The Track Bike Part 4

28 Aug

So we now finally go to the last part of the discussion about the track bike. You can review the previous posts if you feel lost. This time we’re going to discuss about one of the most important things regarding a track bike: GEARS.

The biggest difference between track and road racing is the attitude towards and use of gears. Gearing on the road isn’t thought about all that much, except perhaps for juniors who have to comply with gear restrictions. At any given time, riders commonly don’t know what gear they are in. By contrast, on the track, gears are a precise matter, and gears are chosen very specifically for each event.

As an opening note, track racers talk in gear inches – not teeth. It’s much more precise and frankly easier to say. A roadie at the track is easy to spot because they will talk about gears in terms of teeth rather than inches. If you’re going to get into track racing, it’s worth learning and thinking about gears in terms of inches. To help you do that, I’ll make reference to both systems below.

Track racers invariably use much smaller gears (and therefore, pedal at much higher cadences) than their peers on the road. When Tom Boonen winds up a sprint on the road, he is in a 53 x 11 or 53 x 12, which yield 126” and 116” gears, respectively. If his sprint tops out at 60kph (37mph), his cadence will max out at either 100 rpm’s exactly (in the 53 x 11), or 109 rpm’s (in the 53 x 12).

By comparison, elite track racers commonly hit 60kph, but would never use a gear larger than 50 x 14 (94”), and more likely would be riding a 49 x14 (92”) or 51 x 15 (90”). So, at 60kph, their cadence is between 134rpms (50 x 14) and 141rpms (51 x 15). To put this in road terms, for an elite track race – say, the World Points Race Championship – the world’s top riders will do the entire race in a gear just a little bit smaller than a 53 x 15.

That’s a pretty big difference in approach. A road racer would never limit himself to a maximum of a 53 x 15 – but that’s what the top track racers do.

The real difference between road and track racing is best understood when you realize that track racers don’t just provide short bursts at 140rpms. Because elite track races commonly proceed at 50 – 55kph (31 – 34mph) for long periods, track racers sustain 120 – 130rpms throughout much of the race, and then accelerate to over 140rpms for the sprints. Hitting 140rpm’s for a sprint isn’t hard – any roadie can do that. Sustaining 120 to 130rpm’s for an entire race (no freewheeling!) and then hitting 140+ rpm’s in the sprint is impossible for most roadies – it takes some training.

So – understandably, when they start out on the track, many experienced roadies just figure that the track racers must have it wrong, and choose an enormous gear (say, a 51 x 14 – 95.5”). That’s what I did. It doesn’t work. After a while, they come around.

So, why do track racers use such small gears? There are probably other explanations beyond what I will offer here. I am not a physicist. But I’ll give you my angle on it.

If you’re going into a race with only one gear, you are going to optimize that gear to the most critical moments in the race. But the most critical moments in a race aren’t just the sprints; they are the accelerations, too. The problem with riding a relatively large gear on the track is that it accelerates more slowly (a distinct disadvantage when you need to jump hard to stay near the front), and ramping that gear up for repeated accelerations will burn your legs out over the course of a race.

So, in simple terms, you want a gear that can do two things: efficiently get you through repeated accelerations from 40 to 50kph, and also get you up to 55 – 60kph for the sprints. In a typical 92” gear (49 x 14), when the field is proceeding along at 40kph (25mph), you will be turning 91rpm’s. When there’s an acceleration up to 50kph, you will need to produce 114rpm’s. To accelerate again up to 60kph, you will hit 137rpm’s.

These accelerations are easier to do in a smaller gear than in a larger one. A true roadie might choose a 53 x 14 (99”) for a perfectly flat race where the speeds range from 40 to 60kph. Certainly, for the 60kph sprints, that gear will wind up to a respectable 126rpm’s. But at 40kph, a 99” gear will be grinding along at 84rpms, and at 35kph (22mph) the gear would truly be in slow motion at 73rpm’s.

Now, I suspect this analysis won’t be entirely satisfying, especially to roadies who haven’t tried the track. I won’t claim that this is the whole story – there are surely more and better explanations for why experienced trackies all use smaller gears than road racers do. Other factors may include the fact that there is no freewheeling – so track racers never get to rest their legs altogether between major efforts. Or the fact that it’s harder to get out of the saddle on the track, particularly in the corners of a steeply banked track, so simply accelerating a large gear by standing up and using your body weight for leverage isn’t as easy to do.

In any event, the fact remains that track racers do all use smaller gears. And while Tom Boonen may be more likely to turn a 53 x 11 than a local amateur roadie, world champion trackies are not more likely to use large gears than local amateur trackies. If anything, elite track racers tend to use smaller gears than amateur trackies do.

So, what does track gearing look like in practice? The table below shows a typical selection of chainrings and cogs that a track racer would keep in stock, and the gear inches they produce with a 700 x 23 tire, rounded to the nearest half-inch.1 For easy comparison to road gears, I have included the gears on a 53 chainring in the far-right column, even though a 53 would be an unusual (though not unheard-of) chainring to find on a track bike.

The gears that might actually be used in races are shaded in gray. The gear combinations that yield gears lower than what is shaded might be used for warm-up. The largest gear shown here (96”, 51 x 14) would likely only be used for a Keirin or another unusual event like the 200 meter time trial; it would rarely be used for mass-start track races.

Looking at this, the short answer to how track and road gears compare is that track racers generally use something roughly equivalent to a 53 x 15, give or take, for most everything they do. They would almost never use anything as large as a 53 x 14, and would occasionally go down as low as a 53 x 16 – but that would be the lower boundary for most track racers.

For a little more detail on this – because it’s near and dear to track racers – I asked an elite track cyclist to discuss his approach to gearing in different races. His answer was so thorough and helpful that I’m just reproducing it below.

Here’s how I generally do it for different types of races:

Scratch: 48×14 [90”]

Match sprint: 51×15 [89”] (I like having a little more acceleration)

Team sprint:

51×15 [89”] (starter)

48×14 [90”] (second)

52×15[91”] (anchor)

Chariot: 51×15[89”] or 48×14 [90”], depending on how I feel

Points: 51×15 [89”] usually, sometimes a 48×14 [90”] later in the season

Madison: 51×15 [89”] here (see Euro stuff below)

If I’m racing at altitude, like at Colorado Springs, I’ll usually go up a tooth on my chainring, and race scratches in a 49×14 [91.8”], and points in either a 48 or a 49 depending on the strength of the field. I haven’t done any sprint stuff at altitude, so I can’t really say if that changes.

As for the little Euro track [note: six-day tracks in Europe are commonly between 150 and 200 meters – very short and very steeply banked], I go much lower in gearing. Particularly for madisons, and for multi-day events. In the 6-days we’re capped at either a 49×15 [85.7”] or a 52×16 [85.2”] (they’re nearly equivalent). In Geneva we didn’t have a gear restriction, so I tried going up to a 50×15 [87.4”]. By the third day my legs were so blown that I had to go back down to the 49×15 [85.7”]. It sounds like a tiny gear, but you can really get that thing moving. We’d regularly get our mid-race sprints into the 64-65 km/h range, and the finish would sometimes crest 66-67 km/h. [Note: in a 85.7” gear, 66kph requires 161rpm’s.]

The highest speed I ever hit in Blaine was nearly 69 km/h behind the motor, in a 48×15! [That’s just over 170rpm’s.] You don’t need a huge gear to really get flying, just good, smooth form. If you can pull that off, all the accelerations in a points race, madison, or scratch become much easier to handle, and you don’t load your legs up as quickly.

Another funny story: I won the state Madison a couple years ago in an 86″ gear. [48 x 15] I didn’t know at the time that I was still in my warm up gear, and didn’t figure it out until I tried to find my 15 tooth cog the next week at training. That really drove the point home for me: it’s all mental. You don’t need big gears to go fast.

As for the real legit guys, all the 6-day pros race on a 49×15. I haven’t really heard of anyone going smaller than that at a really high level event, but that’s smaller than pretty much anyone stateside runs. The largest I’ve heard of is probably a few pursuiters who have been known to push gears in the 51- 52×14 range, but that’s really getting up there.

Because it relates to this topic, particularly how you train on the road if  part of your goal is to race well on the track, I’ll make a few notes about road gears in general.

Twelve-tooth and eleven-tooth cogs only became available in the last few decades, even though they seem obvious now. Eddy Merckx won his races with a 53 x 13 [107”] top gear. What should be obvious now – and can easily be confirmed with an online gear calculator – is that any amateur roadie who claims to use his 12-tooth cog for anything much is actually slowing himself down. In general, an 11 is a waste of space.

A little more arithmetic. A 53 x 12 at 90rpm’s is going 50kmh (31mph). Most amateur roadies will turn a flat, fast time trial no faster than this, and frankly, much slower. A Cat. 1/2 road racer who turns a respectable 55:00 40km time trial has just averaged 43.6kph (27.1mph) – which, in a 53 x 12 translates to a grinding cadence of 79rpm’s. He has no need for this gear at all; even a 53 x 13 is too big (average cadence of 85 rpm’s). He should be riding in his 14 and 15 cogs most of the time, with an occasional dip into the 13 for fast sections. The uselessness of an 11, or of chainrings larger than 53, should be apparent.

Lance Armstrong operated at cadences between 100 and 110 rpm’s with some success. If you do the math, working backwards from his time trial average speeds, his cadences suggest that he didn’t use his 11 or even his 12 very often. And while this will not work for everyone, there is simply no reason to let your cadence drop much below 90. It turns out that Eddy Merckx’s old 52 x 13 will basically do everyone fine. At 64kmh (40mph), a 52 x 13 is turning at 128rpm’s. This is about the right cadence for road sprinting, and it’s fully 30rpm’s less than elite track riders turn during accelerations. Oh, and most amateurs have never gone 40mph in a road sprint before in their lives – and even today, most pro road sprints max out at or below this speed.

So much for needing a 12. But more to the point, training on a gear cluster that has such high gears will encourage you to grind in low gears rather than train where you should – at 100rpms or higher.


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