how is the merits of clipless over platforms even contentious?

It is like horse drawn or internal conbustion engine powered. Which do you prefer?

It's not contentious. There are 57 people in America who are scared/skeptical of clipless. They are disproportionately active on cycling forums.

Are you asking an Amish?

I've recently experimented with platforms on mtbs after many years of clipless. They are great for leisurely rides, freeride and dirt jumping. Everything in bewteen....not so much.

Totally, as they say now. This is ridiculous.

I only had to read it once for the laugh.

It's funny..when I was about 9 or 10 and started racing bikes and was riding in toe clips with a cleat, the pedaling action this old pro Euro bike racer taught us was to pull...the old "Scraping mud off the shoe" action. His comment was that your foot will naturally come down. It's the "up" part you can add to your pedal stroke. It's the difference between buying a bike and a book and becoming an instant expert, and actually being coached from an early age by someone that knows what they are talking about.

But a "study" (I love "studies" because they help academics understand what people with talent do naturally) shows otherwise. See sig line below...

Got it.

You know, I THINK the issue here is that you're mixing up force with energy with power. At least that's what i'm getting from the language in your post. But I'll do my best to answer your questions. Also, it seemed like you were trying to correct me about elliptical cranksets, but you don't seem to have done that in any way - unless I'm missing something.
But as for your questions:

Would you care to calculate how much force is required to lift your leg? Or do you imagine that lifting 10% of your body's mass requires no energy whatsoever?

Yeah, sure I could calculate that, I guess? Assume I mass 70kg, and one leg is ~15% for simplicity (closer to 16.7, but w/e) and the leg travels a mass-distance average of 0.2m (I'd do the real integral, but the assumptions I'd make would just add as much margin of error as this anyways) and at a cadence of 90 rpm. It looks like you're also talking about just lifting vertical, so we'll ignore the forward backward of traveling the crank if that's cool by you. Even acceleration gives us 1.2 m/(s^2). (70*0.15)kg*1.2m/(s^2) gives a net force of 12.6N. Add that to the static balance and I guess that makes it + (70*0.15)*9.81m/(s^2) which together make 115.6N.

Although, anything greater than the static ( > 103N) is enough force to move your leg but I don't think that's the answer you were looking for. But now I'm confused, because I'm not sure what you get from this. That leg has got to come up anyways otherwise you're going for a very short ride. So, am I missing something?

2) you're right that it's not designed to exert AS MUCH force as pushing down, for instance consider a flight of stairs that you have to climb up. but consider running where your forward step curls and you pull back on your leg until you push off from it. It's not as significant as the push, but it's definitely still there. So yeah, you're kinda right, you won't get as much from the pull as the push, but you certainly do get something.

3) Again, SORTA right. Yes, the more energy you put in just from a Cal perspective, the less efficient you're going to be (think driving 75 vs 35 in your car) but that doesn't have to do with the 'direction' of the force.

If you think differently, I'm not perfect, so let me know if I've made a mistake. I guess I'd rather learn something than be right, haha. But yeah, i hope something in here is helpful.

Interesting idea.

In cellular respiration, there is a set joule per oxygen yield. That becomes a question of whether some muscles lose more energy to heat than others, which I don't THINK is the case, but I don't really know about that. I would have assumed they had the same efficiency - differing from one another mostly in max force - but I guess I'm not sure. Definitely worth looking into.

This doesn't account for uneven generation of lactic acid and sending one muscle set into anaerobic work without the other, but but's a whole new can.

As I read the posted studies, including exerpts quoted by Pallen, it appears that deliberately pulling up in that test situation led to increased power, but also greater "gross inefficiency" as measured by O2 consumption. So yes, it seems proportionately more O2 is consumed for the results you get pulling up. If so, pulling up may give you a temporary edge, but is not a good long-term strategy. Mind you, I only read the abstracts and I am not a sports physiologist.

I just got clipless pedals after 900 miles w cages.... I will never go back. 30 mile rides are no problem anymore and my speed has increased by abt 1 mph. My feet don't hurt and unclipping is easy, only prob I've had was starting on a bit of a hill but dot get nervous and just cycle with one leg til you get more momentum and can look down and clip in.

Must be a miscommunication -- I haven't discussed elliptical or oval chainrings in this thread. (As far as I know, the data on those is inconclusive.)


Just the actual power data from strain gauges in pedal-based power meters.

Here's a vector map for a typical (clipped-in) pedal stroke. You'll notice how on the upstroke, there is still negative force applied to the pedal.



Presumably this is because you can't lift your leg fast enough to completely "get out of the way" of the upstroke.


And here's the power profile of a typical pedal stroke (again, clipped in):



Your math is slightly off, in your favor; each leg is 10% of your body's weight, not 15%. Still, let's say it takes 75N to lift your leg @ 90rpm. That's a significant amount of force in this context, yes?


You might also note that as cadence increases, the amount of effective force per rotation also decreases. We see the same thing with low cadence as we see with intentionally pulling on the upstroke -- the force is greater, but overall gross efficiency is lower. Similar to with foot retention, mashing feels more powerful, because each pedal stroke is more powerful. As an overall method, though, it's detrimental.

What makes comparative studies so difficult is that it takes a long period of adaptation and coaching to use particular equipment. I spent my first year of training on a modern road bike mostly learning how to pedal properly with clipless. I clearly remember the day when I made three consecutive perfect pedal strokes on a MUP. A few weeks later, I pedaled properly continuously for 100'. 15 years later, I'm still working on it.

One of the fun things about riding a mixed tandem is that we can feel each other pedaling. It's kind of like dancing together to exhaustion. So when one of us lapses into "push-down," which is easy to do, the other says, "Pedal circles!" When we both do it right, I don't think the bike accelerates noticeably, but it climbs almost effortlessly at the same HR. If you're doing it right, the bike should float up the climb. Yesterday, we climbed for 4 hours at 90% of LT and our legs aren't sore today. Almost bonked, but ate our way out of it.

Huh. Everything I find is saying they're heavier than 10% This being the most concise example: https://www.exrx.net/Kinesiology/Segments.html
But that's beside the point, really. I don't think it matters for the discussion.

Yes, that 75N would be significant amount of force given the maximum is around ~425ish. I buy that. But keep in mind that you would need that net 75N upward in order to get your leg back to the top of the crank - whether that force is made by your lifting or pushing and transferred through the crank is irrelevant. My thoughts were that adding a little more would be beneficial, but I also looked back at the articles you cited earlier - if we were having this discussion during the academic year I would have already ordered those articles through the university, but alas, no luck =P I'm wondering how their efficiency is measured - by measure of what to what. My thoughts are that if they're just pedaling faster, it makes sense that it would be less efficient, but something that we would totally be able to support. <- That sentence doesn't make much sense, but I just mean I don't really have much to construct without a better look at that article.

I'm really surprised that there isn't more consistent force applied. I FEEL like I do a much more consistent force than that diagram shows, but of course I couldn't tell you that definitively, and it would just be me. The closest I have to real evidence to that is even when using cages (commuter bike) I find my feet slip out the back since I'd started using SLRs. Still, you're going to have me very pedal-conscious on the next few rides XD

Here's an idea:
1. If you ride faster/farther/easier with clipless, ride clipless.
2. If you ride faster/farther/easier with platforms, ride with platforms.
3. If you fall down less with platforms, use platforms.
4. If you don't fall down with clipless (or you don't mind falling down) ride clipless.

On average, a person's leg accounts for 14.5% of his/her body weight.

Source: I'm a cannibal.

Ya'll know that it is possible for something to be more powerful and less efficient at the same time, right? What are you all arguing? Power or efficiency? It is quite possible that "pulling up" benefits only one of these two metrics.

It is clear to me as a long time cyclist and racer that clipless (or any other solid foot retention, such as clips and straps or the duct tape you see on "breaking away") increases the amount of power you can put to the wheel. Does it increase efficiency? That is less clear. But sometimes you just need power.

Case in point: one time before a cyclocross race, I was riding around the venue with regular shoes (no clipless or straps). I went down a short, relatively steep driveway entrance to talk to someone; turning around to come back up, I had to almost walk the bike because I couldn't generate enough torque without lifting the recovering foot to get me up that hill in the gear I was in. With clipless I would just power up. Without I was limited to standing essentially one legged on the drivetrain to make it move.

Now then, picture a steady state, flat time trial; would I need clipless or straps? Probably not, if there is minimal acceleration required. The only advantage of foot retention in that case are the secondary effects of keeping your foot placement consistent and bike control. This is why, before clipless, road riders would ride with their straps relatively loose unless they had to climb, accelerate, or sprint. It used to be an indicator of someone about ready to launch a breakaway that he or she would tighten their straps prior to the effort.

OK, I stand corrected.


Well, here's the hitch. Any force that is used to lift your leg is force that doesn't make it to the drivetrain. If you need 100N to pull your leg up, and only happen to produce 90N on the upstroke, that's 10N which doesn't propel the bike.


Yep.... The bike is basically a two-stroke engine. The illustration in post #85 in this thread makes that quite clear.


Heh

Yeah, losing contact will definitely not help. A good pair of platforms will have enough grip for most uses, though it will almost certainly not be sufficient for some situations (e.g. high-cadence high-power sprints).

You keep using that word. I do not think it means what you think it means.

So if I do a lot of high cadence high power sprints, and slip off with platform pedals, am I losing power? What would you recommend? What if I ride in the wet? What does a powermeter say then?

I rode my bike to a doctor's appointment this afternoon and just used my dangerous clipless pedals as platforms. It's funny, whenever I started from a dead stop, like at a traffic light, my foot kept lifting off the pedal on the upstroke. Then I remembered this thread and realized that couldn't possibly be true because science proves otherwise.

No.

Andy Pruitt and bacciagalupe prove otherwise.

And we are all proved wrong.

Again.

There is still that question which niggles at me: One-legged training drills?

To me, that is a classic demonstration of the pull-up that occurs in some circumstances. If you don't pull up with force on the pedal (ie, in addition to lifting your leg), you are going to go nowhere after the first downward stroke.

I can see one legged drills can be done on platforms, but there is a need to "scrape" the pedal (and therefore there has to be an upward vector force involved) and a dead spot definitely would appear on a segment of the upward stroke, the pedal instead relying on momentum to get it through to a smidge after TDC.

I do tend to agree that the higher the cadence, and therefore the lower the gear, the less force is used to lift the pedal, but then there is less force used on the downstroke, too.

Of course, all this is open to being disproved. By Andy Pruitt. And bacciagalupe.

I've solved this whole pedaling conundrum...and how do you like my new Enve mismatched wheels BTW...

if you do not have to get off and walk a lot, use clipless pedals. it is infinitely better and it is not more dangerous than platforms.

that's all i need to say.

Hard to believe it took 200 posts to conclude that clipless is better.

I feel sorry for the future searchers that uncover this incredible waste of cyberspace.