Ultimate climbing guide, part 1: gearing

Andy Hampsten’s ride over the Gavia at the 1988 Giro d’Italia is the stuff of legend (read more about it here). Once he’d claimed the maglia rosa, however, there were still eight days of racing to go and Erik Breukink – the winner of the Gavia stage – was just 15 seconds behind. Urs Zimmerman, later to ride for 7-Eleven, was also snapping at his heels.

One of the key tests before Milan was the 18-kilometre hill climb time trial from Levico Terme to Vetriolo. But Hampsten was ready and had already inspected the course. Based on his observations, he swapped out his 39 chainring for a 42 and fitted an 8-speed cassette starting from a 21 and dropping 19-18-17 [etc] rather than the usual 23-21-19-17 [etc] to make his gearing higher again and to also keep the ratios closer together.

Hampsten won the stage and pushed Breukink out of contention. “I hurt so bad it was like a meditation,” Hampsten said, according to journalist John Wilcockson. “I knew I was winning… but I wasn’t conscious of the fact.” He survived a scare from Zimmerman in the last mountain stage in the Dolomites, saved by exemplary team tactics, and after the final time trial in Milan the Giro was his.

Gearing

Hampsten’s story is interesting because of the attention he paid to his gearing for the uphill time trial. To climb faster, a rider has two choices: spin the pedals faster; or push a harder gear – or the correct combination of the two. Finding the optimal gear and spin can be a detailed business.

Your author is fascinated with the process of gear choice, given his interest in climbing and his particular enjoyment of the hill climb race (for which, it must be noted, his performances are decidedly modest). At present his preferred lowest gear is a 36×25. This gives a metres development of 3.1 (the distance moved with one crank turn, a different measurement to the usual gear inches), which is slightly easier than a 39×26 (or equivalent to a 34×23 for a compact crank) but noticeably tougher than a 34×25 (and a full kilometre per hour (kph) faster at 80 rpm).  Also, having a 25-23-21 [etc] ratio on the cassette instead of, say, 26-23-21 [etc] means that there is not a big jump between the lowest gear and the next cog on the cassette – keeping the ratios not too far apart.

A compact crankset, or nearly so, makes a lot of sense for a lot of serious climbing but it can be limiting to have a 34 for flatter riding instead of a 39 (hence why your author swapped out the 34 for a 36). SRAM compact cranks have a variety of after-market chainrings and a 38 (paired with a 52) is an option. To get a 3.1 metres development ratio would require a 26 cog but the 13% change in ratio from a 26 to a 23, instead of 9% between the 25 and the 23, can be disconcerting when riding – it feels too wide. At 3.3 metres development, a 38×25 – or 3.4 metres for a 39×25 – might be too tough to spin effectively. Each 0.1 metre change is about a 3% difference, so switching to a 39 would be nearly a 10% harder gear to push.

According to many experts, the optimal cadence is around 80 rpm, although for climbing some argue that it is closer to 70 rpm. This balances both efficiency and fatigue, apparently. So, ideally, you want a gear that you can spin at this rate for the climb that you want to go fastest on (the rest of the time, we make do with the gears we have and adapt). This is an interesting exercise to do if you have a cadence monitor and don’t mind staring at your screen during a hill climb. Simply sit at 75 rpm and shift gears to keep your cadence constant. It is a particularly methodical way to approach the problem of how to gauge your efforts but can yield useful results.

Over time, you will want to be able to push a larger gear at the same cadence on the same part of the climb. For example, being able to spin the 36×23 at 75 rpm instead of the 36×25 gives a speed increase of 1.3 kph – a noticeable increase on a long, steep climb.

Keeping your cadence constant is one approach. The other, of course, is to fit a harder gear and just tough it out. Fight to find your spin and force yourself to ride faster. Forget about the cadence monitor. If your legs are burning, choose an easier gear; if your lungs are crying out for relief, choose a harder gear. If both are at their limit, and you’ve run out of gearing options, there’s not much you can do…

Ratios versus cadence

Lance Armstrong’s Tour de France in 2001 provides an interesting study in the issue of gear ratios versus cadence. As is well known, Armstrong developed a high cadence climbing style, spinning at 90 rpm and over. “It takes better aerobic conditioning to pedal at a higher cadence,” according to his coach Chris Carmichael. “And you have to train a lot at high cadence to develop efficiency. Most people are more efficient at 80 rpm than they are at 90 rpm.”

Armstrong’s spin was easy to see in action, but it was certainly not the case that he was using ridiculously lower gears. His cassettes in 20o1 typically ran 23-21-19 [etc] like most other riders. So it was a case of spinning a slightly easier gear slightly faster. For example, if Jan Ullrich, known for his ‘big gear’ style was in his 39×19 at 75 rpm he would be at nearly 20 kph. If Armstrong was spinning at 90 rpm in a 39×25 he would be at about the same speed; to drop Ullrich he would need to spin up to 95 rpm (21 kph) or drop into his 23 (21.5 kph). Better still, spin the 21 at 95 rpm for 23 kph, which is what he did for part of the climb of Alpe d’Huez in 2001 (he averaged 22.1 kph for the 14 kilometres) when he won the stage by two minutes from Ullrich, famously giving him ‘The Look’ as he left him behind.

Interestingly, the next day, in the hill climb time trial to Chamrousse, Armstrong adjusted his gearing to suit the conditions, like Hampsten did in the example at the start of this post. According to John Wilcockson, Armstrong felt that the 23 on Alpe d’Huez had been too low (oh to have that feeling!) but the 21 a bit high. So for the time trial he fitted a 12-22 cassette so that his lowest gears were 22-21-20-19, thus keeping the ratio difference at around 5% between each gear. Whether it was this gear change, his high cadence style, or the familiarity he had with the course after scouting it out before the Tour, he won the stage and took another minute out of Ullrich. He would, of course, go on to win his third Tour in a row that year.

Part 2…

Climbing faster is not just about the gear you can push and how fast you can spin it (and the methods you use to achieve that), but it is in practical terms the primary route. As you develop more strength, endurance, power, conditioning or whatever, you need a practical way to translate that into performance. And taking on a harder gear, or a faster spin, or a combination of the two is how you put it into practice. For most of us, developing a high-cadence style much more than 80-85 rpm is not a possibility, so keeping a constant spin at around this level but graduating to bigger gears is the route to more speed.

Other than our own mediocrity, the principal impediment to more speed is gravity, which will be the subject of part 2 to this ultimate climbing guide, coming soon.

Ullrich concedes to the superior climbing of Armstrong

This post was modified from the original following reference to sources. Also, your author has just noted that the tags on this blog are apparently not working. Hopefully this will prove to be an easy fix (one suspects not) but please bear with for the duration of this problem.

7 thoughts on “Ultimate climbing guide, part 1: gearing

  1. Your observations and investigation are interesting and have a consistent methodology with what I did when I raced. I often preferred a 42 x 22 to a 21, because I had a naturally higher spin.

    An observation I have made when climbing is that at some point, your cadence is going to be what it is, regardless of gear choice; meaning if you natural rhythm is 78, at some point going to a lower gear is only going to be counterproductive because your cadence is going to be 78 whether you are in a 34×23 or a 34×25 on a given grade. Thus you should choose the largest gear where you can maintain your natural climbing cadence, and reserve a lower gear for steeper grades, bail out, and inevitable fatigue.

  2. Ed Burke in High-Tech Cycling notes that most riders probably find their ‘optimum’ cadence suited to their physiology, so your instinct is probably right!

  3. There were some interesting articles published on gearing after last year’s (sensational) stage finish atop the Angliru climb at the Vuelta. JJ Cobo apparently used a compact while Wiggo stuck with his Osymmetric chainrings which had a 42T small ring. Not ideal for 20%+ grades.

Comments are closed.