Shadowing Practice: How Tire Rolling Resistance Affects Cycling Speed ? - Learn English Speaking with Video

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What is rolling resistance and why should you think about it on the bike?
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Rolling resistance is, quite simply, the energy that is lost as a tyre rolls along a surface.
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The energy is mostly lost because of the constant deformation of that tyre against the surface.
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Now, whilst paying attention to rolling resistance is important, it's not actually the biggest resistance factor when it comes to cycling fast.
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Air resistance rises in a squared ratio with increased speed.
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At a speed of 20 kilometers an hour on a level ground, air resistance has already become the main resistance force.
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And the faster you go, the more air resistance increases exponentially.
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So before even thinking about rolling resistance, get aero.
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Acceleration energy is also expended, for instance, the weight of the wheels is of great importance when this mass has to be brought up to rotation.
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Then when riding uphill, the main resistance force to be overcome is the gradient resistance.
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This is basically the additional resistance added by fighting gravity.
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And in addition to these, there are other friction resistances in the chain, the bottom bracket, and other rotating parts.
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Now, in a well-serviced bicycle, these represent a very minor part of the total resistance.
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So, should you just ignore rolling resistance then?
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Well, no. Because improving your rolling resistance may be the cheapest
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and easiest upgrade you can make to your bike to go faster.
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You can improve all the others by getting aero, by getting a good bike fit and spending the time getting used to it, by getting aerodynamic and light frame,
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by getting some aerodynamic race wheels, and even by upgrading the bearings to maybe ceramic bearings.
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But you can get big gains simply by upgrading your tires and improving your rolling resistance.
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And of course, pumping those tires to the right pressure.
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It's pretty simple.
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A tire with a higher rolling resistance will require more power
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to attain the same speed than a tire with a lower rolling resistance, will require less power.
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So what factors affect the tyres rolling resistance?
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Tyre pressure.
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On a completely smooth surface the following applies.
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The higher the inflation pressure the less the tyre deforms and thus the lower the rolling resistance.
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However on an imperfect surface which we are always riding on lower inflation pressures cause the opposite, lower rolling resistance.
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Imperfections in the road on a very hard tyre will cause bouncing and skipping and increased resistance, not to mention the toll that takes on the rider in terms of fatigue.
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Whereas a tyre with low inflation pressure can adapt better to the rugged surface.
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It sinks into the ground less and absorbs imperfections rather than pushing against them and bouncing off them.
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And so with a softer tyre the whole rotational mass is held back much less on the uneven surface.
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Tire width.
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At the same tyre pressure on a smooth surface a wider tyre will have lower rolling resistance than a narrower tyre.
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This is essentially because a wider tyre with the same pressure actually has an effect of higher pressure
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because a wider tyre with a higher air volume will have a higher casing tension.
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Basically the wider tyre will be harder because it needs more air to fill it and the contact patch, the bit of the tire touching the road, will be smaller and wider, decreasing the rolling resistance.
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But again this only holds true on a smooth surface.
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On an imperfect surface with the pressure corrected for the width to get the tire to the right hardness, the contact patch on the road for a wider tire will be shorter and wider than a narrow tire,
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decreasing the rolling resistance.
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Importantly the wider the tyre will have more versatility and the range of pressures you can actually use, allowing you to more easily correct for the roughness of the surface.
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Tyre construction.
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Obviously the tyre construction has an effect on rolling resistance.
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By using less material, less material can and will be deformed.
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And the more flexible the material is, such as the rubber compound, the less energy is lost through deformation.
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Generally, smoother treads have a lower rolling resistance than rougher treads
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and that is why almost all road
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and triathlon racing tires have very smooth tread patterns
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if any tread pattern at all interestingly actually in racing tires for the road the tread pattern
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that is there is actually not there for grip
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or water dispersion it's mostly there for aerodynamics
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because the tread pattern actually trips the laminar flow as
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that of that air that's hitting the tire to improve the aerodynamics So,
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should you consult a website like BicycleRollingResistance.com where they list all the tested rolling resistance of all tyres
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and simply choose the one from the top of the list?
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Well, yes and no. Yes, the tires on the top of that list will be the fastest.
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However, they're always compromises.
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Some of them may sacrifice durability for that extra speed and be more prone to punctures.
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Some of them may have a different compound that sacrifices comfort
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and grip and road feel and some may simply not work well with your wheel and bike setup.
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It's also worth pointing out that the difference between the top of
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that list of racing tires and the middle of
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that list of racing tires is about a two to three watt saving
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which is an almost imperceptible difference for most mere mortals.
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They will however have a significant difference in those racing tires over your standard training tires.
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So the answer is that the best tire for you depends on many factors
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but it is worth considering investing the $100 to $200 in a good pair of racing tyres.
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It may just be the cheapest watts you buy this season.
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One more thing before we go, you may be asking which is faster rolling resistance-wise, tubeless or clincher?
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Well, the speed of a tyre actually depends on its construction and not whether it's set up clincher or tubeless.
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So, a slow tubeless tyre will actually be slower than a fast clincher tyre.
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However, generally speaking, setup does have better rolling resistance than a tube setup.
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However, if you put a latex tube in a clincher, the rolling resistance is actually the same as tubeless.
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I hope you've enjoyed this video.
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Happy riding!

Vocabulario y notas de pronunciación para esta lección

Este vídeo tiene 75 frases y 1065 palabras para practicar shadowing. La parte hablada dura 5:59. El hablante habla a un ritmo natural de unas 178 palabras por minuto, cercano a una conversación cotidiana. Solo el 76 % de las palabras está entre las 3.000 más comunes del inglés, por lo que el vocabulario es exigente.

Vocabulario clave de este vídeo

15 palabras del vídeo que vale la pena aprender, con su pronunciación y significado:

PalabraPronunciaciónSignificado
tyre sustantivo/taɪə(ɹ)/neumático, caucho
tire verbo/ˈtaɪ̯ɚ/cansar, cansarse
tread verbo/tɹɛd/zapatear, pisotear
upgrade verbo/əpˈɡɹeɪd/embonar, mejorar
inflation sustantivo/ɪnˈfleɪ.ʃən/inflación
narrow adjetivo/ˈnæɹəʊ/estrecho, angosto
tube sustantivo/tuːb/tubo, chisguete
sacrifice sustantivo/ˈsæk.ɹɪ.faɪs/sacrificio
bearing sustantivo/ˈbɛɹɪŋ/cojinete
depend verbo/dɪˈpɛnd/depender/pender (de), ser dependiente (de)
patch sustantivo/pæt͡ʃ/parche, cureta
compound sustantivo/ˈkɑmpaʊnd/compuesto
decrease verbo/dɪˈkɹiːs/mermar[se], descrecer
grip sustantivo/ˈɡɹɪp/agarre
bounce verbo/baʊns/rebotar, repercutir

Phrasal verbs que vas a escuchar

PalabraSignificado
hold back verbofrenarse, refrenarse
point out verboseñalar, apuntar

Pronunciación a tener en cuenta

  • Los sonidos de “th”: smooth /smuːð/, width /ˈwɪtθ/, triathlon /tɹaɪˈæθˌlɑn/
  • Los sonidos de “sh” y “zh”: inflation /ɪnˈfleɪ.ʃən/, essentially /ɪˈsɛnʃəli/, ratio /ˈɹeɪ.ʃoʊ/, tension /ˈtɛnʃən/, rotation /ɹoʊˈteɪʃən/
  • Palabras largas — cuida el acento: essentially /ɪˈsɛnʃəli/, importantly /ɪmˈpɔɹ.tənt.li/, acceleration /əkˌsɛl.əˈɹeɪ.ʃən/, aerodynamic /ˌɛəɹəʊdaɪˈnæmɪk/, deformation /ˌdɛfəˈmeɪʃən/

Cómo practicar con este vídeo

  1. Escucha el vídeo entero una vez sin hablar y anota las palabras que no conoces.
  2. Empieza a velocidad 0,75×, haz shadowing frase por frase y vuelve a la velocidad normal cuando te resulte fácil.
  3. Grábate y compara con el original, prestando atención a palabras como tyre, tire, tread.

Gramática en este vídeo

Las estructuras que más usa el hablante, con las palabras exactas del vídeo:

EstructuraEn el vídeo
Voz pasiva be + participio pasado — importa lo que ocurre, no quién lo haceis lost · is also expended · be overcome
Present perfect have/has + participio pasado — una acción pasada que sigue importando ahorahas already become · you've enjoyed

¿Qué es la Técnica de Shadowing?

Shadowing es una técnica de aprendizaje de idiomas respaldada por la ciencia, desarrollada originalmente para la formación de intérpretes profesionales y popularizada por el políglota Dr. Alexander Arguelles. El método es simple pero poderoso: escuchas audio en inglés nativo y lo repites en voz alta de inmediato, como una sombra que sigue al hablante con solo 1-2 segundos de retraso. A diferencia de la escucha pasiva o los ejercicios de gramática, el shadowing obliga a tu cerebro y músculos de la boca a procesar y reproducir simultáneamente patrones de habla reales. Las investigaciones muestran que mejora significativamente la precisión de la pronunciación, la entonación, el ritmo, el habla conectada, la comprensión auditiva y la fluidez al hablar, convirtiéndola en una de las metodologías más efectivas para la preparación del IELTS Speaking y la comunicación en inglés en el mundo real.

Técnica de shadowing: lee la guía completa paso a paso →