Steering geometry - confirmation bias

Bite your ignorant tongue off Al. Peel is NOT flexy in the sense of light frame rubber mounted Commandos nor even your Seleely. Peel has robust Lords elastometric cushioned helm joint radius rods, placed far from iso mounts for leverage of Watt's like triangulated, horizontal stableized, fastening together of two weaker components, rubbery connected, into 2 over lapped strengthened one-ness, to take at least twice load before the compliant twist/flex/stretch/compress comes into play.

Sorry but counter steering limited corner cripples can not reach Peel orbits of energy planting to twist her frame detectably, as crashes rigids long before Peel leaves ordinary phase 2 counter steer and begins trip down fall overs to pull her sling shot back for the release of G spikes at least traction apexes to literally take my breath away dimming to tunnel vision. Peel has very robust fork brace to tie weak pongo sticks together, which both takes away their rubber band twist/release onsetting direct steer loads but also raised their vibration freq above tire sonics of howl, squeal and screech resonance so front 110 tire can twist frame harder just before triggering sling shot leap out of there.

YET Peel retains Commando engine vibe isolation and delicious softness that absorbs minor road imperfections so mainly just patch grip sense gets through. Peel is abnormality to point best handling gotten 60 PSI rear & 58 front, incredible precise ice skater on razor edge slicing traction!!! But about killed me touching THE Gravel so let air down. Next Mz Peel air station can fill to suit.

Yoose rigid corner cripples can only relate to neck and neck type cornering competition and not crashing to do it, not for me on Peel.

Oh yeah road racing loads don't require another external layer of triangulated strengthening but leaps off bluff edges, launched off in air not to hang up hi centered, so as Bugs Bunny says after- stepping out a cartoon plane at gun point by Elmer Fud, That 1st Step is a louLoU. Peel has a hard shell, like me, but a softy in the center, not like me.

http://i184.photobucket.com/albums/x93/hoboter/DSCN2665_zps8741c116.jpg

SOB! poopoobucket has prevented displaying full image even taken form public google images, Tag up google images, 2nd row 1st column https://www.google.com/search?q=rgm...uw0rXYAhVs44MKHemcBVgQsAQIKA&biw=1088&bih=476

If you ride a near-original Commando quickly around a hairpin bend and relax while you are doing it, where does the bike tend to go, if you don't intentionally steer it ? Does it stay in the middle of the road, tend to run wide as you come out of the corner, or does it tend to tighten it's line ? - Simple question !

Relax, whilst going quickly around a hairpin... how does one do that...?

And not steer?

If a cycle can not go around a decent turn hands off then its a dangerous unpredicable corner cripple as what ever effort it takes to save hands off leaning going wrong by some bar control effort is the same amount of force out of line with natural physics, so when traction and balance get to point of maxing out the slight little pilot effort is enough to bring curtain down. DAMHIK>

The increasing hands off wiggles slowing down that scares us at some point to re grip quickly - is especially strong in iso Commandos, but occurs in all cycles, (but maybe 2 isolastic baby buggies), is what can onset at high speed under power, so the instants of tires or frame loads exceed tolerating this slightly extra forces out of line with road holding aiming by just low bar stabilizing forces can be enough to surprise a snatch down or fly up.

If a steering damper is found help pilot confidence then sure sign its a corner cripple that can over come even the most strong quick reflex skilled pilot as can't predict when all the influences suddendly pile up to spike loads a tiny bit over tolerance. If lucky pilot may still be able to hang on to bike dragged and bouncing off to one side, so forks can snap in/out direct&counter steering to self correct with ignorant on lookers jaw dropped at the pilot skills recovering. ROFLOL till crocodile tears.

Only hobot and possibly Doug Mcrae know what a truly neutral handling cycle is. I'm pretty sure I'm the only one able to use hands off body slams to get a lean going on mt pubic hyw starting at 110 mph so enough momentum to complete a turn before slowing up to much to be thrilling. I tested Peel hands off 100 mph giving bars a Hard slap to only have bars instantly snap back to neutral upright steady state with a ripple through frame like a flag in a breeze but still very secured to the pole. If too sharp a turn as speed to be able to slam a lean fast/far enough over in time must use bar to tip down then can let go Peels bars to go around stuck on rails secure ease.

NOTE!!! at some point steering damper will hinder the fast oscillation of forks required to stay in control > SPLAT - w/o knowing why - except hobot.

For sense how much loads Peel can tolerate, go 15 mph in parking lot and try to direct steer, imagine Peel how harsh that becomes at nearly 100 mph yet in Peels case these steering forces are reversed so it literal throws us around the turns insanely fast no thought or possible use of braking upsets. Thank goodness as much load a Peel takes on she relieves it off pilot. Real races are worn down after a race while I'm refreshed not wanting to get off.

At some point the energy is too high to stay on surface but only Peel can induce this on purpose for the advantage of turning in air & or dramatically changing position of line through a turn before landing on smashed rear patch to trigger off another blinding leap out of there.

Again as maybe only 2 cycles capable of this but only one pilot willing to press into crash states for fun, all's ya corner cripples have no experience to relate to so reflexly deny what I already enjoyed in spades and maybe even Al's altered Seleely to some degree to.

So rage on in aragant ignorance but hobot chuckling, on a Comanche Commando in the works to scalp all comers in power planting energy handling up to its obsolete engine and tire capacity delivery of 3 more Phases of control beyond coutner steering at speed.

acotrel said:

I.............I have never consciously counter-steered a motorcycle in my life. If I had to do that, I would not ride it.

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Well, you may have missed something in life! I rode significantly over 100,000 miles on big touring bikes, think FJ1200 and ST1100 Pan European, 550lb and 650lb motorcycles, but a lot of the time two up with full luggage! And think France, Austria, Germany, Italy, Alps, Pyrenees, Dolomites....7 mountain passes over 2000 metres in one day ride outs included!

All miles sat firmly in the middle of the seat, no weight shifting to aid in turns, and all 'conciously' countersteered!

But I learnt about countersteering on a 750 Fastback when studying gyroscopes in RAF training! So I also 'conciously' countersteered whilst racing in the '70s! Best way through Cadwell Park Gooseneck was push on right bar till the right exhaust hit the floor, then push hard on the left until the left exhaust hit the floor! (he only reason it doesn't work like these days is because I have a high level exhaust!, oh! and I am the best part of 40 years older)

I worry when people say they don't countersteer, or don't do it conciously, or don't like to do it, or are in any way afraid of it. Because at the end of the day it means they don't fully understand the basic dynamics of a motorcyle and are not relaxed enough on the bike to explore what it will do, or they simply never learnt enough finesse in applying the forces.

Your continual return to this issue of offset and steering suggests that for all of your race history, today you aren't comfortable!

Maybe it is time to swap the Seeley for a nice road bike and enjoy some Sunday riding?

And yes, it will happen to me one day, when?, I just don't yet know.

... and, not understanding the basic science of rake, trail, and offset means that you communicate in hyperbolic phrases that don't discribe the science of what is happening, but instead you suggest possible voodoo like results from making minor adjustments rather than make scientific predictions to handling based on making changes to rake, trail and offset which science dictates have predictable results.

The thing that keeps you from learning the science is the pretense that you already know it because you've been a racer for many years. Take the time to read and digest Foale's book, then discuss it with someone who has extensive knowlege about setting up bike geometry. You'll come away with a much more science based, and intuitive understanding of why your set up feels the way it does, and what specific adjustments you can make to adjust it's handling to where you want it...

"Best way through Cadwell Park Gooseneck was push on right bar till the right exhaust hit the floor, then push hard on the left until the left exhaust hit the floor!"

HOT DAM SteveA, absolute mastery example of risking life controlling a corner cripple!! What this means to me is you know something about direct steering intense direction changes controlling crashing as that's exactly what ya had to do to pop out of extreme lean to turn the other way but cycle not able to tolerate staying in direct steer so wisely-innately next instant back to counter steering. Corner cripples can only tolerate instants of direct steering to stop or save falling over but not the delights of direct steering to induce turns with a counter steer fork snap into new direction to carry on in direct steering hook up. control.

All the technical points made on scope of rake/trail/squat etc in counter steering are proven valid in all cycles, but fails to cover the over doing of coordinated turns into higher G's of reversed control states. Fine tune forks by trial/error best ya can just realize there will still be situations that finest forks fail to control counter steering tire conflicts but even crappy old forks can by direct you know what...

You finally got it right!

acotrel said:

I have thought about what Dances said about back-calculating the trail. When I installed the TZ350 fork yokes, the trail became about 92mm. The Ducati fork yokes have 26mm more offset. Because the line through the steering head and the vertical through the axle intersect, the larger offset reduces the trail by about 26mm to about 66mm. With the change of rake when braking hard when cranked over a bit, the combination becomes dangerous.

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Then you apparently reverted back to your old inverted way of thinking and blew it!

acotrel said:

I have told you guys what this is. If any of you decide to reduce your yoke offset with a frame which has 27 degree rake, please be careful. There is obviously a limit to how much you can safely quicken your steering. .........................

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Up is down, down is up; left is right and right is left. Got it. Are you trolling or truly struggling here? Slow down and revisit your comparative analysis on the Ducati vs TZ350 fork yokes offsets and their impact on trail - your assessment was correct there.

Now, back to my garage where I will be on my hands and knees pounding my forehead on the concrete floor.

acotrel said:

It is an original 1966 Seeley Mk3 frame.

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Sorry to all if you think this a petty point, but it has been nagging at me, so thanks to a bit of insomnia I got out my Seeley history book. The Seeley Mk3 didn't get into any customer hands until 1969. I would think it may have taken even longer for one to get to Australia, I would doubt yours is earlier than '70. In '66 Colin was bronze welding his prototype Mk1s.

hobot said:

HOT DAM SteveA, absolute mastery example of risking life controlling a corner cripple!!

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I wouldn't call it mastery of anything, the best result I ever got at Cadwell was a 4th place, on my 4th season on the bike and when the masters were busy elsewhere!

Brooking 850 said:

And not steer?

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Use The Force Luke...

Regardless if you won the race or not - that ' Richochet Rabit 'maneuver is a peak of human experience few of us get and as it worked out as intended - no question to me did not happen by accident. Reflect on the bar action that saved the fouling slam downs twice in a row!!

Amazingly I had exactly same happen on stock Trixie Combat, after a failed Texas Lake of Pines trip in almost freezing rain all day delayed with Wesley's electric gremlins, no food, long waits between fatiguing kicking and investigating so after 100 miles of Pig Trail at night finally got 5 m from home on THE Gravel weary with poor foggy vision going about 25 mph hit a big long puddle for world to go nutz feeling impact on L knee then next instant a lessor impact on the R knee to bounce out of puddle perfectly in line no correction needed. All in maybe a second at most. So quick and bleary headed was not sure what happened, only what if felt like, till got home to see tiny nick in L knee rain suit and scuff on R, after being VERY alert not to nick rain suit or get wet chilled to the core.

Then I knew exactly what happened and likely same with you. Off road direct steer had become so auto-2nd-nature spinal reflexes, faster than brain control, direct steered as we went down on L to cause hi side fully onto R side with same direct steer reflex slightly ahead of impact so hi sided 2n time to full upright. This happened too fast to fully register in consciousness at the time. The heavy camp cargo merely bungee'd on also impacted to help prevent show stopper in puddle but was the only thing noticed swaying some afterwards. Too slow for hydroplaning so likey slick muddy uneven bottom.

Mz Peel competition is robotic motorcycles which can direct steer. Pikes Pike is a piece of cake to point Mz Peel seeks downhill pecking order. Please forward to Tony and reflect on my rants above....

acotrel said:

If you ride a near-original Commando quickly around a hairpin bend and relax while you are doing it, where does the bike tend to go, if you don't intentionally steer it ? Does it stay in the middle of the road, tend to run wide as you come out of the corner, or does it tend to tighten it's line ? - Simple question !

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Simple question yet poorly framed. You neglected to mention throttle control (neutral, off, or rolling on the throttle), rather important, don’t you think?

That tells you how it works Steve.

The initial countersteering force initiates the turn. Then the force on the 'bar' is removed, relax. What takes over now is the reaction force between the tyre and the track surface. The spring is set light enough to allow the tyre to track the turn. Angle of lean and speed determine turn radius. You want to finish the turn or turn the other way, countersteer in the opposite direction, and work the throttle.

To me the spring also illustrates my comments about being relaxed in the turn. In a tight left/right or right/left there is no time between force inputs. In any longer turn when you have initiated the turn, you don't want more force inputs until you are ready to exit the turn, so relax and let it do what it wants. Any spurious inputs, from moving on the bike, turning the throttle harshly, whatever, can upset it, so if you do something you have to be concious of the potential effect

Is this easy, no I don't thinks so, it only seems to come to few riders naturally, the rest of us have to actively think relax, at least as we start riding fast. You just don't fight it.

Alan makes me think he has spent a riding life fighting the machine. My style may not have won many races, but it has benefits, particularly at my age. In my racing career I have fallen 3 times, twice after being hit by other riders! Once under braking.

In 2015 at one meeting I did run wide and leave the circuit, 3 times, at the same corner, twice in the same race! After the second time I retired from the race, went and sat in the paddock and thought it through, sure enough I was tensing up right when I didn't need to. Went back out in the next race, conciously thinking relax, and logged faster laps.

Dances with Shrapnel said:

Simple question yet poorly framed. You neglected to mention throttle control (neutral, off, or rolling on the throttle), rather important, don’t you think?

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Definitely with you on the throttle input here Dances. But lets step back to the question.

Unless you intentionally apply steering forces going into your hairpin, you won't turn at all. Once you have the bike turning you don't continue making steering inputs unless you need to tighten or open the line. When you are not steering, you relax the forces. Exiting the turn you want to hook up and get as much exit speed as possible, so you will be working the throttle, and you may need to make more steering inputs.

If you are comfortable riding and thinking at the speed you are going you will be 'relaxed' and may conciously recognise the different phases. These are the basics of learning the characteristics of the bike you are riding at the time, you need to know what it does in a given circumstance. Relaxation at this point isn't dozing on the sofa, it is stopping your self from making unwanted inputs between the inputs you need too make.

If you don't recognise the different phases of turning and steering you are probably not relaxed enough at the given speed! Whilst riding like that can be exciting, it normally isn't fast!

SteveA said:

Definitely with you on the throttle input here Dances. But lets step back to the question.

Unless you intentionally apply steering forces going into your hairpin, you won't turn at all. Once you have the bike turning you don't continue making steering inputs unless you need to tighten or open the line. When you are not steering, you relax the forces. Exiting the turn you want to hook up and get as much exit speed as possible, so you will be working the throttle, and you may need to make more steering inputs.

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Agreed with the counter steering to initiate and modulate a turn but lets not loose sight of the original post which has to do with geometery and has now drifted into turn dynamics - which is ok.

You can complete a turn with neutral throttle but Alan asked in the context of quickly, so this is not a neutral throttle scenario. In other words, throttle and handlebar inputs are intertwined within the literal context of Alan's question. If one were to enter transition and exit a turn at fixed throttle, the steering sequence is counter steer to shift the center of gravity (of the bike and rider) towards the side you want to turn to and initiate the turn, modulate through steer/countersteer (balance) and then counter steer to get the center of gravity back in the vertical plane with the bike to exit the turn. Even with a neutral throttle funny things happen with the engine outputs due to changes in the effective radius of the rear tire when leaned versus when vertical.

Quick transitions from one turn to the next gets even trickier in that the transition through vertical loads the suspension as opposed to starting a turn with a relatively neutral suspension.

Lots of things happening with turning a bike. I can still remember my father shoving me off on my first ever bicycle ride, it was holy shit, WTF (sensory overload) for about a second and then "magic"; no time to think, just do.