Notes from a Novice #5: Shift is NOT a 4-Letter Word – Part 2

Cycling STCC Logo Web Settings SkillsSorry it’s been so long. We’ve had some technical difficulties with the site. But I’m back again for some more chat on shifting. I’ll start with the easy stuff first and then if you’re still with me, we will get into some of the “why”. I’m a curious sort, so it helps me to know a little of the “why”. Hopefully it will help you too.

In Part 1 we learned that we want to shift in order to stay at roughly the same cadence. On a ride with a lot of changes in terrain or a lot of stops, that will mean a lot of shifting. Your bike gears are designed to be changed while the pedals are moving. However, your components will work better and last longer if the pressure on your pedals is lighter during the shift. So if it’s possible, ease up just a tad when you shift until you hear/feel the click. Then pick back up where you left off. Also, try not to shift when you are starting to stand up in the saddle. That hard pressure might make your chain come off.

In Part 1 we also talked about anticipating the shift when you are coming to a stop or gearing up to take off in a “go zone”. Being in the right gear at the right time is key. But have you ever shifted from a gear to the one that you think is “right next to it” and get a shock when your feet all of a sudden spun way too fast? Or have you shifted the chain ring on the front and all of a sudden you can barely make the pedals go around? If it’s all about steady cadence, you don’t want to drastically change the level of difficulty at which you are pedaling in one shift of the gears.

So who thought (thinks) that on a 20 speed bike that gears 1-10 are on the small chain ring and 11-20 are on the big chain ring? Yeah, if only it were that easy. Stupid math and physics. Essentially the ordering of the gears is a ratio called “gear inches” that takes into account the number of teeth on the front chain ring divided by the number of teeth in the rear sprocket that your chain is sitting on. DON’T DOZE OFF! It’s not important to be able to do the math. But it is important to roughly understand where your gears are on your particular bike so that you can shift smoothly.

To illustrate, I calculated (well a website calculated) how my bike’s gears lay out. I have a 50/34 “crankset” on the front (big chain ring has 50 teeth, small chain ring has 34) and a 10-gear “cassette” on the back that ranges from 11-28 teeth. There are a bunch of websites that can spit out these calculations. Here are a couple I found.

HTML5 Gear Calculator

Mike Sherman's Gear Calculator

By the way, don’t worry if you don’t know what crankset or cassette is on your bike. I had to go look in the garage for the tiny print on the components. But now I can sound like a serious cyclist. I was just recently having a beer and grilled cheese after a ride and the guys were chatting about their 50/34’s vs. 52/39’s and debating the merits. And I was all like, “Yeah, I’ve got the compact 50/34.” I’m not this crazy into cycling, but serious racers will even trade out the components depending on the type of race. More and lower gears in the back gives your more options on a really hilly ride.

Anyway, back to my bike, which I think is pretty standard “off the rack” for a road bike, but if you get curious – or bored – you should check out yours. And if you have three chain rings up front, you should really check yours out because it will be even more different. 

Gear CRxFW GI GIDiff
1 34x28 33.51 16.67%
2 34x24 39.10 14.29%
3 34x21 44.69 10.29%
4 50x28 49.29 0.21%
5 34x19 49.39 11.76%
6 34x17 55.20 4.17%
7 50x24 57.50 8.80%
8 34x15 62.56 5.04%
9 50x21 65.71 2.00%
10 34x14 67.03 7.69%
11 34x13 72.18 0.62%
12 50x19 72.63 7.67%
13 34x12 78.20 3.81%
14 50x17 81.18 5.09%
15 34x11 85.31 7.84%
16 50x15 92.00 7.14%
17 50x14 98.57 7.69%
18 50x13 106.15 8.33%
19 50x12 115.00 9.09%
20  50x11 125.45 0.00%

CRxFW = Chain Ring (front) and FreeWheel (back)

GI = Gear Inches

GIDiff = % Difference between that gear and the next higher gear

 

Gear 1 is the easiest. Gear 20 is the hardest. You see that gears 1-3 are on the small chain ring by the “34” of “34x28”, but then gear 4 is on the big chain ring because of the “50” in “50x28”. Then look at the “GI” (gear inches) column and see how similar gears 4 and 5 are, even though 4 uses the small chain ring and 5 uses the big chain ring. Same thing with gears 11 and 12. The math just works out that way. Mostly I want you to see that there are very similar gears on both chain rings but that putting them in relative position they kind of jump around. Then notice the “GIDiff” (gear inches difference) column and how big a difference there is between gears 1, 2 and 3 on the small chain ring. If you have ever shifted too soon going up a hill, you have felt that because all of a sudden your legs spin out.
So what does this mean to me? Do I have my “gear inches” memorized? Nope. My brother the engineer does, but I don’t. However, the more I ride the more I am learning the relative position of the gears for certain scenarios.

Let’s take a ride!  So it’s a nice Thursday night and I’m pedaling down Teel in the group. I’m in the pack so I’m getting good draft and I haven’t really been paying attention, but now I am on the small chain ring and the outer gear on the back (34x11). We are just turning the corner for the Stonebrook “go zone” and I feel good tonight. I know I am maxed out on torque for the small chain ring and I realize I need to shift up because I want more power. But now I’m out of gears on the small chain ring. (It happens to be gear #15, but I just learned that looking at this chart.)

Actually that’s a gear you aren’t supposed to stay in for long periods of time because it’s hard on the drive train. If you look down at your chain, it is at the sharpest angle it can be. It’s called “cross-chaining”. Perhaps I should worry, but I don’t worry too much if I’m only going to be in the gear for a couple minutes. But if I know I want to keep going for a long time at that “gear feel” or I want to even shift up for more power, I know I need to shift up to the big chain ring because that’s where the rest of the gears are. If you have three chain rings up front, you have to be even a little more aware of the angles of some of the gears because the angle can be sharper because the crankset up front is wider. Just take some time to look at your chain while you are riding and learn where the “no-no” gears are.

Anyway, if I am in gear 15 (34x11) and I only change the big chain ring, all of a sudden I will be jumping to gear 20 (50x11). That’s a lot of gears for my legs to absorb in one fell swoop. My cadence will likely drastically drop, slowing my overall speed too, which I don’t want. I want control over my cadence and to keep it as much the same as possible. So I have learned to dump a couple gears from the back and then not exactly at the same time, but a split second after switch to the big chain ring. Changing both front and back at exactly the same time may cause your chain to come off, which is why I pause momentarily. Experiment on your bike to see how your components respond. That multi-step shift gets me to about gear 17 (50x14) and then my legs only jumped from 15 to 17, instead of from 15 to 20. Then I can step up one gear at a time on the back to 18, 19, and then 20.
If you remember from Part 1, I mentioned that on my bike, with my components, if I tap the right shifter it will change one gear at a time in the back. But if I hold the right shifter for a second or two, it will shift a couple gears at a time. Now you see why that is useful.
It’s really important to watch the upcoming terrain and shift accordingly. Now let’s say that I’ve been cruising in a pretty high gear on the big chain ring up Lebanon because I’m still feeling really good but I know that the Compass hill is coming up. I don’t know about you, but I’m not ashamed to say that I prefer most hills on the small chain ring. And for that hill, I might need to go all the way down to gear #1. So if I’m on the big chain ring, I will again try to get somewhere close to the middle of the cassette and drop to the small chain ring. Why do I drop a few gears first? Well look at “50x11” vs. “34x11”. That’s dropping from gear 20 to gear to 15. Doing that all in one swoop and my cadence is likely going to change drastically and my legs may “spin out”. That’s wasted energy and I’ll slow down. If I shift down a bit I can step up my cadence just a tad as it gets easier to keep my momentum and then when I switch to the small chain ring there isn’t as much of a jolt. Then I can adjust up a gear if I need to, saving me all those gears on the small chain ring for Compass.

Now we are leaving the parking lot after the Compass climb and I probably shifted all the way or nearly all the way down. But now it’s time for a nice downhill on Legacy. Guess when I’m going do to? Yep. As we head towards the start of the “go zone”, I’m going to get in the middle of the cassette and pop into the big chain ring. Because I want all the big gears going down the Legacy hill!

As you can tell, I might actually use all 20 gears on a simple Thursday Night D ride.  That’s OK. I paid for ‘em. So I’m going to use ‘em. And you should too.
I hope you hung in to very end. Math and all. Now this is all great in theory, but the only way to really get good? Go ride your bike and practice shifting. But always remember to be kind to your fellow riders. If you are going to ride in a group and you want to experiment with some of these techniques, tell your ride leader that you are going to practice shifting and ask to ride in the back. Then once you learn how your bike will respond, you can step up to the front and help pull that group by keeping your cadence steady with your great shifting skills.
And to any of you experienced riders, if you have read something that you think needs correcting or you have additional advice, please comment. Inquiring minds want to know!

Click Here to Meet Amy!

Leave a Reply