Arch cleats??

n crowley

This appears more like the Powercrank sales talk. If the boundaries of the longest possible downward power stroke are 12 and 6 o'c, where is that extra power input taking place. Are you confusing conscious power application with momentum.

biomac

A fond hello to Dublin and the Green Island!
bio-mxc² has got nothing to do with PowerCrank, in fact it even has some opposite aspects as it does n o t emphasize on m.iliopsoas-action at all. I do not want to condemm extra training of the psoas and the lower spine, as for some sports way apart from cycling, this specific addition to a muscle chain may have a few positive aspects, we decided it does not so for a road cyclist, so cut it out almost completely.
Please note that only because we try to simplify comparing the cyclist's spinning action with a watch - biomechanists, please forgive - does by no means imply that we had anything similar in mind when designing our patented bicycle shoe sole for automatic pedals. In the opposite, 'goat-scraping', pulling or whatever you may call it, gets almost extincted as with bio-mxc² the foot remains much closer to the bottom bracket between '10to6' 'til '5past 12' than with any other setup. Therefore, dead zone, or 'pulling' gets almost abolished when using bio-mxc². Apart from the more direct power transfer of the hip flexors and the diminished contribution of the knee
flexors, arch pedaling dramatically reduces these, in comparison to buttocks and thighs much weaker muscles' activity. Unlike a longer crank, where apart from the undenieable benefits during downstroke, the increasing 'dead' zone, i.e. the 'pulling zone', gets intollereably dominant, thus deleting what you have just gained unproportionally, bio-mxc² tremendously favours downstroke. Think of a crank almost 210mm in length during downstroke but just 135mm when pulling and you come close to the different circle, bio-mxc² puts on any rider, no matter whether skilled or unskilled, trained or untrained.
The result: notably less pain in calves and peri-genual zone, more endurance at threshold and almost crazy leverage uphill. This is why Lennard Zinn once reported, that while in China, he had wittnessed some locals carrying refrigerators uphill on their bikes. Mind you, this has got nothing to do with the mythic Power of the Yellow Dragon, this is instinctively applied laws of geometry and mechanics, gentlemen!
And here is a simple exercise which may create an understanding how a different use of the same muscles can make a huge change to endurance, no matter what laboratory parameters, powermeters or heart rate monitors report:
Screen your performance while doing push-ups on your finger- tips and then, for a joke, execute them on your palms. You wouldn't push a fridge with your fingertips if you had the chance to do it with the palms of your hands, would you? Now who on earth made us propel our cranks with our toes instead of our arches?! A pair of biomac's Y² for him who can name this Bean.

Piotr

Clearly, fingers were always meant for eating, grabbing, maybe flipping the bird , not pushing refrigerators. Feet on the other hand are for walking, running, jumping... Then, why not cycling? There's got to be a reason why those calf muscles are so dense. This arch pedalling style may be useful in a triathlon or a TT, but in a bike race where jumps and accellerations are frequent de-emphasizing the calf muscles will be a detriment.

Let's also clarify, that cyclists are not ballerinas and they don't pedal with their toes, but the ball of the foot. Just FYI

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Alex Simmons

Why mid foot? Why not go all the way and place the cleat under the ankle? (don't bother with the obvious such as front wheel overlap)That's effectively what I'll be doing when I ultimately get my prosthetic cycling limb, it will connect directly to the end of the crank arm so all the upper leg force will go directly into the crank, no calf to speak of required to stabilise a foot.

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biomac

Ok Alex, as this discussion is beginning to pick up momentum on a rather high niveau where Watts and angles remain in the drawers, let's get down to reality and move your limb at say, 70rpm with the cleat right under your stick (which "obvious toe overlap" are you possibly referring to?).
You may, no, you will discover, that there is a big improvement in terms of w h e r e your thigh and hip muscles have to contract, i.e. way further proximal than with the traditional setup. So in the area where they have huge diameters, so considerably less pressure on the perigenual aerea and buttocks, which for their first time ever, will be happy to join in the concerto of huge and forceful muscle groups.

But, what will happen to your accelleration speed, to jumping, kicking, to your sprinting abilities, altogether techniques which do require a rather wide torque-range in order to remain competitive in a bunch, on an ondulated terrain or in the corners? While with bio-mxc² a rider who still has his calve muscles under control can produce a fluent movement which keeps up a continuous drag on his chain and backwheel(remember, although he has a virtually longer crank during downstroke but a much shorter one during pulling?see previous postings), hammering the cranks at say, 50rpm to maintain his speed against gravitation on a hillclimb or against the wind will eventually become a drag on the muscles involved due to the enormous torque peaks he'll have to produce every single stroke.

Get what we are aiming at? While for a crippeled rider, your suggested setup is indeed the best way to propel his bike and right now, we are involved in the process of building lightweight prothesis for people who are fate-stricken with this problem, an athlete who is blessed to call two healthy legs his own indeed starts 'walking his bike', thus taking advantage of the most endurable muscle slope man has inherited. In super-lightweight balley shoes of course, PIOTR, as like with the rest of the bike, only the best is good enough for us .

Since the UCI has accepted bio-mxc² as a legitimate technique to propel your cranks in any race on the UCI calendar, question is not whether this is right or wrong, question is whether this improves (not boosts) an athlete's performance without the well-known side-effects of some other mechanical set-ups.
Believe it or not, or better: experience it yourself - it does!

Alex Simmons

I think I get the idea, I joined discussion late. Whether or not it results in sustainable gains in performance is the key.

Indeed I have a club mate using mid foot cleat position right now and he is a world class masters rider. No firm conclusions yet on his part but he is giving it a serious crack.

I was just curious as to the logic not extending to the scenario I am about to face for the first time, i.e. directly connected prosthesis or should one choose to mount cleat under the heel of the foot (the toe overlap was reference to this latter impractical scenario - I was just playing thought games).

Of course I will have an interesting imbalance as the other leg is fine and will pedal normally (maybe not any more). I have seen the shoes, I reckon I'd break 'em! I'm notorious for doing that with normal shoes.

Presumably with a suitable cleat type you can have both arch and forward cleat positions available on the same shoe giving the rider some choice depending on the race situation.

I am interested in learning more about your cycling prosthesis solutions. I am a recent below the knee amputee. Steve Hogg is my LBS and fitter and we are investigating the options to get me back on a bike at some stage in my rehab.

__________________
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http://www.cyclecoach.com/

biomac

Alex, now the penny has dropped, as although I heard of your accident recently, I didn't know whom to relate to it and so couldn't figure out why someone who would cycle with a prosthesis could be aware of toe overlap, sorry.
As you indicated, I trust that Steve Hogg from www.Cyclefitcentre.com in Sydney is definitely the person to see, as
1st Steve is familiar with bio-mxc² and
2nd he is one of the few positioning experts on this planet who call a reasonable torque analysis tool their own which runs on the latest powermeter hardware of today.
Apart from some naturally gifted people, the majority of self-elected experts are just some sort of moles who make their clients believe they could tell what happens when a rider distributes his various forces onto a bike.
Because keep in mind, you cannot just hop on the bike and ride with one leg in the traditional, the other in arch-position or even further back as different reach will require that either you vary your crank length according to the different points of attachment or, and this is what seems to make more sense in your case, adapt the cleat position of the existant foot to such a degree that both legs end up with similar reach. From my (limited) experience on cases like yours, I trust that the arch cleat may work better than a cleat in direct extension of the prosthesis for the reasons mentioned in my previous posting.
I'll be always available to answer any occuring questions on this subject at info@biomac.biz and wish you a quick and thorough recovery.

jbvcoaching

Eugene Meyer? He invented the ordinary, where it was advantageousto pedal with one's toes.

n crowley

What pedalling style (circular or mashing) is used with these shoes and what is responsible for the power increase (cleat position or shoes), if both how is the percentage of their contribution divided.

biomac

re cleat position or shoes
Crowley, its definitly the position. First we applied for Patent's Grant on a (modified) cycling shoe sole, then, when none of the big shoe companies wanted to take the risk of introducing the position, we started the making of a shoe ourselves. Being former competitive bike-riders, we never liked heavy boots which would strangle the feet, bend them to some shape and make them sweat. Instead, our feet were longing for a snuggly sock, each with a stiff sole.
re percentage
Wanna bet? To be honest, we couldn't tell beforehand as everyone is different, isn't he? That's why we resort to torque-analysis. Not that our program is perfect, but it gives you a good idea of how much force each leg transmits to the crank with the traditional and with the bio-mxc² setup. We all have different proportions, leverage and moving patterns. What is the difference between a 170mm and a 210mm crank during downstroke and a 170mm vs. 135mm crank during pulling everyone skilled to the art of simple geometry will calculate easily. Still, not every athlete can re-distribute his forces imediately, so will perform up to his natural abilities from scratch when put on bio-mxc². As a rule of thumb, professional cyclists learn very fast, leisure riders have more blocked hip-flexors, so some do require a good introduction by a skilled expert to wake up their hips and thighs. As you want figures: During the last 10 years of torque-analysis we experienced everything inbetween 3 and 20% of i m p r o v e d efficiency from scratch, i.e. 30ks. Acceptance was 99% at first contact. Only two guys claimed to get no benefit of it at all, one of them didn't want his girl-friend who was a pro triathlete to make the change although his curves showed significant improvements. Compared to their male compatriots, women have a better adaptation which enables them to tell within 20ks what and where the changes take place. Also they tend to understand faster the nature of the improvement, this is l e s s peak power for the same effort which eventually leads to some kind of p r o l o n g e d endurance.
re circular vs. mashing
For people brought up with the German language this is indeed a new comparison - no, not circular, just mighty. Huge leverage, no dead zone. No puffing and panting, just going flat out while still being fully orientated. Before this becomes poetry, let's resort to the members of the famous Swiss Army Cycling Division. When we first hit the market, we would receive plenty of messages from them, telling us yes, although traditionally used to their ball-above-axle position on their racing bikes, on the heavy army bikes with their ordinary pedals, no toe-clips or cleats, most of them would instinctively switch to the arch-above-axle technique when the going got tough...

n crowley

No dead zone ? When foot/shoe is in the 12 o'c position, in what direction is pressure being applied from shoe to pedal axle and how does this power application compare to the power applied at 3 o'c.

biomac

Crowley, sorry if I expressed myself incorrectly or you got me wrong.
The UCI-approved setup on the bike does of course include a zone where a cyclist's leg's contribution to the forward movement of his bike is minimal, so a certain amount of dead zone is in any case part of the cyclist's movement. Nevertheless, compared to the traditional ball-above-axle setup, while riding with bio-mxc², this zone f e e l s almost absent. With decent tools designed to measure the energy transferrd from a rider's foot to the chain of his chainring, you are of course able to display where and when this takes place and how much exactly it differs from rider to rider due to his individual measurements, moving pattern and adaptation to the bike. Again, this very individual curve changes significantly when the same athlete is put on his bike that way, his arches being positioned above the pedal's axle rather than the metatarsals. We of course leave it to unbiased scientists, to dig into this phenomenon and comment on the subject.
Please specify your question if you want to raise the standard of this discussion to a scientific level and we can make an appointment where I will be happy to pass on data that has been collected with the help of leading measuring instruments.
Instead, and that is how I understood your query, if you are aiming at h o w i t f e e l s and what noteable differences can be reported by someone riding his bike under equal conditions except for his foot and leg position, the vast majority of pros, amateurs, women and kids taking advantage of our biomechanically improved bicycle shoe sole will tell you that it f e e l s as if they had "more power on the pedal", therefore it doesn't feel "circular or mashing" as you may have expected but 'mighty' as they could definitely ride a bigger gear or maintain equal effort longer than with the traditional ball-above-axle setup.
What proves them right is not only their rather subjective feeling but their results using this setup which is noteably better.
As we are far from opposing our findings on anyone who wants to just take advantage of a modern cycling shoe, which weight is reduced to a necessary minimum, maximised in fit and designed to support a rider's performance rather than counteract it, biomac leaves it to the customer where he wants his favoured cleat system to be mounted (see www.biomac.biz shoe fitting) and provide him with the most advanced custom- or production shoe on today's market.
You are of course warmly invited to try yourself what we believe is one of the most stunning findings in cycling so far.

biomac

Crowley, sorry if I expressed myself incorrectly or you got me wrong.
The UCI-approved setup on the bike does of course include a zone where a cyclist's leg's contribution to the forward movement of his bike is minimal, so a certain amount of dead zone is in any case part of the cyclist's movement. Nevertheless, compared to the traditional ball-above-axle setup, while riding with bio-mxc², this zone f e e l s almost absent. With decent tools designed to measure the energy transferrd from a rider's foot to the chain of his chainring, you are of course able to display where and when this takes place and how much exactly it differs from rider to rider due to his individual measurements, moving pattern and adaptation to the bike. Again, this very individual curve changes significantly when the same athlete is put on his bike that way, his arches being positioned above the pedal's axle rather than the metatarsals. We of course leave it to unbiased scientists, to dig into this phenomenon and comment on the subject.
Please specify your question if you want to raise the standard of this discussion to a scientific level and we can make an appointment where I will be happy to pass on data that has been collected with the help of leading measuring instruments.
Instead, and that is how I understood your query, if you are aiming at h o w i t f e e l s and what noteable differences can be reported by someone riding his bike under equal conditions except for his foot and leg position, the vast majority of pros, amateurs, women and kids taking advantage of our biomechanically improved bicycle shoe sole will tell you that it f e e l s as if they had "more power on the pedal", therefore it doesn't feel "circular or mashing" as you may have expected but 'mighty' as they could definitely ride a bigger gear or maintain equal effort longer than with the traditional ball-above-axle setup.
What proves them right is not only their rather subjective feeling but their results using this setup which is noteably better.
As we are far from opposing our findings on anyone who wants to just take advantage of a modern cycling shoe, which weight is reduced to a necessary minimum, maximised in fit and designed to support a rider's performance rather than counteract it, biomac leaves it to the customer where he wants his favoured cleat system to be mounted (see www.biomac.biz shoe fitting) and provide him with the most advanced custom- or production shoe on today's market.
You are of course warmly invited to try yourself what we believe is one of the most stunning findings in cycling so far.

Ergoman

What race results can you show for the biomac system? How have competitors done using arch cleats and your shoes?