Another silly pedaling musing from me

[Martin318is]

Yep like I thought I just said. There would be a big drop off in performance as you get to the fringe of any of those limits. I would just expect that there is a comparatively large range in the middle of those adjustments where the biggest factor would be rider comfort rather than performance gain.

So as you say, moving saddle in direction by a few mm away from a traditional position would likely have no impact on performance for a rider or two but it may impact comfort and may result in longer term injury (I would think - based upon the writings of people such as Steve Hogg in conjunction with my own experience working with my on bike position)

 

[CoachFergie]

What is a traditional position? A popular seat height method is 25 degree bend in the knee through the bottom of the stroke. You can buy some pretty expensive video analysis software to determine this but when I looked at the cycling related injury literature it was a case of Dr Andy Pruitt said it and it became Gospel. Also assumes people have a similar or symmetrical anatomy.

I think what the research indicates is that within this so called "ideal" set up there is scope to push the boundaries of aerodynamics or comfort without a cost to performance.

 

[Martin318is]

Who are you arguing against Fergie?

seriously. read back the last few posts properly..

 

[FrankDay]

There is always going to be a point where performance diminishes. Stupid long cranks, stupid short, stupid high seat, stupid low seat, stupid high cadence, stupid low cadence etc. But no where within those ranges is a magical point where performance will dramatically improve.

Fergie, what you seem to be missing is that:

1. in some of these discussions we are not talking dramatic improvements. Why would a serious athlete want to pass up even a small benefit, if it were available from a simple, small, change. Since you are a coach perhaps you can best explain why an athlete would want to ignore an easily achievable small improvement because it involves being different?

2. You seem to be locked into power as being the only metric that measures performance while some of these discussions go to the whole milleau that involves the integration of power, comfort, and aerodynamics - the three major determinants of cycling performance (after training is taken into account). You equate power with performance. They are not the same. If all one is measuring is power one cannot say anything about outcome if the other aspects are potentially affected by the change.

 

[CoachFergie]

Who are you arguing against Fergie?

seriously. read back the last few posts properly..

Seriously read my posts and you will see I am agreeing with you

 

[CoachFergie]

1. in some of these discussions we are not talking dramatic improvements.

There is a difference between small improvement gains and gains that are a figment of ones imagination or part of a marketing campaign to support a product or service.

Why would a serious athlete want to pass up even a small benefit, if it were available from a simple, small, change. Since you are a coach perhaps you can best explain why an athlete would want to ignore an easily achievable small improvement because it involves being different?

I don't. I frequently stress to my riders that cycling is a sport of incremental gains.

2. You seem to be locked into power as being the only metric that measures performance while some of these discussions go to the whole milleau that involves the integration of power, comfort, and aerodynamics - the three major determinants of cycling performance (after training is taken into account).

I also use power to weight, power to frontal area, distribution of power over a race and variety of other metrics. I have always talked of the compromise between power, aerodynamics and comfort. I would add weight to that list as well if one is heading uphill.

 

[Martin318is]

Seriously read my posts and you will see I am agreeing with you

Exactly, and I am violently agreeing with you - so lets drop it shall we?

 

[Alex Simmons/RST]

I didn't read all this thread in detail but all I really have is a couple of anecdotes (LOL - that's especially for Jim) and thoughts. Tried to post yesterday but the forum died on me.

With regard to cleat placement "regualr" vs "mid-foot/arch":

For predominantly steady state cycling, there isn't much difference in performance.

When you need to have rapid accelerations, it is a disadvantage to have the cleats further back.

There are other considerations, including a requirement to change bike set up including the lowering of saddle height and adjusting the fore/aft saddle position and the resulting bar height/reach adjustments.

Due to the substantial change required it may or may not be possible to achieve such changes on a given rider's existing frame, or require additional cost for new components, or even perhaps make UCI legal saddle placement more difficult, especially if you are already very close the the UCI limit.

Also, it can result in significant toe overlap of the front wheel, which may or may not concern some riders.

I coach a rider who set world masters hour record who has/does train and race using both "normal" and mid foot cleat placement. His power output for such efforts is the same using either (after a reasonable adaptation period).

There is a shoe manufacturer, Biomac shoes, (Goetz Heine) that's been producing and promoting this for many years, they even have a patent on it. I met him maybe 6 years ago when he was demonstrating the SRM Torque Analysis tools in Steve Hogg's shop while a rider was using the shoes/cleat placement.

Their shoes are very stiff and light and allow for arch cleat placement. They are also very expensive.:
http://www.bikeradar.com/gear/category/clothing/shoes/product/review-biomac-bio-mxc2-shoes-09-34720/

With SPD cleats you can even fit two cleats on the shoe, although it's not all that practical since clicking out of one and into the other just makes your bike position "wrong".

Of course he proposes lots of benefits, but was unable to provide substantive evidence on the efficacy of this solution, relying on pedal force analysis to claim a more even pedaling output around the pedal stroke (by examining the raw torque data from an SRM equipped with torque analysis hardware), and improved "efficiency" (sic) which we know doesn't really mean much in terms of performance, and secondly, on celebrity "endorsement".

Sounds a pretty familiar tale really.

Not sure he was too impressed being asked some "difficult" questions, rather than have someone just take such assumptions/claims on face value.

My other anecdote is personal. As you know, I am now an now amputee rider after trans tibial amputation in 2007. On my right leg, I have regular cycling shoe and cleat placement (by Steve Hogg incidentally) and on my left, the cleat is placed effectively under where my heel would be if I had one, since it is connected to my prosthetic via a straight pylon.

My steady state power output (W/kg) for durations from 4-minutes and longer is the same (if not better) post-amputation than it was pre-amputation. My sprint power (peak and 5-sec power) has suffered a drop of ~ 250W (and that results in a drop in longer range average sprint power as well, but primarily because the initial high power isn't there. My fatigue rate isn't much different than before).


From a cycling performance POV, I think this is a solution looking for a problem that likely doesn't exist, however I am certainly open to inspecting additional real evidence should any be published.

 

[oldborn]

On my right leg, I have regular cycling shoe and cleat placement (by Steve Hogg incidentally) and on my left, the cleat is placed effectively under where my heel would be if I had one, since it is connected to my prosthetic via a straight pylon.

How long it takes to get used (if possible)? What about your asimetrical knee placement, I mean your right leg/knee is further than left one?

My steady state power output (W/kg) for durations from 4-minutes and longer is the same (if not better) post-amputation than it was pre-amputation. My sprint power (peak and 5-sec power) has suffered a drop of ~ 250W (and that results in a drop in longer range average sprint power as well, but primarily because the initial high power isn't there. My fatigue rate isn't much different than before).

Interesting how Pistorius can accelerate, though it is not same movement, but anyway.

P.S. my bloody dog was eating mouse cable, so I am out for a while.

 

[Martin318is]

Interesting how Pistorius can accelerate, though it is not same movement, but anyway.
.

his prosthesis is an efficient spring though isn't it?

 

[oldborn]

his prosthesis is an efficient spring though isn't it?

I guess it is act (prosthesis) like spring, which is not quite efficient in start, but still damn fast.
I juts watch Beijing Paralympics 100m final. He ran 11.17 sec., but he was last until 30 or so meters until he accelerate. Somehow he stores energy it is for sure.

 

[FrankDay]

When you need to have rapid accelerations, it is a disadvantage to have the cleats further back.

Could you explain why you believe this to be true.

Also, it can result in significant toe overlap of the front wheel, which may or may not concern some riders.

Not if the rider is combining this with shorter cranks. For every 10 mm you shorten your cranks you can move your cleat back 10 mm and keep the exact same overlap.

I coach a rider who set world masters hour record who has/does train and race using both "normal" and mid foot cleat placement. His power output for such efforts is the same using either (after a reasonable adaptation period).

My argument here is not one necessarily of more power but a change in fatiguability and energy management. Does your rider have any experience/comments with this?

My other anecdote is personal. As you know, I am now an now amputee rider after trans tibial amputation in 2007. On my right leg, I have regular cycling shoe and cleat placement (by Steve Hogg incidentally) and on my left, the cleat is placed effectively under where my heel would be if I had one, since it is connected to my prosthetic via a straight pylon.

How do you deal with the obvious bike fit issue. It seems to be a non-issue.
I guess you can make the needed length difference in the prosthesis but one side will be effectively slacker than the other. apparently not a problem. As usual, humans seem capable of adapting pretty well to anything.

From a cycling performance POV, I think this is a solution looking for a problem that likely doesn't exist, however I am certainly open to inspecting additional real evidence should any be published.

Perhaps you are right. However, without ever considering the possibility the issue will never get looked at. Even with this discussion of the possibility this issue probably won't get looked at scientifically until someone comes along and is seeing good race results after making this change.

 

[Alex Simmons/RST]

How long it takes to get used (if possible)?

I was talking about my client wrt adaptation time, which I'd say is a few weeks or less.

As for me, I'm not sure how to answer the question really. There were many issues/problems to solve to enable me to pedal relatively normally, both due to my physical problems, very low starting fitness and also equipment issues that needed to be solved/resolved. My first attempt to pedal required me to use a 100mm left crank arm as I had very limited range of motion in my knee at that time.

What about your asimetrical knee placement, I mean your right leg/knee is further than left one?

No lateral asymmetry as far as I know, my hips are the same as before, so i don't see why my knees would change position laterally.

The pylon is made as long as is necessary. There are a few consequences (apart from the obvious missing skeletal/muscle system to contribute to power) to having such a pylon:

- with a regular ankle and foot, you make your own adjustments to pedal reach while pedaling by flexing/extending the ankle (you don't actually think about it - it just happens). This is not possible with a prosthetic as reach is dictated by hip and knee flex/extension only (assuming you are not rocking pelvis side to side, which would be poor form/bike fit). IOW you can't "drop your heels" or some such change of pedal action at time (whether conscious or otherwise). The pedal reach you have is what you have.

- since you are missing an ankle, then you also no longer have the lateral flex an ankle naturally provides. We don't realise how much this happens when riding and how important it is to cycling - it allows you to "rock the bike sideways" under you, especially when out of the saddle and to remain in completely control of the bike. Imagine if your leg could only remain in the same plane as the bike frame/crank? Sprinting becomes impossible and bike control quite dangerous. It was I can tell you, a very unpleasant experience on a bike, and can easily lead to a crash (nearly did in my first attempt to race on it). You have to manufacture an "artificial ankle" to enable lateral flex at the point the prosthetic connects to the pedal (the pedal's own rotation looks after that plane of motion). I resolved that problem by coming up with something akin to a suspension bushing (a 2mm layer of hard rubber) between the cleat and the prosthetic. I can now do full gas track sprints, albeit slower than I was before and the bike feels pretty normal under me.

- the point at which downstroke force is applied by each leg is not 180 degrees apart, but rather it's out of phase, with the prosthetic side being a bit later. Now whether that matters or not is hard to say. It is possible to create a leg which places the cleat where a regular cleat would have been but prosthetics specialists don't particularly like the potential for this to create moments and shearing forces in the prosthetic socket. They much prefer the line of force to be down the line of the remaining bone structure (or roughly so). Nevertheless, there are successful cyclists who have legs like made that. It is very expensive though and a leg can go from $5,000 to $25,000+ to get that right.

- standing starts are the worst part, way too many things going on there to write about it here....

Interesting how Pistorius can accelerate, though it is not same movement, but anyway.

He doesn't actually accelerate all that quickly (watch him in a 100m race with single leg amputees - he is left behind until the final third of race where his top end speed is far superior).

Besides, his prosthetics confer a mechanical advantage that does not exist with a cycling prosthetic.

It is certainly possible to generate high power with a lower leg cycling prosthetic, as Jody Cundy of GB ably demonstrates with his 1km TT time of 65 seconds. Apart from being an excellent athlete, Jody was brought up with that impairment from a young age. I acquired mine late in life and I suspect there is probably quite a difference.

P.S. my bloody dog was eating mouse cable, so I am out for a while.

Wireless mouse...

 

[Alex Simmons/RST]

Could you explain why you believe this to be true.

1. rider in question does not accelerate as well as with regular cleat placement. He prefer to ride highly variable power events with regular cleat placement
2. It's taking a significant amount of lower leg musculature away from a lever arm to apply the rapid short term higher forces, for what seems to be no gain in the rate at which forces can be applied.

As I said in my opening, I was only posting thoughts and anecdotes.

My argument here is not one necessarily of more power but a change in fatiguability and energy management. Does your rider have any experience/comments with this?

No specific comment. He's a perennial bike fit fidget and what feels good this week needs an adjustment next week as it's "not quite right".

As for fatigue/energy management, it's power for the duration and performance for specific events we are interested in, not how rooted he is afterwards. I'm perfectly fine for him to be less efficient but more powerful for the duration.

He can perform steady state stuff with either cleat position equally well, but when his race season includes things like track points racing, he felt much better having regular cleat placement as he got tired of swapping the bike set up around all the time to accommodate the different cleat positions. He does have a world masters points race title as well.

 

[FrankDay]

1. rider in question does not accelerate as well as with regular cleat placement. He prefer to ride highly variable power events with regular cleat placement
2. It's taking a significant amount of lower leg musculature away from a lever arm to apply the rapid short term higher forces, for what seems to be no gain in the rate at which forces can be applied.

As I said in my opening, I was only posting thoughts and anecdotes.

While it is taking a significant amount of leg musculature away, that leg musculature is in series with the other muscles. The output of muscles in series should be limited by the weakest muscle in the chain. It is that issue that makes me question how that muscle is used to increase power. So, if he his not accelerating as well, how can this be explained? What is the mechanism that explains this finding or is this finding a figment of his imagination or a placebo effect?

 

[oldborn]

No lateral asymmetry as far as I know, my hips are the same as before, so i don't see why my knees would change position laterally.

Thanks Alex.
Maybe I got something wrong. I mean if your right cleat is at "standard" position, your left cleat is placed under where your heel would be if you had one. How is possible to get knee alignment, you know rigth knee is touching your elbows while left one does not (just example)

He doesn't actually accelerate all that quickly (watch him in a 100m race with single leg amputees - he is left behind until the final third of race where his top end speed is far superior).

Yes agree, but it still a sprint discipline, and Dude has speed.

It is certainly possible to generate high power with a lower leg cycling prosthetic, as Jody Cundy of GB ably demonstrates with his 1km TT time of 65 seconds. Apart from being an excellent athlete, Jody was brought up with that impairment from a young age. I acquired mine late in life and I suspect there is probably quite a difference..

You and Jody should came here, 1min 14sec is 2011 track nationals winner time, and 1min 11sec 94 is national record (open velodrome)

Wireless mouse...

Duct tape

 

[FrankDay]

Another potential "advantage" of "arch cleats" that I didn't think of is better aerodynamics. Drew, the fellow I mentioned before that is going to try them just did. He commented: "so with the arch cleats my saddle is back down (on the b-2 the saddle was actually about 3 cm above the limit line before the arch cleats with the 115s). Now I am thinking i could lower the front end a lot more now and get very low."

So, if one lowers the saddle as one moves the cleat back, it seems one could also lower the front end, reducing frontal area.

 

[CoachFergie]

So he has shelled out for shorter cranks for no proven gain, had to buy or butcher a pair of shoes to mount the cleats on the arch for no proven gain to drop the saddle back down below the limit to put him in a position which most people can attain with normal length cranks and cleats mounted under the ball of the foot.

Well done Frank, a very successful rearrangement of the deck chairs on the Titanic.

 

[FrankDay]

So he has shelled out for shorter cranks for no proven gain, had to buy or butcher a pair of shoes to mount the cleats on the arch for no proven gain to drop the saddle back down below the limit to put him in a position which most people can attain with normal length cranks and cleats mounted under the ball of the foot.

Well done Frank, a very successful rearrangement of the deck chairs on the Titanic.

Even though he may not be able to prove any gains to you, he seems quite pleased with the improvements he is seeing. You might be surprised to learn he doesn't seem to care if you are convinced or not. He has done some experimenting and likes the changes he has seen. I guess we will see how he does in his next two races, the Everest Challenge and Furnace Creek 508 and perhaps that will help us to better understand if these changes have helped, hurt, or are neutral.

 

[Alex Simmons/RST]

The output of muscles in series should be limited by the weakest muscle in the chain.

I don't agree with your premise to start with.

There is an entire skeletal system, not just muscles, that transmit forces to the pedals. Secondly the forces are not exactly large (especially in steady state cycling) for this to be a problem. Thirdly, since even the most powerful cyclists in the world who are putting doing circa 2.5kW are not inhibited by such ball of foot cleat placement (or thereabouts), then it suggests otherwise.

 

[FrankDay]

I don't agree with your premise to start with.

You don't agree with the premise that the output of muscles in series are limited by the weakest muscle of the chain? If not, then what is it limited by?

 

[CoachFergie]

Even though he may not be able to prove any gains to you, he seems quite pleased with the improvements he is seeing.

Dare I ask what metric he is using to assess these "improvements".

 

[FrankDay]

Dare I ask what metric he is using to assess these "improvements".

Not sure all the metrics but one I remember was how fresh he felt after a 200 mile training ride compared to his usual. This guy isn't your typical cyclist.

 

[CoachFergie]

You don't agree with the premise that the output of muscles in series are limited by the weakest muscle of the chain? If not, then what is it limited by?

Energy supply to the working muscle or Tim Noakes would argue a Central Governor that serves to protect us from harm.

 

[CoachFergie]

Not sure all the metrics but one I remember was how fresh he felt after a 200 mile training ride compared to his usual. This guy isn't your typical cyclist.