Header, Main

  Cycling Performance Simplified

Navigation Bar Header

[ American Road Cycling Forum ]   

Header, Main
Lynn History Navigation
Cycling Performance Simplified

 




Skip Navigation Links
Cover
About
Forum
Contents
Acknowledgements
Preface
Introduction
Basics
Impossible
Prequel
Torque
t@P/W
Orthotic (NOT)
Dead Spot
Training Program
Video Links
Power Calculator
Physics
Watts vs Speed
Powertap
File Structure
Tactics
̶S̶t̶r̶e̶t̶c̶h̶
Never Chase
Flight Check
Wish List
Naturally Thin
Appendices
Course Outline
Glossary
References
Subject Index
Climbing Calculator
Back Cover

 
Updated January 22, 2016 | By Bob Fugett

Torque

<-- prev | next -->

In summary the number you have been looking for is Torque not Watts.

Torque is an absolute reference to strength.

Watts are an absolute reference to speed.

Efficiency can be understood as the ratio of Watts/Torque.
 

In order to improve your cycling leg torque (strength) once you understand the concepts presented below be sure to review the Training Program.

The information below is very closely related to the Dead Spot.

The following discussion has broad application but focuses on Watts and Torque as measured by Powertap on-bicycle power meters.

Once you know how these three metrics interact you will understand that surprisingly little effort is required for an impressively powerful performance.

You will also understand that Torque provides the best metric to guide improvement of your cycling strength.

Below is a chart showing a rider holding Watts which are almost 50 times greater than his force on the pedals.

This is a front rider during the final sprint of a competitive 36 mile club ride renowned for being a race without numbers.

 

Torque: --- Watts: --- Speed: --- Heart Rate: --- Cadence: ---


Front rider final ¼ mile of competitive club ride holding Watts = 44.6 × Torque

Click for Full Image
  

You may have noticed that sometimes you push hard for few Watts, but sometimes you push with relative ease for lots of Watts.

The Internet is full of confused discussions stemming from this phenomenon.

The fact is you cannot feel Watts (as currently implemented), but you can feel Torque which is the proximate measurement of force you are pushing into the pedals.

For point of reference, this is not about such efforts as at the end of a sprint where you are pushing as hard as you can but have nothing.

This is about what you feel when you are fresh, on a windless flat, when you actually do know where you have pushed hard and where you have gone easy.

It is a baseline for understanding what happens on hills, tight turns, jumps in a race, bridging attempts, pushing into a headwind, being pushed by a tailwind, starting from stop, and all other variables that affect your cycling speed.

In the sport of cycling there is a widespread mistaken belief that Watts measure strength.

Watts only indirectly refer to strength while Torque measures strength directly.

If you look at your Torque (only Powertap gives it, and not during a ride), you will see it tracks very closely with how hard you know you pushed, but the number of Watts you can achieve will vary significantly against what you feel.

Caveat: A Cadence Sensor (with a magnet on the pedal crank) is an absolute necessity for correct Torque measurements with a Powertap.

After you see how your Torque tracks closely with what is felt, you will notice a given measured effort gives a variable range of power.

Sometimes great effort is weak: sometimes light effort is powerful.

The difference can be your efficiency which is often a function of cadence—pedal chainring revolutions per minute.

Obviously you can go a lot faster on your bike than if you are walking or running on a smoothly paved road.

Your bicycle offers significant mechanical advantage providing much greater power output than your input effort of pedaling.

Under the correct circumstances fifty times the force you push into the pedals will be translated into forward momentum at the wheel.

That is to say it is possible for your power output to be equal to 50 times your pedaling input.

On the other hand it is quite possible for a maximum effort on the pedals to add absolutely nothing to forward speed.

It all depends on your skill pedaling.

Try this: go stand squarely facing a brick wall a few feet away from it.

Lean in with both hands and push as hard as you can against the wall while counting to ten.

How many Watts is that?

The answer: zero, none, nada!

Measurement of Watts includes displacement, and the wall has not moved, so the result is zero.

Think about it on your bicycle.

On a flat section go fast enough for easy balance.

Now, stand coasting for 10 seconds with your pedals level across at 9 o'clock and 3 o'clock positions.

How many Watts is that?

The answer: zero, none, nada.

Just like against the brick wall you can waste the full force of your entire bodyweight on the pedals and get nothing.

You will agree it is important for your cycling performance to stay as far away from beating your head against a brick wall as possible.

Insight into the difference between pushing hard for nothing and pushing easily for great gain is found by comparing Torque to Watts.

Torque is the input: Watts are the output.

Whereas Watts will vary higher or lower depending on a range of variables, Torque gives a more direct reading of force against the pedals.

To go back to our brick wall analogy, it would be as if you pushed a bathroom scale against the wall instead of putting your hands on it directly.

The wall would still not move (so zero Watts), but you could see how hard you are pushing by the weight applied to the scale.

The Torque measurement is that bathroom scale.

Precision progressive training gives you the greatest gain in performance in the shortest possible time, but progressive strength training in cycling requires an exact measurement of the force you are able to push into the pedals.

Powertap Torque readings provide that measurement.

Your effort may or may not be getting all the way through to your wheel (to be recorded as Watts), but Torque will show just how hard you are pushing.

On the other hand you may be getting lots of Watts with very little effort, but once again Torque will show your soft pedaling.

In order to assess how much of your effort is making it through to maintain or add to your speed, divide Watts by Torque.

The result will be a number that is directly related to efficiency, and it is the first thing to look at when assessing rider performance.

The result of Watts/Torque is your functional index with the descriptor fx.

Don't bother searching functional index and fx online.

I coined the term for use in this instance, because this aspect of cycling performance has been totally overlooked in the literature.

There may be a few references to efficiency but no direct pointers to finding the essence of efficiency by inspecting leg strength measured as Torque and comparing it to output measured in Watts.

Once you understand how the two separate measurements of Watts and Torque interact you will pursue three separate goals in your training programs focusing on the following three aspects:

  1. more Torque = stronger
  2. more Watts = faster
  3. more Efficient = greater speed for less effort

More Watts always equals more speed.

Though more Watts always equals more speed, conventional wisdom also states more Watts equals more strength, but truthfully more Watts can merely be the result of greater efficiency—not greater strength.

As a rule of thumb (if your flexibility is correct and your spin remains balanced) a faster spin always results in greater efficiency.

A higher cadence is inherently more powerful.

Put your truck in its lowest gear and rev the engine to pull that stump out of the ground.

You will understand this better after your first hard hill wherein you blow-up near the top, click down, ease off and spin faster, but you notice your power has actually jumped up 10 or 15 watts higher and is continuing to rise... while your effort is less!

Once you experience this in the real world and see you can significantly increase power while lowering effort (profoundly counter intuitive), you will understand how unlikely it would be for anybody on a bicycle to recognize this physical reality without a tool to measure the effect in real time, on a real hill.

No wonder the myth persists that standing heavy stomping grunt cycling provides the most power.

Nevertheless, stronger is better, so use Torque as the basis to apply tried and true old-timey strength training techniques directly to your cycling.

In summary that means: repetitions of measured short intense efforts, repeated in sets, with large amounts of recovery time between both the sets and the reps.

Except now (just like your bench press) you will know exactly how strong you are such as, "Damn... torqued 35 at 103 rpm for 2½ minutes! Next time 36 at 104. People are gonna suffer."

Finally, a rational expression of true cycling effort.

You are on the cutting edge of next generation power meter use.

When you understand Torque measures your strength while more Watts (your absolute reference to more speed) is actually a function of your efficiency (faster spin not more strength), you will truly enjoy your next steep hill where all the burly he-men of legendary strength and resolve stand to stomp in wild competition, but you only smile without rising, rest, and spin easily along beside them.

Don't forget to loudly call them a bunch of weak loser pussies as you easily pace them, because that will make them stomp even harder and your job of kicking their asses at the top will be all the easier.

When people around me begin to stand on a hill I always sigh quietly to myself, "Good. That's over. Now it gets easy."

It is simple physics.

Now that you have glimpsed the mountaintop, I must introduce this one slight complication to help you fend off naysayers who wish to keep you stupid.

Strictly speaking Torque is a measure of one thing while Watts measure something else, but Powertap derives both measurements from the same strain gauge in the hub.

A case could be made that Powertap is only splitting differences off the same measurement.

True, but these numbers are settled science though few people understand them and choose to look only at their Watts with no concern for how they got there.

Regardless, despite measuring different things (rotational vs linear power), Torque and Watts are in fact two sides of the same coin.

Conversion tables and calculators exist to exchange the information that both measurements provide.

Unfortunately Torque is recorded under the wretched name Newton Meters, so people like to stop thinking about it.

But know this: the conversion of Newton Meters to Watts is 1 to 1.

That is: 1 Watt = 1 Newton Meter and vice versa.

Therefore Torque quantities don't really need to be called Newton Meters because for purposes of comparison calling them Watts at the pedal would be just as correct.

In any case, your Powertap data will show your Torque generally in the 10's while your Watts are in the 100's, because your bicycle is providing a mechanical gain making your effective output greater than your actual input.

The inherent similarity of these two quantifiers is why you can divide your measured Watts by Torque to get an efficiency index which will show a range of Watts generally 10 to 50 times greater than your Torque.

Pay attention to that multiplier and work to improve it.

Hint: To improve Torque (strength) perform a baseline on (then use) a wind sheltered hill of regular slope at a defined cadence.

Gradually increase the average cadence (rpm) you can achieve on it while maintaining a functional index (fx) no less than 30.

You can also increase time and distance covered on the hill.

After good results (which may take a few weeks with significant attention to floor exercises taken from these books) click up a gear, or even better calculate your gear inches and pick the gear combination with the least amount of increase to repeat the process again.

Keep repeating incrementally until you are as strong as you want, or until everybody you know has been beaten, whichever comes last.

Caveat: A Cadence Sensor (with a magnet on the pedal crank) is an absolute necessity for correct Torque measurements with a Powertap. 

 


<-- prev | next -->

 

A KEYTAP Publication