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FEATURES: TWENTY TECH QUESTIONS
Richard Cunningham
October 21, 2009
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1. Do I really need to do intervals to get faster?
Brute strength can get you over the first climb and close gaps for the first 45 minutes of a race, but after that, it is the condition of your cardiovascular system that determines your fate. Road riding is about sustained efforts at near-maximum output and about how fast your body can recover. Both of these situations are maximized by interval training. You will ride like you train. As much as intervals hurt, as ill as you feel as you struggle to recover from each successive effort, this will be the measure of pain and suffering that you will be able to inflict upon your rivals come race day or the next club ride. Think about intervals as storing suffering in a can—the more you store, the more whoop you’ll have later to dump on your rivals.
2. How does a tubeless tire work? What do you do if you flat?
Tubeless tires and rims are similar to standard clincher types in all but a few details. Tubeless rims must be sealed where there are spoke holes and at the joint area and use a special valve stem with O-ring seals on either side. Most tubeless rim makers, like Shimano and Campagnolo, eliminate the rim’s inner spoke holes completely, and thus the need for a rim strip. Stan’s NoTubes makes a retrofit rim strip which converts conventional wheelsets to tubeless in conjunction with their latex-based sealant. Tubeless tires have an inner coating of rubber to seal the carcass (standard clincher tires are too porous to hold air for any length of time) and the reinforcing cords molded into the beads must be stronger to prevent the tire from blowing off of the rim when inflated at high pressures. At present, only Hutchinson makes tubeless tires for the road—under its own brand and for Specialized. Hutchinson’s tubeless tires use a carbon fiber bead.
The way tubeless tires and rims inflate is that the rim and tire are designed to contact each other just tightly enough to make a reasonably airtight seal when the tire is loose on the rim and uninflated (automotive tires operate exactly like this). A quick burst of air pressure spreads the tire beads outwards towards the rim flanges. The inner rim profile is tapered to fit the tire beads more snugly as they spread outward, so once the tubeless tire is “started,” easy hand pumping is all that is required to finish the job. When enough air pressure is achieved, the beads “pop” into place audibly and are sealed.
There are three strategies to fix a punctured tubeless tire. The first is to remove it exactly as you would a standard clincher: Unscrew the valve stem with finger pressure and then install a conventional tube—this is the preferred method because it is a no-brainer. The second is to patch the inside of the tire carcass with a glueless patch from Innovations in Cycling, and the third is to inject a one-ounce bottle of Stan’s NoTubes into the tire (usually, by removing the valve core and squeezing the fluid into the stem—reinflate it and go).
3. Why don’t more riders use triples?
Triple cranksets provide a comfortably low gear range for climbing while retaining a closely spaced racing-type cogset to enhance riding on the flats and rollers. The alternative to a triple is a widely spaced cogset (12 x 28), which is still not low enough to make a huge improvement on excruciatingly long climbs, and creates big jumps between gears—which makes riding on the flats quite annoying.
Foolish pride is the main reason that most roadies will not resort to a triple chainring setup. Pro racers don’t use triples, and they set the fashion for rank-and-file riders. We don’t want to be seen riding a triple because it screams out that we are unwilling (or unable) to suffer profusely on climbs—like the “real men” in the peloton. Another reason is that most rear derailleurs cannot handle the capacity (take up enough chain) of a three-ring crankset, nor can many front derailleurs swing wide enough to correctly shift three chainrings. Now that Shimano Dura-Ace and Campagnolo Record groups feature triples, that is a moot point. Any less-than-Sastre rider who spends a lot of time in the mountains or plans on following the hilly stages of the Tour de France should consider this wonder of drivetrain technology.
4. People talk about 53/11’s or describe what gearing they use on a certain climb. Please explain the basics.Most cyclists call out their gearing by making reference to the number of teeth on the chainring and cog selection that they are using. Thus, a “53/11” would be the big chainring and the smallest cog—a selection that you might use on a fast descent or the downwind leg of a time trial. Climbers like to talk gearing, like: “I busted out Tragic Mountain in my 39/15 yesterday.” Picking up or slipping down one gear on a familiar climb or time trial course is big news. The difference between early season fitness and peak season form may only be one gear, but learn the number of teeth on each cog on your cassette before you boast, because most riders will call you out if you are off by a single one.
5. Glasses over the helmet straps or under?
However Lance wears them is a defensible position. Presently, the fashion is over the straps.
6. How many tubes should I bring on a ride?
Two tubes is the perfect number. You’ll need one to fix the only flat you’ll get today, and you’ll wave the second one at the jerk who never brings his own spares—or only brought one and punctured a second time. Wave the tube, but never offer it—the only thing you should leave an unprepared rider with is a memorable lesson. Also, many of us forget to repair or stow a punctured tube and bring it along for the next ride. Having the second is a godsend in such cases.
7. What things should I check before every ride?
Always check the quick-release levers. Open them a little less than half way, not so far that you mess with the wheel alignment, but enough so you can check that they close tightly. Next, check tire pressure—always ride the same pressure so you will be able to trust your bike in the corners. I spin the wheels to check for brake drag, cuts in the tires and wiggly rims, quickly put the front tire in between my knees and twist the stem to ensure it is tight, and then squeeze the brake levers to ensure that the pads hit the rims at the right place. If I am using tubular tires (I almost always do), I grab the tire at a random point and roll it on the rim to ensure that it is securely glued, and then I ride.
8. How much air pressure should I run?
Every tire has a sweet spot where it rolls faster and yet absorbs road shock—and more pressure is not always better, as many believe. Three features determine where this mythical tire pressure should be set. First, check the ratings on the tire. Some are rated as high as 220psi and others as low as 125psi—usually there is a high/low range, and the best place to begin is the middle. Second is the diameter of the tire. Smaller-diameter tires (19mm) require significantly more pressure to support the same weight when compared with a larger-volume tire. 100psi may be more than ample for a 25mm casing while a 19mm TT tire will run almost flat at that pressure. Third is rider weight. All you need is sufficient air pressure to prevent unnecessary tire flex, and not so much that you bounce all over the road on rough pavement. Riders in the 200-pound range will discover that they can get a smooth, efficient ride at close to the tire’s maximum rated pressure, while a 105-pound female or junior rider may achieve the same performance near the tire’s minimum pressure rating.
Any time your bicycle bounces, you are trading horizontal momentum for upward acceleration that is never recovered. What makes a pneumatic tire efficient is that it deflects over objects it contacts without lifting the mass above it (you and your bike), and as it rolls over the object, it springs back and returns most of the energy it stored as it rolls over the back side of the object. This happen billions of times in a day’s ride, so if you use the correct tire pressure, you can save gobs of energy in the form of better rolling resistance. Too much pressure will rob your strength—especially if you are a lightweight rider. If your bicycle bounces, release five or ten ounces.
9. How often should I upgrade my helmet?
Replacing
your helmet once a year is probably reasonable for a high-time cyclist
(2000 miles a month), and the rest of us should consider a replacement
after two years. Crashing is a different story. The closed-cell foam
that protects your head is a one-time deal; once it has been
compressed, it will not dissipate the shock as well the next time. If
you crash hard enough to scar the shell, you should buy a new helmet.
Six seconds in the hospital emergency room costs more than the best
helmet made—don’t sweat the price.
10. How many CO2 cartridges should I carry?
If you run tubeless tires, carry two, because you’ll need one sometimes to get the tire bead reset and may have to use the second to pressurize the tire. If you are unsupported and competing in a road race, carry two—use one to inflate the tire and the second as a backup in case you mess up the first try. All others should carry one cartridge and a tiny hand pump (Leyzine makes the best ones). I only use CO2 cartridges when I am in a time crunch—like a race, a training ride or group situation where others are waiting for me to fix a flat. CO2 fillers are foolishly wasteful in an environmental sense (although they are recyclable), and a hand pump can refill a thousand tires without running out of air. Before you reach for that steel cartridge, consider a hand pump.
11. How often should I lube my chain?
The correct method to lubricate a chain is “lightly and often,” but most cyclists follow that advice by oiling the chain before every ride, which coats the drivetrain and leaves a black, gritty mess where a once-pristine drivetrain once meshed. Unless it rains during your rides, once a week or every 250 miles is more than enough time between chain lubrication intervals. Keeping your drivetrain clean is more important than oiling it regularly, because grit and grime cause more friction and do more damage to your drivetrain than running your chain dry will ever do.
Wipe your chain and sprockets clean with a terrycloth towel first and then, using a light-viscosity lubricant like Finish Line Pro, carefully drop the oil at the gaps between the rollers and the sideplates. Turn the cranks at a moderate rpm so as not to spray oil all over the bike to work the lubricant into the chain’s internals and then wipe all of the residual oil from the chain and sprockets. The chain does not rotate on the sprocket teeth, so the teeth, chain rollers and sideplates should be dry when you are done. Only the inside of the chain’s rollers and pins need to be oiled—do this and your bike will stay clean, and your drivetrain will enjoy a long and efficient life.
12. Why don’t more tire companies make tubeless tires if they are that good?
Road
Tubeless is the most important innovation to come from the tire and
wheel arena since the birth of the high-performance clincher somewhere
back in the 1970s. The catch is that developing a successful tubeless
road tire required massive investments from Hutchinson and Shimano with
no guarantee of a successful launch. Most bike brands make claims that
they are innovators, but few will be willing to gamble that kind of
money to develop a tubeless road tire—that is, until the market is
large enough to support it. With Campagnolo and Fulcrum on board with
Road Tubeless wheels, we should expect some action from tire makers by
2010.
13. Do you put lube on your pedals?
NO.
Modern pedals are equipped with sealed bearings and do not need regular
maintenance. Theories that oiling your pedal’s engagement areas will
assist you in clicking free in the event of an emergency are fabricated
by anxious Freds who should be on roller blades in Brazil. Dry pedals
and cleats will release consistently at the same pressure. Spray-lube
will cause them to release too easily initially, and as the lubricant
sloughs off or combines with dirt, the release pressure will become
erratic as it firms up. Use mountain bike shoes and pedals for
cyclocross, because, unlike plastic road cleats, their smaller,
metal-to-metal interfaces release consistently in wet, muddy and dry
conditions.
14. Do gloves really make a difference?
Unless you or your
team is sponsored by a Rodeo Drive manicurist, gloves should be a
mandatory part of your kit. Gloves are great for wiping your nose and
preventing salty sweat from dripping into your eyes on a scorching
climb, and they keep your hands clean, should you make a roadside
repair. The best argument for gloves (full-fingered are best), is that
when you crash, you will instinctively use your hands to protect your
nearly naked body from being ground into hamburger on the hot asphalt.
You can get around fine with a bad case of road rash, but every aspect
of your life will be compromised if your hands are bandaged up.
15. How many gels should I carry with me?
The rule of thumb is that 15 minutes before your start and every 45 minutes afterwards is the minimum interval between food intake. Those who can’t eat solid or gel-type foods while they are in motion use carbohydrate fluids in their water bottles. I prefer gels because there are times during a high-watt interval when my stomach can not handle anything but water, so I can continue to hydrate—which is most important—and eat later.
16. Do I need both water bottle cages?
Not necessarily. One water bottle contains about as much as an average body sweats in 45 minutes to an hour of cycling. Your body can store about an hour’s worth of water, so a single bottle can get you safely through a two-hour ride before your body will enter the throes of dehydration. Two bottles are perfect for longer rides, or where you will be riding unsupported. Another reason to use two bottles is that you can put water in one and mix the other with an electrolyte/carbohydrate substance. Use each as needed, and the pure water can double as a cooling spray during hot weather.
17. What does compact mean? Why doesn’t everyone ride it?
Tradition dictates most of cycling’s trends, and standard, 53 x 39-tooth chainrings have been the choice of champions for almost 50 years. Compact cranksets use smaller-diameter chainrings (50 x 34 compared to 53 x 39). The theory is that compact cranksets are lighter weight, and when used in conjunction with an 11-tooth cassette cog, provide a lower climbing gear without sacrificing top speed (this assumes that we are comparing an 11 x 50 compact with standard 52 x 12-tooth gearing). SRAM Red takes full advantage of the wide gearing range of a compact system while Shimano Dura-Ace and Campagnolo Super Record maintain the 53 x 12 standard as their preferred gearing. Compact is best for most cyclists, although the advantage of running a 53 x 12 is that one always has the option of switching to an 11-tooth cassette for faster courses and time trialing. Compact riders are limited in this respect.
18. How do I choose handlebar width?
For starters, those with wider shoulders should ride wider handlebars. This is to keep your chest open and unconstricted for breathing. Climbers and sometimes sprinters like wider handlebars because the extra leverage makes it easier for the upper body to counter the lateral force generated by 1600-watt pedal strokes. Choose a bar that is too wide and your slightest body movement will steer the bike offline. Choose a bar that is too narrow and you will waver offline while you are sprinting or climbing because your upper and lower body will not be in sync. Most road bikes come with bars in the 42 to 44 centimeter range; use these numbers as an average and choose a different width according to how much you deviate from the norm. If you excelled as a linebacker in high school football, consider a 46-centimeter bar. If you jumped horses, you are probably a perfect 42.
19. What about crank length?
Two factors determine crank length: “leg speed,” which varies according to genetics and to a degree, conditioning, and leg length, which centers on the length of the thighbone (femur). Both factors determine the perfect crankarm length, but history has shown that almost all riders can adapt to a single crankarm length. Here’s the longer version:
Leg speed: Because muscles contract at a finite rate of speed, a cyclist using long crankarms will turn a slower rpm but generate more torque. Given the exact gearing, longer crankarms make steep, low-gear climbs much easier on the legs. Shorter crankarms require your legs to work harder to climb with the same gear because you must make up for the extra torque with muscle power. Conversely, on the flats, riders using shorter crankarms can spin at a higher rpm because the lever is shorter and the feet don’t have to move as fast to turn the cranks at the same rpm. To get your head around this, consider that you would have to run 24,000 mph to keep up with the Earth at the equator, but a mile from North Pole, you’d have 24 hours to walk a leisurely 3.14-mile circle.
Leg length: Tall riders can ride longer crankarms, and this is where the equation gets muddy. A leg with a longer femur can move the foot faster with the same muscle contraction rate. Basically, the longer the femur bone, the longer the crankarm can be without sacrificing leg speed and rpm range. So the taller rider would seem to be at a huge advantage over a short one because he has the climbing benefit of a long crankarm without the penalty of reduced cadence rpm—but such is not the case. Because the bones are longer, the taller person’s muscles have less mechanical advantage and thus must develop more torque to produce the same leg power as a short-legged person. The result is parity—short or tall, choose the correct crank length and you will be riding on the same playing field.
What it all means: The best crankarm length is always a compromise between comfortable climbing and the ability to spin efficiently at higher cadences. Almost all cyclists will do fine with the 172.5mm standard crankarm length. Track riders are limited to one gear, so they prefer slightly shorter cranks because they can spin them faster and achieve a significantly higher top speed. Climbers rarely spin in the higher rpm ranges and thus can take advantage of a 5mm longer arm. Today’s 172.5mm crankarm standard was a compromise between the previously accepted 170mm crank length of the pre-1970 era and the popular 175mm length of the 1980s. In the end, we all could live with 172.5mm arms and be done with it.
20. If I have gearing options in the rear, what are some parameters to choosing?
Unless you cycle alone most of the time, your gearing choices will be dictated by the group that you ride with. To ride with a group means matching your speed, cadence and gearing with the others with whom you will be riding—especially the leaders. Of course, you can use a 12 x 27 cassette and opt not to use the two lowest cogs, but you will be sacrificing the closer-spaced shifts of a 12 x 23 cassette and will always be fighting to match the cadence of the peloton. The advantage of closely spaced cassettes is that a rider can almost always stay in the comfort zone and match his or her optimum cadence with the speed that the group is traveling. Slower-paced groups generally ride with wider-range, lower gearing, so once you have chosen your group, you have automatically selected your cassette and crank options.
The best all-around gearing for club rides and amateur racing seems to be 11 x 25 for compact cranksets and 12 x 27 for standard cranksets. These combinations can get you up and over some pretty tough climbs and still offer gear spacing that is close enough to keep you in contact with a fast-paced peloton. That said, don’t let fashion dictate your gearing—if you want low gears, choose a triple crankset or a wider-range cassette. Climbing and all-day rides can (and should) be enjoyable, and proper gearing is the key to enjoying all forms of cycling. |
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