Shifting Strategy

A bicyclist from Chapel Hill wrote to the Blue Ridge Bicycle Club's email list server to inquire about when to shift. Our own Bob Geyer selflessly offered the benefit of his long experience on the subject.

This one is about shifting strategy. I just updated my bike to a triple chainring (amongst other stuff) and a new freewheel (which is still a 6 speed - OK, it's an old bike, I admit!). It's all smooth as silk and much faster, which is pretty great.

On hills, what is the strategy for shifting? For both casual and training rides, what gear are you in at the bottom of the hill? When do you start pedaling? When do you stand up, if you do? When do you shift to the small ring? What gear are you in when you shift?

If I wait until I've cycled down (up?) to the largest cog in the back before I shift, it seems like I only get one extra gear. Do you only use it when you see a big hill coming up, then just use the small chainring exclusively? I stay primarily on my middle chainring now -- just using the large one for flats and long slopes (as opposed to the many small one-right-after-another hills we have around here in Chapel Hill).

In the alternative, if someone can suggest a good printed resource (reckon that would be a "book") I'll be happy to read it and stop pestering y'all with questions!

P.S. When are you shifting "up" and when are you shifting "down", for front and rear? Sigh . . . I'm so confused! %>0

Thanks,
Tom Sisk

Learning when to shift is a significant key to efficiency and enjoyment on a derailleur bike.

You've got six cogs in the rear and three in the front, yielding 18 gears, but that doesn't mean you have 18 unique gears. First, two of them are not recommended: the combination of large chain ring and large rear cog, and the combination of small chain ring and small rear cog. These two gears position the chain at a relatively extreme diagonal to the bike, thereby increasing strain and wear on the cogs and chain and decreasing efficiency.

For the rest of this explanation it would be useful for you to understand a common method for describing gears: gear inches. This term goes back to the days of high-wheel bikes. The larger the drive wheel, the further the bike travels in one pedal revolution (and, of course, the more difficult to pedal). Bikes were identified by the diameter of their large wheel. When gearing came about, a calculation was made to express what the diameter of the drive wheel would need to be to produce identical results.

On the Internet I've seen gearing calculators that will show you the "shifting order" for your gear combinations. These calculations determine the gear inches of each unique gear combination and sort them from smallest to largest. (E.g. the Gear Inch & Shifting Pattern Calculator at Barry Masterson's website). But looking at such a list you'll soon see that some combinations produce very similar gear inches. For example 52 (front) by 21 (rear) and 42 by 17 are within a quarter inch of each other, and 42x21 and 30x15 produce exactly the same gear inches.

Though using such calculations to produce a "shifting order" is misguided, knowing about your gearing may be interesting for you. But be assured that it is not vital information. Many cyclists spend their entire lives enjoying the sport without having a clue about its technical side. If you have a technical bent, a good resource is Sheldon Brown's Gear Calculator, which shows not just gear inches, but all sorts of other things to entertain a bike nerd for many a cold winter evening.

But back on the road... Think of your bike as having three gear "ranges," one for each chain ring. As you observed, the large ring is for descents, the small for long or steep climbs, and the middle for... well, the middle. The cardinal rule of shifting is to anticipate your shifts. This is more true for the front than the back, because the front gears do not change as easily or quickly as the rear. And it's more true for shifting down than up, because when you're shifting down you're usually climbing, which means you are applying a fair amount of pressure to the pedals, which makes shifting more difficult. In fact, on a steep climb it's often necessary to ease the pressure on the pedals to shift into the small chain ring.

Shift down before you need to. Better to spin a bit more for a moment than to get lugged down in too high a gear. So, down-shift early, and if you anticipate you will need to be in the little ring on a climb, get into it before you need it. When I shift to the little front ring, I always simultaneously up-shift one gear in the rear. This produces only a small gear change, but mostly it's to get my chain on the small front ring in anticipation of needing to shift down again soon.

The most common mistake of derailleur newbies is to not shift often enough. This problem is exacerbated by inconvenient shift lever placement. The most inconvenient location is on the down-tube. If yours are there, I strongly recommend you look into bar-end shifters. They're not expensive, they're reliable, and they're convenient. The most convenient location is the new style of brake/shift combo levers, but they're not available for six-speed gearing. But wherever your levers are, use them often! Get used to making small shifts to pedal at a cadence (leg speed) that is most comfortable for you. Don't adjust your cadence to accommodate your gear; adjust your gear to accommodate your cadence.

Finally, while I've got your attention, a word on cadence. Most cycling newbies use a relatively low cadence. (Why pedal any faster than you need to?) But once your cardiovascular system has acclimated to it, a higher cadence is definitely more efficient and easier on the body. If you've any doubt about this, just watch Lance Armstrong ride. You want to work at getting your average cadence up over 80 revolutions per minute. (Count pedal strokes for six seconds and multiply by 10.) At first, you'll find that it requires more effort to do this, but with practice it will become the most efficient cadence, and it is easier on your body because the faster you're pedaling for a given speed, the less effort you're exerting on each pedal stroke.

You also asked what it means to shift up and down on the front and rear derailleur. Up is to a higher gear and down is to a lower gear. Because some gear combinations are so similar, it can be difficult to determine empirically whether you're actually shifting up or down, but your question is not so esoteric. In the front, moving from a larger ring to a smaller one is shifting down. In the rear it's the reverse; shifting from a smaller ring to larger is shifting down, which you do when you're going up hill. The motion on each of your two shift levers is opposite each other. For integrated shifters, click the right lever clockwise and the left level counter-clockwise to increase the gear, and vice versa to decrease the gear. For downtube shifters, the highest gear has one forward and the other back and lowest gear is the opposite. (The two gears you avoid are both all the way forward and both all the way back.)

I hope this rather lengthy response has been helpful.

See you on the road.

-Bob Geyer
Bike Geek

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