Twin engine docking

-When docking (perpendicular) should I be steering the boat when maneuvering or using the engines to spin the boat 90 degrees? I'm having a hard time with spinning it and keeping it where it needs to be. ARG!!! So far every time I've tried to spin it I've had to abandon that effort and steer it in. It works but I don't want to get accustom to doing that if it's actually easier to use the engines.

ANY helpful advice on this subject would be greatly appreciated.

Thanks.

Because you can recumbent in them?

But to keep the turn going, pressure must be maintained on the handlebar, else the bike will right itself.

By Jove, I think you've got it!

Or Nebraska.

From what I have been able to see in this thread, the old man is starting to act very *Kevinesque* in that he refuses to drop it and admit when *he* was wrong.

Stay away from motorcycles and bicycles, especially if you are in an emergency situation, unless you're walking the bike of course.

I hope the old man did not teach his grandchildren, great grandchildren and great, great grandchildren how to ride a bicycle. If he did, they all must have spent time in the emergency ward at the local hospital.

Of course, the Motorcycle Safety Foundation, and anyone else who knows anything about motorcycles, is wrong also.

Joe

Actually makes sense.

The sad thing is that I love motorcycles and would love to own and ride one again.

And yes, stay away from high speed motorcycles. ;-)

If it weren't for all of those people that "just can't see motorcycles....."

http://tinyurl.com/hb7c7

Just enter your state.

2) Maybe I don't understand what you are saying. How can you:

a) Be moving b) push on a right handlebar, causing it to move a little c) continue pushing on the handlebar d) have the handlebar not continue moving forward or stay in position in the direction it is pushed, thus not moving the tire to the left e) hence, not causing the motorcycle to turn left?

Now, if you are saying that this has something to do with a brief push on the handlebar and an ensuing off-balance condition causing a lean, which then causes a turn, I understand that! If so, I return to my original position that this special case is way more about understanding balance on a motorcycle than it has with steerage. Assuming the given that *any* lean on a motorcycle will cause a turn.

3) Somewhere, I lost the connection between this phenomenon and docking?

I still cannot comprehend how adding a motor causes the opposite.

There are a lot of factors in play when you make a turn on a two-wheeled vehicle. Try this sometime on you're bicycle. Ride along, nice and straight and without leaning. As you pedal along, gently push one of the handlebars away from you. (no leaning) Note which way the bike tries to turn.

Eisboch

I was never talking about those conditions.

Every bicycle I ever used turned right when I pushed the left side of the handle bar away me. Every motorcycle I ever owned did the same. Thus my analogy in my original post.

I never thought my original post to this thread would evolve into dirt bike racing maneuvers or disagreements on how to ride a bicycle.

'nuf said. ;-)

Steve P.

I guess you all will have to just go try it. It's due to the gryoscopic stability of the bike. Now .... did you know that helicopters were impossible to fly until gyroscopic progression was recognized and accounted for in the control of the rotating airfoils?

Somehow boating will tie into this somewhere.....

Eisboch

"The concept of turning the front wheel one way to go the opposite way certainly is counterintuitive. Those of us who started riding before there was rider training probably had to grasp the concept by ourselves, and perhaps we did it subconsciously. And some people never quite realize that you steer left to go right and vice versa. In fact, I have heard some longtime riders insist that that's not the case, that motorcycles steer the way the front wheel is initially turned. I have also heard bicyclists deny that a bicycle steers this way. The issue is also confused by the fact that you can steer a motorcycle by leaning, as anyone who has ridden any distance with their hands off the bars (a practice that can lead to disaster if you hit something in the road or have a flat tire, I need to point out) can testify. Some motorcyclists will tell you that shifting your body weight is the primary way to steer a motorcycle."

Source:

http://www.motorcyclecruiser.com/streetsurvival/motorcycle_countersteering/

Eisboch

otn

> "Joe" <golfvergnugen@earthlink.net> wrote in message

Look at your shifters/throttles. See how the port throttle bends or is angled towards starboard? And the reverse is true for the starboard throttle/shifter? This was done for ergonomics, but it's a great helper as well. The part of the boat you want to steer will always follow that bend. So if you want the stern to go to starboard in reverse, then the port shifter should be used (in reverse). Visualize it... you pull the port shifter to reverse, and that bend is pointing starboard... the stern will go the direction of the bend. Take that same port shiter and move it forward, and the bow will move to starboard... same direction as the bend. Want to go in circles about the boat? On ahead and one aft, and the boat will pivot in the direction of the bend in the shifters. Try it.

--Mike

"Joe" <golfvergnugen@earthlink.net> wrote in message

"If we intentionally move the contact patch line from vertically beneath the Center of Gravity, the bike will start to lean. For example, if while riding the bike straight ahead, we press on the left bar the front wheel points to the right. The front wheel tracks to the right (sometimes called “out tracking”). So the weight of bike and rider is now to the LEFT of it’s “support” on the ground, the tire contact patches. Because the weight is to the left, the bike leans to the left. It is important to note, for a LEFT turn, we initiate a lean to the left by pressing on the left bar, turning the front wheel to the RIGHT. This is often referred to as COUNTERSTEERING: a turn to the left initiated by turning the front wheel to the right."

It is an interesting action though and may be readily experienced if you ride straight and level at a constant speed, then very gently push one of the bars without leaning or correcting in any other way. Push too hard and you *will* have to take corrective action, otherwise you will go down.

Oh, well. Enough of that.

Eisboch

The shifting of weight will lower the center of gravity, enabling a sharper turn with less lean angle. I think Tom was just experimenting with a bike at rest. If he had any speed on the bike, he'd be on the ground.

Try it, you'll like it. It's also one reason kids have a hard time transitioning from a tricycle to a bicycle.

If you don't realize this, don't ride your bike in touchy situations where you may have to suddenly swerve.

No it doesn't. Try it. Shifting the weight just enables you to turn without as much bike lean.

What will cause handlebars to 'snap back' is often referred to as 'high siding'. This is caused by releasing the rear brake while the bike is in a rear-wheel skid. The sudden resumption of traction will cause the bike to suddenly right itself, often too far.

Thank you.

"This is often referred to as COUNTERSTEERING"

Here is where I think the concepts are confusing.

Just for giggles, I borrowed the dirt bike from the kid across the street and did some experiments on the straight and the S curves on my road.

There is no way you can initiate a left hand turn by pushing the left handlebar forward at speed going straight. It's not possible.

Now, if I lean left, I can control the turn by pushing the handlebar up to maintain the angle of the turn and the angle of attack to the curve. Just like a bicycle. That is entirely different than initiating a left hand turn by pushing the left handlebar forward.

And in case you are wondering what the neighbors thought of me running up and down the road at differing speeds on a dirt bike at 6:40 AM and turning right and left back and forth, don't worry about it. My neighbors are used to the occasional slice of weirdness from me.

It's cheap entertainment. :>)

See anything interesting?

As to speed, there is a long hill with a right hand curve that I use to build speed for a long straight run - that's where I did my experimenting.

I didn't hit the ground.

Not the same thing.

I still say those who are on the left/left side of the argument are confusing two seperate issues.

That's my story and I'm sticking to it. :>)

Eisboch :-)

Eisboch

Damn straight.

Hey, I'm only here for the discussion. :>)

Besides, I'm not a motorcycle person. Hate the things actually.

I regard motorcycle riders in the same vein as PWC riders.

I won't say which vein that is. :>)

An endless and fascinating virtual world.

Did you happen to know Jimmy Hoffa? :>)

This phenomenon is just an exercise in balance control, not steerage.

http://www.msgroup.org/TIP163.html

Or, it could be that a lot of people in the 'know' are just lying to you. If, however, you are ever in a position where you must make a sudden swerve, it helps to know how to do it. Guesswork causes people to go off the edge of the road or hit the automobile they were trying to avoid.

Unfortunately, she ain't buying it.

~~ sigh ~~

Corvettes are the only thing GM ever made worth a damn.

http://www.msgroup.org/TIP163.html

Why would Eisboch and I lie about this?

I want to see this "taught" myself because I agree with you - it's more about maintaining momentum and angle of attack in a turn than actually steering.

" �Speed Stabilizes the motorcycle� and �press left, lean left, go left� are two phrases heard by students taking the MRC:RSS rider course. During the course students may be told to �trust us on this one...it REALLY works� Well, it DOES really work, but during the course there is little time to explain why speed DOES stabilize the motorcycle and yes, you DO press the left bar to initiate a turn to the left." (from the 'lookie her' site)

Not knowing is not a criminal offense. Hell, most folks don't know this. One of my brothers, a Harley rider for years, didn't know it. Another, who was a motorcycle cop, knows it very well!

But, don't do it in an emergency.

When I would stern in with our larger boat (with twins) I would slowly go past the slip (on the starboard side) while centering the wheel and engines at idle, put port in reverse while bumping starboard in and out of forward or reverse as I needed to adjust my position. When finalizing the approach and parallel to the slip I would nudge both engines in and then out of forward to stop the boats reverse progress.

This worked for me. This worked for me

Push left, go left. Push right, go right. Just the opposite of a tricycle.

Take it back for a refund. :-)

Many boaters rely almost exclusively on the engines when docking a twin engine boat under normal conditions.

Don't forget to visualize your "pivot point" which will be about halfway between your bow and your stern on most twin engine vessels.

Also, you could easily find yourself moving ahead of the spot where you hope to pivot when you put one engine in forward and the other in reserse. The reason for this is that the prop works a lot more efficiently in forward than in reverse, so if you want the reverse side to come back at the same speed that the forward side is going ahead you will need to use a bit more throttle on the reverse engine.

You might try approaching the dock at less of an angle than "perpendicular" -unless you have very strong wind blowing you directly off the dock and in that case the closer to perpendicular the better. Try something closer to about 30-35 degrees. As you get close to the dock use your twins to "pivot" the bow out a bit so that it doesn't wack anything and that will of course also pivot your stern toward the dock.Remember that momentum will continue to carry your boat toward the dock as you pivot, closing the "gap" that would otherwise exist between the side of your boat and the dock.

Don't approach the dock any faster than you are willing to hit it.

Don't be afraid to back off and go around again. (Just as I had to do last weekend when a gust of wind blew up at the wrong moment.....)

Don't expect to be really good at this without a lot of practice, but you can become passably capable in an afternoon.

Try it sometime.

Eisboch

"Spin" a boat with outboards is possible, but it requires practice. The simplest way to manuever is to put the opposite engine in reverse (or forward depending) and use the other engine to change the direction of the bow. Occasionally, you will need to reverse that process while manuevering as conditions warrant.

Backing into any spot is also the best way to use vectored thrust in my opinion. In reverse, you are pulling the boat much like you would a front wheel drive car - the way you turn the wheel is the way the boat will go - much like backing up a trailer. Once you get a line of the dock, the rest is just applying power in the appropriate direction to bring the bow into alignment.

What I find very helpful in teaching docking manuevers is to pick a bouy ( or even a floating dock if there aren't any swimmers around) and use that for practice. Just spent an hour or so learning how the boat reacts using different approaches and experiment with the proper combination of power and thrust.

Pushing the left handlebar forward moves the front wheel to the right.

Pushing the right handlebar forward moves the front wheel to the left.

Eisboch

Eisboch

I can see several people are having trouble with this. Don't feel bad. So did I until I tried it.

Eisboch

True, standing still, the front wheel will move as described. But when moving ... the bike (not the front wheel) will turn to the side that you are pushing on.

Eisboch

http://www.rider-ed.com/tips/motorcyclestability.htm

Eisboch

Get some practice in open water and find out what works on your particular boat. If you want to spin quickly to port, put the starboard shifter forward, and the port shifter in reverse. In addition, turn the wheel hard to port for some vectored thrust. Everything is opposite for spinning to starboard. Be wary of trying to spin the bow into the wind in close quarters.

Wind is not your friend on a lighter boat and you need to maneuver quickly and decisively, all the time controling your speed to the minimum required to accomplish all of that. It can be a delicate balance at times and requires practice.

Eisboch