Different Spokes FOR Different Folks : Recreation: Bikes are changing for the better. The 10-speed you once dreamed about may not be what you want now. Maybe you need a mountain bike, or hybrid.

So you thought you’d buy a new bicycle. Run down to the local bike shop, check out the 10-speeds, spend maybe $125 and be riding by the afternoon.

My, how things have changed. In case you don’t know it, the standard-spoked bicycle has gone through a revolution of sorts since your youth. Thanks to technology, new designs and radical new features, the old two-wheeled steed has undergone a dizzying number of changes, making it easier, and more enjoyable, to ride than ever before.

It’s never been this much fun--or this costly.

In a word: If you haven’t bought a bicycle recently but are eager to take advantage of Orange County’s ideal biking weather and myriad bike trails, be ready for a shock the next time you drop by your local bike shop. You might not even recognize some of the machines on display, and worse yet, you might not know how to operate them.

But first, discard the idea of dusting off that old 10-speed in the garage. It may still work all right, but if the biking industry standard a decade ago was a Volkswagen beetle--sturdy and dependable--today it’s more of a Volvo, equally durable but capable of so much more. So unless that relic in the garage was a collector’s item when you bought it, consider it garage-sale fodder and let it go.

And if you’re still intent on going on the cheap, consider this: by the time you take your old bike in for a tuneup, replace the tires and a few cables and get it overhauled, you’ll have a bill upwards of $150--if it’s done right. And even then all you’ll have is a spruced-up antique. What is it they say? You can give a bum a shave and a haircut, but he’s still a bum.

Like anything--cars, computers, stereos--you’re better off knowing what is out there, and what your needs are, before you set foot in the bike shop. A good salesman will walk you though the new lines and what is available, but a little knowledge goes a long way.

Which bike you select depends on what kind of riding you plan on doing, but generally there are three basic types of bicycles on the market.

* Road bikes: This is the much-beloved classic 10-speed, the European-designed import that was so popular during the bicycle boom of the early 1970s. This skinny tire, drop handlebar machine was designed for speed and remains popular with traditionalists and those who have taken to biking for fitness and racing.

But some industry experts, including Bicycling magazine, already seem prepared to write its obituary. The problem: the drop handlebars, designed to put the rider in the most aerodynamic position possible, have proved too uncomfortable for the mass market and the tires, while great for speed on the road, are prone to flats. Still, if you’re looking to drop a few pounds or stay in shape, there is nothing that beats a road bike for overall versatility and plain, aesthetic beauty. Purists will ride nothing else, and think nothing of spending $2,000 to $5,000 for a custom model.

Road bikes generally come with 12, 14 or 16 speeds--the term 10-speed has hence become a misnomer--and feature steel, aluminum, carbon fiber or composite frames. Prices for entry-level production road bikes start around $350 to $400. Mid-range road bikes, those with higher quality brakes, gears, frame tubing and components, run around $650.

* Mountain bikes: This particularly American invention burst onto the scene 10 years ago and has single-handedly changed the way the world looks at the bicycle. Immensely popular, these fat tire bikes featuring upright handlebars were designed to go off the road but have proved popular on asphalt as well.

Dealers say most people who buy mountain bikes rarely leave the road. Mountain bikes comprise about 70% of the total bike sales in the United States, and they currently are the rage of Europe. Even some of Europe’s most revered names in racing bikes (Colnago and Pinarello among them) have broken with tradition and are marketing their own version of the American mountain bike.

The advantages: The fat, knobby tires rarely give way to flats, and the upright handlebars and padded seats make for a generally more comfortable ride for the recreational cyclist.

Mountain bikes also feature a third “granny” gear in the front, giving riders an additional set of gears--most come with 21 gears--to take the steep hills with ease. On the downside, these bikes, like a four-wheel-drive Jeep, were not designed for the street, and they can be clearly limiting on longer rides.

Prices for good quality mountain bikes begin around $300. Look for mid-range models, again featuring better grades of chromoly steel and superior components, in the $500-$600 range.

* Hybrids: Perhaps the most interesting, and promising, development of the past few years has been the introduction of what is known as the hybrid bike.

Sensing the public’s desire for a more comfortable ride but the ability to go greater distances, manufacturers took the best of both the road and mountain bikes and came up with the hybrid, which is known by a number of names--cross trainers, cross terrain, multi-track, to name a few. Most of the hybrids come with upright handlebars, allowing the rider to avoid the hunched-over racing position of the classic road bike. The tires are thinner than the mountain bike’s but still thicker, and therefore more durable, than the road bike’s standard slicks.

Some industry experts see the hybrid as the bike of the future, one that avoids the extremes of the road and mountain bikes while providing a clean, fast, trouble-free ride. Prices begin around $300 and escalate from there.

If the prices scare you, take heart. The bike of 1990 is nothing like its distant cousin of a decade ago. Like computers, the technology has moved so fast that it is almost unthinkable to be riding anything but one of the new generation of bikes.

They are lighter, faster and feature superior designs and frame materials. And--this can’t be emphasized enough--they also are easier to handle.

Take, for example, what has happened to shifting. Thanks to a Japanese company, SunTour, most bikes now come equipped with what is known as “indexed” or “click” shifting. A simple click of a lever or push of a button throws the bike into a new gear. No more looking back at the rear freewheel to make sure the chain hits the right cog. Want to go up three gears? Click the lever three times.

What this does is render obsolete that tired old question: Why do I need 21 gears? Do you ever use all of them? Thanks to trouble-free shifting, riders are zipping through the gears with healthy abandon.

Equally important (but probably overemphasized by those who know no better) is weight. Advances in design and construction have made bikes lighter than ever before. Pick up any new bike if you doubt it. Aluminum bikes are even lighter and new materials (carbon fiber, composites) are taking this quest for lightness to new extremes.

But weight should not be the only consideration. More important are the components--brakes, derailleurs, gearing, chain rings, etc.--and the frame. If you want a better bike, pay attention to the frame and components and don’t be reluctant to pay an extra $75 to $100, or even $200, for a superior bicycle. In the highly competitive world of bikes, you truly get what you pay for.

Pedal systems have also been vastly improved, cranks are more durable and lighter and brakes have never been as sure. Good quality name-brand bikes (we are excluding department and discount store models) will also come with knock-off wheels, meaning that removing the front or rear wheel can be done by releasing a simple lever. The height of the seat post is also adjustable with a lever.

The final, and perhaps most important, aspect of bike shopping is finding the right shop. Unfortunately, all bike shops are not equal. Shop around. Find a shop that carries name brands with solid reputations (Trek, Specialized, Centurion are three) and has a mechanic who knows what he’s doing.

Ask for references. How long has he been in business? Does he race? Look around the shop. Check the prices. Generally, the better shops offering more expertise will carry a number of higher-end models catering to racers or serious recreational cyclists.

And lastly there is the fit. Ten years ago people paid little attention to sizing, but today the size of the frame, the height of the stem, the width of the handlebars and the position of the seat post are all important in providing the most comfortable ride possible.

Good shops will fit you for the right size bike at no cost (this involves measuring the inseam, upper body, shoulders, etc). Others will sell you a bike, no matter how big or small, to move it off the floor. A good bike shop should be like the family doctor--the expert to which you go with your problems.

Bikers have a name for dilettantes who think they know what they’re doing but don’t. You see them on the road riding bikes too small or large for them and spinning along in the wrong gear. They’re called Freds. So shop around, find the right shop, buy the bike that suits your needs and stay out of Fred’s shop.