Changer de Braquet

Changer de Braquet

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Some people are supremely good at it, reducing complex situations into matters of simple black and white. This isn’t my particular area of expertise; I enjoy wading through the pools of ambiguity a bit too much to go about bludgeoning this beautiful world into absolutes. In fact, I would venture that delighting in nuance is part of what distinguishes La Vie Velominatus from the simple act of riding a bicycle.

I’ve spent the summer wrapping myself in the Rules handed down by the Apostle Museeuw during Keepers Tour 2012, with particular emphasis on Rule #90. Climbing Sur la Plaque is a cruel business, rising upwards under the crushing weight of physics as you fight to maintain your rhythm and momentum. At first, it’s a struggle to maintain speed on the smaller climbs as you learn how to change your pedaling action to compensate for changes in gradient. You focus on loading the pedals and forcing them around; the moment you lose the rhythm, gravity sinks her claws into your tires and tries to drag you back down the hill. On the other hand, if you maintain your cadence and power through the ramps, what is usually an intimidating slope will disappear under your wheels, making molehills of mountains.

If the Big Ring is a hammer, then not every climb is a nail. (I realize too late that referring to the road as a nail is sure to bring the Puncture Apocalypse on today’s ride.) The guns get more massive from the practice of Rule #90, but it comes at a hefty price: souplesse withers like a delicate flower as one seeks to conquer the art of mashing a huge gear. Indeed, one of the great pleasures in Cycling is to sense a certain fluidity of your stroke which belies the feeling of strength in your muscles as you continue to heap coals on the fire.

This requires an art altogether different from moving Sur la Plaque; it relies on turning the pedals at a higher cadence and shifting gear whenever the gradient changes. Rhythm holds court over everything else and is maintained at all costs. As the gradient steepens, the chain is slipped into the next smaller gear; as the gradient eases, it is droped back down. Not every climb suits this style of riding; the rear cluster must be matched perfectly to accomodate the changes in pitch such that maximum speed is maintained and the legs allowed to continue their relentless churn. When synchronized perfectly, it is the gateway to La Volupté; when not: disaster.

Such is the nuance of shifting gear, such is the nature of Cycling.

// Technique // The Hardmen // The Rules

  1. Alright, I’ll testify.  I live in Colorado, and I like to ride long climbs like most of us here. Mostly, I ride a compact with a 12-28 that I use in the mountains and over passes like Loveland, Monarch, Hoosier, etc (either from the east or west), or Pikes Peak Highway which opened to cyclists the entire month of September for $10. I also ride a 53-39 with a 12-28 that I usually use on longer rides along the front range but don’t require 1000m of climbing in 2 or 6 Km, BUT, I can still climb with. That’s what I love about where I live…go west to the mountains and big climbs, go east to the high plains and flats and wind.

    What and how you ride surely depends on where you are at, at the time.  Last summer, the VMH and I went home to southern Illinois for a short vacation over Independence Day with great expectations of long rides on back country roads.  Foolishly, and I’m not sure why or how, I packed the compact.  While riding the old stomping grounds, I quickly determined that my recollections of the hilly terrain were greatly exaggerated.  I quickly spun out of the high gear.  Only the humid air, “damning elevation” of 165m, and the mosquitos of the Heartland held me back. The mosquitos were the worst.

    My point is is that the big ring and cassette that you use ought to be for the terrain you ride, and mash it hard.  For the average dude, if you want to use a 53-39 and 11-26 around Colorado, I’ll see you at the bottom of the next pass.  For the rest of you, don’t drink all the beer before I get there.

  2. @niksch

    Dude, you need to work on your cadence.

    You’re spinning out at 68 km/h at 130rpm based on the development of a 50×12.

    FWIW I’m on a 50×34, 11-25.  The 11 helps.  The only time I’ve ever spun out was descending a gradient of more than 10%.

    Anyhoo, my point is that I’m pretty happy with the compact thus far.  Maybe if I turn into a real man in the next year or so, i’ll go back to the 53/42 of my yoot.

  3. @mouse

    @niksch

    Dude, you need to work on your cadence.

    You’re spinning out at 68 km/h at 130rpm based on the development of a 50×12.

    FWIW I’m on a 50×34, 11-25.  The 11 helps.  The only time I’ve ever spun out was descending a gradient of more than 10%.

    Anyhoo, my point is that I’m pretty happy with the compact thus far.  Maybe if I turn into a real man in the next year or so, i’ll go back to the 53/42 of my yoot.

    Or to summarise, you don’t want your testicles to hang so low that they get caught up in your chainring.

  4. @scaler911 Keep your pretty words to yourself cassanova I”M A BLOKE.

    Fair enough then, suppose that gets you off the hook this time.

  5. @Marcus

    @minion Canberra has changed you.

    I know, now I’m just like the rest of you climatically spoiled fucktards. On the upside, I might be working in your Parliament soon (for realsies!) I’ll introduce you to Peter Slipper when you come visit, you;ll get on like houses on fire.

  6. @Ken Ho

    @mouse

    @niksch

    Dude, you need to work on your cadence.

    You’re spinning out at 68 km/h at 130rpm based on the development of a 50×12.

    FWIW I’m on a 50×34, 11-25.  The 11 helps.  The only time I’ve ever spun out was descending a gradient of more than 10%.

    Anyhoo, my point is that I’m pretty happy with the compact thus far.  Maybe if I turn into a real man in the next year or so, i’ll go back to the 53/42 of my yoot.

    Or to summarise, you don’t want your testicles to hang so low that they get caught up in your chainring.

    You do get more clearance with a compact…

    Nah, I’m not really having a go at @niksch.  Horses for courses.  He’s got a system that works for him.  That’s awesome.

    If I had the funds to get a second bike, I’d probably go with a standard 52/42 just so I could have the choice.

  7. @minion

    @Marcus

    @minion Canberra has changed you.

    I know, now I’m just like the rest of you climatically spoiled fucktards. On the upside, I might be working in your Parliament soon (for realsies!) I’ll introduce you to Peter Slipper when you come visit, you;ll get on like houses on fire.

    Jaysus.  Parliamentary democracy will never be the same.

    You gonna be Christopher Pynes’ (weasly little cunt) scriptwriter?

  8. @mouse

    @niksch

    Dude, you need to work on your cadence.

    You’re spinning out at 68 km/h at 130rpm based on the development of a 50×12.

    FWIW I’m on a 50×34, 11-25.  The 11 helps.  The only time I’ve ever spun out was descending a gradient of more than 10%.

    Anyhoo, my point is that I’m pretty happy with the compact thus far.  Maybe if I turn into a real man in the next year or so, i’ll go back to the 53/42 of my yoot.

    I’m just happy I can get my fat ass up some of these mountains.  The flat terrain in Illinois felt like cheating.

  9. @Nate Ah, lawyers and physics; like oil and water.

  10. @frank

    @Nate Ah, the Dutch and physics; like oil and water.

    Fixed your post for you — the point being, if the gear ratio is the same, the effort to do a certain amount of work is the same, no?

  11. @Oli

    @frank

    @unversio I surely don’t unnnerstan’ them vector diagram things , but I do know how gears work thanks, man.

    And I know you know. I often await your superb logic with other threads. The vector diagram only provides an understanding (realization) that some forces (most) are acting in the direction of the chain. And some component forces (slight) are acting perpendicular to the chain. The greater the angle of cross-chaining, then there is a greater component (force) that is acting to kill your chain and cassette. Your logic was 100 percent. Frank is possibly working out some other theory.

  12. @Nate

    @frank

    @Nate Ah, the Dutch and physics; like oil and water.

    Fixed your post for you “” the point being, if the gear ratio is the same, the effort to do a certain amount of work is the same, no?

    No, in fact. If the gear size is the same, depending on where your points of leverage are in the system, you will have a better mechanical advantage.

    As for the quip about the Dutch and physics, go get an education, you cretin! Most of the country is below sea level; takes some serious engineering to keep the country from drowning.

    (Business Time just came up on a Genius for Audioslave’s Original Fire. WTF?)

  13. @frank I used the same “truth” with leverage when I rode 177.5 cranks. Great for chasing down after a climb, but not so good for climbing. The rotations (cadence) is longer and tough to maintain. 172.5 cranks would do better in climbing. Oh please tell me that I’m “getting it” — oh well shit!

  14. @frank

    @Nate

    @frank

    @Nate Ah, the Dutch and physics; like oil and water.

    Fixed your post for you “” the point being, if the gear ratio is the same, the effort to do a certain amount of work is the same, no?

    No, in fact. If the gear size is the same, depending on where your points of leverage are in the system, you will have a better mechanical advantage.

    As for the quip about the Dutch and physics, go get an education, you cretin! Most of the country is below sea level; takes some serious engineering to keep the country from drowning.

    (Business Time just came up on a Genius for Audioslave’s Original Fire. WTF?)

    If the gear inches are the same any increase in “leverage” between the big ring and small ring is compensated for by stepping the leverage back down with a different gear in the back.  E.g.,53×23 and 39×17 both develop 4.8 meters on a standard road bike for one crack rev.

    There is research out there.  It has little to do with keeping the Low Countries dry but it suggests there ranges of efficiency and these depend largely on chain tension and sprocket size; larger sprockets seem to have less friction so you may be right that you are better off in the big ring and bigger cog than in the smaller ring and smaller cog.  Interestingly, this means that a bicycle drivetrain is more mechanically efficient if you are spinning rather than mashing.  It’s not a function of leverage, however.

  15. @frank

    Also:  Apologies in advance for exposing you to research — I momentarily forgot your aversion to it.

  16. @Nate

    @frank

    Also: Apologies in advance for exposing you to research “” I momentarily forgot your aversion to it.

    You’re missing the point completely. We’ll sort this out when we finally get around to having a ride together.

    And I have no aversion to research, smart arse, but the trouble with you lawyers is you always believe everything your read. Didn’t your mamma tell you something about that?

  17. @frank

    Missing the point of the article, or your theories on chainrings and Newtonian physics? The general point of your article is one I understand well.  If it’s the latter, I don’t think you’ve formulated them yet, and I thought you’d find Springer, et al. interesting food for thought, my gratuitous dig notwithstanding. I think it supports your assertions, but comes to a different conclusion about why.  Curious about your reaction to it.

    Once your mechanical theories are in a more developed state I look forward to testing them out on a ride together, although I suspect they will only reach their fullest development with ample marination in ales.  And if you think lawyers believe everything they read, you probably need a new lawyer.

  18. @Nate Thanx for digging up that research. I needed it.

  19. And ordering a new chain for Winter.

  20. @Oli

     It’s best avoided if possible, as is the fatigue to your legs, hence the reason double chainrings were invented.

    I agree. I spent last year mashing the big ring in hopes that it would make me stronger. Perhaps it did in a minor way, but I have learned that judicious use of the appropriate small ring/cog combination allows you to keep momentum and still save the legs. I was able to put this in practice on a century ride a couple weeks back where I closed a large  gap between myself and a young (20 something rider), and then maintained a gap all the way to the end. I knew he was mashing the big ring all day long and could see the overall fatigue of the miles and time on the bike taking its toll. I know it was a matter of time and he would not be able to stay up with me once I made the effort to gap him.  

    I have commented elsewhere that to me the biggest advantage to STI shifting has been the ability to drop the big ring and simultaneously grab a handfull of cogs to maintain momentum to climb and stay on the wheel . I was never a smooth shifter back in the day of DT shifting so I basically found a suitable gear and rode my bike like it was a single speed with only major adjustments being dictated by the terrain. Needless to say some of the same rides I do today with signficant souplesse, are the rides that kicked my ass back in the 70’s . Notwithstanding the fact that I engaged in social behaviors that were counterintuitive to VO2 max and rode a 30 lb steel bike, the ability to always be in a gear that facilitates easy spinning is likely a factor for the difference in performance.

    All things being equal, I will say that dropping the 28 cog on an 11-28 cassette in favor of 12-27 has been a good move for me.  I feel like I was getting weaker by depending on the 28 to bail me out on climbs I could do with the 27 and only slight increase in heart rate. The most noticable drawback has been the loss of top end without the 11T.   However its only on the descents and I am arguably fast enough  downhill in the drops, perhaps too fast given the potential to have a deer jump out of the woods and cross the road in front of me.  As others here have said, it is not a lack of ratios that hold me back as much as it is the limitations of plane of fittness and conditioning mediated by physiology.  At 58, there is not much I am able to do to improve those parameters as much as I can with smart shifting to preserve my legs over the distance.    

     

     

  21. @GottaRideTodat Good post, I have been wanting to check and make sure that people know the little ring is good for training the aerobic system, and that it’s no good being able to mash a big gear for 20 minutes if you’re going slower than everyone else and can’t respond to changes in pace.

  22. Interesting indeed.

    I played with the 100+ cadence after switching to road from mountain right around 2002-3. Of course, the big expert was Chris Carmichel, I mean he was coach to the world’s best! Or so I thought at the time. After struggling with a nice fast spin, I realized that I needed to do what was right for me. And I slowed down to 80-95. That and some better understanding of how a cat 5 peloton works (it doesn’t) made me a better rider. Then I started riding the track….

  23. @mouse

    @frank

    @MartinD

    @frank

    On the other hand, I’m 100% sure you have a better mechanical advantage in the 53×26 than in the 39×19 or whatever the equivalent-sized gear ratio is in the 39.

    Without wanting to seem more of a grumpy old bastard than absolutely necessary …

    10 and 11 speed cassettes and compact cranks certainly mean that the idea of putting it in the big ring isn’t what it used to be. My 1977 Peugeot PX-10 came with a 45-52 and 5 speed 13-21. This cluster was of course just used for training. Everyone raced on a 13-17 (a beautiful Regina Oro version for me – probably the classiest thing on the bike). Some friends had 42 tooth inner rings, but I don’t think anyone had a 39.

    It was relatively flat where I grew up, but windy enough that a large part of many races was in the small ring.

    I think it was some time in the 80″²s when the 39 was introduced after the modern spider was developed. Another good thing. Before that, 42 was as low as you could go.

    Wow, a 13×17. Was it hard to see with all that hair on your chest?

    Yeah, 13×17 was what you wanted ’cause it looked so fucking cool. You of course would be spat out the back on the first hill, but you’d look cool doing it.

    You were right about the timing of modern cranks with the smaller BCD that enabled chainrings t ogo down to 39, but I know for a fact that Campagnolo made either a 40 of 41 that fit on Super Record cranks around about 88 or 89.

    I recall being looking on very jealously as my teammate showed his off before the start of the Provincials that year on a very hilly parcours.

    There wasn’t anything very steep in South West Victoria. I think the biggest climb I ever did in a race was only 100 m vertical rise or so. Besides we all had 13-17s so it didn’t really matter.

    The feeling I remember before getting dropped was switching backwards and forwards between adjacent gears like the 15 and 16 with one feeling too hard to push and the other like I was spinning too fast. The desperate search for that perfect gear was always a sign of impending disaster.

  24. @Cyclops

  25. @frank

    @snoov

    Interesting, I wonder if the large rings (less friction) balances out with the straighter chain, which I’m assuming also has less friction.

    That’s always got my noodle going. With how close the chain rings are on modern cranksets, I’m not sure its a significant difference between being in the 39×25 vs 53×23. But being in a bigger cog in the back is for sure more efficient by a considerable margin; consider turning the wheel by the axle vs turning it by the tire; the farther out the chain is, the better. Similarly, in the big ring, you’re creating better leverage by sitting in the 53.

    But the matter is muddied considerably by friction of the chain entering the chainring, less friction by distributing the load over a larger surface and bending the links less, and the bend in the chain as it moves from chain ring to cog.

    All delightfully nuanced and messy, per the subject of the article.

    Interesting Frank. Considering the chain distance from the axle, you are correct, it should be more efficient to run a chain around a larger curve. Quite some research has worked on exactly how efficient a chain is at transfering power.

    I thought of this, and considering the effort applied by the rider to the drivetrain through the fixed length of the crank, the leverage applied to the chainline must be reduced because the force of the resistance you are pedalling against (the hill and your gravitational mass through the chain to the crank) intersects at a point on the crank arm further out and closer to the pedal axle when you are in big ring. Thus reducing the mechanical leverage The Guns have on the drivetrain?

    Presuming you are in the same mathematical ratio, with the big ring or the small ring, and The Guns are providing the same effort (your max watts), with the small ring the crank arm has more leverage on the chainline, than in the big ring?

    Just a meandering thought, and welcoming your retort.

     

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