World Championships 2019 - 19-21 July - Nandax - France

[LarryOz]

Here is the first video I shot from my bike the day before the racing began. We were supposed to tour all the race sites. They were in different towns maybe 6-10 km apart.
tour of area and sprint site and Nandax:

 

[ed72]

My HR averaged 177 for the nearly 17 minutes it took me to do the climb, maxing out at 187bpm - I could not have really gone much harder.

Great effort and great race. Congrats. Travel, heat, excitement isn't easy on the system.

I wish I had your heart rate. Astounding. I make 240 watts at 130 BPM HR. I need a turbocharger or maybe I am just a diesel.

 

[LarryOz]

Didn't want to start a discussion about geo, this is definitely not the place. I'm just sorry there was no opportunity for Larry to test ride bikes in the homeland of the Traction Directe. Comparing different concepts gives ideas and insights that can hardly be foreseen theoretically.

Yes, I really missed not being able to try a few things that were different. Most MBB bikes were not that adjustable - but I should have been a little more pro-active in searching out that ones that might have fit me and asked to try them. Maybe next year!

 

[LarryOz]

Here is my video of the 5Km Hill Climb race:

As a comparison, check out the overall winner (Richard) in this velomobile - just incredible - be nice to have that kind of power!

 

[ed72]

Larry, something is wrong. Either the gradients were higher or your brake was dragging. At 4% and 240 watts, you should have been doing at least 13 mph and not 11 mph unless you got as fat as me (198 lbs). If you plug the numbers into an online calculator like Gribble, you'll see what I mean, there is 40-50 watts missing. Nerdy me has a look-up table memorized for speed vs gradient vs power and your power vs speed vs gradient was perhaps a touch worse. I am being serious.

 

[ak-tux]

Larry, something is wrong. Either the gradients were higher or your brake was dragging. At 4% and 240 watts, you should have been doing at least 13 mph and not 11 mph unless you got as fat as me (198 lbs). If you plug the numbers into an online calculator like Gribble, you'll see what I mean, there is 40-50 watts missing. Nerdy me has a look-up table memorized for speed vs gradient vs power and your power vs speed vs gradient was perhaps a touch worse. I am being serious.

Maybe there needed to have been a few days of acclimatization period for Larry?

 

[Supertramp]

For comparison: about 2:23 into your video you come up to Jürgen (black and white jersey, rear wheel cover) who rode his Baron with power meter and finished 4 places behind you.
https://www.strava.com/activities/2555228414/analysis

 

[LarryOz]

Larry, something is wrong. Either the gradients were higher or your brake was dragging. At 4% and 240 watts, you should have been doing at least 13 mph and not 11 mph unless you got as fat as me (198 lbs). If you plug the numbers into an online calculator like Gribble, you'll see what I mean, there is 40-50 watts missing. Nerdy me has a look-up table memorized for speed vs gradient vs power and your power vs speed vs gradient was perhaps a touch worse. I am being serious.

When I was actually riding the hill climb my road gradiant % was usually showing 5% (and I think the avg grade was close to 5%. (Doing the math - 738'(if you can believe strava) climbed for 3milea (=15849') = 4.66% grade . On my data for the video it seems lower than actual for some reason.
Either way I was slow - be nice if it could be explained with a brake rub - but oh that would be a bummer. Marco - I averaged 285 watts and climbed it at 12.8mph (I think we both weigh about 155-160 lbs) Odd that he only records it as 2.90 miles



and mine in 2.97 miles (he might have cropped it too much). I hit my lap button at the start and end, then copped it. Marco averaged 50 watts more than I, and 2.1mph faster. HR were about the same. His bike is more aero, but not sure that matters at 12mph. That "seems" to make sense, but I have not run the "math"

 

[ed72]

Maybe there needed to have been a few days of acclimatization period for Larry?

I don't know. Maybe. From all the videos of Larry with power, one suspects 290 watts for 12-13 minutes would be more like his normal off say an FTP in the 265-270 range although I suspect it is higher. Not 240 watts for this climb. Heat had to be a huge factor. Strava showed 99F.

The question that I was relating is different. His speed for given actual power seems off or it was more than 4% gradient. In other words, his speed should have been higher. Head wind (12-13 mph approx.)? Brake drag? The course rose 700 feet in 3 miles for an average gradient of 4.45%. I also checked ToPo maps. That is very close to the actual gradient. If Larry and V20 weighed 185 lbs together, it should have taken around 200 watts for his race time of 16:59. His comment on the video about it felt like his brake was dragging or something like that in conjunction with his power, speed, and indicated gradient got me to observe that his speeds were similar to tubby me. I would have guessed more like 14:40 for his time (at the actual race power) and if he was at his best with a clean start and normal power, more like 13 minutes or a touch less. BUT...that's racing. Great overall results nonetheless

Note/Edit: I had typed this out before seeing Larry's post above.

 

[LarryOz]

Next up my pitiful 200M and 2m sprints video.
Video is worth it just to see the huge array of bents at the end of each event.
Sprint videos:

working on the 3hour race video next - it my take some time. It is not a quick process merging all the files and data and annotating everything.
As an extra bonus: Here is my crash video from last Saturday during the 50-lap race at Northbrook:
short crash video:

entire 50-lap race:

 

[markciccio]

Actually, Larry's power seems to be correct.
Please follow me, I know it is a bit complex or there may be some mistakes...

This is a part of an excel table where I have put some datas of some of the riders, form the Strava activities, trying to get out some interesting conclusions.

I have put both the "gibeau climb" segment (the first part of the climb) and the whole climb , the "Salita Jarnosse Campionato mondo" in the table. Unfortunatly I have not the whole Strava segment of my ride recorded so I have entered just the whole strava activity, the same for other riders like Marvin Tunnat. Some of the weight values are hypothesized.

The value "W Ambrosini" is the teorical power that a rider on a traditional 7kg bike should put into pedals to complete the climb. The important column is the "W/W ambrosini". The less the better. Because it means that our recumbent bike is better than a DF bike of that fraction of value. As you see me and Larry have nearly the same value (0.93) meaning that our bikes on that path are very similar in performance. In other words, if we could ride a7 kg diamond frame bike, with the same power we have put in the recumbent, we had to put more power (7%) to have the same average speed of the recumbent. The exact value is 253W for Larry (he reached 236W in the Vendetta) and 306W for me (I reached 285W in my HTH). So he was slover but according to the theoretical performance.

There is also an other column that can be analysed: the W/ km/h. It means that you need those Watts for every km/h of average speed. Of course if you need less, your bike is ligher and has more efficiency, on that segment. The less, the better. As you see Larry has a 13.64 value while I have 14.039. That means Larry's "rider+bike" performance is a little better (3%). I hypothesized Larry's weight but I think it is nearly correct. But we must say that if a rider has a higher speed, the drag increases with the square of the speed value and in this way can be explained the better value of the Vendetta vs the HTH. That's because a prefer the W/W ambrosini value to make comparisons because it is independent on average speed. Actually to have a perfect comparison you should climb with the same speed and then see how much the average power was...

As you see is very intersting the DF XL value: Peter Coppens needed to put at list 17% power more than me to have the same performance (we have nearly the same average speed so it is well comparable). Than there is Marvin Tunnat, with his incredible Troytec, with only 12.61 W per km/h, 8% better than the Vendetta! But I think that the Strava value is not correct because the official average speed was 23,7 km/h and not 27....

To compare these values on an other segment, you can see the same values for the first part of the climb, the "giebeau from jarnosse". You can see very similar values but the Troytec has much more similar values to the other bikes and that confirms that there is something wrong on Marvin's Strava activity.

As you can see, the W/W ambrosini is, for all the riders, arount 0.85. Good recumbents are better than traditional bike by 15%. At least on that route.

I will make a video about this data analysis soon, I hope it may be of interest.

 

[ed72]

The value "W Ambrosini" is the teorical power that a rider on a traditional 7kg bike should put into pedals to complete the climb. The important column is the "W/W ambrosini"

How did you calculate the theoretical power?

I used Gribble with assumptions of 185 pounds for the bike and rider, Rho of 1.16 kg/m3, Crr of 0.005, CdA of 0.160 m^2, and 1% drivetrain losses. 17 km/h corresponded to 200 watts using Gribble. A 20 km/h headwind would bump the required power to 240 watts or thereabouts.

Were the power figures in your table estimated by Strava or actual numbers from a power meter? (Strava's estimates are usually wrong). Many/most riders on Strava do not use a power meter and Strava puts an estimate for their power. Unless the power listed in Strava has a "lightning bolt" next to it, that power figure is an estimate and is terribly unreliable.

What is not clear is how you established the W Ambrosini power.

https://www.gribble.org/cycling/power_v_speed.html

 

[markciccio]

I use this formula:

pW = [[P*(p / 100 +a)+(KS*v*v)]*v]*9,81

See also here:

http://forum.cicloweb.it/viewtopic.php?t=5573

https://www.rivaluta.it/ciclismo/watt.asp

The formula calculates the power with the real weight of the rider (or at least estimated by me the best I could) and 7 kg, as for the bike. Aero coefficient and others are in the links above. It is a very efficient formula, I made many tests with my upright bike and values were always very close to the ones of the power meter. It calculates the power of an upright bike, not a recumbent or something different. My aim is to compare the performance of a traditional bicycle with the others. So all the coefficients in the formula are the ones of a traditional DF bike.

I used the Strava power data but only on the riders that really use power meter. Strava estimates values that are very far from the real. So it is easy to undestand if they are fake or not.

On the other hand, I am sure Larry uses a power meter and also Peter Coppens, Jo Stein, Geoffry Lelieve and of course me, because you can see here the lighting bolt on those riders in the list:

https://www.strava.com/segments/7173938?filter=overall

I am sure that Marvin Tunnat used the power meter during the first and the second day. See here:

https://www.strava.com/segments/16759078?filter=overall

He did not uploaded any data on sunday race. As for Stijn Van Der Maele, he is the only rider that I am not sure about how and when he used the power meter. Eventually, we may not consider him.

I have made some videos about these topics but they are all in italian:

Next videos about this topic will be translated or subbed, I promise...

 

[ed72]

Aero coefficient and others are in the links above.

0.45m^2 CdA for upright is very high in theory and in practice for an experienced racer. Air Density of 1.22 for actual conditions at 90-99F is virtually impossible.

Your second link

a = friction coefficient, set at 0.01 for asphalt in good condition
KS = typical aerodynamic coefficient, set at 0.021

We used different values for key performance attributes. I have never measured such horrible coefficient of friction...??. The magazine's and online pundits report superlow values of around 0.0028, I usually measure around 0.0045 for my roads and tires but used 0.005 for this exercise. I had written my assumption of Larry's CdA, which was based upon observation of his TT values and something that he had written. His CdA is clearly not 0.21. Air density is also a critical factor and using a default of 1.22 creates a large error. Initial conditions and assumptions matter.

I stand by my opinion. It is easy to plug real numbers into Gribble. Sorry.

 

[ed72]

My mental lookup table is pretty simple.

10% slope at 250 watts equals 5 mph.

Linear interpolation for all others. (aero effects ignored at that speed)

How is this useful? If I am climbing a 10% slope and it turns upwards and my power to maintain 5 mph is now 350 watts, I have incurred a 40% increase. Since I have an anaerobic reserve of 28kJ over FTP, I know I am toast in 400 seconds and therefore have a a pacing decision to make. Sometimes, I get out the 24 inch gear.

 

[LarryOz]

As for Stijn Van Der Maele, he is the only rider that I am not sure about how and when he used the power meter. Eventually, we may not consider him.

I talked directly to Stijn - he does not use a power meter

 

[markciccio]

My idea is not to predict average power of recumbent. I have the power meter and I trust it and for every one that has a power meter, I assume it is accurate.

My aim is to compare an "ideal" traditional bike to different kind of recumbents. The Ambrosini formula simulates very well a standard upright bike. In all my tests my Assioma power meter values are very close to Ambrosini values, especially with my Trek Emonda upright. There was a max of 2-3% difference between real and expected data.
So, every time I make a strava segment, I can compare my performance to the one I could reach in a standard bike, even if I have not one, using my excel table. And every now and then I directly compare, see for example:

The excel table works like that. For exaple, if Larry had ridden a 7 kg upright on the first day race course, how much power would he had to put more (or less) on the pedals, instead of using his Vendetta? The answer is: he would have put 7% more power on the pedals in that 5 km sector (0.93 W/W Ambrosini).

In the study case, me and Larry have the same values (0.93 in the 5 km sector and 0,85/0.86 in the first sector of the climb,which confirms the data above) . That means that we both have a similar bikes and similar performance. And that power meters were correctly working.

What is the reason I make all these comparisons? Because I want to see where and when recumbents are better than traditional bikes and, in parallel, this let me compare different types of recumbents.

For example I want answer the question: on the championship 3 hour course, it was better to use a velomobile or a recumbent to set the fastest time or to spend less energy during the whole competition?

This is possible even without "Ambrosini" values. See for example this:

These are some data of a single lap of the 3 hour championship.
I have taken the ones that are near to 33 km/h average speed. If you have the same speed, you can see the average power needed. The less, the better bike.

This let me compare bike performance (and not rider). Because you can generally compare two bikes that ride with the same speed or with the same power. In this case it is easier to take data with the same speed.

What I see is that the average power used by riders are: 179W for Larry, 153W for me, 190 for Peter in the velombile, 174 for Geoffry in the Zokra. Unfortunatly Jo has not set a 33 km/h average speed lap, so I have to compare a 35,3 km/h lap, with 240W (of course he had an higher power but how much higher?) .

So, what I see is that, for that course, the HTH is a little more efficient because I only needed 153W. Larry needed 179W (15% more).

And this was not the performance of a single lap. Infact at the end of the race me and Larry had very similar average power (and also heart rate and infact we have nearly the same FTP at the same heart rate, and that confirms that power meter data are right). But my average speed was 34 km/h and Larry's 31 km/h. If you see the W/W ambrosini data, you see the same values. The HTH has a 0,64 performance, while the Vendetta 0,75. The DF XL was worse, meaning that, on that course, probably, it was better to ride a recumbent than a velombile. Jo Stein effort is even better, because his valute is the worst of all (0,87). So we can say that he had probably the worst bike but the best legs.... Probably, if he had set a 33 km/h lap, the value could be 0,80 but not less.
I repeat, this is my way of comparing bikes because I want to know how bad or good is my bike compared the others, and so I can try to improve its performance in the condition where it is worse.
I think it can be useful in some way but I also undestand it is complicated and maybe not to intuitive (or maybe there may be better ways to analyse bike performances).

 

[LarryOz]

And this was not the performance of a single lap. Infact at the end of the race me and Larry had very similar average power (and also heart rate and infact we have nearly the same FTP at the same heart rate, and that confirms that power meter data are right). But my average speed was 34 km/h and Larry's 31 km/h. If you see the W/W ambrosini data, you see the same values. The HTH has a 0,64 performance, while the Vendetta 0,75. The DF XL was worse, meaning that, on that course, probably, it was better to ride a recumbent than a velombile. Jo Stein effort is even better, because his valute is the worst of all (0,87). So we can say that he had probably the worst bike but the best legs.... Probably, if he had set a 33 km/h lap, the value could be 0,80 but not less.
I repeat, this is my way of comparing bikes because I want to know how bad or good is my bike compared the others, and so I can try to improve its performance in the condition where it is worse.
I think it can be useful in some way but I also undestand it is complicated and maybe not to intuitive (or maybe there may be better ways to analyse bike performances).

This is all so fantastic (and accurate from what I can) Marco - you have done an excellent job!

 

[LarryOz]

Here is my video of the 3-hour race from my Vendetta.
I am sad to say that the battery died about 10 minutes from the end so missed that part.
That is sad, as it was probably the most exciting part as I rode very fast and passed many other riders during that time.
Enjoy it: Best watched while you are on your training riding - Turn the lights off and you can feel like you are there riding with me!

 

[cpml123]

Someone posted this video of the race. Larry is in parts of the video. So is the bamboo MBB recumbent bike. Pretty cool!