Modern Vespa

Huh? Where do you get that from?

riders doing salt flats runs at Bonneville found out that high speeds the input to the handle bars needs to change direction. instead of push left go left, they had to push right to go left. I think Cal Rayborn found this out when he tried the first few runs on a HD. They touched a bit on it in the movie " On any Sunday".

http://www.hulu.com/watch/79438

Without watching the whole movie to find out what was opined (unless someone can come up with any other link, I've just spent 10 minutes searching for any reference to this supposed effect), I'm sticking to what racers on the track find - countersteering happens at all speeds, up to 350 kph (the fastest as far as I know that's been clocked in Moto GP).

sorry should have told you where the spot is. right at the 59 min of the movie. But you should really watch the whole thing its a great movie.

I'd love to watch it if I had time! This house re-model is coming down to the wire...

oh it'll wait.

This is contrary to pretty much every other public statement by people who ride both. You could be right, but that would imply that thousands of other people are wrong.

Speaking for myself (I ride both, extensively) the motorcycle is much, much harder to push off its line at speed, and requires significantly more countersteer in order to make a sudden swerve. Physics would tend to back that assertion, since the motorcycle wheels represent significantly more spinning mass.

This whole thing is about physics and geometry. The exercise is to shift the center of gravity to the inside of the intended turn. Since the front wheel is on a caster, and offers the resistance of a gyroscope, pushing it a little one way results in an equal but opposite push on the scooter's center of gravity. Shove the wheel a bit to the left, and the scooter falls a bit to the right. Then, again due to the caster of the front wheel, the wheel comes right on its own accord trying to compensate for the off center, off balance, configuration of the scooter. And, bingo! We have a right turn. Now if you can shift the center of gravity enough to start this process without nudging the handlebars, then OK, it works the same. If any of you have ridden a bicycle "no hands," then you know about steering with your body (butt) weight. That works just like I've described, and is easy because of the light weight and slow speed of the bicycle, especially the wheels. It's just a question of the forces necessary to overcome the gyroscopically generated inertia, and shift the center of gravity of the vehicle. A fat guy riding a moped would have abetter chance than a skinny guy riding a Gold Wing. But on motorcycles, inducing turns by shifting body weight is an inefficient and unreliable way to go.

You guys are all either overthinking or underthinking this.

The illustration below lifted from "Proficient Motorcycling" reveals all.

If you can get a PTW to lean, it will turn -- due to the effect shown below. The farther the lean, the tighter the turn.

The question boils down to how to initiate the lean. By far the easiest and most controllable way to do it is to countersteer, then centrifugal force does all the work of creating the lean.

I believe this describes what I was referring to.
Mega.


Edit* I should know better than to try and quote somebody else's experience in life, I have never done it and I doubt I ever will.
I apologize for the confusion I have caused.
Mega.

Perhaps I am just more comfortable on a motorcycle but it seems to me I am having a harder time on my scooter avoiding man hole covers like I used to on my bike.
I could throw the bike out to the side and the tires would miss but I clip them on the scoot, to me the scoot reacts slower.
Mega.

Mike Hailwood.

Harv

I tried turning my bicycle with no hands this morning and they way it worked for me seemed to be a series of quick weight shifts to the side of the direction I wanted to turn which made for a series of tiny counter steers and tiny adjustments. Perhaps if you dedicated your life to it you could be the smooth-turning bike guy in Cirque de Soleil, but it's otherwise not too effiecient.

I am with the 1000's who say the scooter is much more nimble than either of my prior bikes, one being a ducati 996. A quick push or pull of the bars and the scooter swerves right around potholes, manhole covers, rabbits, cats and the occasional bandit.

With smaller tires that carry less gyroscopic effect it stands to reason that it should be more nimble.
I rode my Derbi Atlantis all summer and it is underpowered and fun though almost scary going down big steep hills. After all its not much more than a kitchen chair with handlebars.
I rode my Vespa for just over a week before I tore it apart for paint and body work and its unbelievable the difference between the two, its incredible!

On my CBR I was a part of the machine and with my KTM motard I was on one wheel a lot of the time but I would still play the game of Not running over anything slippery, painted lines, man hole covers and tar snakes.
I am glad that thousands find it more maneuverable and I believe that's a good thing.

Perhaps having both legs reconstructed and then having to learn to walk again after half a year in a wheelchair has made me a little skittish.
I know it has made me rusty.
I am far more comfortable on my Vespa than the Derbi and I am not willing to take chances that I used to without thought.

I am glad for your honest answers, I love motorcycles but It might be better to stay with what I have for now. Until I get some more muscle strength and a bit more confidence.
Mega.

Most scooters are designed for low speed, most motorcycles are designed for higher speeds. Twitchy wouldn't be a good thing on a motorcycle that can exceed 100 mph...

OTOH, trials motorcycles (my first was a Hodaka Ace decades ago) of necessity have to be extremely twitchy. The guys now who jump from log top to log top are so amazingly precise!

It's all about suspension design, and the right compromises for the job. If you want quick response, reduce the trail. To make it more stable, increase the trail.

(I know this is over-simplified - I'm leaving out mass and inertia and gyroscopic effects and on and on. But given equal parameters between two bikes, suspension geometry is key.)

If you've never seen this stuff, here's a YouTube video my local club shot...

Happy Thanksgiving!

John

At the risk of offending some people I believe it is possible to turn without counter-steering albeit with a lot more difficulty. When I read about it I am reminded of the basic principles in ice skating. Figure eight: take off on right foot on outside edge to the right with right shoulders and hip forward. This circle is the hardest to accomplish because one needs the forward propulsion alone to acomplish it. Once you complete the circle and put your free foot forward, retract your shoulder and hip, the counter steering is evident. This is when you finish the other circle on the inside edge with ease. On the scooter I have to say that it happens in a much more fluid and spontaneous fashion. Still if turninng left, the left ass cheeck, shoulder, as well as the right "nudge" (which has been so aptly described by VegasGeorge) all work in harmony to maximize the counter steering.

Putting aside all the physics and 'rithmatic...

I read and understood the concepts about counter-steering before I took ownership of my first PTW. I was determined to be a prepared new rider.

Still, as a newbie rider I found that yes, I was steering by throwing my weight around, leaning the bike, as it were. (I know now that counter-steering was still in effect, albeit by a different method, that's been already covered here, but in my mind, I was just leaning.) It was working, I wasn't falling over, and I hadn't ridden off any cliffs, so I stopped worrying about it.

Eventually I read a post here that counter-steering by pushing the handlebars felt a lot more accurate so I worked at it until I got it.

It is. I can define my riding lines much better with good handlebar control than by throwing my weight around. Much better.

On the subject of the comparative nimbleness of scooters vs motorcycles, My experience is that my scooter is far, far more nimble my cruiser.
(Of course, it's a cruiser...so what isn't? )

If scooters/motorcycles could be designed to be controlled in typical riding situations no hands , there would be many, many sold to enable doo-dadders to use their handheld electronic doodads while riding.