All skills being equal, the cycling portion of a triathlon is the great X-factor in a triathlete's finishing time.

As accomplished triathlete and coach Chet "the Jet" Blanton notes, the potential difference in times between an average performance and a strong performance is greater in the cycling leg than in either the swimming or running portions simply because the overall time and distance spent on the bike is greater.

In an Olympic-distance triathlon, for example, a couple of minutes may be all that separates the front of the pack from the middle. On the run, triathletes would need to step up their pace by 30 seconds per mile just to improve by three minutes.

But in the cycling leg (12 miles for a sprint, 25 for Olympic distance, and 56 for a half-Ironman), precious minutes can be easily shaved by quality training a few simple adjustments.

So why do so many beginning and intermediate triathletes neglect their cycling, concentrating instead on the other two events?

"A lot of beginners think that they already know how to ride a bike, so they focus on the other two," said Raul Boca, founder of the Boca Hawai'i training program. "But there is a big difference between riding your bike and racing your bike. Racing your bike is one of the hardest things to do. It's very difficult. People realize this when they get out into a race and see how fast everyone else is going."

CHOOSING YOUR BIKE

Much of cycling a good race depends on having the right bike and equipment. Thus, a smart triathlete can cut minutes off of his time simply by making the right decisions at the bike shop.

When shopping for the right bike, proper fit and good aerodynamics are key.

If it fits the budget, a light-weight, thin-wheeled road bike is much preferable to heavier, bulkier mountain bikes.

"Road bikes are much faster because there's less drag and resistance and higher tire pressure," Boca said. "Everything has to do with resistance."

In general, a rider should be able to stand over the top lateral tube of the frame with an inch to spare. In determining seat height, the rider's leg should extend to a 30-degree angle at the lowest point of the pedal stroke. The rider's arms and torso should be able to align at a 90-degree angle without the rider hunching.

But these are general rules-of-thumb. Both Blanton and Boca recommend a proper fitting from a qualified bicycle salesperson (specialty bike shops are your best bet).

"Fit is No. 1," said Blanton. "Even small things can have a big impact on how you race."

Blanton said he once traced a breathing problem that forced him to sit up periodically while riding to a set of handlebars that was too narrow for him.

FINDING RIGHT APPAREL, EQUIPMENT

Equipment and apparel can also make a difference. A form-fitting cycling top and padded bike shorts offer less wind resistance than a cotton T-shirt and running shorts (bike compression shorts can also help stabilize thigh muscles for better performance).

And, while high-tech disc brakes can be cost-prohibitive, Boca says a good, aerodynamic helmet can be just as effective in shaving time from a ride.

Clip-on bike shoes are also a standard part of triathlete's gear bag. The shoes, which lock directly onto the pedals of the bike, allow for the most efficient transfer of energy between rider and bicycle and promotes proper pedaling technique. New riders should practice clipping in and out of the pedals at home before trying it on the road.

RIDING TECHNIQUE

With the right equipment in hand, riders should next focus on safe, efficient riding technique, which includes keeping the knees in toward the frame of the bike, riding in the drop position (with head and torso lowered to reduce wind resistance) and eliminating unnecessary side-to-side motion.

"Simply by dropping my head, I can reduce the drag and ride 1.5 miles per hour faster," Blanton said.

Minutes can also be saved by practicing proper pedaling mechanics. While many beginning riders tend to alternate pushing down with either leg to power their bikes, Boca said the best cyclists go through the entire circular motion with both legs.

"On the down stroke, when your foot is at the 4 o'clock position, imagine cleaning mud off your shoe: push down and scoop up," he said. "From the 6- to 12 o'clock positions, you should lift your leg up. You don't want the weight of that leg to have to be carried by the other leg."

To practice pedaling form, Boca suggests using a stationary bike to ride one leg at a time, alternating every 30 seconds to three minutes depending on conditioning.

Boca said riders should try to maintain a consistent pace of 80 to 90 pedal rotations per minute, shifting gears up or down according to changing grades.

SPECIFIC WORKOUTS

Both Blanton and Boca recommend a weekly regiment of three rides: a slow and long endurance workout at between 65 percent and 75 percent exertion, a shorter, high-intensity ride focusing on speed and strength, and an easy, moderate ride for recovery.

For the high-intensity workout, Boca recommends alternating week to week between hill and tempo workouts. Riding hills, he said, is especially useful for building strength and practicing proper gear-shifting technique.

To maximize these hill workouts, Boca said riders should try to stay in the saddle (remain seated). Boca also stressed that riders should consider doing their strenuous workouts indoors or on wide roads with very little traffic to ensure safety.

While triathletes who devote time and energy to their cycling almost invariably improve their times, it can take a while to become truly attuned to the nuances of efficient racing.

"It can take two to three years," Boca said. "The first year, you'll improve somewhat, but in the second and third years your body will get adjusted, you'll understand and appreciate what good form is, and you'll really be able to make big progress."

Reach Michael Tsai at mtsai@honoluluadvertiser.com.