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Show Cycling-Buying A Bike . ( -w ll may have taken an energy shortage in" the yearly lightening T I lie OI'FC vise Id create the current popwlariat inn of ihe liicvle. fast year sales of new h'u vcles in Ihis loimlry totaled more than iliose of the four wheeled Detroit aliernativcs anil many melro areas have responded wilh bikeways and paths to accomodate the traffic. In Park City there are rumors of a possible cycle route which. would bring the town up to date with Aspen and Sun Valley where similar routes arc heavily used. With this rapid growth of interest many individuals are faced with the first and most important cycling question: What kind of bicycle . should I buy? The answer lies in first examining two determining factors: How much do you want to spend and how do you intend to use a bicycle? Bicylcing magazine recently conducted a road test of 10 bicycles with price tags beginning at -$250 and ending at $4,000. Obviously your bank account must draw some boundaries so first consider usability. If you arc eeruun that your cycling interest is lii.iited s.r,)it grocery store trips and an " occasional Sunday 10-miler, then your decision is easy aim your bank account is in luck. Most thrift stores have a collection of cheap used bikes to satisfy your needs. What do you do when you later decide that if the old crate you bought last year was lighter or easier to ride you would use it more often, maybe ieave the car and take the bike or join some friends for longer recreational noes, possibly even race'.' If vott have arrived at this impasse the best advice is to buy the bike wilh the best quality frame. Once vou bas e a good frame as a base you can build on it later by changing components and accessories. A good quality frame will move your lower price limit up to S250 or $300 but keep in mind that bicycles, when cared for. don't suffer from bleak automotive depreciation schedules. Look for lug fitted frames. Lugs are the sculptured looking metal fittings which join the tubing at brazing points contributing to a stronger frame. When replacing the mild or soft steel tubing of the bargain basement bike you will find materials such as Reynolds 531 and the words double-butted. The numbers indicate a recipe for the allov of metals used in the tubing, ingredients beina chrome steel, molv steel, etc. Double-butting- refers to the extrusion of the frame materials so that the wall thickness is thinner at midtube and thicker at the ends where the brazing is done. The result .is strength with less weight and a frame with a feeling for the road, the ability to absorb shock and to flex with your movements yet not so much as to dampen your efforts. frames are manufactured in various sizes and il nensions to accomodate different bod -i.'cs and cycling purposes. Consider the accompanying illustration: the prime measurement is the distance between the centerline of the bottom bracket (the axle to which the pedal cranks attach) and the top of the seat tube. This measurement is generally refered to as the frame size and is expressed in inches from 21 to 25. mailer or larger sizes usually are custom made. A rule of thumb in determining your correct frame size is to straddle the top tube with both feet flat on the ground. The distnee between the top tube and your crotch should be no more than an inch and no less than just touching. Other important dimensions are the head set Mil 11 Willi Mill llll IEiIIIHHI IIU ID-lull WIIH II Mil Willi anil seat tube angles (72 degrees or slighilv less lor a louring frame. 74 degrees or slightly more for racing) and the wheelbase which is the distance between front and rear axles. The sleeper angles make for quicker response which the racer needs and the shallower angles tend to smooth out the ride for bumpy roads encountered when touring. Chainstay distances of Ib'i inches are found on racing bikes along with the sleeper headset and seal tube angles for quickness of handling whle louring lengths of TA inches sjiiooth the ride. Fork rake, measured form the plane of the dropouts to Ihe centerline of the steering column should be keyed to the headtube angle, more rake (2 inches or. more) for touring, less rake (l'i inchess) for racing. Trail is measured from the point where the tire touches the ground to the point where the steering column centerline intersects the ground: Trail is actually a function of head tube angle and fork rake. The dynamics of trail are worth an entire page of physics but basically at normal speed, on a bide wilh normal head tube angle, more trail means mroe stability. It is usually felt as a difference in the bike's ability to roll on a straight line or to be easily deflected off course. Trail is typically between 1 'A inches to 2'A inches. The choice to spend the extra money now for the bike with a high quality frame will effectively open the door to the sport of cycling. There are numerous manufacturers from Europe, Japan and America to select from and every cycle shop will present you with wjhat they presume is the best. Shop around and listen to the different sales pitches then deal with the shop you trust the most. Look for competent salespeople and mechanics to help you choose the proper frame size and deminstions. Once you have made the purchase decision there are numerous adjustments and modifications to be made to properly fit the bike to your body. Next week in this column I will offer some tips which will spell the difference between riding pleasure and pain. HEAD TUBE ANGLE fc3 , . EAl TUBE A ' FORK RAKE BOTTOM BRACKfT HEIGHT . TRAIL |