The Optimum Hip Angle for Maximum power?

[ak-tux]

I came a cross this interrestting study https://digitalcommons.brockport.edu/cgi/viewcontent.cgi?article=1093&context=pes_facpub

It shows that a hip angle of 75 deg relative to the line parallel to the BB is the most optimum for power production.

Having also read some tests and studies by Marcociccio (Marco Ruga) he seems to concur that a seat angle of around 37deg and a botttom bracket just about the same height or only slightly higher than the lowest part of the seat will result in the highest climbing power.

That means the S40 and the older S30v2 are in the ballpark and in theory, if properly fitted without raising the BB too high and the component weights kept as low as possible, should be the best climbing cruzbikes around.



And talking about fit, Maria @Maria Parker , below has the finest fitted S40 I've seen todate. The BB position and the arm extension is textbook stuff!

 

[MrSteve]

You're right when your bike fits you and works most efficiently with you.
Plus, it's your bike that, hopefully, fits you.

My bike is not set up to work well with anyone else, so for my bike, these
'optimal' numbers are sub-optimal.

 

[LarryOz]

And talking about fit, Maria @Maria Parker , below has the finest fitted S40 I've seen todate. The BB position and the arm extension is textbook stuff!

Any that is why "she" is the "so stinking fast" - Maria is the Queen of Cruzbike.

This also matching the testing I did back when I has a Silvio 2.0 and a Vendetta 2.0. I could make so much more power on the Silvio. Problem is "aero is still King".
Further confirmed when I built up "Frank" last year for a record attempt. I was had a nearly flat seat, and it was oh-so-hard to make power. I could make 200watts or 5-hours on my V20 at the time. On Frank, I was toast after about 2 1/2 hours at 200 - then I died. By the end of my record attempt near for hours I could barely pedal 150watts!

Yes - Maria may be "Queen", but aero is still "King"! haha. Yeah she is aero too - if you look at her on her V20!
Solution - Vendetta for the flats and downhills, and Silvio for the climbs!

 

[ak-tux]

Any that is why "she" is the "so stinking fast" - Maria is the Queen of Cruzbike.

This also matching the testing I did back when I has a Silvio 2.0 and a Vendetta 2.0. I could make so much more power on the Silvio. Problem is "aero is still King".
Further confirmed when I built up "Frank" last year for a record attempt. I was had a nearly flat seat, and it was oh-so-hard to make power. I could make 200watts or 5-hours on my V20 at the time. On Frank, I was toast after about 2 1/2 hours at 200 - then I died. By the end of my record attempt near for hours I could barely pedal 150watts!

Yes - Maria may be "Queen", but aero is still "King"! haha. Yeah she is aero too - if you look at her on her V20!
Solution - Vendetta for the flats and downhills, and Silvio for the climbs!

If you were to ride an 80 to 100 mile route with mixed terrain, some steep short 10%+ climbs and long moderate 4-5-6% climbs and some flat sections in equal messure, which do you think will have a better time with all else equal? Silvio-S30V2, S40, or V20?

 

[LarryOz]

If you were to ride an 80 to 100 mile route with mixed terrain, some steep short 10%+ climbs and long moderate 4-5-6% climbs and some flat sections in equal messure, which do you think will have a better time with all else equal? Silvio-S30V2, S40, or V20?

If you are talking 40 miles of 4-6% climbs then I would probably go with S40. That is still a lot of climbing and long 6% climbs on a V2o would really wear you down.
I also think that adaptation would come into it a little bit. i.e. If regularly rode lots of miles on the 4-6% climbs, then you would most likely get more efficient on them.
What you really need is an nice adjustable seat on the Vendetta (some have made them) - that you can change on the fly. (this might be one of my winter projects). Then you pop it up for the uphills, and lay it back for the flats and downhills!

 

[tiltmaniac]

With handlebars set "correctly" you can also sit up to change the hip angle.

I did this quite a bit during my tour-of-the-east-coast on the S30. I used the normal laid-back position for everywhere but the really steep stuff, and for that I'd be sitting up with chest rubbing (but not pushing) on the handle bars.
This also had the side-effect of putting more of the weight distribution on the front (drive) wheel, which gave slightly better traction.

Aside: The S30v2 definitely climbs better than the S30.

 

[Balor]

But of an old news, but Burrows seems to concur (as per his 'Soap dragon' video), BUT change in bracing may also account for some of the difference.
It may also greatly depend on your pedalling style, and your pedalling style may change with position to get the best out of it.


This article basically rises more question than answers:

One question is, why is cycling performance in one hip position greater than that in another position? Are these differences in performance due to changes in muscle length, moment arm length, joint angles, or other variables such as EMG patterns? Because subjects have reported that local muscle fatigue varies with changes in hip position, it may be that muscle activation and recruitment pattems have been altered with changes in hip position. It has not been determined whether the intensity, duration, and EMG pattems of a given muscle group will change (or how) with manipulations in hip position, or whether unfamiliar hip positions will affect the sequence and/or timing parameters of the different muscle groups involved in cycling.

Another question is, do changes in trunk orientation affect cycling performance, as determined by power production rather than minimizing aerodynamic drag, while controlling for hip position/configuration? In this investigation the trunk orientation was upright and perpendicular to the ground. Changing the trunk orientation will alter the lower limb orientation with respect to the line of gravity. Whether this change in trunk orientation will alter the lower limb weight contribution to the pedal, and how substantial or significant this contribution may be, is uncertain. If there is an effect or trend in cycling perfonnance with a systematic manipulation in trunk orientation, will this trend be consistent with a different hip position/configuration or will there be an interaction effect?

 

[ed72]

There really are not many competitive or maybe should say athletic upright riders who have long power file histories who have converted to recumbent riding with a power meter.

How many of those who do claim an increase in maximum power output when switching to a recumbent?

Balor's point about EMG and firing patterns makes sense and in terms of anaerobic power, I think it is an under appreciated adaptation needed when converting to recumbent riding.

I could barely max out at 55o watts for my first 6 months or thereabouts on my bent whereas 1100-1200 watts, depending upon training, would have been my max on an upright. It is not like I was not trying or was not training or putting the time in. I surmised it could be a muscle recruitment problem. So, I embarked upon punishing the legs. 20 seconds max power with brief rest. 10 times. At least twice per week. Maximum power got up to 727 watts iirc. I put a Rotor RS4x crank on and now am knocking on the door of 1000 watts......986 watts iirc. The change in power was immediate upon putting a Rotor crank on and I started crushing every single short hill climb although still under my upright times.

 

[ak-tux]

There really are not many competitive or maybe should say athletic upright riders who have long power file histories who have converted to recumbent riding with a power meter.

How many of those who do claim an increase in maximum power output when switching to a recumbent?

Balor's point about EMG and firing patterns makes sense and in terms of anaerobic power, I think it is an under appreciated adaptation needed when converting to recumbent riding.

..

It would be interesting to know which recumbent position requires the least level of adaption to generate similar(not exact) levels of power at the pedals if one switches from a standard racing upright road bicycle. I know it may be subjective but there seems to me to be a certain optimum seat-angle/BB/handlebar postion e.t.c. for most riders.

For instance, I commute on a road bike on week days and ride my recumbent for group rides on weekends. I kept tweaking my position on the recumbent until I arrived at a postion at which my percieved pedaling effort and performance seems similar to my road bike at approximately similar gear ratios (especially for climbing 2-3-4% grades). Considering that my recumbent is significantly heavier than my road bike(16 Kgs vs 11Kgs ), there is something here I am just curious about. It still could be all subjective though.

 

[Balor]

Likely something akin to LWB with low BB and fairly upright seat.
You can hardly call it 'recumbent' though, more of a crankforward... same (or even worse) problems with 'seat comfort'... unless you use very wide mesh seat, perhaps.

 

[ed72]

It would be interesting to know which recumbent position requires the least level of adaption to generate similar(not exact) levels of power at the pedals if one switches from a standard racing upright road bicycle. I know it may be subjective but there seems to me to be a certain optimum seat-angle/BB/handlebar postion e.t.c. for most riders.

For instance, I commute on a road bike on week days and ride my recumbent for group rides on weekends. I kept tweaking my position on the recumbent until I arrived at a postion at which my percieved pedaling effort and performance seems similar to my road bike at approximately similar gear ratios (especially for climbing 2-3-4% grades). Considering that my recumbent is significantly heavier than my road bike(16 Kgs vs 11Kgs ), there is something here I am just curious about. It still could be all subjective though.

i don't know the answer but I did give considerable thought and review of literature on the subject.

I came to the conclusion that the two best candidates were the S30 and the Morciglio hammerhead (25-30 degrees and low BB) in terms of climbing and overall speed on the types of roads that I ride (hilly and lots of twists and turns)

 

[Balor]

https://www.strava.com/activities/1936222485/analysis/966/1274

See those pictures? Those are worth plus 35 watts! (actually more like 30 in 'real' watts, but still).

I'll try this seat mod with 'conventional' pedalling direction as well. Looks like you can have your hip angle and AND aero as well.

 

[ed72]

https://www.strava.com/activities/1936222485/analysis/966/1274

See those pictures? Those are worth plus 35 watts! (actually more like 30 in 'real' watts, but still).

I'll try this seat mod with 'conventional' pedalling direction as well. Looks like you can have your hip angle and AND aero as well.

Wow. I wasn't thinking that much of a "bump" or hump in the seat but it was just a thought in my mind. Do you have the dual freewheel, pedal backwards/forwards mod on it?

 

[Balor]

that's not dual freewheel, I've simply crossed the chain. Since this is FWD-MBB, only one gear turned out to be useable, but luckily one I use most when the bike is on trainer anyway.

Now, the ultimate test would be to simply remove rear wheel, ending up with "midracer" configuration with same hip angle, but different trunk orientation against the gravity. (BB ends up 12cm higher than the seat, seat nearly horizontal... unrideable of corse - I cannot see the road at all - but a good enough test for a trainer!)
Of course "leg weight" has nothing to do with it, but *bracing using gravity* is!
Cannot test "shoulder boosters" this way unfortunately, cause I don't have them yet. may have to think of something.

 

[Balor]

PS still get about 10-15 "extra" watts when I rise un in seat further even with the seat mod, but effect no longer as drastic, so there is a limit to this (obviously).
Still, difference in perceved exertion is enormous compared to lying down in unmodified seat.

 

[bladderhead]

simply remove rear wheel

You end up with a unicycle.

 

[Balor]

It is not supposed to be rideable outside of a trainer, if it works I'll make an other one with geometry like that. But I suspect that it will not work without 'shoulder boosters' at the very least.

 

[Balor]

By the way, at least one streamliner used 5-point harness for that... not that practicable on a unfaired bent though.

 

[Balor]

Anyway, 'reverse pedalling' totally works at least for me - it finally takes load from my hamstrings that seem to be permanently overloaded and moves it back to my (rather sizeable) quads that seem to sit unused on a bent - instead of 'scraping' you 'kick', resulting in a rather natural 'semi-circular' motion.
I also suspect that with BB low enough reverse pedalling allows one to use gravity as a 'bracing force' once again, no need for any seat bracing, shoulder boosters or otherwise - like above mentioned crankforward/LWB, BUT with BB at least 10 inches higher. It certainly feels like that at least!

 

[Balor]

I had to stop 'reverse pedalling' experiment after noticing the chain sawing a significant groove into my *steel* chainstay... additional power seems all the more surprising in light of this.
And, unfortunately, reclining ENTIRE structure preserving hip angle still results in a significant power drop, my legs simply start feeling *weak*, even under rather low power - come to think about, not unlike weakness you feel when doing something with your hands above your head as compared to to hands below heart level. Definitely a circulation issue.

I think what you did with your 'leg punishing', Ed, is actually angiogenesis first and foremost. Bracing and leg angles are still vital, but unless you have an extremely robust circulation system - secondary issues... well, I have a 'reverse' of 'robust' circulation (up to and including fainting sometimes), hence small wonder I'm having trouble with higher BBs and/or lower reclines.

More experiments are needed, I think I'll try digging up my LWB and using it for 'reverse pedalling experiments' instead, it seems particularly well-suited for this.