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OT: "Push" steering question

10/04/2007 10:39 AM

I've been riding dirt for years but this summer I moved to riding sport bikes on the street. (GSX-R 600)

Most of my riding in the dirt has been a completely different experience then the street. One of the most glaring differences is "push" steering. Push steering is where you push the handlebar forward on the side you want to turn towards.

Can anyone explain in simpler terms how this works? It reminds me a bit of a challenge question we had here about a year ago, (the one with the spinning wheel in the briefcase) what are these forces at work that make the bike behave this way? Does pushing the steering in the direction you want to go change the angular momentum, which forces the bike to lean in that direction?

I do not understand how it works completely. Anyone up to finding a diagram as to how it works, displaying the forces at work?

Simple question I know, and yeah I could probably Google/Wiki this for other explainations but I like to hear what you guys have to say.

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#1

Re: OT: "Push" steering question

10/04/2007 1:14 PM

After 2 years, and 2 surgeries on an ankle broken in 15 places, my advice is not to change your current riding practices. The "push" technique works, but changing your own training is difficult.

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#2
In reply to #1

Re: OT: "Push" steering question

10/04/2007 1:43 PM

Yeah, the thought of what could happen if... is never too far from the mind when I ride. I ALWAYS ride in full gear (2 piece race suit, gloves,boots, helmet and hearing protection) though regardless of where I am going.

I have had a couple scares now, mostly from lack of confidence... fearing I am going too fast for the corner, hitting the brakes (which stands the bike up), focusing on the side of the road (target fixation) and going straight for it. I kept the shiny side up and came to a relatively controlled stop or managed to hold the road.

I have had aquaintences die or be seriously injured on bikes, but thats not going to stop me from riding.

I am not looking to change the way I ride I was just trying to understand it better so I could better explain it to others. The topic came up in the office this morning.

Replying to this brings to mind another query... how does the braking negate turning on a motorcycle. I don't understand it but I know that if I'm hard into a corner and put on some brakes the bike "stands up" and I lose some of my cornering ability.

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#4
In reply to #2

Re: OT: "Push" steering question

10/04/2007 4:27 PM

I have had a couple scares now, mostly from lack of confidence... fearing I am going too fast for the corner, hitting the brakes (which stands the bike up), focusing on the side of the road (target fixation) and going straight for it. I kept the shiny side up and came to a relatively controlled stop or managed to hold the road.

Yikes -- this is deadly. I've been a successful road racer, and long time motorcyclist, and I too get into exactly the situation you are describing, despite knowing how to get the bike around a turn very fast... but something goes haywire, and you start to turn the bars away from the thing you are trying not to hit -- like the edge of the road, or the car in the lane into which you are starting to drift -- and bingo -- you go just where you don't want to.

The explanation is very simple. First, and most obvious, is the the CG of a motor cycle is well above the road. When you turn the handlebars to the right, the front wheel moves out from under the CG, toward the right. The bike has to fall (bank) to the left, and will regain balance once the "centrifugal force" associated with the turn rate balances the bank angle.

The other explanation works in exactly the same direction: when you turn the handlebars to the right, gyroscopic precession of the front wheel also banks the bike to the left.

Everyday, consciously practice pushing right to go right. Don't do it aggressively at first, but pay attention to the way it feels, and notice that it feels awkward. Find a wide clear street and weave back and forth for awhile. Don't use body motion, because it confuses the issue. If you are going straight at 20 mph, and you turn the bars ever slightly to the right, the bike has to bank to the left. Eventually, if you are so inclined, you will find that you can use this technique to bank the bike right down to knee dragging in a couple tenths of a second. The folks who think it is all "body english" are deluded: if you want to really control the bike you have to countersteer.

Keith Code modified a bike to demonstrate the principal. Interestingly enough, I raced against Reggy Pridmore, a guy mentioned in Keith's site as promoting body english instead of counter steer. I could always beat him through the turns, but I attributed it to having a better handling bike -- I was not his caliber, as a racer. But now I wonder -- maybe he really didn't understand how to get a bike to quickly bank: it was in series of tight turns that I'd catch him, then he'd blow past me on the straights.

BTW, hitting the brakes alone does not stand the bike up -- you can brake racer level hard and still get the bike to turn. I think hitting the brakes is just the first step in the mild panic that causes you to very subtly turn the bars away from what you want to avoid ------- sending you right into it. It's a classic motorcycle accident, and just what the Motorcycle Safety Foundation was trying to cure when they came up with the "push right, go right" slogan.

Do change the way you ride. If you are going wide on a turn, and you have not firmly grounded the exhaust system or pegs to cause you to go wide, then what you are doing is causing you to go wide. You've got to do it differently, or you'll join your dead friends.

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#8
In reply to #4

Re: OT: "Push" steering question

10/05/2007 8:33 AM

Good post.

BTW, hitting the brakes alone does not stand the bike up -- you can brake racer level hard and still get the bike to turn. I think hitting the brakes is just the first step in the mild panic that causes you to very subtly turn the bars away from what you want to avoid ------- sending you right into it.

I was under the impression that braking negated some of the tires centrifgal force, I suppose this has to be true, and this would make the panic reflex of trying to steer away from something easier.

I notice that in high speed turns 130km/h ish that push steering becomes more difficult, requiring more force. This could be just my bike, or is it that it requires more force to move the tire due to more centrifugal force?

Do change the way you ride. If you are going wide on a turn, and you have not firmly grounded the exhaust system or pegs to cause you to go wide, then what you are doing is causing you to go wide. You've got to do it differently, or you'll join your dead friends.

This took me a bit to understand at first when I started riding. It's a confidence thing I think. This is the second time I have heard this advice... If you are into a corner and feel you wont make it, push steer and lean harder.

I go out everyday for a lunch time ride, on a deserted section of road with about 3 consecutive S turns. Everyday I push it a little further, take the corners a bit faster. I found this the best way to progressivly increase my confidence in high speed turns. I started taking these corners at the reccomended speed of 60Km/h when I first got my bike a few months ago and now am very comfortable taking them at 130. Chicken strips are for losers! (which makes me a loser as I still have 1/4 of tire tread that has yet to meet the road)

I'm hoping next year to take the track course at Mosport. Maybe then I'll be able to wear my suit and not be ashamed of the unscuffed knee pucks LOL.

Anyways, thanks for the replies, I was hoping for a diagram of the forces involved, I'll see if I can find one.

this site tries to explain it. http://www.msgroup.org/TIP048.html

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#10
In reply to #8

Re: OT: "Push" steering question

10/05/2007 10:55 AM

I was under the impression that braking negated some of the tires centrifgal force, I suppose this has to be true, and this would make the panic reflex of trying to steer away from something easier.

If braking slowed the wheel quickly, it would be gyroscopic effect that decreases, not centrifugal force* (which really doesn't exist, despite the fact that I used the term in my explanation above.) But during the couple of tenths of a second during which you are trying to get a turn established, the speed changes very little, so the gyroscopic effect also changes very little. Applying the brakes does, however, tend to make the front wheel align with the bike's vector, because of the effect of "trail". Trail is the distance from the extended steering head pivot axis, (where it contacts the ground) to the center of the tire contact patch. It is on the order of three or four inches on many bikes. So if you apply the brakes, you strengthen caster effect (the patch is more firmly pulled into line), making the bike a little resistant to steering inputs.

I notice that in high speed turns 130km/h ish that push steering becomes more difficult, requiring more force. This could be just my bike, or is it that it requires more force to move the tire due to more centrifugal force?

It happens on every bike. The faster you go, the more stable it becomes. So if you set the bike up to turn easily at high speed, it is too twitchy at low speeds, and vice versa. It's the central classic optimization problem in bike handling. You have a bike that is very nearly perfect in my view: both flickable but also stable. But you'll find that when you go to Mosport, you'll be amazed at the effort required to throw the bike into a turn at high speed. With two wheels both furiously spinning, the motorcycle really does not want to go anywhere but straight, due to very strong gyroscopic effect.

You can demonstrate the strength of gyro effect with a bicycle wheel. You can easily spin one fast enough by hand to feel that is takes effort to turn it, and when you do turn it it will also turn on a perpendicular axis -- like it has a mind of its own. Just increasing the mass of the wheel by 20 times has a huge effect alone, but speeding it up by a factor of 10 or 15 so has a huge effect.

(Ken's tearing up and going to wax nostalgic -- well OK, I'm not really tearing up.) Thinking back to the early 70's, our team won (!!! -- we think to this day -- but in the official standings we were 2nd overall) the 24 hours of Nelson Ledges by minimizing gyroscopic effects -- namely by riding a small, light bike. Most teams switched riders at one hour intervals, and after an hour, you'd be shot. We wouldn't be as shot though, because we didn't have to work so hard to get the bike into turns. On our little 350 four cylinder Honda, there were only a few bikes we could pass on the straights, but we could pass everything in the turns, inside the line, outside the line, etc. Nelson ledges has a long, high speed turn (The Carousel) that we'd take at full throttle in maybe fourth or fifth, and as we'd exit that turn we really had very little speed left -- we were already going close to as fast as we could go. So big bikes would motor by us down the long back straightaway, but we'd catch em and pass em in the turns. Plus, because we weren't as worn out, we'd crash less -- so while they were fixing stuff, we were making laps. I always like to tell Harley riders that the only bikes we could pass on the straights were the souped up tricked out Sportsters, with three times our displacement. (There were actually a few others too -- in fact there was a 250 cc class back then.) But there were loads of 500, 750, and open class bikes -- and we whooped em all by having a bike that was easy to ride. (The deluded people who think they won by one lap were riding a 350 Yamaha two stroke -- even lighter than our bike.)

Yet more rambling: Eric Buell was an excellent rider, and I think he rode on our team one year. He campaigned a 250 two-stroke Harley (Aermacchi, really) GP bike, that would have handily blown the doors off our 350 in a short race, but it would have needed about three or four overhauls in a 2000 mile race.

Gads, I could ramble about this stuff forever... Definitely go to Mosport, and if you have the time and money, do some racing -- it's time very well spent.

* (When I put "centrifugal force" in quotes in my original reply, I wondered if I'd regret it. As you probably know, there is no such force, which you can prove by swinging something around on a string, and then letting go of the string. If there were actually a force pushing out, the item would go flying off radially --- but, in fact, it flies off at a tangent to the circle.)

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#11
In reply to #2

Re: OT: "Push" steering question

10/05/2007 12:21 PM

Keith Code talked about your traction account. You only have so much traction in the bank. If you are using all your traction to corner, and you then apply the front brake, you will overdraw your account with predictable results. More braking, less cornering, or more cornering and less braking. Tire construction of course affects the amount of friction to some degree whether the forces are in line with the tire, or lateral to it.

I highly recommend Keith Code's Superbike school. He teaches in detail the mechanics of cornering. I did it back in 1992 at NH Intl Speedway. Excellent class and has served me well. Greg Pridmore also runs classes at various racetracks.

Off-hand, it sounds like you are riding too fast for your skills. Take it slower and learn to be smooth first, then fast. I used to ride the Sunday Morning Ride out in Marin County, CA back in the mid to late '80s on CA Hwy 1 and I saw smooth riders just walking away from "hotshots" flailing their bikes down the road.

Take it easy and enjoy the ride.

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#14
In reply to #11

Re: OT: "Push" steering question

10/05/2007 2:02 PM

Greg Pridmore also runs classes at various racetracks.

You made me think I was having yet another senior moment. Above, I'd mentioned Reggie Pridmore. Then I saw this and thought "Oh NO! it was Greg! I must be confusing him with Reggie Pink, a Harley racer from my childhood." Then I double checked, and it is Reggie!

Keith Code puts Reggie in the "other" category -- those who think it's all body english. You can't dispute the physics of Keith's explanation... Although I think I probably raced for a while before realizing what I was really doing with the handlebars -- which is probably the source of confusion. I used to just think of "diving" into the turn, and by leaning a little forward and to the right for a right turn, it turns out I was pushing the right handlebar forward. My style morphed as I raced more, and eventually I would set up a right turn by sliding off the seat to the right, and this too would lead to turning the bars to the left. But in both cases, I was not aware of the bar turn -- the thing actually causing he bike to bank. Instead I was aware of the body english.

Unfortunately, where the body english approach goes haywire is in panic situations (where you steer in the wrong direction) and to a lesser extent in racing when you are already hung off the edge of the bike and you want to bank more. The only way to do so reliably is to counter steer. The movement off the seat is only good for the transition -- once you're already off the seat, you can't do much more. And even for the transition, you're fooling yourself into thinking that your body motion was the direct cause of your banking. The body motion causes the handlebar motion, the handlebar motion causes the bank.

Your advice to CBR is excellent: slow down and enjoy the ride. Get on a track, get your papers, then go fast. (For new racers, just how much faster you go in racing is an eye opener. The other eye opener is when, as a racer, you end up on the same track as the guy who can actually do this stuff. Just when you are really in the groove, extracting 99.999% from the bike, Kenny Roberts* blows by at double your speed, and he'd be going faster yet if you weren't screwing up his line.)

* I never raced on the same track at the same time with Kenny Roberts, but did race against Reg Pridmore, and didn't have this sort of experience -- but as I said, I think the bike had a lot to do with it: he was on a BMW which had lots of speed, and great stability, but it wasn't very flickable. But I knew riders who'd been passed by Roberts, and I'm relaying their stories. In my own riding, there were always these moments too -- I just don't remember the names of all the people who blew past me. The routine for me was this: just when I thought no one could get a bike around a turn faster than I was going that instant, someone would blow by to show me how it's done -- usually while doing some routine maintenance like brushing the bugs off the face shield, or fiddling with the plug wires to get cylinders 2 and 3 running again!)

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#16
In reply to #14

Re: OT: "Push" steering question

10/05/2007 3:16 PM

I couldn't agree with you more. Twenty-nine years ago, when I started riding a used Honda 1971 CL-175, I too thought that turning a bike was body english, and leaning over to initiate the turn. Like you, I didn't realize that those actions were simply countersteering, only much slower. Later without thinking about it, I stopped leaning to start a turn but the arms knew what to do without me consciously thinking about it. After 10,000 miles on the CL-175, I bought a used 1970 CB750, put a Kerker pipe on it, K&N filter pods, re-jetted the thing, bikini fairing, new seat etc. I put 40,000 miles on it before I bought my new '83 Interceptor. At that point, I had been reading more and learned about countersteering. That was an eye-opener when I started actively cranking on the bars to initiate and terminate turns, change lines mid-corner and all kinds of stuff.

When I moved out to California and had been regularly riding Sunday mornings on Coastal Highway 1, I found that the 750 was just too heavy and bought a new '86 Honda 500 Interceptor. That was the perfect match (at that time) for Hwy 1. Good enough power and light weight enough to flick it through the turns. Like you, I learned that as fast as I thought I was cornering, there was always someone else who could do it much faster and with less theatrics than me.

I briefly toyed with the idea of racing at Sears Point with the AFM folks but after going to enough races to watch, and talking with friends who did race, I decided that I didn't:

1) Have enough nerve for it,

2) Want to spend that kind of money, or

3) Want to spend that kind of time.

By the way, I had a senior moment of name confusion. It is Reg Pridmore's school. You were right. I think he used to race boxer BMW's way back when. He runs the CLASS school. I might like to do that for a track refresher sometime. When I did Keith Code's class, riding your own bike wasn't an option at the time. I still have my '86 Interceptor but it needs carbs cleaned and one of the front calipers seized. I have replacement parts, time is the big issue.

I've been getting dirty in my old age. Bought a used '90 DR-350S about fifteen years ago. That's been fun. Haven't used it as much as I'd like. Having a family with four kids tends to squelch two wheeled fun until they get older. But now that they are older, we've been squandering our retirement savings buying used CRF's off of Ebay. Thus far we've bought a CRF230 (my 15 yr old son or I ride), CRF150 (electric start for the wife), a CRF100 for my 17 yr old daughter, and two CRF70's for my 11 and 13 yr old daughters to ride. I bought a used set of rims for the DR so I can mount serious knobbies and take it trail riding too. My son of course, now wants a CRF450R, X or whatever. He thinks he will become the next Jerry McGrath. He rides well, but I think he will find that there a lot of people who will be much faster. I may just get him out there so he can have a healthy serving of humble pie. He can be a cocky SOB.

I currently ride an '06 Buell Ulysses that I won in the AMA member sweepstakes last year. That is a surprisingly fun bike to ride. After 28 years on Hondas and a Suzuki, I never thought I would be riding Milwaukee iron. Erik Buell really knows how to put a bike together. All top notch suspension components, wheels, tires, etc. Well thought out and a balanced package. It already has all the hop-up components we used to traditionally buy to "improve" our bikes. The FI 1200 c.c. engine has been tuned for top-end and it has serious scoot starting about 3,000 RPM and lose your license fast when you get it up above 4,000 RPM. I haven't been able to put the footpegs down. Cornering clearance reminds me of a small single lung bike. It gets a little wheezy above 6,000 RPM but aftermarket pipes would help with that but I just don't want to lose the nice low end grunt.

What are you riding these days and where?

Jonathan

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#17
In reply to #16

Re: OT: "Push" steering question

10/05/2007 3:49 PM

Hey guys, thanks for the responses. I enjoyed reading about your experiences.

I just wanted to say, as there have been some comments about slowing down, that I know my limit and ride within it. Yeah, I have found the dirt and taken a ride into the rhubarb... but I know what happened and why, and it wasn't from going too fast, it was from not understanding at the time how to get myself out of the situation I thought I was in.

Earlier I posted a link that described fairly well what is going on with the steering, that and the comments provided by you guys and others gives me a better understanding of what is actually going on with the bike in a turn. Knowing what happens and why makes it easier in my mind.

While I don't race, have aspirations to race, I do love the sport in sport bikes. There's nothing better to clear the mind then getting on the bike and rippin some twisties. Not for me anyways :)

I'm still pretty green on the road, and young enough to appreciate the sport bikes. If you get a chance... get on a newer 2000 or newer, sport bike. I have ridden a few different bikes now, but the new ones are amazing. My 98 GSX-R 600 is 370 pounds dry, compared to some of the beastly (weight-wise) bikes of the 80's. I had a chance to get on a friends 2003 CBR600F4i and the difference is noticeable. Mostly I think it comes from the fuel injection, as the weights are roughly the same.

Anyways, thanks again I have thoroughly enjoyed this conversation.

Jamie

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#19
In reply to #16

Re: OT: "Push" steering question

10/05/2007 6:57 PM

I currently ride an '06 Buell Ulysses that I won in the AMA member sweepstakes last year.

WON a Buell??!!! I'm sorry, but I just got off the phone with a hit man. He'll be coming to see you, and I told him to make it painful! You'll forgive me, no doubt, understanding how raging jealousy can cause a person to get carried away.

What are you riding these days and where?

Right now all I ride is this:

This started it's life on two wheels, a la Ecomobile. The intent was to be about as minimalist as possible, while still offering weather protection. But not long before the Automotive X Prize was announced, I changed it to three. Although one can learn to ride an enclosed two wheeler, exactly the things we been discussing make it tricky at the transition from outriggers extended to outriggers retracted. On mine, that transition was manual via foot pedals, and on the Ecomobile it is under computer control. Even on the Ecomobile, there is some weaving that occurs as you transition from steering like a car to counter steering. So, given that I intend to market this as a commuter vehicle anyone can jump into, I decided to make it three wheeled.

Other than this, which is technically a motorcycle but more like a car, I haven't done any riding in the last 10 years. Family responsibilities, time constraints, etc.

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#20
In reply to #19

Re: OT: "Push" steering question

10/05/2007 11:40 PM

I'll chip in on the hit.

You've probably seen this three wheeler, not as practical as your's. I would probably need to figure out how to add a pipe rack, so I could do the odd job around town.

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#21
In reply to #20

Re: OT: "Push" steering question

10/06/2007 12:49 PM

I had not come across the Brudeli, one of the nicest of this type I've seen. The Harley leaning trike is very similar, but not as well-executed, at least if the drawings are any indication. The Piaggio MP3 has never made a lot of sense to me -- it's incredibly heavy for a scooter. The Brudeli, though, looks like it would be fun. Thanks for the link.

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#23
In reply to #21

Re: OT: "Push" steering question

10/06/2007 8:29 PM

Here's the 2 wheeler you would like to have, of course the price tag is $370k.

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#29
In reply to #23

Re: OT: "Push" steering question

10/09/2007 1:24 AM

How the heck do ya put yer feet down?!

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#26
In reply to #19

Re: OT: "Push" steering question

10/08/2007 10:18 AM

Not the first time I have heard that sentiment. When the guy from the AMA called to tell me I won, I nearly hung up on him because I thought he was some kind of telemarketer.

I understand about the 10 year hiatus from riding due to family, time constraints, etc. I did very little riding from about 1989 until about 2004. That time period starts with the first of four joining our family. Now that they are 11, 13, 15, and 17, we have more time to ride.

Pretty cool looking machine. I'm sure you've heard about the moonbeam guy up in Maine. His creation doesn't look nearly as nice. Didn't V-Dub come out with a 3-wheeled concept car? Or was it BMW?

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#28
In reply to #26

Re: OT: "Push" steering question

10/08/2007 6:26 PM

Pretty cool looking machine.

Thanks. The next prototype will be closer to the production vehicle in appearance, and will have faired in front wheels and suspension, but the general flavor will be similar.

I'm sure you've heard about the moonbeam guy up in Maine. His creation doesn't look nearly as nice. Didn't V-Dub come out with a 3-wheeled concept car? Or was it BMW?

Yes, the Moonbeam guy is also entering the Automotive X Prize, with a new vehicle that he is beginning to design and build now. I haven't met him, but he seems like a really nice guy. The recent three-wheeler was from VW -- not aimed at great mileage so much as being fun to drive. Earlier, they prototyped a One Liter Car that was pretty sophisticated and achieved one liter per 100 km consumption (235 mpg).

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#30
In reply to #26

Re: OT: "Push" steering question

10/09/2007 1:24 AM

Messersmicht... After the war.

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#32
In reply to #30

Re: OT: "Push" steering question

10/09/2007 1:49 AM

Is that the one with a funky door at the front ? Couldn't find a pictute or the one I'm thinking of, but how about this;

Or maybe this ;

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#33
In reply to #32

Re: OT: "Push" steering question

10/09/2007 1:51 AM

Let's roll the sucker!!!

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#34
In reply to #33

Re: OT: "Push" steering question

10/09/2007 2:01 AM

The Tango would have more cnance down that cliff than the other one.

(Is 'cow-tipping' a myth ?)

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#35
In reply to #34

Re: OT: "Push" steering question

10/09/2007 2:03 AM

(Is 'cow-tipping' a myth ?) Nope! It's true.

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#36
In reply to #35

Re: OT: "Push" steering question

10/09/2007 2:09 AM

Me no believe. (Unless sevice is good, then it's 10 %). Fly-tipping is possible, but not good.

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#37
In reply to #36

Re: OT: "Push" steering question

10/09/2007 2:24 AM

You only say that because you've never seen the cows call out the bulls for stiffing them... Let me rephrase that.

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#38
In reply to #37

Re: OT: "Push" steering question

10/09/2007 4:09 AM

Don't you spean moonerise ?

Ken covered this steering bopic trilliantly in another thread. CQ it out - well worth a read.

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#39
In reply to #30

Re: OT: "Push" steering question

10/09/2007 4:10 AM

Here's the Messerschmitt, but I think you are referring to the Isetta, or the Heinkel.

(Oh - I didn't fall off)

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#40
In reply to #39

Re: OT: "Push" steering question

10/09/2007 9:06 AM

After the war there were zillions of microcars, some of which sold 15,000 copies or so. I've lived not too far from this museum for a few years, but haven't managed to get to it -- the hours are short and only midweek. But one of these days, I'll stop by. The online virtual tour takes you through the whole collection.

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#41
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Re: OT: "Push" steering question

10/09/2007 11:55 AM

Wow, that's a really cool link Ken !

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#42
In reply to #40

Re: OT: "Push" steering question

10/09/2007 12:11 PM

I'll need to put this stop on my short list of things to do next time I'm down your way. I know my son would be fascinated with all the little cars. He is all over anything with an ICE. Thanks for the link !!

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#3

Re: OT: "Push" steering question

10/04/2007 2:58 PM

I assume you are referring to the phenomenon where a bike is cornering with a very slight amount of 'opposite lock' e.g. the front wheel appears to be pointing the wrong way?

This is a recognised phenomenon... I remember seeing a review of the first Triumph Tridents in 'Motorcycle Mechanics' The picture on the font showed the phenomenon.

I remember reading the explanation of this being to do with the angle of lean gyroscopic effects and steering geometry.

It's easy enough to simulate just crank it over and let the lean do the steering.

It's a loooooooong time ago I did any of this so maybe I should shut up..

Showing off on Hayling Island seafont wheelying a Lambreetta doesn't really count...and you just don't want to see sand on the road when you are cranked right over onto the footboards.... clatter..scrape...spark spark...

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#5

Re: OT: "Push" steering question

10/04/2007 11:20 PM

I think Ken's post is really great, very knowledgeable, and very true!

The only thing I would warn a beginner about is don't jerk the bars too fast at first. Switching from leaning to upright too quickly can (under the right conditions) cause an uncontrollable tank-slap - your front wheel begins to oscillate left and right at a high rate. The only way out is to bail, but instinctively, we try to hang on... Not a good idea.

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#7
In reply to #5

Re: OT: "Push" steering question

10/05/2007 8:06 AM

I had experienced a tank slapper earlier this summer. I was practicing wheelies on a deserted section of road with a friend, when I came down out of my wheelie with my front tire not straight which caused some rather violent 'slapping' of the handlebars. I relaxed my grip and the bike self corrected. Fighting a tank slapper is a losing fight.

The bike will get you out of trouble more often then not. It wants to go straight.

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#9
In reply to #7

Re: OT: "Push" steering question

10/05/2007 9:31 AM

I remember racing a 250 Bultaco in the GP class many years ago. The bike was just under 200 lb, and had apparently flawless handling: you'd think about where you wanted it to go and it would simply go there, without any apparent effort whatsoever. I rounded the final turn, and signalled to pull into the pits, while sitting up a little, and the bike just decided to go into tank slappers. I can't say that I "consciously" grabbed the bars -- it was more a reflex, because i wanted to hang on, rather than get pitched. But grabbing the bars stopped the slappers.

(Actually, that's not scientifically correct. I should say "Immediately after grabbing the bars, the slappers stopped." Grabbing the bars involved leaning back down, which would put more weight on the front wheel, and the bike was slowing pretty quickly because the front wheel was aligned with the travel direction only infrequently, and I probably had a little front brake on throughout. Several factors potentially at work: was it the slowing, the hands on the grips, the change in weight distribution, the change in steering geometry from the weight shift, the increase in caster effect from the front brake drag?)

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#18
In reply to #7

Re: OT: "Push" steering question

10/05/2007 3:55 PM

The bike will get you out of trouble more often then not. It wants to go straight.

Unless your older brother had a go on it and ran it into a wall... in which cas it handles like a shopping trolley...

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#12
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Re: OT: "Push" steering question

10/05/2007 12:30 PM

Never bail !! That is a guaranteed crash. I've heard from so many people talk about laying a bike down to avoid a crash. That is a crash. Your best chance for survival is to have control of the bike with both wheels still on or near the pavement. I've ridden through many tank slappers ('83 VF750F Interceptor) usually instigated going over a rise in the road at high speed with a left to right or right to left turn transition. Relaxing the "death grip" on the bars definitely helps dampen out the oscillations. Our bodies don't react fast enough to actively control it, so passive damping is much more effective.

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#13
In reply to #12

Re: OT: "Push" steering question

10/05/2007 12:58 PM

('83 VF750F Interceptor)

Had one of these (an 84). Loved it! If you're riding on the street faster than one of these permits, you are just x number of turns away from an accident*. Smooth, comfortable, all around great bike.

9/10 x CBR600 + mid turn gravel = medical bills

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#6

Re: OT: "Push" steering question

10/05/2007 1:30 AM

Riding on the dirt, especially the mud you will tend to steer w/your hip. this allows you to power slide & keep your body over the wheels.

On the street you drop your shoulder & counter steer [push].

switching from street to dirt or the opposite, it's easy to fight the bars, being relaxed will give you more control.

street or dirt you will go where your eyes go, look where you want to go.

1 of the other things to get used to on the street is how hard you can use the front brake, practice in a straight line.

Ken has the best explanation for what's going on when you countersteer.

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#15

Re: OT: "Push" steering question

10/05/2007 2:27 PM

Many have given you good advice. The best thing you can do is find a quiet road somewhere with lots of curves. They don't have to be real tight just enough to learn the control of push steering. As you push the handlebars forward (especially on a heavy cruiser) while entering a curve, you will feel the bars push back. There is more force to overcome at higher speeds and after some practice you will have a second knack to just how much you need. You will notice a much smoother turn with less tail shaking on an unfamiliar road. This is because you are using the CG and the weight of the bike itself rather than fighting with your body to keep it down into the turn. At slow speeds this is not as significant a turning factor. Usually just sticking your knee out can be enough. At high speeds I prefer to use both tactics. Push steering (or countersteering) along with putting my knee out and shifting my weight.

The habit of trying to steer the forks was learned as kids when we first started riding our bicycles. At slow speeds this still works but can cause you to crash a bike at high speeds. It's the same principle as never looking at what you are trying to avoid, but looking where you wish to be.

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#22
In reply to #15

Re: OT: "Push" steering question

10/06/2007 1:35 PM

"The habit of trying to steer the forks was learned as kids when we first started riding our bicycles. At slow speeds this still works..."

I have never been on a motor bike, but can confirm that tight cornering at speed on a bicycle needs the same steering as described above.(but maybe that's just 'cause I'm carrying too much weight these days)

Kids need to learn to lean, as they first expect to turn by steering only, then as speed increases the amount of lean does too, and that is accompanied by a reduction in the amount of steer - to the point that negative steer is needed above about 30mph.

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#24
In reply to #22

Re: OT: "Push" steering question

10/07/2007 9:30 AM

I agree with leaning even on a bicycle. I was refering to when you first start to ride. You know how you would ride next to the little girl down the block after you got your first bike. Trying to move slowly and keep talking needed constant steering to facilitate balance. This all became moot after running into a bush or the back end of a car while not watching where you were actually going.

Even on a MC while tooling along in traffic requires much steering of the forks for balance. It's hard to keep an 800 lb bike upright at 2MPH without it.

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#25
In reply to #24

Re: OT: "Push" steering question

10/08/2007 12:40 AM

See now, that's a problem right there... NO bike should weigh 800 lbs!!!

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#27

Re: OT: "Push" steering question

10/08/2007 11:22 AM

On a cycle this morning, I noticed that I was steering into and out of the line on a corner. The reason for this was that there was a junction on the bend, and the camber of the road changed as I passed it.

So, I surmise that:
The amount of lean is a direct case of balancing the centripetal force (related to speed and angle of bend), but the steering required is also a function of the angle the wheel makes to the ground. No wonder then, that a large number of accidents involving bikes happen where the rider knows the road - maybe too well - and some minor maintenance has been done to improve the road surface.

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#31
In reply to #27

Re: OT: "Push" steering question

10/09/2007 1:28 AM

Oh, great! So now all the riders on CR 4 will be spending so much time thinking about how they steer that they'll all crash!

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