Best cadence for time trials?

Bhima

For the past three days, i've been out and done a 5mile stretch in both directions, in almost identical conditions (heat, wind speed, wind direction, hydration, nutrition, sleep, percieved fatigue, time of day, etc) in Time Trial mode but i've done each day differently - each time i've used a different cadence.

I've read on here 3 or 4 times that a lower cadence is more efficient but there has always been confusion between the words "efficient" & "effective"...

Anyway, I naturally ride at a massive cadence compared to most people, so I decided to do it at 150 RPM as much as I could on day 1 - my normal sprint/TT cadence, 120 on day 2 - apparently, what Lance Armstrong does so I thought i'd try it :roll: and 90 on day 3 - 90 being mentioned a lot as most people's "favourite" cadence.

Here are my results (remember, I did the 5 mile stretch twice).

Day 1 [150 RPM] - 14:04 / 14:20 - Seriously out of breath and sweaty! Legs felt ok.
Day 2 [110 RPM] - 15:11 / 15:36
Day 3 [90 RPM] - 15:44 / 15:58 - Legs felt really tired after this.

I'm quite intrigued by the maximum speeds I could register - each was held for about 10 seconds too, so they are not just unexplainable bursts/peaks which could occur from irregular riding conditions. I can't believe there's such drop, once the cadence goes below 150...

Day 1 [150 RPM] - 38.0 mph
Day 2 [110 RPM] - 31.2 mph
Day 3 [90 RPM] - 27.8 mph

I keep heaing how lower cadences are more efficient and I was watching the Tour de France last year and Cadel Evans was grinding a MASSIVE gear at one point and he got 2nd place on that particular TT, I think. So....

I am uncertain how I should interpret these results - does is confirm to me that nothing is wrong and I should continue doing my high cadence work or is it a wakeup call about my low quality performance in the lower cadences, which I should take action on to improve...? Is it a reasonable target to try to have a similar level of performance at all cadences at TT intensity, or does it not work like that? If lower cadences are better, it's possble I am not reaching my full potential. Then again, everyone's different, so perhaps the lower cadences just aren't for me...

Slow1972

Was this a flat course? You say you sustained 38 mph at 150 rpm for 10s yet managed an average speed of 21.4 mph, significant difference in those speeds if you pushing hard the rest of the time.

You may find it easier at the moment but I find it hard to believe that with training you wouldnt get higher average speed pushing a bigger gear at lower cadence than spinning away at 150 rpm.

Alex_Simmons/RST

Bhima wrote:

I am uncertain how I should interpret these results

You rode a TT three days in a row and got slower each day. That is hardly surprising.

Bhima wrote:

I keep heaing how lower cadences are more efficient and I was watching the Tour de France last year and Cadel Evans was grinding a MASSIVE gear at one point and he got 2nd place on that particular TT, I think. So....

Commentators typically hyperbolise wrt to gearing/cadence. e.g. the supposed difference between Lance Armstrong's and Jan Ullrich's pedalling rate, which was no where near what they would have you believe.


The conclusion you should draw is that when riding a TT (or at any time for that matter) is to pick a gear that feels right for you and the effort level and speed you are riding at. It is no more complicated that that.

Bhima

Right.

What I forgot to write was that on Day 4 (yesterday), I tried the 150 RPM test again and got a time only 2 seconds slower one way and 4 seconds slower the other way, so I don't think tiredness was an issue.

I found that around 110 RPM it was a lot easier to pace myself, compared to the other two, which made small adjustments in how much power you put out difficult without changing speed, but that was not as quick a time as when I was going around the 150 RPM mark...

I guess you're right though - the more I learn about cycling, the more I realise that there really aren't any rules, it's just about what feels good for the individual.

Alex_Simmons/RST

even so, time/speed is a poor indicator of such things for a range of reasons.
power would reveal the true(r) story

still, fun to experiment

i know from examining a local TT I've done recently a couple of times that I want to review my gearing strategy for the return leg (which overall declines). IOW I think I may be better off riding a bigger gear than I would typically ride on that portion of the course. it'll be a while before I get to test that hypothesis though. i have some other TTs to ride before I'll get to do that one again.

Pokerface

Basically you are probably not pushing a big enough gear and not pushing enough power at slower RPMs.

As RPMs decrease - your power should increase to compensate. Because you're so used to spinning at high RPMs, the perceived effort it takes at a slower RPM is LESS than the actual effort it should take.

As Alex said - you really need a power meter to get accurate results - but I would wager any amount of money that if you are NOT pushing a higher wattage at the slower RPMs.

I think this makes sense!

redddraggon

Pokerface wrote:

As RPMs decrease - your power should increase to compensate. Because you're so used to spinning at high RPMs, the perceived effort it takes at a slower RPM is LESS than the actual effort it should take.

When you say power, you mean torque?

will3

I guess he must do. It's like this:
Power is torque x rpm
Hence to get the same power at lower rpm you need to prodcuce more torque.
There are two ways of doing this: use longer crank arms, or push the pedals harder.

That you cannot produce the same power at lower rpms just shows that you are incapable of pusing the pedals hard enough.

Pokerface

I meant wattage.

I think it would depend on the gearing?

If he is using the same gearing, but just reducing RPM each time, then the times will obviously slow down.

If he uses a bigger gear as the RPMs slow down, then times should remain constant. However - if he doesn't use a big enough gear at a slower RPM - or use produce enough power (measured in watts), then times will also slow down.

Maybe I have this all wrong - but I can see how the times would slow down under these circumstances.

Alex_Simmons/RST

will3 wrote:

I guess he must do. It's like this:
Power is torque x rpm
Hence to get the same power at lower rpm you need to prodcuce more torque.
There are two ways of doing this: use longer crank arms, or push the pedals harder.

That you cannot produce the same power at lower rpms just shows that you are incapable of pusing the pedals hard enough.

While it might sound logical, that statement does not follow the ones above.

The forces, even in such low(er) cadence high(er) gear efforts, are very low, certainly well below the maximal force (peak or average) a rider can produce on the pedals. For instance, simply accelerating from a dead stop up to cruise speed in a time frame typical for most club level cyclists requires much greater forces to be applied to the pedals.

will3

Alex_Simmons/RST wrote:

will3 wrote:

I guess he must do. It's like this:
Power is torque x rpm
Hence to get the same power at lower rpm you need to prodcuce more torque.
There are two ways of doing this: use longer crank arms, or push the pedals harder.

That you cannot produce the same power at lower rpms just shows that you are incapable of pusing the pedals hard enough.

While it might sound logical, that statement does not follow the ones above.

The forces, even in such low(er) cadence high(er) gear efforts, are very low, certainly well below the maximal force (peak or average) a rider can produce on the pedals. For instance, simply accelerating from a dead stop up to cruise speed in a time frame typical for most club level cyclists requires much greater forces to be applied to the pedals.

Sorry, I should have added 'in a sustained effort', though I thought this would be obviously implied :roll:. Yes anyone can push harder for a one off than in continuous mode. I think what it comes down to is that each person's max sustained power will be at a different cadence. It seems that Bhima's is at the higher end.

Pokerface

Interesting that an article relating to cadence just popped up on the home page - suggesting that slower cadences MAY be beneficial and more efficient: http://www.bikeradar.com/fitness/articl ... slow-20920

However, it seems to indicate that HIGHER cadences work better over shorter distances - such as in a time trial!

Also indicates that cadence is innate - and each rider has a cadence almost 'inbred' that they are comfortable with.

eh

Was this a flat course? You say you sustained 38 mph at 150 rpm for 10s yet managed an average speed of 21.4 mph,

Seconded these figures look weird (yet again!!) you sure you've calibrated your computer right?

Also how was cadence measured?

IMO 90 rpm cadence isn't slow most of the hour records were set at around 100 rpm.

I've always believed that you should be able to pedal a wide range of cadences because they all have advantages in certain situations.

Pokerface

eh wrote:

Was this a flat course? You say you sustained 38 mph at 150 rpm for 10s yet managed an average speed of 21.4 mph,

Seconded these figures look weird (yet again!!) you sure you've calibrated your computer right?

IMO 90 rpm cadence isn't slow most of the hour records were set at around 100 rpm.

I have to agree that these cadence figures seem WAY off. Especially when compared to your 10 mile times. Plus it is VERY difficult to maintain such high cadence for any length of time (and certainly not the 200+ cadence you claim to regularly ride at).

I also have to wonder how your cadence is being measured and how far off it is from reality.

Slow1972

Bhima wrote:

Is it a reasonable target to try to have a similar level of performance at all cadences at TT intensity, or does it not work like that? If lower cadences are better, it's possble I am not reaching my full potential. Then again, everyone's different, so perhaps the lower cadences just aren't for me...

Surely your target is to go forwards as quickly as you can at TT intensity, and use whatever combination of cadence / gearing that helps you achieve that. At the moment your time , assuming you can sustain the 150 rpm for as long as you like, for a 10 mile equates to about 28 minutes and given how much training you say you do, and the average speed you've previously said you achieve on hilly rides I'd expect you to be able to go a quicker than that if you were really were at the TT intensity for a short TT distance.

To increase your speed (ignoring aerodynamic / drag effects) you can do two things - turn the same gear round faster or push a bigger gear at the same or lower speed.

Unless you are going to spin your legs even faster than you are already you're going to have to start pushing bigger gears anyway if you want to see improvements on those times. I wonder if you're used to spinning away like that so you are just not used to pushing bigger gears at lower cadence so it feels a lot harder effort than you were actually doing. How did your HR compare on each of those tests for instance (obviously power would give a much better guide)

I also still think your average speeds against a speed you say you can sustain for at least 10 seconds looks suspect - if you could increase your average speed and can really sprint at almost 40 mph for 10 seconds you should be road racing instead of TTing - you'd be p****ing the sprints in a Cat 3/4 bunch finish.... I suspect most Cat 3/4s would struggle to peak at that speed, let alone hold it for 10 seconds as you do

will3

Pokerface wrote:

eh wrote:

Was this a flat course? You say you sustained 38 mph at 150 rpm for 10s yet managed an average speed of 21.4 mph,

Seconded these figures look weird (yet again!!) you sure you've calibrated your computer right?

IMO 90 rpm cadence isn't slow most of the hour records were set at around 100 rpm.

I have to agree that these cadence figures seem WAY off. Especially when compared to your 10 mile times. Plus it is VERY difficult to maintain such high cadence for any length of time (and certainly not the 200+ cadence you claim to regularly ride at).

I also have to wonder how your cadence is being measured and how far off it is from reality.

Just a though Bhima, you do realise that 1 rpm is one complete revolution of the cranks, ie 2 pedal strokes (one right, one left), not 1rpm = 1 pedal stroke

Bhima

Yes, I do realize that and, now just to clear a few things up:

- I over-exaggerated. The maximim speeds were held for more like 7/8 seconds. The highest was less, more like 4.

- I do not claim to be going 200 RPM most of the time. I have stated on here that I have hit 200 RPM+ before, but these were short bursts. Search and you'll find that i've often said that my average is 110 and sometimes I don't go below 100ish.

- Yes, I can sustain 150 RPM for 15 minutes. Like I said before and in a previous thread, you get very sweaty and out of breath though.

- I did not measure heart rate. No reason why, I just forgot.

- I measure cadence with a hand-held portable audio recorder, strapped to the frame, which records the sounds my pedals make. Because I run a recording studio as a business, I have more than sufficient tools in order to analyse the audio later and calculate the cadence from the sounds. I keep cadence solid by recording beeps at a particular BPM and playing them to myself through an earphone via my phone. Sounds rather far-fetched, but this is actually the most accurate way I know. Because a particular part of the pedal stroke is a lot louder than the rest (as your foot is closest to the mic), using my computer, you can see the peaks and create something called a "tempo map", which will allow you to see exactly how close you are to the solid cadence in the earpiece. For example, I can see that, when going up to 150 RPM, i'm almost spot on most of the time but, above that, I can go out by 3/4 RPM/BPM while trying to keep up. You can also work out average cadence extremely accurately. It also means that if you shout words like "hill 10%" or "headwind", you can hear these later on the recording and can analyse how the cadence changes with different conditions.

I'll reply in more detail later, as I don't have much time now. Going to go out in a minute to do the test again - probably around 60-90 RPM, really mashing the big gears this time.

reppohkcor

Whats that i smell??...

Pokerface

And I measure speed on my bike by putting a playing card between the spokes, recording the 'fwap-fwap' sound it makes and using advanced calculus to decipher how fast I am going. :roll:

Bhima

What can I say? I don't have money to spend on a fancy cadence system for my bike!

Ok, just been out and did the time trial to a constant beep at 75RPM. The times were 14:32 / 14:55, max speed 30.7 mph - so almost as good as 150 RPM! Didn't expect such a good result!

Legs are dead now though.

Alex_Simmons/RST

Which all just goes to show that the only sensible conclusion one can draw from the experiment is that speed is a poor comparative indicator.

Alex_Simmons/RST

will3 wrote:

Alex_Simmons/RST wrote:

will3 wrote:

I guess he must do. It's like this:
Power is torque x rpm
Hence to get the same power at lower rpm you need to prodcuce more torque.
There are two ways of doing this: use longer crank arms, or push the pedals harder.

That you cannot produce the same power at lower rpms just shows that you are incapable of pusing the pedals hard enough.

While it might sound logical, that statement does not follow the ones above.

The forces, even in such low(er) cadence high(er) gear efforts, are very low, certainly well below the maximal force (peak or average) a rider can produce on the pedals. For instance, simply accelerating from a dead stop up to cruise speed in a time frame typical for most club level cyclists requires much greater forces to be applied to the pedals.

Sorry, I should have added 'in a sustained effort', though I thought this would be obviously implied :roll:. Yes anyone can push harder for a one off than in continuous mode. I think what it comes down to is that each person's max sustained power will be at a different cadence. It seems that Bhima's is at the higher end.

I understand that's what you implied, however your logic is still flawed. He is power limited, not force limited. That is even more the case for sustained efforts.

will3

Alex_Simmons/RST wrote:

will3 wrote:

Alex_Simmons/RST wrote:

will3 wrote:

I guess he must do. It's like this:
Power is torque x rpm
Hence to get the same power at lower rpm you need to prodcuce more torque.
There are two ways of doing this: use longer crank arms, or push the pedals harder.

That you cannot produce the same power at lower rpms just shows that you are incapable of pusing the pedals hard enough.

While it might sound logical, that statement does not follow the ones above.

The forces, even in such low(er) cadence high(er) gear efforts, are very low, certainly well below the maximal force (peak or average) a rider can produce on the pedals. For instance, simply accelerating from a dead stop up to cruise speed in a time frame typical for most club level cyclists requires much greater forces to be applied to the pedals.

Sorry, I should have added 'in a sustained effort', though I thought this would be obviously implied :roll:. Yes anyone can push harder for a one off than in continuous mode. I think what it comes down to is that each person's max sustained power will be at a different cadence. It seems that Bhima's is at the higher end.

I understand that's what you implied, however your logic is still flawed. He is power limited, not force limited. That is even more the case for sustained efforts.

Yes of course power is limited, but power at any given RPM is limited by the force you can exert on the pedals at that particular frequency (it cannot be otherwise).

will3

Bhima wrote:

What can I say? I don't have money to spend on a fancy cadence system for my bike!

Ok, just been out and did the time trial to a constant beep at 75RPM. The times were 14:32 / 14:55, max speed 30.7 mph - so almost as good as 150 RPM! Didn't expect such a good result!

Legs are dead now though.

MMmmm Science!

eh

- Yes, I can sustain 150 RPM for 15 minutes. Like I said before and in a previous thread, you get very sweaty and out of breath though.

What???? Are you saying you aren't getting out of breath at lower cadences?


If you are going to post numbers here's an idea post the real ones, not some "look at how great I am" ones.

Bhima

All numbers are real. :?

I'm sure anyone could replicate what i've done if they get used to training how I train. There's nothing special about these figures...?

Of course I get out of breath at lower cadences, but not as much as the higher ones.

Alex_Simmons/RST

will3 wrote:

Yes of course power is limited, but power at any given RPM is limited by the force you can exert on the pedals at that particular frequency (it cannot be otherwise).

I think you are falling into the trap of thinking one can independently control force and cadence.

Again, the force production is not limited by the pedal speed (within reason, gets a bit tricky out at 200 rpm). The rider in question is quite capable of producing much higher forces at both very low and very high cadences. Ability to apply force is not the limiter.

will3

Alex_Simmons/RST wrote:

will3 wrote:

Yes of course power is limited, but power at any given RPM is limited by the force you can exert on the pedals at that particular frequency (it cannot be otherwise).

I think you are falling into the trap of thinking one can independently control force and cadence.

Again, the force production is not limited by the pedal speed (within reason, gets a bit tricky out at 200 rpm). The rider in question is quite capable of producing much higher forces at both very low and very high cadences. Ability to apply force is not the limiter.

I never said it was limited by pedal speed, I said it was limited by the frequency at which you are applying the force.
And see the bit in red? That's where I'm deffinitely not saying that cadence and force are independent.

Slow1972

Bhima wrote:

All numbers are real. :?

I'm sure anyone could replicate what i've done if they get used to training how I train. There's nothing special about these figures...?

Of course I get out of breath at lower cadences, but not as much as the higher ones.

The trouble is that whilst your numbers may be real, they don't actually mean very much if you are working harder when you do your 150 rpm test than your 100 rpm test. Your 75 rpm results seem to bear this out.

All you have is different times for different cadences, they don't actually tell you anything other than you get out breath before your legs tire when you pedal at 150 rpm...

eh

There's nothing special about these figures...?

Correct because all you've proved is that trying harder makes you go faster!

Oh if people want a cheap cadence meter I recommend a watch with a second hand. Cadence isn't some magically thing it's actually one of the easiest things to measure.

redddraggon

Bloody hell, Bhima's threads make the Hubmeister's threads seem sensible and intelligent.