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If you’re new to triathlon, some aspects of your bike can be something of a mystery. Though it may be tempting to just “hop on and ride,” learning how to shift your bike’s gears correctly can help you ride faster, more comfortably, and more efficiently. So let’s make sure you have the knowledge and confidence to put all those gears to work on your behalf.
First, let’s start with the basics. It won’t have you ready to take on a job as a mechanic at your local shop, but it will leave you fluent in the important terminology and workings of your ride.
Get To Know Your Bike’s Gears, Even Before You Shift Them
Most road or tri bikes have two chainrings in the front—attached to the crank arms and pedals—along with ten or more cogs on a cassette in the back, and they’re connected by the chain. If you have two gears in the front and ten gears in the back, in theory, you have a 20-speed bike. (More on the “in theory” part a little later.) The chain is moved between your front chainrings chainrings by your front derailleur, which is controlled by your left shifter in most places. The rear derailleur is controlled by the right shifter, and moves the chain from cog to cog on the gears in your rear wheel. Clear as mud? That’s OK for now. Once we discuss how to put them to use, it should help you make sense of it.
What Do The Gears Even Do?
At the risk of oversimplifying things, the basic function of gearing it to make hills into “flats on an angle.” As the terrain changes, you can shift in order to compensate for the hills. On an incline, the approach is to use a small (or “low” or easy) gear. You do this by shifting to your small ring in the front, and a relatively big cog in the back. That will make it much easier to pedal, and allow you to keep your cadence—how quickly you’re spinning your legs—from dropping too much. Conversely, if you’re descending a hill, shift your bike into a big (or “higher” or harder) gear. A big gear involves your big ring in the front and a relatively small gear in the back. Pedaling will be harder, but you’ll travel farther with each revolution.
How Should I Shift My Bike’s Gears Properly?
This is where there’s a little more art than science. Those who have been riding bikes for a long time have a natural sense of which gear to be in at which time (more on that below), and while that will take some trial and error, knowing when to shift and how to do it right is something that takes far less practice. First, as you approach a hill, stop sign, stop light, or potential moment to stop, apply slightly less pressure on your pedals than you would normally. As you’re pedaling with only a tiny bit less power, shift your gears into a lower—or easier—gear. The key in this exercise is to not mash down hard as you shift because it can cause your chain to skip or even come off if it’s not adjusted correctly. Starting back up to speed or going downhill? Get moving with that low or easy gear, apply slightly less pressure once you’re moving at a safe speed, and shift into a higher, or harder, gear. Again, don’t force the pressure as you shift, and try to plan ahead.
How To Choose The Right Gear
There’s no such thing as the right or wrong gear for everyone. Rather than thinking, “What gear should I be in?” try to let your cadence dictate your gearing. For instance, if you’re generally pretty comfortable pedalling at 80-90 revolutions per minute (rpm), once you find it hard to maintain that a cadence of 80, shift your bike into a smaller gear. That should let your cadence return to the 80-90 range without overworking you. On the other hand, if you’re spinning in excess of 90 rpm, try shifting to a bigger gear, which should bring you back below 90. Without question, there will be exceptions to this rule of thumb. For example, on steep climbs you may find your cadence well below 80, but as long as you’ve shifted to your smallest gear, you’re using the gears to their fullest.
For smaller, quick adjustments, you’ll usually rely on your rear derailleur. The gear changes are more subtle, and they’re mechanically quicker. This explains why in most places your right (presumably dominant) hand controls the rear derailleur. For bigger, more drastic gear changes, you’ll rely on the chainrings in the front on your left shifter. These require a little more finesse (in other words, lay off the pressure even more as you make the shift), and you need to be prepared for a large change in cadence. Use the front derailleur when approaching a big, longer hill (shift your bike’s gears into the smaller ring) or as you crest the top of a climb (shift into the bigger ring).
Shift Your Bike Gears Like A Pro
On race day, choosing the appropriate gear starts even before your ride does. Be sure to rack your bike in transition in a gear that is suitable for the road right outside of T1. Remember that you’ll likely be starting from a dead stop Struggling to turn your pedals because you’re in an overly difficult gear is never a fun way to start your ride, and if you’re mashing them down as you shift back into an easier gear, you could throw the chain. Plan ahead!
Too many riders avoid using their so-called “granny” gear—the smallest gear ratio at their disposal—as some sort of badge of honor. The truth is, it’s there for a reason. If you need it, use it. There’s no shame in doing so, and you’re doing yourself a disservice if you avoid it just for the sake of avoiding it. That said, there are some gears you should avoid for very real reasons.
Using the combination of your big ring and biggest cog, or your small ring and smallest cog places the chain at an extreme angle. This is called “cross-chaining,” and it’s mechanically very inefficient. It can damage the drivetrain or wear out the chain, and it can be prone to slipping, so you should avoid it. Experienced riders learn to know when they’re getting close to that combination and shifting into the next chainring before it happens. (That’s why a bike with two chainrings and ten cogs is a 20-speed in theory but really has 18 functional speeds that you should use.)
Finally, don’t be shy. Don’t overthink it. The best way to find your shifting mojo is to practice. Shift early. Shift often. If you make a mistake and shift the bike’s gears the wrong way, correcting it is as simple as hitting an undo key on a computer—just shift back the other way, and then once more to get where you wanted to go. Once you get the hang of it, you’ll be a better, faster, and more efficient rider for it.