If you look at track cycling, you will notice nearly everybody in pursuit or team pursuit is moving to mantis. Same for Hour Records. With the limit of UCI rule (10cm maximum from bottom of pad to top of bar).

Because it is more efficient aero.
And with power output very high (around PMA for individual pursuit, and burst to 150% of PMA for team pursuit).

And look at the shoulders : no much rock and roll
OK, RPM are higher, but force on pedal is still higher than in TT or Tri
If you rock and roll shoulders on track, someone will quickly explain to you that you need to work on your core.

Maybe mantis make R&R shoulder more difficult, then is a problem if your core is not strong enough ?

I don't do anything longer than a 40k. The longer the effort is, the less power you apply and the less you'd need to stabilize with your arms and shoulders. But I don't see mantis being deterrent to that anyway. All the KGF guys used mantis for team pursuit (~4 minute effort). The most popular TT in the UK is 10mi.

My forearms are at ~30 degrees currently.


You don't need a "solid core". Gravity takes care of it. At 90rpm and 300W the peak force is typically ~80lbs. And all of that is close to straight down. So long as weight on your saddle is more than that, you won't "lift off". At high outputs I pedal faster, so the power output needs to be >600W before I need to do any overt stabilizing. Sure in a sprint you need to bring the rest of the body into play, but we aren't talking about that.

By "poor fit" I mean you aren't stable in the saddle. Usually your pedal stroke is tending to make you slide off the front, so you have to constantly counteract this with your arms and shoulders. Seems to me like you should be able to let gravity do the work by moving your elbows forward a bit, and if anything I'd expect tilting the forearms and pads up would help. So I'll ask a 3rd time; exactly what forces do you need to apply in order to stabilize?

  
Ok. I think I might have this figured out.

I did a test the last two days on the indoor trainer. For reference, my FTP on this device is around 260 watts. So I did a fair effort, but nowhere near max.

Trial #1 Mantis Position
Elevation: 2200 feet
Temp: 70 deg. (no fan)
Avg Power: 240 (erg mode)
Duration: 40 minutes
Avg. HR: 141

Trial #2: 10 deg aerobars (same drop &etc. as Trial 1)
Elevation: 2200 feet
Temp: 70 deg. (no fan)
Avg Power: 240 (erg mode)
Duration: 40 minutes
Avg. HR: 140


So really no difference. That contrasts with the limited tests I've done outdoors, where I have felt like there's about a 10-15 watt power difference.

I have a theory, but am interested in what you guys think is going on....


Hint #1:

Here's a photo of my t-shirt after the workout:




Hint #2

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My latest book: "Out of the Melting Pot, Into the Fire" is on sale on Amazon and at other online and local booksellers

I don't think core strength has anything to do with it. Rather posture and technique. The core muscles aren't getting used enough to fatigue in other words.

It was explained to me by competent peoples (national staff coaches, ex pro, ...)

Basically, when pedaling with some strength, if your core is not strong enough, you tend to compensate this lack of core strength using your muscular chain arms/shoulders/torso, creating tension in arms, shoulder, torso, and this create torso move left/ride.

This is why, to work core on the bike, coaches recommend to work force (slower RPM) with the hands just put on the bar, with no force in arm and shoulders, arms and shoulders totally relaxed.

When capable of pushing big gears with no tensions in arms / shoulders / up-torso, because core is strong enough, torso moves disappear, and you can move to mantis without power penalty.

 
Hmm. No takers?

Suppose I repeat the two trials (mantis & non-mantis), except I have a giant fan raised to point level at me. Do you think the results would be different?

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My latest book: "Out of the Melting Pot, Into the Fire" is on sale on Amazon and at other online and local booksellers

I can't believe you are doing efforts like that without a fan in the first place! I don't have any idea why you'd lose power outside, but supposedly not while overheating on the trainer.

I say again forces to hold a position that you can drive the pedals around and by creating a solid foundation I relied less on my core and was more efficient. I found it best to hold me in position as gravity isn't doing it for me. You accept at higher power you need a strong core and foundation and that filters down to racing is common sense. Of course you need a strong core in cycling and triathlon. Why would your pedal stroke try and slide you off the front of your saddle? That sounds like a poor fit or wrong saddle? If you take note of what I have said all along I found at lower power such as an IM as my core fatigued I lost power and I lost peak power with raised hands until I locked in the front end. In training and up to race pace I could produce normal power but I rely on core not that solid front end to generate my power. That is what I have found ok. Maybe you haven't?

Have a look at the last Olympics and most of them are doing what I sound fixed the problem including Martin who has gone more mantis having cocked wrists to tense the front end. They also have pads away from elbows to create fulcrum and lever on the bars to generate power pushing down at the elbows and lifting at the hands. Cancellara has gone the extreme and won gold I might add has pads in front of elbows and hands lower than elbows in the examples I showed with Evans and Ullrich. They are all keeping a tense front end to generate power. There front end is not relaxed and gravity taking course...

https://www.ridemedia.com.au/features/tt-tech-observations-from-the-olympics/

Are you moving your torso left/right after 2 or 3 hours at race pace ?
Are your arms/shoulders/up-torso "tense and working" or "relaxed" after 2 or 3 hours at race pace ?

I agree you need a strong core and as you get more mantis I find it harder to create that solid foundation but as I have said that I found by cocking my wrists to tense my front end locking my shoulders I don't have to rely on my primary core muscles to hold position so much which at lower power than these guys fatigue over an Ironman. I agree 100% with you. Pursuiters are only riding 4min so maybe get away a bit more but I am sure they have all the experts to develop a solid foundation and not using generic bars. I see Team Sky have the lower hand to cock their wrists as do many track riders that I found helped me.

https://www.shopforwatts.co.uk/collections/all-products/products/custom-carbon-aero-extensions

I feel like I have to autoquote one of my studies in order to explain some basics about cycling and Newton's 2nd law (sorry!):


Basically:

- 3 main vertical forces exist in cycling (applied on the pedals, applied on the handlebar, weight on the saddle)

- the harder you push downward on the pedals (higher power/lower cadence), the more reaction force in the opposite (upward) direction you get. Think about a jump: the harder you push on the ground, the higher you will jump... Once you exceed your bodyweight!

- the upward reaction force on the pedals can commonly exceed the weight on the saddle

- if you want to stay seated and/or stable on your saddle, you have to either 1) pull on the controlateral pedal 2) pull on the handlebar 3) accelerate your trunk downward

Hope this helps!

Full paper published in the Journal of Biomechanics here for those interested:https://hal-laas.archives-ouvertes.fr/hal-01663013/document

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- Antony Costes -
PhD in Biomechanics / Professional Triathlete (9 pro wins)

"If you cannot measure it, you cannot improve it."
Lord Kelvin

Like I said, that is posture and technique, not strength. People don't move around because their core is weak, but because they aren't trying to use their core to restrict motion; or the motion feels natural. You see variations in this because people develop different habits, probably stemming from when they learned to ride.

I don't think it really matters. Some very good TTers move around quite a lot.

Thank you Antony someone in extreme mantis and highly knowledgeable on this now Rruff may actually take note and listen?
Thanks for your input.

I wanted to test a theory.




When I ride outside in a conventional position, I have a 25-30 mph wind blowing from my neck all the way down the front of my torso. Not so when riding in the Mantis position. The wind is deflected off the aerobars and my arms to a large degree.

When I did the recent field test, even though it was fairly cool, I noticed the front of my skinsuit was quite wet afterwards. I'd never noticed this when riding in a conventional position, presumably because the greater airflow was drying the front of the skinsuit (and cooling me off)

Evaporative cooling makes a big difference, particularly at 70 degrees (or hotter) in the dry western US, like where I live. If you're racing in the UK, where it's 50 degrees and 90% humidity on a good day, it's not much of a factor.

So I'd bet you dollars to donuts, if I repeat the trial outdoors, or indoors with a big fan, there will be a significant disparity in average heartrates between the mantis and conventional positions. And that difference will be due to differential rates of cooling, not bio-mechanics.

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My latest book: "Out of the Melting Pot, Into the Fire" is on sale on Amazon and at other online and local booksellers

I'm amazed he didn't clip a pedal - he corners inside foot down -

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Are you ready to do an Ultraman? | How I calculate Ironman race fueling | Strength Training for Athletes |

Just goes to show how far you have to lean it to clip pedal. That wasn't even close to the leans in crits. Impressive descent though!

I will ask the question. When you first went to your 'mantis' position did you lose power initially? If so how did you adapt to ride as well as you can now and obviously generate solid power? Are you pulling down from the hands or cocking your wrists to tense the front end to pull on the bars? If you care to read my posts I found I lost that solid foundation to pull on the bars as my hands went up and you are the most extreme out there.

 



https://www.ncbi.nlm.nih.gov/pubmed/28985477

https://www.ncbi.nlm.nih.gov/pubmed/21214352

https://www.ncbi.nlm.nih.gov/pubmed/27571045

https://www.ncbi.nlm.nih.gov/pubmed/1490985

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My latest book: "Out of the Melting Pot, Into the Fire" is on sale on Amazon and at other online and local booksellers

Bonjour Antony

amusant de se croiser sur un forum américain alors que l'on est tous les deux du sud ouest (je suis né a Cahors).

Congrats for your race in Kona, it was great. See you in the main group during bike was really excellent news for french triathlon !
It was also great exposure for the Morftec, as you look so aero and different.

I would love to know your CdA with the Morftech, but I guess it is confidential. 0.195 ? (just trying :-)

Personnally (much lower level than you are) I ride at race pace really relaxed on the hand and arms and shoulders (was the same in pursuit), so probably keep stabilized pulling on the other pedal, or just locking the hip with the core (less pressure than my weight on the working pedal).
I can raise my hand very high, it doesn't impact my pedaling mechanics, apparently. Good candidate for the MorfTech.
Is it commercial yet ?

Maybe you should read the report. He's talking about forces so great that you naturally stand on the bike. That isn't IM cruising speeds. And if Mantis interfered with his ability to "generate power" why do you think he uses it?

Mate read what he wrote...

Basically:

- 3 main vertical forces exist in cycling (applied on the pedals, applied on the handlebar, weight on the saddle)

- the harder you push downward on the pedals (higher power/lower cadence), the more reaction force in the opposite (upward) direction you get. Think about a jump: the harder you push on the ground, the higher you will jump... Once you exceed your bodyweight!

- the upward reaction force on the pedals can commonly exceed the weight on the saddle

- if you want to stay seated and/or stable on your saddle, you have to either 1) pull on the controlateral pedal 2) pull on the handlebar 3) accelerate your trunk downward

Note 'the common reaction force on the pedals commonly exceed the weight on the saddle.' Commonly not unusually and not in reference to the study. Hence you need to pull on the handle bar as I have been saying not just support your weight that your pedal stroke will not exceed as you have been claiming.

I was asking him to explain if it did and if so there was a way he overcame it. You've already been proved wrong so let the expert and man I asked answer if he wants to.

In the summer, avg high in London is 78F and probably humid. Humidity greatly inhibits the ability of the body to reject heat via sweating and evaporation. I'll take dry western US air any day!

The studies you referenced were about cooling in excessively hot environments. If you aren't flirting with your bodies temperature handling limits (core temperature rising) I don't think you'd suffer a power loss in either position.

I suggest you look up the forces applied to the pedals at typical racing speeds. Your constant assertion that you need to crank on the bars with your arms in order to pedal is plain silly. Sure if you weigh 100 lbs and can do a 112mi TT at >400W you may generate enough force to lift off the saddle, but I doubt that is what you are experiencing ;)

Antony

also noticed the strips on your left calf.
Move the boundary layer from laminar to turbulent to reduce calf drag ? Same principles as "picot" vortex generation, but in linear form ?

In St Georges you had some calf compression kit with a strip at the same place also ? Commercially available ?

Mate in you opinion not engineer Antony it seems you disagree with? Thanks for adding nothing to what I am hoping to get answered yet again. I am wanting to create a solid foundation to the front end and rely less on my core for stability. It all trickles down from producing large power to racing power you need it for efficiency. Maybe tonking along on an easy training ride not so much. I am basing all this on my findings not crap you probably read on this forum and are now an expert?