closetbiker

just wondering...

waldowales

To keep certain BF members from freaking out!

closetbiker

... perhaps compliance with a MHL?

Square & Compas

To make them more aero. What is with the training wheels?

UnsafeAlpine

Balancing is an extremely complex maneuver. It's doubtful that it would be possible for anyone to keep the bike upright without the help of training wheels.

Allen

I'm going with another theory. I bet getting the robot on and off the bike is a serious PITA.
The training wheels are not to make the bike easier to handle but to make the robot easier to deal with.

closetbiker

... maybe he's just trying to "fit in"

jfmckenna

Regardless it's a pretty cool machine.

Square & Compas

UA, I beg to differ. On RAGBRAI there is are always solo tandem riders. I have seen one with a skeleton on the back as stoker. My favorite was the guy with the blow up doll, fully dressed in a matching bike kit, complete with helmet and a sign on the back that said, "IF YOU CAN READ THIS, THE ***** FELL OFF!" None of the solo tandem riders had a live human stoker and none had training wheels. So it can easily be done.

Cyclist0084

I bet that turns a few heads and raises a few eyebrows when seen going down the road.

Joe_Mo

Man that robot isn't pulling his weight. Looks like they're barely going over 8mph!

Glottis

It's a machine that took a lot of time and money to build, I guess. The guy doesn't want to risk breaking it.

From the official site:

RacerOne

Lots of time and effort into that, I'm sure it's much cooler in person.

UnsafeAlpine

Riding a tandem singly or riding it with a lightweight dummy is not the same as what this guy is doing. This is a powered automaton, likely weighing close to that of a normal person but without the balancing functions people have. Think of riding a tandem with someone on the back who is dead weight.

For more info on what it actually takes to ride a bike (the physics that are involved) see Bicycling Science by David Gordon Wilson.

Square & Compas

Are you alluding that I do not know the physics of riding a bike? If you are, I take exception to that. Especially since I ride a recumbent. I can attest it takes differant physics and more balance to ride a recumbent then it does a wedgie bike. I;ve been riding mine for over 7 years now, so I know something about it. But thanks for being as insulting and condescending here as you are in P&R anyway.

UnsafeAlpine

That book is more in depth than most people realize. It's a collection of papers written by those studying the physics of cycling. It wasn't meant as an insult but as a compendium to your already existing knowledge.

Of course, you tried comparing a stoker-less tandem to this mechanism, so I don't have a clue what you know...

Square & Compas

Somewhere on my computer hard drive I have a diagram of a human leg and a graph that shows the physics of the muscles during a pedal stroke. It is based on a wedgie bike, vs. a recumbent, but perhaps it came from the book you mentioned. I do not remember where I got it on the internet. I'll try to post it here. Is there a link to this book?

UnsafeAlpine

Bicycling Science

Square & Compas

Here is the diagram and graph showing the physics of a pedal stroke.

dougmc

I've got the book and have read it, and don't recall anything about riding a tandem without a stoker, or with a robotic stoker.

Ultimately, we all know what it actually takes to ride a bike, because we do it. The book is interesting, but it doesn't really tell you what it takes to ride a bike. Instead, it's mostly about riding better -- faster, mostly. It talks about aerodynamics, training, bike design, etc. I recall it talking a little bit about the balancing act that keeps the bike upright, but 1) we all do that without thinking about it and 2) it's only a small part of the book and 3) it's basically the same on a tandem anyways.

In any event, to suggest that the book is relevant to the comment you responded to is somewhere between nonsensical and insulting.

UnsafeAlpine

Except that this is a human sized robot without the balancing coordination that we all take for granted and a question was asked about training wheels. Without being able to talk to the guy that built the contraption, I can only offer my best guess. The book explains about robotic balancing and why it's so difficult to make a robotic two wheeled device. I thought it might be relevant, sorry that you feel the exact opposite.

dougmc

I don't recall the book talking about robotic balancing, but perhaps that's just because I have an older version of the book (not sure if it's 1st or 2nd edition, but it's clearly not the 3rd edition.) Or perhaps I didn't pay much attention to that part?

Training wheels probably make sense simply because if the bike falls over the robot guy is likely to get broken. And even if he does know how to balance properly, that won't help when the bike is stopped -- I doubt it knows how to put his foot out like a human would.

Either way, if the robot doesn't have balancing stuff built in, then he'd just be like a heavy weight back there, and then it's like riding with a heavy weight mounted pretty high on the back of your bike. Or like a tandem with a person who's just sitting there and not leaning with you (which seems to me to be how the stoker should normally be unless the pilot requests otherwise, though I've never ridden a tandem so perhaps I'm wrong there.) If your stoker does attempt to lean with you, it could cause problems unless he always leans the right amount at the right time -- which seems very unlikely.

UnsafeAlpine

My other reason for bringing up balance is the speed at which this thing is moving. As we all know, the faster we ride, the easier it is to keep upright. My guess is that bike is doing under 15kmh (which may just be a function of showing it off") which would be extremely hard to keep upright with an anchor like that in the rear. However, a stoker will naturally balance on the bike, involuntarily, thus helping the overall stability of the cycle. This gadget would not function similarly.

It would be interesting to ask the designer himself about the training wheels, since this is all pure speculation.

dougmc

I've never ridden on a tandem, so I could be wrong, but I have ridden on the back of a motorcycle and I was told to not help turn -- to just keep my body straight.

Balancing a bike is a mixture of turning the bars and moving your body (shifting your center of gravity.) In the case of riding no handed, you leave the bars out of it. In the case of a recumbent with a seat that goes all the way up your back, you can't shift your CoG much and you do almost all of it with the handlebars. (And it takes some getting used to, let me tell you!)

But in the case of a tandem, there's two different people who could shift their center of gravity, but only one controls the bars. It seems logical to me that the stoker should keep his body straight and shift his center of gravity as little as possible so as not to confuse the actions of the pilot, and indeed Sheldon Brown seems to agree --

... it seems that our robotic friend should be very good at this. (Leaning with it as it leans through corners would be simply keeping your body rigid -- not actually bending anything, just sitting there.)

Again, I suspect the training wheels are there simply for convenience, such as when the bike is stopped, as the robotic guy probably can't get off by himself, but the pilot can't get off and help him off as he needs to keep the bike from falling over (if there are no training wheels.)

manicmike

If you cant understand the difference between balancing something that weighs ounces as opposed to balancing a giant METAL robot on the back of your bike, you have bigger problems than anyone here can give you!