inventor

Treadmill bikes are propelled by walking; URBs would be propelled by upright rowing. Saying that the closest thing to a URB is a treadmill bike is the same thing as saying that walking is the closest thing to upright rowing.

ThermionicScott 

That particular benefit is already enjoyed by Elliptigo riders (a demonstrably stable and efficient means of upright locomotion) and few would argue it. But that's low-hanging fruit -- it's your means of propulsion that's the sticking point. The best way for you to convince any of us that this isn't a totally stupid idea would be to put some skin in the game and prove us wrong. As posted earlier in the thread, used welders, junked rowing machines, pulleys, wheels, etc are all easy to come by, so that's no longer an excuse. Have you even done a patent search to see if something like this has been proposed in the past?

That's a lot of hopeful imagining. It's a lot easier to imagine someone saying "**** that, I'll walk or drive." How about taking that amazing brain and trying harder to figure out how to build one?

BlazingPedals

Op has no intention of building the device, and it looks like nobody here is likely to do it, either. I'd say stick a fork in this thread, it's done.

ThermionicScott 

+1.

corrado33

I think you're completely wrong with most of this statement. Like I mentioned before, you're reducing the effectiveness of some of the strongest muscles in the body (glutes, quads, hamstrings, etc.) Your device won't be able to reach anywhere near the speeds of a bike. Not to mention it's much less aerodynamic and once you get above ~20MPH you're mainly battling air anyway. You mention that during the push phase you'll be using your pecs.. do you realize how weak your pectoral muscles are compared to your legs? Have you ever done exercises targeted at your pecs compared with your legs? I can lift hundreds of pounds with my legs. I can't even get close to that with my pecs. And that's with using your pecs at an optimal geometry! I'm not saying that you're only using your pecs to propel this bike, but again, reducing the effectiveness of the much stronger muscles of the body. You may argue that you're still using the leg muscles, but you really aren't. Work is a force x distance, and your leg muscles aren't moving nearly as much as they would on a bike or running, meaning they're doing much less work.

As for the second point "load-carrying capabilities," well, that's a load of crap. Any exercise device can be made to carry the same amount as a bike if built with the proper frame attachments. Heck, some bikes can't carry ANYTHING. (Any specific aero road bike without braze ons.) In essence, this is a strawman argument. Just because you've envisioned your device with the ability to carry a load does not mean that other devices like the elliptical thing above cannot without the proper attachments. In fact, any trike theoretically has the ability to carry more than any bike, given the proper attachments.

OH and PS. That elliptical thing above HAS a rack on the back so... yeah. There's 60% of the ability of a bike to carry a load. Make a quick bracket for the front and you're easily at 90-100%. These devices weren't designed to tour. They have no NEED to carry a load other than the person. I'm sure if a "touring" elliptical thing like above was invented it'd be able to carry more than any bike.

CliffordK

Rowing is one type of water locomotion, and can be done with either a movable seat or a fixed seat.

I'm happy with my (inflatable) kayak, paddled with primarily pulling the paddles, but in reality both pulling one side and pushing the other. Of course, the river current is nice too, but one can paddle for quite some time, and with great force.

One of the limitations in cycling may not be the strength of the legs, but rather one's cardiac fitness. So, while the legs can push out 500 watts for a short time, the heart and lungs can't keep up. That may also be why drugs such as EPO have such a positive benefit in cycling.

Anyway, the strength of the legs is great for sprinting, but one may be able to use a lot less brute strength for ordinary riding (thus, various hand cycles and wheel chairs can keep up a decent pace).

I doubt this URB would be capable of competing at the elite racing levels, but it may do just fine getting people to the corner store.

corrado33

Agreed, but if you really want to get into it you have to look at the biology behind human muscles. If you've ever seen the book "bicycling science" it explains this really well because I'm bound to butcher it.

Fast twitch muscles are much more efficient at using energy than slow twitch muscles (or rather, use a more efficient source of energy.) That energy source switches over when you "contract" your muscle for more than X seconds, where X is longer than a typical pedal stroke (or running stride.) I don't remember the actual number, but I do remember that it's longer than what cyclists or runners use. That that means is that on a bike or running, your mainly using "fast twitch muscles" and therefore the more efficient energy pathway. If I recall correctly, most people can maintain using fast twitch muscles almost indefinitely without fatigue. (Until the entire body no longer has energy to give.) Using the "slow twitch muscles" uses energy sources that are closer to the muscle, and are hard to replenish. Now, I know seated rowers can reach pretty high cadences, but I can't imagine a standing rower reaching a high enough cadence to utilize that more efficient energy pathway. So yes, this could work, there's no way this URB could ever keep up with a normal bike. Trips to the local corner store, sure. 30 mile exercise rides? Not so much.

wphamilton

Because those are the advantages that upright bikes have in general over recumbent bikes. That's why I felt it a more likely claim than the dubious power arguments.

Tman1965

Is your rowing machine a Concept II?
Use Watts Calculator on their website.
If you can't get to at least 150 Watts easily, forget about it. (150W is my recovery pace on the bike)
That's an easy option to check the feasibility of your project.
Good luck.

p.s.the watt calculator is only valid for their machines

Tman1965

If you replace "slow-twitch" with "fast-twitch" and vice versa then your post makes more sense.

inventor

Okay.

The means of propulsion isn't the sticking point, it's what's so great about the whole thing.

That’s not important to me; I just want to get the word out.

I’ve been proving you wrong for several days now.

I’m not aware of having made any excuses for myself.

Yes. I came up blank.

You said: „I'm interested to see how people with impaired balance are going to be coaxed onto a contraption with a sliding platform on top of two wheels...“ In response I provided three arguments showing why such a person might consider riding a URB even if standard bikes aren’t an option for him. This has nothing to do with hoping or imagining anything.

Okay.

inventor

From Section 8, „Efficiency,“ of my PDF: „The greater air resistance would make them (URBs) noticeably less efficient (than standard bikes), but most people don’t care very much about air resistance.” “Cyclists on standard bicycles encounter more air resistance than recumbent riders, and yet standard bicycles are far more widespread than recumbents. It seems that, when it comes to cycling, most people don’t care much about air resistance.”

Like i said last time, „you’re talking about the power you can apply during a single short burst of strength, which is irrelevant to human-powered vehicles, where the question (when going uphill or fighting a headwind) is, How much power can you apply during a sustained effort?“

In other words, what I'm saying is that your one rep max on the leg press is completely irrelevant to your ability to manage a tough climb on a bike; what you’re saying is that it’s the decisive factor.

My point is simply that URBs could be designed and outfitted to carry loads similar to those standard bikes can carry (I'm referring, of course, to standard bikes that are designed and outfitted to do so).

inventor

Thanks for your post.

Yes, I do use a Concept II, and yes, I can easily maintain 150 Watts by means of upright rowing.

By the way (and this may not be apparent even to rowers – including indoor rowers – reading this thread), propelling a URB, if practised vigorously over a long distance, would, like cycling and running, tax one’s endurance rather than one’s strength-endurance (as regular rowing and erging do): propulsion would be applied both when sliding forward and sliding back, i.e. continuously, and not only during the „drive“ phase, which means there wouldn't be a "recovery" (or, to put it another way, the recovery would be used to provide propulsion). However, as I state in Section 18 of the PDF, „it would be possible to remove one or the other of the drivetrains and propel a URB by pushing or pulling only in order to accommodate an injury or disability or achieve a certain training effect.” If you did that, you would be training strength-endurance.

Tman1965

Video, or it didn't happen...

ThermionicScott 

Hardly. Proof would involve something convincing. Pretty much all the rest of us have the same realistic mental picture of how this thing would work. And "work" is being charitable.

You said that you don't have the resources, then later, the interest in actually building one. Are you scared that your contraption won't work as you imagine? Since you haven't found any prior attempts at a machine like this, the next step for a legitimate "inventor" would be to try to build one. That would show a little more conviction in your idea than just arguing with people on the Internet.

Sure it does. None of those "arguments" are going to steer someone toward your contraption, plain and simple. They already have better options.

Until you have a real-life demonstration, this is all imaginary! That is inarguable.

BlazingPedals

Inventor, nobody here wants to do your work for you and develop your idea. Is that clear enough?

Nermal

Well, that seemed to be the intent in the beginning, but it seems to have morphed into a very adversarial thread, which is why I'm no longer interested.

inventor

As far as the viability of upright rowing as a means to propel a human-powered vehicle is concerned, that's been proven by many different cultures in many different parts of the world throughout history. Gondalas are only the best-known example, there are many others (I've already mentioned the Swiss Weidlinge).

Therefore, as far as the viability of URBs is concerned, the two basic questons to be considered are:

(1) Would URBs in some way force a posture or movement on the rider that would prevent him from generating the same kind of power he'd be able to generate in a boat (I mean a boat designed for upright rowing)? The answer is obviously no, since that would be a basic consideration in designing the thing. Hence, for example, the greater height and length of URBs compared to standard bikes -- the length allows for full extension of the arms, the height allows one to push against and pull on the handlebars at shoulder height.

(2) Does the propulsion system or the URB as a whole involve inefficiencies so huge they'd render URBs impactical? The answer, again, is no (see the Section on "Efficiency" in the PDF).

Chris Bamford

[QUOTE=corrado33;18193198]You'd never be able to keep your body stiff enough to move the platform by pushing and pulling against the handlebars. Your back would hurt really bad after a few minutes. If you don't believe me, go stand on ice and push/pull against something. Yes, your feet will move, but not very easily.

I've been following this thread on my iPhone while travelling — had a chance to download and review the PDFs yesterday and I believe corrado33 has it right.

Suggest you do a simple test to check the amount of power available for propulsion: Get a skateboard and a simple pull-type "fish scale". Rig up the scale to an immovable object (in front of and later behind) the skateboard, then pull and push yourself to and from those objects and see how many lbs force are generated at the scale. Compare that to the downward force available at the pedals on a conventional bike.

My prediction is the skateboard forces will be much much less.

inventor

By saying that when trying to row upright you wouldn't be able to keep your body stiff enough, corrado33 is basically saying that Venetian gondoliers are a figment of our collective imagination.

When he says that upright rowing causes back pain, he's simply wrong. Considering (1) how few people have ever attempted upright rowing, (2) the fact that corrado33 doesn't claim ever to have attempted upright rowing himself and (3) the ludicruous statements he makes about it (statements that may sound plausible if you don't know much about rowing and sports theory, but he's not fooling me), it's clear to me that he's grabbing things out of thin air; this back-pain thing is a good example of that.

When he suggests standing on ice (why ice?) and pushing against/pulling on something and says that "yes, your feet will move, but not very easily," he's not making a point relevant to URBs. Since you seem to believe otherwise and that his point is actually valid, let me point out that someone doing so while wearing skates would in fact find it very easy. Not only is corrado33 not making a point, he's wrong about his own thought experiment. This kind of muddled thinking is typical of everything he's said in this thread.

You must have not understood any of the things I've said about muscle strength and power as they apply to propelling human-powered vehicles, and the same goes for what I've said about the real-life implications if I were wrong; otherwise, you wouldn't have written this.

By the way, corrado33 puts great store on the legs: "What you've done is taken away the use of the strongest muscles in the body from a seated rower. While standing you can't directly use your quads or hamstrings to their full extent, something almost every other mode of transportation/exercise (walking, running, biking, rowing) does well." "Work is a force x distance, and your leg muscles aren't moving nearly as much as they would on a bike or running, meaning they're doing much less work." Now, hardly anyone practises upright rowing, so hardly anyone understands how immensely effective it is (a shame, by the way, because talk about a great exercise!), so it may seem reasonable to most people to assume that, yeah, the range of motion of your legs is pretty limited, and since your legs are so much stronger than your arms, and since moving under your own power is so dependent on maximum strength (yeah, right), obviously upright rowing must be inefficient. Well, let me give you an example of a movement that (1) is far more common than upright rowing, so common it's an Olympic sport, (2) doesn't make the slightest bit more use of the leg muscles than upright rowing does and (3) nevertheless allows you to reach serious speeds: flatwater kayaking. I just checked the world record in the 1000 meters: it's 3 minutes and 22 seconds for the men's singles and 3.48 for the women. That's around ten miles an hour -- definitely not something a rower, who knows something about the speeds reached by displacement vessels powered by one person, would sneeze at. So no, a significant range of motion in your legs isn't a prerequisite to applying decent power to human-powered vehicles.

Chris Bamford

It would indeed be easy, as there would be very little resistance offered by skates on ice. This, however, is irrelevant — there would be significant resistance offered by the URB as you are attempting to propel it forward, uphill, etc. Much more akin to the boots-on-ice analogy suggested by corrado33
_ _ _ _ _ _ _

In any event, I suspect your reliance on Venetian gondoliers' technique as so very similar to that proposed for the URB is misguided.

I have been to Venice and seen those gondoliers at work (have you?) and they do a great deal more than simple push-pull-push-pull-push-pull. Some of those rowing techniques are illustrated at this link: Boats - Rowing technique, and the rower's legs, trunk, arms etc take on many positions and motions not anticipated with the URB.

One might also consider that they rarely seem in a hurry to get anywhere, and at $85-$100/hour, who can blame them?

corrado33

You love to contradict yourself. You say that upright rowing would be as efficient as other forms of exercise, then you call it "great exercise" a term generally saved for things that require a lot of effort! "Climbing that mountain would be great exercise!" You then quote that in an olympic sport that does not primarily use legs (kayaking) that they can do the 1000 meters in a bit over 3 minutes. Well, let me enlighten you on something. EVERY OTHER OLYMPIC SPORT that uses legs primarily and does something at similar distances does it faster. Running? Check. Biking? Check, speed walking? probably considering they do 20,000 meters at just over 3 minutes 50 seconds per 1000 meters. Regular rowing? Check. Some of the differences in speed is enormous! Running they do it in a bit over 2 minutes! Biking they do it in seconds! Are you arguing that the runners and bikers are just that much more in shape that's why they can do it faster? No, it's because they're using some of the strongest muscles in the body and using them effectively over a large range of motion!

Oh and PS. Flatwater kayakers use their legs quite a bit. They rotate themselves on their seat. (Some even have rotating seats!) If you read about it, that's where much of the "power" in the stroke comes from.... the legs...

I won't even talk about how being on water offers the advantage of a "low friction" environment where energy is conserved for a while after you stop applying force, and the boats are built to cut through the water with as little effort as possible, unlike running, walking, riding a bike up a steep hill, etc.

Saying that you'd be able to ride a URB on the same roads and even close to similar speeds as a biker? It's preposterous. You won't even have enough power to make it up hills unless the thing had mountain bike gearing.

This cracked me up. You're saying that moving under your own power isn't strength dependent? Then answer me this. Why are professional bicycle sprinters the strongest bikers in the field? They have the biggest legs, with the most muscle mass. They often are bigger men in general (bigger chests, arms, etc.) Why then can chris froome not sprint as fast as the sprinters? Obviously he's in shape enough. Why are olympic sprinters (running) big men? Why are they not skinny like the people who win the 10,000 meter run? In fact, I'd argue that distance runners are in better cardiovascular shape than the sprinters, yet the sprinters would still beat them every time at any short event.

Your arguments (and sarcasm) don't make sense.

EDIT: You should probably read this quote from a flatwater kayaker website.

https://www.flatwaterkayaking.com/how...echniques.html

2manybikes

And, when it's too windy the gondolas do not go out.

ThermionicScott 

Just for S&Gs, I googled "racing gondoliers" and found this video. Note that they need whole teams, bending over and putting their backs into it, to get appreciable speed:


A single person, pushing and pulling at shoulder height, would be at quite the disadvantage by comparison.

inventor

In my last post I mentioned kayaking, thereby voiding corrado33's claim about the absolute necessity of one's legs going through a significant range of motion if you want any chance of propelling an HPV in a way that can be described as efficient or effective.

Now I'm going to void the various claims made about pulling against and pushing on an immovable object and how doing so relates to upright rowing. First off, this is precisely the setup someone would come up with who doesn't know anything about rowing. Let's say you try this experiment on a surface or object that allows you to move back and forth easily -- you're standing on a skateboard, for example, or you're standing on ice and wearing skates. Obviously, even then the mere fact of moving your body back and forth would require a certain amount of effort and would probably be tiring after a while -- and that's just from performing the rowing motion, never mind propelling a vehicle! But as I say in Section 4.2 of the PDF, "since the rider’s mass would be greater than that of the URB, the rider’s speed would remain constant while the road speed of the URB would vary slightly throughout the stroke. The same principle applies to racing shells, where the rower’s mass, centered on the sliding seat, remains constant while the speed of the boat varies throughout the stroke."

Consequently, if you want to check how hard or easy it would be to perform the rowing motion on a moving URB -- remember, just the rowing motion itself, not how hard it would be to use it to provide propulsion -- the simplest way to do it would be to stand in front of a bike, grab it by the handlebars and alternately roll it towards you and away from you using both arms.

Since you're not moving your body mass back and forth, only the mass of the bike, this realistic scenario would be a lot easier than the unrealistic one suggested by Chris Bramford, corrado 33 and ThermionicScott. And on a moving URB it would be easier still, because instead of having to actually reverse the motion of the URB at the beginning of each push/pull, you'd only be accelerating it slightly during the push phase as you pushed it away from your body (again, due to your body's greater mass, its speed would remain -- for all practical purposes -- constant) and slowing it down slightly during the pull phase.

By the way, the same principle applies to rowing machines: on conventional, "static" rowing machines your feet are stationary in relation to the ground, which means you have to accelerate and decelerate your body at the beginning and end of each drive and each recovery. It's not actually a good simulation of on-the-water rowing, and it's tough on the back. Hence the development in recent decades of "dynamic" rowing machines and rowing machines on slides.

I don't know what you mean by "so very similar"; there are obvious similarities between the voga veneta and the motion one would perform on a URB and obvious dissimilarities; so what? A closer match than the voga veneta, by the way, would be the voga alla valesana, I just didn't mention it because it's less well-known and there was no reason to complicate matters.

You're not making any point relevant to URBs.

You seem to be implying that the lack of hurry exhibited by gondoliers when carrying passengers relates to the speeds one could expect to achieve on a URB.