Choosing Appropriate Gearing for Cycling
We?ve all seen Lance Armstrong spin his trademark high cadence up the mountains while his counterparts turn bigger gears.
We've all seen Lance Armstrong spin his trademark high cadence up the mountains while his counterparts turn bigger gears. Because of his great success and specific riding style, more and more cyclists are paying increased attention to pedaling cadence and proper gear selection. In particular, many riders often ask how they can improve their pedaling cadence on the hills.
Many times a rider's ability to use an appropriate cadence is dependent upon the bike's gearing. Often, traditional gearing forces a rider to use too low of a cadence while climbing. The traditional combination of 53 and 39 tooth chainrings with a 12-23 tooth cassette seems to work well for professionals, but such gearing is not ideal for all riders. Fortunately, bike manufacturers are catching on and making adjustments to component specifications. Whether you are looking for a new bike or simply wanting to upgrade your current bike, it is important to consider the gearing that it offers. However, before making any changes it is important to understand the physiology of pedaling cadence and how your gearing affects it.
Physiology of Pedaling Cadence
Using a slightly lower gear with a faster cadence can be more efficient than riding a higher gear with a slower cadence. The difference in efficiency is due to the unique physiological demands of each style. A high cadence pedaling style involves frequent, low muscular force productions while a low cadence pedaling style is comprised of less frequent, but more forceful muscular contractions. Since the slower cadence requires more muscular force per each pedal stroke, a greater percentage of fast twitch muscle fibers are recruited. Fast twitch muscles are not as efficient in their use of glycogen, so your body's energy resources are drained more quickly when they are used. This can lead to increased fatigue late into your rides. During a stage race or when training frequency is high this becomes very important since stresses are compounded from one day to the next. On the other hand, the relatively low muscular force used with a high cadence relies more heavily on the slow twitch fibers, which are more aerobically efficient in using the body's energy stores to produce work.
Typically, a cyclist will be most efficient with a cadence of 80 to 90 revolutions per minute (RPM). Cadences lower than 80 RPM require greater muscular forces, while cadences over 100 RPM place a higher demand on the aerobic system. Incorporating low and high cadence workouts into your routine will have you best prepared for your goals, though a majority of your riding should be done with an average cadence of 80 to 90 RPM.
If you ride in a hilly area and are not able to maintain a cadence of 80 to 90 RPM for the majority of your rides, it would be beneficial to modify your bicycle's gearing.
The first solution to the gearing problem came with the advent of the road triple crankset. Similar to the three chainring combination found on mountain bikes, this option allows riders to use substantially smaller gears when climbing steep roads. It has become common for bike manufacturers to spec entry-level road bikes or touring bikes with triple chainrings. Cyclists doing long rides or tours often take advantage of the triple gearing as it is ideal for vastly changing terrain, as well as giving the legs a break after many hours or days in the saddle. A triple chainring is also a great option for average riders who don't want to mash 40-50 RPMs up hills. Triple chainring setups have had a negative stigma attached to them, as some riders think it will make them appear "weak", but they've become more acceptable as people realize that the benefits outweigh the grief that they may receive from their riding partners. The added weight and seeming complexity of a triple chainring setup may be the only things preventing its further popularity.
A relatively new alternative is the compact crank. Using a double chainring configuration with fewer teeth per ring, riders are able to capitalize on new gear ranges. Compact cranks are finally coming to the forefront as a viable option for riders of all abilities to consider. Anyone living in mountainous or hilly terrain should give serious thought to the benefits of a compact crankset. Rather than using the standard 130mm Bolt Circle Diameter (BCD), compact cranks have a smaller 110mm BCD that allows for smaller chainrings. Compact cranks commonly have a 50 tooth large ring mated with a 34 or 36 tooth inner ring. These smaller rings allow for lower gearing and a higher climbing cadence. With this setup you not only have an additional lower gear, but also a higher gear (when compared to a traditional set up of a 53/39 crankset with a 12-25 cassette). This wider effective gear range is accomplished with fewer duplicate gears. Riders as well as racers are beginning to appreciate the gearing of a compact crank. Only very powerful sprinters or criterium racers that routinely use the 53x11 will be hampered by the having just 50 teeth on the big ring; for most racers this is not a concern. A 53x11 gear will give you 126.6 gear inches when using a 175mm crank and 23mm tires on 700c wheels. This is slightly larger than the 119.5 gear inches of a 50x11. We should also consider the difference in gearing at the low end. A standard 39x23 yields 44.6 gear inches while the 34x23 offers a gear of 38.8 inches. If you switch to a compact crank, but leave your same cassette you'll essentially lose your biggest gear, but gain two lower gears.
Of course, you can simply swap out your rear cassette to give yourself easier gearing options. Your cassette will likely have cogs of 11 or 12 teeth ranging up to cogs of 21, 23, 25, or 27 teeth. Standard cassettes are usually a 12-23 or 12-25. Switching to a larger cassette could be the most cost effective way to achieve a suitable climbing cadence. A 12-25 or 12-27 cassette might make all the difference you need in achieving optimal gearing that allows for an efficient climbing cadence.
So what gearing option is most suitable for your riding? There are a couple of important considerations. First, are most of your rides on flat roads, in the mountains, or somewhere in between? Second, what is your current fitness level? A Cat I racer will be able to use standard gears with an optimal cadence while riding up most climbs. In this situation there is little or no need for lower gearing. If you are very fit or ride mostly flat to gently rolling terrain, a standard double crankset with a standard rear cassette will likely work just fine. However, if you're a novice rider, someone who often does long rides, or a beginner racer, the lower gears of a triple or compact crank may be helpful. Riders and racers living in very hilly or mountainous areas, serious and novice alike, prefer the versatility of a compact crankset coupled with an 11-23 cassette. Touring or recreational riders may prefer the even smaller gear ratios that come with a triple chainring configuration. The smaller third ring typically will have 30 teeth, giving its rider a very low gearing option for the steepest of climbs.
Changing Out Your Gears
Now that you have an idea of what gearing to look for, you can confidently select the appropriate gearing for you. The following will provide a brief overview of what each conversion will require if you are looking to upgrade your current bike.
Switching to a compact crank setup is really quite simple. In most instances, the only necessary purchase is of the crankset itself. Once the new crank is installed you will have to reposition the front derailleur and properly shorten the chain to accommodate for the smaller chainrings. Standard front derailleurs are designed to work with a 14-tooth drop between rings. Even though a 50x34 setup has a 16-tooth drop, proper shifting can be achieved since the rings are smaller and the physical gap is nearly the same. Still, some people have had trouble using a standard front derailleur with their compact rings so companies are now producing foolproof compact specific front derailleurs. With these adjustments made you should have a smooth working setup. The price of a quality compact crank with chainrings will start at around $250.
Converting to a triple crank setup is a more expensive and mechanically involved process. You will need to purchase the crankset, bottom bracket, front derailleur, front shift/brake lever, chain, and a rear derailleur. A triple-compatible front derailleur will allow for the greater chain movement, while the triple-specific shift lever will have the extra detents necessary for the third chainring. The new bottom bracket will be wider so that the chainrings will be aligned properly with the frame. A long cage rear derailleur is necessary to accommodate for the increased chain wrap that the setup requires. The new chain will be longer than the original to fit the longer cage derailleur. This combination of parts will likely cost you anywhere from $350 on up.
Switching to a different rear cassette is the most economical approach; quality cassettes will range in price from $40 on up. With a few tools, you or your mechanic will have the new cassette ready to go within five minutes. Just be sure that your rear derailleur and chain length can accommodate the larger rear cogs.
Whatever your approach, make an attempt to have the proper gearing on your bike. Not only will an appropriate climbing cadence allow greater comfort, but you'll be more efficient as well. With the right gearing, Lance will no longer be the only one able to spin up the mountains.