Jaybird180
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Posts posted by Jaybird180
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53 minutes ago, Dylan Code said:
We used Silkolene, a very good brand as well as well. No we do not provide engine wear data to manufacturers, it's never really an issue. Modern engines are good.
I used Silkolene fork oil when I built my Fireblade.
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5 hours ago, Dylan Code said:
Liqui Moly is now officially our lubricant sponsor. They are the spec brand used in all the Moto2 and Moto3 bikes in the World Championship. We will be running that same oil in our fleet.
What was the previous fleet brand oil? Do you supply engine wear data to the sponsors or bike manufacturers? I suppose from all the years of running Kwaks and now BMW you have tons of engine wear data.
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5 hours ago, Dylan Code said:
Liqui Moly is now officially our lubricant sponsor. They are the spec brand used in all the Moto2 and Moto3 bikes in the World Championship. We will be running that same oil in our fleet.
I've used them happily in my BMW automobiles for years.
5 hours ago, Dylan Code said:The helmet sponsor deal is not finalized, but it is a company many have never heard of that produces the most helmets in the world and manufactures helmets for many other brands you thought made their own.
Now this is just unfair...to tease us with THIS type of information!
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Did I see a rickshaw or 2 on the Indian video?😂
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I have a wall photo in my home office taken during one of my CSS school days at ViR. It's nicely framed and in a place where I look at it frequently as I telework. The photo has me followed by two other riders as I'm nearing the inside edge of a right turning corner about 1-1/2 meters away. I can see the greenery in the background but it's blurred in the distance. Our heads are turned and it appears we are all looking somewhere near the same point. It's possible that being in the front, I might have begun to look toward the corner exit as my vision is slightly elevated relative to the following rider. We are all wearing dark or mirrored shields, so I cannot see any eyes. The bikes are leaned over in successive amounts and our knees are out. I think I'm aiming the bike at the apex.
I can see that neither of us are trailing the brakes and two of us appear relaxed and in a stable body position based upon front zipper alignment and head/shoulder direction. It didn't dawn on me until writing this post, how uncomfortable the second rider looks. It also looks like the camera added 25lbs to my stature, but that's not pertinent to riding technique (or is it???).
I can see the position of our toes on the pegs...and the uncomfortable rider's foot position makes it look like he might be supporting his weight in his hip, sorta scrunched up.
Being in the front, I have more fork extension than the 2nd rider. We're both on Black BMW school bikes, and based on that I ascertain that I'm on the gas more and both our right wrists are straight and aligned to the elbow. I can't see the 3rd rider's forks on his red and white GSXR, but his wrist is bent, indicating that he intends to roll his hand and leave his elbow behind. I can see significant daylight in the area formed by the back of his knee, the bike and his butt- he's hanging off a lot. I also think he might be a 1/2 nanosecond late on his 3-step vision because although he has some distance before he arrives where we are, his helmet doesn't appear to be pointed as deep into the corner as we are.
How well did I do describing the photo? Are you able to see it in your mind's eye?
Did I miss any important bits that are in every photo? What other information can be learned by observing a photo?
Next person to play the game: Describe a Moto pic and the technical information about the rider's technique.
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Perhaps you should consider racing. When I get Open track time, that is for me to work on a skill, I couldn’t care less when I’m using that time to work on that skill because I purposely back it down to 70% and then gradually turn up the wick. I felt like you before I started racing.
I’m still slow and have no delusions about my skill, but racing has given me a better barometer and takes my mind off the technicals of riding and it becomes just about chasing the guy in front or keeping the guy, who’s intake I can now hear behind me. Keep doing that for X number of laps and the race is over. It’s always gratifying to beat the guy who last beat you or a higher classed machine.
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SPOILER ALERT: KC mentions 2 news sponsors: A helmet sponsor and something else that I can't make out (must be that California accent- LoL)....what did he say?
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54 minutes ago, yakaru said:
This sounds like the hook turn more than pivot steering to me.
Yes! Yes! You’re right! Thank you. Wrong technique.
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@Cobie Fair IIRC when I did L3 and we did Pivot Steering, I tried it at a 2 turn section that can be run as a double apex turn using PS in the second portion. As I recall, we didn't add a second steering input but instead changed the body position to alter the steering geometry.
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1 minute ago, Hotfoot said:
Good gracious, what a story. I spent in summer in Wisconsin and couldn't believe the number of deer there and they certainly can jump out very suddenly. Sounds like you have a good plan for really serious protective gear for future, which is great.... but is there a way you can find a place to do some track riding, where conditions are a little more controlled? Local track days, or riding schools?
Have you ever considered getting into a mini-moto or super-moto bike that you could ride at local go-kart tracks? They really are a lot of fun and you can ride at a high level (performance wise) at relatively low speed, and there's a whole lot less chance of a deer leaping out at you. It is inexpensive and it can be pretty easy to get a group of buddies to go with, which makes it even more fun.
I have to second this. I got into Minimoto in 2018 and it's now my primary consideration for riding. I get a lot of enjoyment out of it and it's the best bang for buck going. Most of the bikes are inexpensive and nearly unbreakable, speeds are lower so if you do take a spill there's lower risk or severity of injury, maintenance is simple (though you end up doing some simple tasks more often) and the fun quotient is really high. Another factor is that they really highlight areas for needed skill improvement especially when a 9-13yo blasts by you on a similar or lower classed machine.
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18 minutes ago, Hotfoot said:
Ah, this makes more sense, now I'm with ya.
Yes, that is EXACTLY what a rider would have to do, if they were not strong enough to get a good lock on with the lower body, and not strong enough to support their upper body with their core muscles, they would be forced to use their arms to support themselves under straight line braking, then do their best to get off the bars when it is time to steer. What else could one do, other than trying to add tank grip or other anchoring devices to make it easier to lock on to the bike?
This is my only option on my minimoto. I think Supermoto riders have the same issue.
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I like that accordion discussion.
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9 minutes ago, Hotfoot said:
What IS the purpose of the discussion, if you are not interested in handling issues?
The net gain in resolving this would be saved attention. If it doesn't matter where the rider locks on during braking then it's one less thing to "correct". If it were practical, the rider could stiffen during braking then relax when making the steering input. There might be some lost "cool points" for style, but who cares if it gets the rider progressively closer to the podium, right? This rider would also need to understand that some ability for the bike to correct for surface imperfections in the braking zone will be sacrificed if using this technique.
I also think it explains the Leg Dangle.
1 minute ago, Hotfoot said:A rider cannot change the location of the COM within their body, no. However they CAN change the position of their body. Do we agree that when a rider hangs off the inside of the bike, their COM is moved farther to the inside of the corner?
I agree that the rider CoM is moved to the inside of the corner.
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51 minutes ago, Hotfoot said:
Do we agree that if a rider sits up high, that the rider's COM is higher than that of the bike, producing a rotational "moment" that wants to make the bike rotate around the front tire's contact patch and create a "stoppie"?
I'll agree to the stipulation if we agree that a stoppie is by definition a condition where the rear tire is not supporting any weight.
51 minutes ago, Hotfoot said:If we agree on this point, then the remaining questions is: does that situation cause more fork compression? My thinking is that yes, it would, because the "moment" created is a new force, in addition to the normal braking/deceleration force from mass of bike & rider. (The farther apart vertically the COM are, the bigger that "moment" becomes.) That rotational force, which centers around the front tire contact patch, can be resolved into two components, where the rider connects to the handlebars: a forward force and a downward force. It is that additional downward force that puts a new vertical load on the bars and THAT is what I think causes more fork compression.
I think you're saying that the rider has the ability to change the fulcrum of the point of rotation and that this action of having more mass further from the fulcrum creates more inertia for fork compression. As kinematic theory I believe it would produce the desired conclusion.
I believe that it fails in practice because (taking the extreme example) your rider can't alter her mass to be centered in her head anymore than she can focus it at her feet. It goes back to the discussion where a student asked if the rider weight should be on the pegs or seat during a turn and Dylan in summation said to put the weight in the seat for the simple reason of physical exertion, but to the bike it didn't matter.
51 minutes ago, Hotfoot said:If the rider sits very low on the bike, and braces forward (instead of down) with his/her arms, I do not know if there would be any additional fork compression. My guess is that there would not be. However handling would still be negatively affected simply because the pressure on the bars restricts handlebar movement and if there are any imperfections in the road, the bars cannot move as they need to, to compensate. And obviously if the rider is entering a corner it is much more difficult to make a precise steering input when one's weight is on the bars.
The reality on an S1000rr is that they have unbelievable stopping power, and at maximum braking it is quite difficult to hold on well enough with your lower body to have zero pressure on the bars, especially on a hard braking track over the course of a long race. That said, when would it be MOST important for rider to be light on the bars? During straight line braking or when entering a corner? When is the best time to get the hardest braking done, straight up or leaned over? If a rider does have some pressure on the bars during hardest braking, is it better to be sitting straight upright, or to be down low? Is it better for any bar pressure to be forward on the bars, or downwards?
I'd imagine that if we did see a net gain, riders would no longer sit upright for straight line braking to get the aero braking effect.
For the purposes of this discussion, can we leave handling issues aside? I think it's universally agreed (???) that relaxed arms are in better control of steering and decoupling road induced oscillations that could happen if the rider were stiff and the bike needed to self-correct.
If you could slow from 200mph to 100mph, assuming same brake on/off points on Brand X but can't do it on a BMW using the tank only, then we're getting into ergonomic and possibly aerodynamic engineering. May I suggest this is also outside the scope of the discussion at this point and may distract from getting an answer.
50 minutes ago, faffi said:Well, I am probably guilty of everything you pointed out, Jaybird 😄 However, when it comes to lowering and/or lengthening a vehicle for better stopping or acceleration, it is a result of the vehicle's ability to resist flopping over forwards or backwards. Although only if you already slowed or accelerated hard enough for that to be an issue, of course. This partly explains it https://www.physio-pedia.com/Centre_of_Gravity#:~:text=Stability and the Centre of Gravity,-The direction of&text=When the line of gravity,is said to be stable.
Sorry if I just dug myself a bigger grave here 🤪
Yes, CoG may lie outside the body when the body is in certain positions or planes of motion with limbs away from the upright, resting CoM.
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9 hours ago, Hotfoot said:
If the position of center of mass is not relevant, what do believe causes a bike to do a stoppie?
Shameless Confession: I've never done a stoppie and only small wheelies or big ones unintentionally so this answer is based on observation sans competent experience.
In a wheelie, there's timing associated with the rider shifting rearward (and in some cases to cause the front suspension to rebound) and excess thrust brings the wheel up. A stoppie is excess braking and a rider timed movement to spring the rear shock. I've observed both being executed at various speeds.
I should have said that vertical position of CoM wouldn't be the differentiating factor for fork travel under braking. I think it matters for a stoppie and maybe (???) for a wheelie.
9 hours ago, Hotfoot said:I didn’t follow your reasoning on why you “or 99.9% of the riding population” couldn’t try the experiment with the zip tie on the fork? We do very similar braking drills with students all the time, at schools.
I've ridden the brake bike at the school. The intention of that drill is different. The goal of the brake bike drill is to practice getting the braking to the edge of a skid or over the edge, experience it and get comfortable being there and practice the recovery in a safe manner. It skids when the Coefficient of Friction between the pavement and tire is exceeded. I don't think this would be useful for this purpose.
In order to use your practical exercise to find the answer to the question, we have to ensure that all parameters are same and only change rider brace point. I already have a fork travel indicator installed on my forks; it's a little ring but not the same type of material as a zip-tie but with the same purpose and it works. I could then setup cones in a flat section of pavement for start and stop points and try my best to make speed consistent across several runs and then take the measurement.
I could take all of the preload and compression damping off the forks to exacerbate the fork dive and increase the rebound damping to aid consistency; might be sketchy from a safety standpoint. I'd then dismount the machine, measure and record fork travel, reset and repeat. This only requires slightly less discipline than finding how many licks it takes to get to the center of a Tootsie Roll Tootsie Pop. It's possible, but I doubt its practicality. But being game, I reached out to a friend and asked if he'd help run a motorcycle experiment (no details given) and he said "Maybe?", which is exceedingly funny to me, knowing this friend....And after giving him the details, he agreed to help. It's too bad that we have to wait for weather to cooperate. It's cold and wet here.
4 hours ago, faffi said:(Premise)If you lower the CoG, less weight will be shifted forward and you can stop harder before you do a stoppie. (Rationale offered as "proof" for premise) Which is also why a long and low bike can stop (and accelerate) harder than a tall and short one. However, I am not certain that (conclusion) the fork will compress more doing a stoppie while sitting upright with stiff arms, than doing a stoppie laying low with the resulting lower CoG. (Conclusion based on Rationale above)Since you can now slow down harder, would not even more force be fed into the suspension? But for the same rate of retardation, you probably will end up with slightly less compression of the fork laying down.
In logic, the conclusion flows directly from premises of a statement. The truth of the premise is not considered in evaluating the structure of statements. According to logic, it is presumed to result in a correct conclusion which is a flaw in classical logic.
In the red and blue statements above I've added color, italics and bold to indicate where I see premise, conclusion and rationale. The conclusion could actually be true, but we must stipulate the premise as true. This thread is about evaluating this very premise considering we have each in our own ways observed this apparent behavior. I think we are guilty of observational error.
4 hours ago, faffi said:However, will - if the rider position is the same - the point of ancorage matter? If I imagine in my head a 200 lb steel pole being welded to the footpegs, and another identical pole being welded to the handlebars with imaginary weightless arms between the pole and said bars, my flawed logic would indicate that the pole welded to the pegs would carry a greater rotating force forward during braking than the pole supported at the handlebars.
Put differently; if the riding position is the same, would supporting the weight on the arms make the fork compress any differently to supporting it fully with the knees, since bars and tank sit at similar levels on a sports bike?
I agree that you correctly transliterated my OP.
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Firstly let me say that I recognize that you’re helping me work this out. On my own, I haven’t been able to crucible this to ground truth. So your contributions are invaluable.
In my experience, whenever I’ve locked on using the tank my braking distance has been improved, controllability and everything I’d want is in-fact better.
However, I don’t think I, nor 99.9% of the riding population for that matter have the ability or the tools to get repeatable performance or accurate enough measurements to prove either premise.
I also don’t have the ability to program computer simulations to see how changing rider structural point makes a difference, similar to pressing weight on a foot peg to change a line; makes no real effect despite repeated claims to the contrary.
According to my Physics lessons, Newton did not observe center of mass to be mathematically relevant to acceleration (F= MA). As a believer in Newtonian physics, that’s all I have as a stable datum to rely upon.Eliminating the above, the remaining choices leads me to believe that most likely we’re dealing with observational error.
I don’t know why lock on is better, but if I had to guess, I’d have to say that it’s due to body mechanics, that and having the right amount of input to begin with to allow the bike to self-correct (rake/trail geometry).
If I’m right on this then it means previously I’ve been investing attention unwisely when instead it should have been spent on getting the bike to the right speed (remember: “lately” I’d been riding a bike that doesn’t have tank shrouds wide enough to lock in, and it had been a source of concern) and getting setup for the corner.
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Let's talk about why I asked the question.
Re-reading some threads where we discuss attachment points, I saw consistently that it was a subject of contention. Opinions are all over the place in various internet venues, but they tend to be reigned-in here, which sometimes has the unfortunate side-effect of not allowing incorrect observations to be voiced.
Cobie began to address my question but did so by mixing two separate issues that I didn't do enough of a job to confine. Cobie explored: 1- the geometry change from deceleration and 2- the rider's relative level of control with each technique. Separate things, but important to note.
I read one place where (I believe KC) said, consistent cornering come from a consistent position on the bike. It sounds like something Mr. Code would say, and whoever said it, I agree with it and it makes sense to me (two separate things).
I've been led to believe that locking the arms during braking could cause the steering to sharpen too much as a result of deeper fork compression. After thinking about it the night before my OP, I beg to differ. I think, controllability and consistency concerns aside the braking forces and consequently the geometry changes would be the same in either scenario. The simple reason is that if the deceleration is the same, the amount of force on the front tire producing the deceleration would also be equivalent.
I asked the question the way I did, while not a pure troll post, I was hoping to get 2 camps on either side of the discussion so I could test my above idea with no risk of being wrong.
Now that I've outted myself, I'm fully prepared to be shown wrong.
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2 hours ago, Cobie Fair said:
If the arms are locked, does that throw more weight on the front? If they are locked, does it allow the front to correct for the imperfections?
Has the rider’s mass been altered? Please, no suppositions about the squid who misses the braking point and involuntarily alters his suit’s mass. 😂
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If it were possible to enter the same heavy braking area at the same speed and same braking pressure but only using different stability technique, which produces more fork travel and why:
- The rider locks his arms and uses his hands to stay on the bike
- The rider locks his knees on the tank and doesn't lock his arms but the arms are fully extended
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On 8/14/2020 at 6:10 PM, rchase said:
Been away for a looooong time but this thread caught my attention.
I have done 2up rides and if you get the right rider who's mission is to teach rather than to scare it's an amazing experience. I found myself at the side of Roebling Road Raceway with such a rider and hopped on. After the ride and the scare (it's unavoidable) it had massive affects on my confidence on the bike. After the experience I wrote an article that appeared in BMW OTL Magazine about it. It's somewhere on the forum here but buried under years of other posts.
The most important aspects of riding 2up is not only hold on tight but to retain a mental space where you can actually absorb the experience while not getting in the way of the rider.
It's well worth the scare IMHO.
Here's the thread
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To summarize:
- You had 2 bikes that would run wide on the throttle
- You change tires on 1 bike and liked the results
- Now neither bike runs wide, despite no changes to the other machine
Your question is: what caused the change?
Do I understand correctly?
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There might be a related nugget here
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Let's see....
I've always wanted to ride Laguna Seca
I contemplated a camp for 2020
......hmmm
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I found the other 2 videos entertaining but the first was an example based on sound and camera angle of how much he is on the throttle post apex. It even seemed that during one of those corners it wasn’t a roll-on but that the power instantly went to full and the engine was willing to rev that easily. I know I don’t have the resources to toss into a WSBK motor to be able to do that or able to exploit such equipment but I can take an example from his technique to get a sense of what is possible; I tend to be unwilling to accelerate that hard.
Dunlop Q4!
in School Questions/General Discussion
Posted
@Dylan CodeDid he give you any starting street pressures?