Hour Record Rules Revisted/Revised

[twothirds]

Why are you so concerned with W/kg? It's a steady state effort. Acceleration is limited to the start and you aren't travelling up hill. Weight is a non-issue for the most part. Watts vs. cda is what matters in an hour record attempt. Because the best climbers make the best hour record riders, right?

 

[TShame]

Watts per kilogram is a standard measurement of strength. A large 6' 2" rider will produce more wattage than a 5' 6" rider. The larger rider, has a larger surface area producing more drag and thus must produce more wattage to go the same speed. However, the ratio of watts per kilogram is very similar for competitive athletes. (You won't get the same results from a short overweight weekend athlete and a tall and under-nourished giant.)

Wattage produced during climbing, as stated previously, does not translate to wattage available for flat, velodrome riding. Carlos Sastre was a good example of a great climber who was terrible in time trials (Frank Schleck comes to mind also). Yes, there are exceptions among the best gc riders. I'm not sure how. Cancellara has never climbed the big mountains with the climbers, nor Cavendish.)

 

[Alex Simmons/RST]

Watts per kilogram is a standard measurement of strength.

No. Strength is the maximal force a muscle or group of muscles can exert. Strength is unrelated to maximal sustainable aerobic power.

A large 6' 2" rider will produce more wattage than a 5' 6" rider. The larger rider, has a larger surface area producing more drag and thus must produce more wattage to go the same speed.

While that's true in general*, i.e. a larger rider has a greater coefficient of drag area (CdA), weight and CdA do not scale linearly, and so riders with similar power to weight ratios will not have the same power to drag ratios. In general*, larger more powerful riders have a higher power to drag ratio meaning they can sustain a higher speed on flat terrain than a smaller rider with same W/kg.

* while this is true in general, there are plenty of taller heavier riders with lower CdA than lighter shorter riders. Morphology and positioning matter a lot wrt aerodynamics.

However, the ratio of watts per kilogram is very similar for competitive athletes. (You won't get the same results from a short overweight weekend athlete and a tall and under-nourished giant.)

I suppose that depends on what you mean by "similar" and "competitive".

Wattage produced during climbing, as stated previously, does not translate to wattage available for flat, velodrome riding. Carlos Sastre was a good example of a great climber who was terrible in time trials (Frank Schleck comes to mind also). Yes, there are exceptions among the best gc riders. I'm not sure how. Cancellara has never climbed the big mountains with the climbers, nor Cavendish.)

IOW W/kg <> W/m^2, and on the track it's W/m^2 that matters.

 

[TShame]

It's speed that matters, not anything else, Alex. This is just what is behind that speed. Indurain was the absolute king at just over 500 watts (500-505). but Boardman did 430-440 in his 52.27 effort. Both were at 6.28 watts per kilogram. Boardman was definitely more aero, but he chose 4 spoke wheels over a double disc. (I have the same Corima wheel and while it is very fast, it can't compete with a full disc. Plus, Indurain had a super frame as I like to call them.) Boardman's second effort at 56.375 was at 442 watts with a cda of .18 and used the Lotus and the Superman position, so it is hard to compare to efforts on other bikes.

If anyone can find a wattage file from any of the hour efforts, please post a link.

 

[Bumeington]

It's speed that matters, not anything else, Alex. This is just what is behind that speed. Indurain was the absolute king at just over 500 watts (500-505). but Boardman did 430-440 in his 52.27 effort. Both were at 6.28 watts per kilogram. Boardman was definitely more aero, but he chose 4 spoke wheels over a double disc. (I have the same Corima wheel and while it is very fast, it can't compete with a full disc. Plus, Indurain had a super frame as I like to call them.) Boardman's second effort at 56.375 was at 442 watts with a cda of .18 and used the Lotus and the Superman position, so it is hard to compare to efforts on other bikes.

If anyone can find a wattage file from any of the hour efforts, please post a link.

It was 409-410W. And for the 56.375 the cdA is 0.184-0.185 by all accounts.

As an aside, Rominger needed 413W for 53km/h, he was small (65kg) but surely this should be a realistic aerodynamic goal for current record attempts

 

[mektronic]

It's speed that matters, not anything else, Alex. This is just what is behind that speed.

No it's not, you have no idea what you're doing.

 

[twothirds]

It's speed that matters, not anything else, Alex. This is just what is behind that speed. Indurain was the absolute king at just over 500 watts (500-505). but Boardman did 430-440 in his 52.27 effort. Both were at 6.28 watts per kilogram. Boardman was definitely more aero, but he chose 4 spoke wheels over a double disc. (I have the same Corima wheel and while it is very fast, it can't compete with a full disc. Plus, Indurain had a super frame as I like to call them.) Boardman's second effort at 56.375 was at 442 watts with a cda of .18 and used the Lotus and the Superman position, so it is hard to compare to efforts on other bikes.

If anyone can find a wattage file from any of the hour efforts, please post a link.

You're confusing what interactions are taking place, or putting too much importance on Watts/Kg. Power makes the cyclist move. More power makes the cyclist move faster. Resistance is what slows the cyclist down. When going up hill, that resistance is gravity and the total pull (or force) of gravity is defined with weight. The interactions are purely between power and weight, hence W/Kg. When travelling horizontally the resistance is due to air, and that is defined with drag, or cDa. Therefore W/cDa is what matters here. That two riders might have a similar W/kg measurement is coincidental.

 

[TShame]

Well, strong opinions here. which are a bit meaningless when you either break the record or not. Boardman's last record (49.4) was at 410. Watts per kilogram is better than watts per cda, unless you are looking at your own results in a wind tunnel. As I said, speed matters. Since all top track riders have similar bikes and positions, the main difference is their size. A small rider needs much less power than a large rider. Facts are facts. No need to try to debate.

What can Dekker do at sea level? and what will that translate to at altitude?

 

[twothirds]

Please explain how watts/kg is better than watts/cda when it comes to an event where aerodynamics are important and there is no elevation gain.

 

[mektronic]

A larger rider needs more watts for the same speed because they're less aero, not because they're heavier.

"No need to try to debate" LOL

 

[Alex Simmons/RST]

Well, strong opinions here. which are a bit meaningless when you either break the record or not.

I'm not providing an opinion. Physics isn't opinion. It just is.

I have coached three of the current world masters men hour records. I have a little experience at this as well

Boardman's last record (49.4) was at 410. Watts per kilogram is better than watts per cda, unless you are looking at your own results in a wind tunnel. As I said, speed matters. Since all top track riders have similar bikes and positions, the main difference is their size. A small rider needs much less power than a large rider. Facts are facts. No need to try to debate.

Boardman didn't change size much between his 49.4km and 56.375km rides and his power wasn't all that different, and hence his W/kg is very similar but clearly his W/m^2 was significantly different.

Facts are facts as you say.

As I said, speed matters.

Well yes it matters, but for the hour record what matters even more than speed are lap times. Once can go faster but have a slower lap time. Technical execution on a curved path matters as well.

What can Dekker do at sea level? and what will that translate to at altitude?

I've posted on that before, but it might be in the other hour record thread.

 

[TShame]

Boardman's watts did go down. I don't consider 442 and 410 to be "not all that different." It was at the end of his career and his back injury prevented him from being in his best form, in his own words. I agree his kg didn't change much. There's a lot of statistics for Boardman, but little for others except for estimates.

So, do you have some wattage files on your three record holders? What was their age, kg, and exact cda? and what kind of bike (old aero, new aero, superman, round tubes and spoked wheels, double disc.)

In the hour attempts, speed is based on lap times. The overall speed for the hour is based on measured distance of track's line. I'm sure you know and meant that.

At least with more standard rules of design, riders can be better compared to one another. I really wanted to see Cancellara with his old record bike attempt (which is now for all purposes, dead).

 

[Alex Simmons/RST]

Boardman's watts did go down. I don't consider 442 and 410 to be "not all that different." It was at the end of his career and his back injury prevented him from being in his best form, in his own words. I agree his kg didn't change much. There's a lot of statistics for Boardman, but little for others except for estimates.

The power to aerodynamic drag ratio (W/m^2) required for:
56.375km is ~2,400 W/m^2
49.441km is ~1,600 W/m^2

1600/2400 = 67%

Yet the power ratio was only 410/442 = 93%

So while the difference in power explains some of the difference in distance attained, the vast bulk of the gap was due to a far more significant difference in aerodynamics.

One thing is for sure, it had nothing to do with the rider's mass.

So, do you have some wattage files on your three record holders? What was their age, kg, and exact cda? and what kind of bike (old aero, new aero, superman, round tubes and spoked wheels, double disc.)

Yes, I have extensive data on my clients. I have data on others as well. Data I am permitted to share has been done so via my blog and I've provided quite a lot via case study there.

All records were set under UCI hour record rules for masters (e.g. bike regs same as for individual pursuit).

One rider attained a CdA slightly better than Boardman's superman position. But then we did spend many many hours of time at track refining such things.

In the hour attempts, speed is based on lap times. The overall speed for the hour is based on measured distance of track's line. I'm sure you know and meant that.

Yes, because that's what I said, i.e. it's lap times that matter.

At least with more standard rules of design, riders can be better compared to one another. I really wanted to see Cancellara with his old record bike attempt (which is now for all purposes, dead).

Perhaps but even before the recent rule changes there were still some not insignificant differences attainable due to tracks, equipment and clothing such that a true comparison would never be possible. e.g. I have measured nearly a 20W difference between skin suits alone, let alone track surfaces, helmet design, better positional refinement etc.

 

[TShame]

The power to aerodynamic drag ratio (W/m^2) required for:
56.375km is ~2,400 W/m^2
49.441km is ~1,600 W/m^2

1600/2400 = 67%

Yet the power ratio was only 410/442 = 93%

So while the difference in power explains some of the difference in distance attained, the vast bulk of the gap was due to a far more significant difference in aerodynamics.

One thing is for sure, it had nothing to do with the rider's mass.

You are comparing Boardman to Boardman. Of course the body is similar, it is the same person. The discussion was clearly comparing one rider to another, large to small.

Boardman's two efforts were 92.76% different by wattage. We can calculate his speed on the old bike had he been able to ride at 440 watts and compare that to Sosenska. Or we can calculate what Boardman could do on a modern pursuit bike. (We already know his bike and position with composite spoke wheels was very similar to Bobridge and his double disc wheeled bike. I thought the difference was something like 82% but either way, it doesn't really matter.) We can also calculate E.M. ride at sea level and compare all three.

I don't see the value of comparing the two very different bicycles. What does one gain from that? I already know that the Lotus with a Superman position is much, much faster even if he rode it with old style box rims and round spokes. The Lotus and position are both illegal, so it is a moot point.

What is of interest is that Boardman achieved a w/k over 6.3. (was he 70 kg,? I forgot his exact weight.) Indurain also achieved 6.3 at 505 watts for an 80 kg rider. The difference then, was due to position and bicycle technology. Both were the two best performances ever in the hour. (I don't count some rider performances but that is for 'The Clinic' forums)

I would love to see the files you posted. Got a link?

 

[mektronic]

So are you agreeing that your previous theory was rubbish yet?

 

[Alex Simmons/RST]

You are comparing Boardman to Boardman.

Because it very clearly demonstrates that mass isn't the issue you kept making it out to be. Power and aerodynamics are what matters. Thankfully that seems to have been understood.

You can see my blog here although not everything I've written on this topic is there.

Enjoy.

 

[Alex Simmons/RST]

The Lotus and position are both illegal, so it is a moot point.

The point is to demonstrate that aerodynamics matters a lot, mass not so much, only in as much as being larger usually means more drag, but it's not a linear or consistent relationship from person to person.


As an aside, I note that Boardman's pursuit record was not scrubbed from the UCI's record books like the hour record was (it remained until Bobridge broke it in 2011) despite the same bike set up being used.

If the UCI were consistent, then when the hour regs changed back to using pursuit bikes, then so should have Boardman's hour record been reinstated as it was ridden on the same set up as his pursuit.

 

[memyselfandI]

Dekker looks good on tracktraining pictures. Position looks really good, hopefully he can keep it 'til the end. I'd say way better looking than JB and par with Dennis. Bike looks good too, is that completely stock bike?

Interesting package in a way Dekker is, longish skinny, big organs = good w/m2, hard life..bit questionmark if traing/racingload is enough compared Dennis et al, so that engine is roaring all out?

 

[TShame]

I'm sure in your mind you are proving some point even though the thread was about comparing one rider to another rider of a different size or at a different altitude.

Doing some quick rough estimates, Boarman may have ridden 54.25 km if his wattage decreased to 410 while riding the Lotus. Or, his old bike ride may have been as high as 50.65 if his wattage had still been up to 442. Pretty substantial differences. But, he did what he did. If he did his 52.27 ride with a full front disc wheel, he goes somewhere between 52.41- 52.56. That would put him right about at Rohan's ride.

While Dekker is looking good to break the record. I'll be calculating what it would have been at sea level. Then we'll see how his performance stacks up.

 

[mektronic]

While Dekker is looking good to break the record. I'll be calculating what it would have been at sea level. Then we'll see how his performance stacks up.

Your numbers are so good so far I can't wait to see what you come up with!

 

[Alex Simmons/RST]

I'm sure in your mind you are proving some point even though the thread was about comparing one rider to another rider of a different size or at a different altitude.

It started with your significant overestimation (by well more than 10%) of Denis's power:

Rohan opened up with his first 7k at about 450, then upped it to about 460.
Overall, probably right around 445-450.

which when challenged you were somewhat surprised to learn that someone could go faster on the same or less power or power to weight ratio:

I'm not sure how I am wrong. So, Jens Voigt did 410-412 and went 51.15K but Rohan only managed 400 and went 52.49? There are lots of riders who can do 400 watts. That sounds incredibly low, or are they much smaller than average?
Boardman was pretty small. His record took only 440 watts compared to Big Mig's whopping 500 to do 53K. But their watts per kilogram was almost identical.

and from this it was clear you had conflated the relative importance of W/kg and W/m^2, as well as misunderstood the relationship between the two, which was further compounded here:

Watts per kilogram is a standard measurement of strength. A large 6' 2" rider will produce more wattage than a 5' 6" rider. The larger rider, has a larger surface area producing more drag and thus must produce more wattage to go the same speed. However, the ratio of watts per kilogram is very similar for competitive athletes.

Well, strong opinions here. which are a bit meaningless when you either break the record or not. Boardman's last record (49.4) was at 410. Watts per kilogram is better than watts per cda, unless you are looking at your own results in a wind tunnel.

So let me spell it out in case you missed it.

Speed sustainable in a velodrome is primarily a function of a rider's W/m^2 and air density.

Which is why riders with similar W/kg end up riding at significantly different speeds.

Pros have widely varying CdAs. Some larger riders actually have equal or even lower CdAs than some smaller riders. That might be hard for some to understand, but aerodynamics is pretty complex, yet the outcomes are pretty simple.

As a non-pro example, I have a mate who is same height, weight and power output as me (when we are race fit). However his CdA on pursuit bike is 30% less than mine (and I've worked on both of us to optimise aerodynamics). Which is why he makes the podium at worlds and I don't even qualify for a state final.

Some riders are aerodynamically gifted. When they are also power gifted, well you have a cracking combination for TTs. If they are also W/kg gifted, well then you have a GC rider.

 

[memyselfandI]

My out of space guess is Dekker's CdA runs somewhere between .2375 and .2400. Means that for new record he must have 430-440w average power, at Mexico?

 

[Alex Simmons/RST]

My out of space guess is Dekker's CdA runs somewhere between .2375 and .2400. Means that for new record he must have 430-440w average power, at Mexico?

~1,650W/m^2 give or take.

 

[memyselfandI]

Your thoughts about CdA of TD with that position and size and Fuji-bike? Less than .2300? His position look maybe just slightly better than RD but is it too deep for him. And somehow I think that TD have more challenge holding perfect line, than superb trackie like RD, which can affect alot too.

 

[Alex Simmons/RST]

Your thoughts about CdA of TD with that position and size and Fuji-bike? Less than .2300? His position look maybe just slightly better than RD but is it too deep for him. And somehow I think that TD have more challenge holding perfect line, than superb trackie like RD, which can affect alot too.

The eye makes for a poor aero meter. Having performed aero tests on many riders, I've learned that initial eyeball estimates are hard to get right. Aerodynamics really is one of those things with so much underlying complexity that measurement is really the only way to know.

I'm definitely not aero gifted, and when at ~78kg / 182cm I attained a CdA of ~ 0.235m^2 on my pursuit bike, so I figure slimmer pros with better set up and equipment than me should be able to do somewhat better than that. But not all can or do.

End of the day, Dekker can either sustain the necessary lap splits* or he can't.

He'll have been there long enough to figure that out beforehand, or know he's close enough that it'll come down to day to day variability in human performance and environmental conditions.


* laps splits being the integral of all the elements that matter