into“smoothed” power-transmission commands for the electricmotor. The motor is a Sanyo DC brushless unit that can produce from150 to 350 watts of synchronized power as needed. As a result, therider can take on hills or long stretches of road without breakinga sweat, should he or she so decide.A ride controller on the handlebar lets you choose among threeoperating modes: Economy (minimum power output), Normal, and Sport(extra boost). Setting the bike’s seven-speed Shimano Nexustransmission system to just the right gear to accommodate theterrain, the power mode and your pedaling effort fine-tunes theTwist Freedom DX’s ride to a very pleasant “T.”As a result the set-up mostly avoids the timing lag riders haveoften experienced when pedaling previous electric auxiliary-powerbicycles. That annoying phenomenon occurs when the stroke is notfully synched with the power-boost.Electric power in the DX is supplied by a pair of four-pound (2kilogram) lithium-ion battery packs that fit over the rear wheel.These lockable modules sit snugly under fabric pannier bags. Thebatteries, which are engaged in sequence via a handlebar control,together supply juice for about 70 miles (113 kilometers) inEconomy mode. The user can rather easily extract them forrecharging via a home wall-plug, which takes a maximum of sixhours. The bicycle works just like a regular bike when the power isdisengaged.Note that the DX’s power-assist system responds only topedaling and has no stand-alone throttle capability, so it’sno electric bicycle or scooter. It’s really a differentbreed. Some purists might debate whether one would define it as atrue “hybrid” as it does not incorporate amuscle-driven electric generator, or downgrade or brakingenergy-recovery system to recharge the batteries, but suchtechnology may have just ended up adding weight, complexity andcost with no certain payoff. The DX does, however, combine electricand muscle power so that makes it a hybrid to most of us.Last year in China, dealers sold almost 20 million bicycles withauxiliary propulsion systems. And this technology is big in Europe where it is seen as a low-cost and green alternative to cars. InGermany, for example, where they’re called“pedelecs,” several companies besides Giant offerelectric-powered models. They include the Gazelle Orange Innergy  the

Hercules EMove sport sl the Matra I-Step Cross and the Riese & Mueller Delite Hybrid.I look forward to seeing these products hit our shores one day (ifthey haven’t already).Giant’s DX hybrid bike has been commercially available fortwo years in Europe, where it has received extensive customer use,so potential buyers in the U.S. shouldn’t worry aboutpotential operating problems, such as biking in the rain and soforth. The thing felt pretty bulletproof during my shorttest-drive. Weighing in at around 50 pounds (23 kilograms),it’s certainly no lightweight, but the power-boost mostlyoffsets that potential problem. Otherwise, the DX seems a solidlybuilt and rather slick package, one that looks like a regularbicycle.Although most people would probably describe the DX as a commuteror urban cruiser, the bike’s clean and straightforwardlyutilitarian design should attract buyers interested in a littlehelp with their daily work run or rides around congested cities,spread-out ‘burbs or longer trips to and from the country.And it’s quiet enough that fellow bikers may not even noticethat you’re getting a performance-assist as you pedal uphills...The Twist Freedom DX is priced at about $2,000 (MSRP) and goes onsale this week at 20 of Giant's top retailers around the U.S. Formore information, go to the Giant Web siteBicycle-Related Stories.How to win the Tour de France