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Elbow Down Old Hat

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Rossi 2000

elbowdown_zpsnhnz5tcu.jpg

 

Ruggia 1991

Ruggia_2_zpskulnkjfx.jpg

 

Ruggia 1989

Ruggia_1_zpsorhefqm2.jpg

 

I find it interesting to see how similar Ruggi is to Marquez considering the 25 years between them.

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I think in the pic of Rossi he is cheating a little due to the curbing and road camber

 

Ruggi looks like he has his ass hung way off but his head still looks to be over the tank, and his elbow is stuck out a lot more compared to Marq, but yes surprisingly similar

 

marc-marquez-circuit-of-the-americas-mot

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Ruggia is also more twisted on the bike and he failed to fully capitalize on his style when it came to results, but he was a pioneer just like Saarinen was with sticking the knee out and hanging off circa 1970. For me it's har to tell why Ruggia didn't benefit from hanging off like that. Could be bikes or tyres or something else entirely. Or maybe he did, maybe he just wasn't good enough to be a consistent front runner and would have been further back with a traditional (for the time) style?

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The portion of the body with more weight is upper and head (plus helmet), not legs and butt. In this sense Ruggia weight positioning is not the most efficient (compare with Marquez upper body).

 

What is impressive to me is how Ruggia was able to reach that kind of lean angle with tires, suspensions and frames of 20 years earlier.

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A highly interesting observation.....thanks Eirik. Has anyone on the forum dragged an elbow though?

 

Oh, sure, I have. Elbow, shoulder, hip... :P

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A highly interesting observation.....thanks Eirik. Has anyone on the forum dragged an elbow though?

 

Oh, sure, I have. Elbow, shoulder, hip... :P

 

 

:lol::lol::lol: ouch!

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What is impressive to me is how Ruggia was able to reach that kind of lean angle with tires, suspensions and frames of 20 years earlier.

 

Way back in 1987, MOTORRAD managed, at low speeds, 52 degrees of lean with a BMW K75 riding on Metzeler touring tyres. I'm sure the racing tyres of 25 years ago would tolerate more than that. What they wouldn't tolerate to the extent of modern rubber is additional forces at big lean. Current race rubber offer lots of grip for acceleration or braking even leaned to 50 degrees, back when you would more or less have to coast.

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Way back in 1987, MOTORRAD managed, at low speeds, 52 degrees of lean with a BMW K75 riding on Metzeler touring tyres. I'm sure the racing tyres of 25 years ago would tolerate more than that. What they wouldn't tolerate to the extent of modern rubber is additional forces at big lean. Current race rubber offer lots of grip for acceleration or braking even leaned to 50 degrees, back when you would more or less have to coast.

 

 

So what this would imply is that today, with modern sport bike and entry-level performance tires (like Michelin Pilot or Dunlop Q3), we can reach a 60 degree lean with moderate acceleration/braking? I'm a bit skeptic because when I look at superbike races they visibly use less lean angle than motogp, I would say around 50/55 degrees maximum.

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No, I think you can coast - at a moderate speed - around a corner leaned to about 60 degrees on a coarse surface, but if you try to feed extra forces in you're likely on your arse pretty quickly. The faster you go, the less lean can be used before you start to slide.

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The faster you go, the less lean can be used before you start to slide.

 

 

I have to disagree with you on this point Eirik, the cornering forces generated by a 60° lean angle will be the same at 40 and 140, the difference will be the radius of the resulting line

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In theory you are correct, but in practice it seems to be a difference. It would be interesting to watch the suspension compression when circling at let's say 50 degrees of lean doing 10 mph vs 100 or 200 mph, to see if it stays the same and that speed really doesn't matter. I know that when MOTORRAD did their test with the K75, it was at a very low speed, like circling inside a garage, and they said it would be impossible to achieve the same thing at higher speeds as the tyres would begin to slide before they reached 45 degrees and also ground clearance was used up before they could reach 45 degrees.

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I have seen Marquez carry 64 degrees of lean as indicated by the lean o meter during the motogp races.

 

I think you need to be going quite fast to carry that kind of lean....at slower speeds you would crash. Also at higher cornering speeds, isnt there an increased force on the tires?

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The faster you go, the less lean can be used before you start to slide.

 

I have to disagree with you on this point Eirik, the cornering forces generated by a 60° lean angle will be the same at 40 and 140, the difference will be the radius of the resulting line

For any given speed you can increase or decrease the lean angle of the BIKE by changing your body position. You can make a tight circle at low speed with LOTS of lean if you push the bike down under you and put your body weight on the 'wrong' side of the bike (towards the outside of the curve).

T, you are talking combined center of gravity of bike and rider, which gives you a fixed lean angle for a given speed, but take your bicycle or motorbike out in some parking lot circles and play with body position and counter leaning and it quickly becomes clear how you can adjust lean angles and circle diameter without changing speed.

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T, you are talking combined center of gravity of bike and rider, which gives you a fixed lean angle for a given speed, but take your bicycle or motorbike out in some parking lot circles and play with body position and counter leaning and it quickly becomes clear how you can adjust lean angles and circle diameter without changing speed.

 

 

 

I was speaking in more genral terms addressing Eirik's comment about speed reducing avaliable lean angle. It's been addressed many times on these forums how the aparant visual angle of a motorcycle is not the same as the effective cornering angle due to changes in CoG and tire width and the like. However all things being the same, IE Same bike lean, same body position and CoG, 1G of cornering force at 40 is the same as 1 g or cornering force at 140. So if you can achieve 50° of lean at 40 you can achieve the same amount of lean at 140

 

I have seen Marquez carry 64 degrees of lean as indicated by the lean o meter during the motogp races.

 

I think you need to be going quite fast to carry that kind of lean....at slower speeds you would crash. Also at higher cornering speeds, isnt there an increased force on the tires?

 

 

There is a minimum speed threshold for any given lean angle, in much the same way there is a given stall speed for a given bank angle on a airplane, however I'd bet its considerably lower than you think, easily demonstrated by various Moto Gymkhana videos and riders practicing dragging knees in parking lots at slow speed.

 

In theory you are correct, but in practice it seems to be a difference. It would be interesting to watch the suspension compression when circling at let's say 50 degrees of lean doing 10 mph vs 100 or 200 mph, to see if it stays the same and that speed really doesn't matter. I know that when MOTORRAD did their test with the K75, it was at a very low speed, like circling inside a garage, and they said it would be impossible to achieve the same thing at higher speeds as the tyres would begin to slide before they reached 45 degrees and also ground clearance was used up before they could reach 45 degrees.

 

Nothing works quite the same in practice as it does in theory, but I still disagree with the generality of that statement. If it were true than Marquez cornering at 62° with his elbow down around a slow corner would generate considerably less G force than the same thing through a very high speed one, which I'm pretty sure telemetry on the bike will show is not the case. My best guess is that the test riders in this scenario were doing circles in a garage, with considerable counter-weighting of the bike and achieved a 50° lean angle but were cornering with less than the G forces a bike would generate at 50° without a rider on it, and then when moving to higher speeds they stopped counter-weighting the bike and were no longer able to achieve the same 50° lean angle because the CoG of the bike had changed and the G force generated at 50° had increased.
The compression of the suspension mid corner of a steady state turn is due entirely to the load factor of the vehicle, and the calculations for determining that have nothing to do with speed, cornering at 1G is the same regardless of your rate of forward motion.
I'm sure there are some other forces at play that reduce the traction available at much higher speeds, like perhaps at a high enough rate of speed the tire cannot deform to match imperfections in the tarmac on a microscopic level fast enough and your available traction becomes reduced etc.

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You are probably spot on about the tester pushing the bike down to achieve the bike lean on the old K75.

 

What would you estimate the actual, combined lean angle is when Lorenzo has his bike leaned over 64 degrees in addition to hanging off?

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What would you estimate the actual, combined lean angle is when Lorenzo has his bike leaned over 64 degrees in addition to hanging off?

 

 

T-McKeen's post #15 fully coincides with what I have learned about Physics.

 

Please, Eirik, take a look at these calculations:

http://forums.superbikeschool.com/index.php?showtopic=3324&page=3

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So we're getting close to 70 degrees of effective lean, although only for brief moments. Pretty spectacular.

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