Lean angle

[oldbike54]

 Yeah , if you are achieving lean angles in the low 40's on the street that is cooking along . Riders like to talk about how far they can lean , not unlike amateur dirt bike guys like to talk about how high and far they can jump . The truth almost never matches their imagination .

 Something like a KTM Duke probably has the highest available lean angle , way more than anyone can use on the street . Marc Marquez could probably achieve 75 degrees on one of those with soft slicks on a clean surface , except he would likely just "back it in" like a good dirt tracker and get it pointed in the right direction .

 Dusty

[Kev m]

As a general rule, Guzzis have good cornering clearance.   Very different from most Harleys. 

A 45 degree lean angle corresponds to 1.0g of cornering force, which is pretty dang good for a street machine with regular tires on a non-track surface. 

Empirical testing from the 1920s establishes that most people feel psychologically “safe” when experiencing a g force of 0.2 while cornering in a car.   So most roads and speed limits are designed loosely around that standard (lots of exceptions for mountain roads).

I’ve read that humans are instinctively fearful of a “lean angle” greater than 22 degrees.   That the sort of slope where human feet often slip, or the upright body falls down, so we are programmed to be leery past 22 degrees.    That’s likely why maybe riders crash in curves that their bike and tires could have negotiated—their brains told them not to be leaning more than 22 degrees.   

They make a gizmo you can mount on the handlebars to determine g forces and lean angles.   I had one once on my V7, which I usually ride pretty conservatively.   It spent most of its life reporting lean angles of 20 to 25 degrees.   

To get into the 30s you needed curvy mountain roads ridden considerably above the advisory speed limits.  In the 30s you feel like you are definitely leaning and working the bike.   It felt like “spirited riding,” but essentially safe and controlled. 

At least for me, getting into the low 40s felt like pushing too far on a public road.  I think I was approaching a limit, but I didn’t crash or slide, so maybe there was more margin.   You would have to be a pretty aggressive rider to routinely ride in the 40s


http://ridewithtech.com/tech-gadgets/the-leanometer/

This sounds pretty reasonable and jives with my experiences with what's reported by Harley in their specs on various models.

Also jives with my perceptions of Guzzi capabilities and how many Harleys are close enough most of the time for my uses.

[chuck peterson]

It will be different in motion as opposed to static.
When moving in a circular path, the force acting down through the machine compresses the suspension. Also there is the variation in the load, both of these combine to “squash” the bike towards the contact patch.
In a 45 degree banked turn, the bike and rider combination weigh 1.4 times normal.
The lean “angle” is not altered by the mass, but the compressing of the suspension effectively reduces the ground clearance, so the first part of the substructure will touch down earlier.

ummmmm...i kinda expect more ground clearance in a corner if I’m “throttle on” in a curve

To me, what you’ve described is going from straight up, then into a curve w no additional throttle, and a loss of speed, while cornering forces pushes you down onto the forks and shocks.

Adding throttle in a corner adds some clearance, given the same lean angle. Adding brake in a corner takes away clearance, given the same lean angle

Leaning more is similar to picking a smaller rear cog on your ten speed. (Visualize the gear cluster from the rear..cogs get smaller on the outside..motorcycle tires get smaller on the outside). One of two things happen ...you slow down or you have to pedal harder

Back to motorcycles..
Leaning more w a steady throttle only, slows you down and compresses the suspension, putting the bike into a decreasing radius turn

Leaning more w a slight increase in throttle keeps a steady speed/pace, reduces the compression on the suspension, putting the bike into a perfect radius turn, a circle if you will

Leaning w a harder increase in throttle than slightly, increases speed, standing up off the suspension less so, putting the bike into an increasing radius turn...

Oh it’s all too complicated I quit ..i so like thinking this shiite while riding

[Guzzistajohn]

European or African?......are you suggesting that coconuts migrate?

I was just watching that on netflix this morning BRING OUT YOUR DEAD.........clang!!!!

[bad Chad]

The Moto Guzzi App, available for newer Guzzi, measures lean angle among a bunch of other mostly useless measurements.

[LowRyter]

Well maybe , there is the problem of finding someone fleet of foot who owns a large protractor .

 Dusty

With your carpentry skills, no problem.....   

[Huzo]

ummmmm...i kinda expect more ground clearance in a corner if I’m “throttle on” in a curve

To me, what you’ve described is going from straight up, then into a curve w no additional throttle, and a loss of speed, while cornering forces pushes you down onto the forks and shocks.

Adding throttle in a corner adds some clearance, given the same lean angle. Adding brake in a corner takes away clearance, given the same lean angle

Leaning more is similar to picking a smaller rear cog on your ten speed. (Visualize the gear cluster from the rear..cogs get smaller on the outside..motorcycle tires get smaller on the outside). One of two things happen ...you slow down or you have to pedal harder

Back to motorcycles..
Leaning more w a steady throttle only, slows you down and compresses the suspension, putting the bike into a decreasing radius turn

Leaning more w a slight increase in throttle keeps a steady speed/pace, reduces the compression on the suspension, putting the bike into a perfect radius turn, a circle if you will

Leaning w a harder increase in throttle than slightly, increases speed, standing up off the suspension less so, putting the bike into an increasing radius turn...

Oh it’s all too complicated I quit ..i so like thinking this shiite while riding

It’s not really complicated, but when you use terms like “throttle on” or “throttle off”, you are not fully describing the situation.
The angle of lean you have, is not something you can “decide” on, it is a function of your velocity and turn radius.
It does not matter if you have more or less throttle, it’s whether your speed has altered.
Not using correct and unambiguous terms is what leads these discussions down a path of anguish sometimes.
The squashing of the suspension in a turn is not because of your slowing down, it is the force accelerating you towards the centre of the turn. If you maintain the the same throttle setting, your bike will slow an amount because you are doing work in changing the bike’s direction and not adding energy to do that work.
Your point about “adding throttle in a corner”, do you mean adding “speed in a corner” ?
The lean of your bike is to balance the force trying to tip your bike towards the outside of the turn, like what happens in your right hand turns with a sidecar.
It would be advantageous if you make one point at a time, so each one can be discussed in isolation.
I could say to you that your favourite corner requires a given throttle at 100 kph, if you are towing a trailer in exactly the same situation at 100 kph, you will need more throttle but the same lean angle.
If you say “add throttle” could you change hat to “add speed”...( or velocity would be nicer).
I would like to hear from Tusayan on this one...

[oldbike54]

With your carpentry skills, no problem.....   

 Still gotta find someone who can run 80 MPH while carrying a large protractor 

 Dusty

[pete mcgee]

I have a photo of me on the lemans 3 hooking through a mountain corner in a very spirited fashion,  from my prospective it felt like I was pushing it, the photo was very unremarkable of some bloke on a bike in a corner. Perspective vs reality. Mick Doohan I am not it seems.
Tyres are another variable in lean angle, I can state that the old Dunlop elites from the late 1980s could be run off the edge of the tyre before the pegs scraped on one road near Canberra, very un nerving, great tyre for the long flat roads in the centre of oz, useless for spirited riding in twisties.
Now I suffer the older I get the faster I was syndrome, I now work on smooth rather than the take no prisoners you only live once cornering technique, less painfull and expensive method.

[lucky phil]

ummmmm...i kinda expect more ground clearance in a corner if I’m “throttle on” in a curve

To me, what you’ve described is going from straight up, then into a curve w no additional throttle, and a loss of speed, while cornering forces pushes you down onto the forks and shocks.

Adding throttle in a corner adds some clearance, given the same lean angle. Adding brake in a corner takes away clearance, given the same lean angle

Leaning more is similar to picking a smaller rear cog on your ten speed. (Visualize the gear cluster from the rear..cogs get smaller on the outside..motorcycle tires get smaller on the outside). One of two things happen ...you slow down or you have to pedal harder

Back to motorcycles..
Leaning more w a steady throttle only, slows you down and compresses the suspension, putting the bike into a decreasing radius turn

Leaning more w a slight increase in throttle keeps a steady speed/pace, reduces the compression on the suspension, putting the bike into a perfect radius turn, a circle if you will

Leaning w a harder increase in throttle than slightly, increases speed, standing up off the suspension less so, putting the bike into an increasing radius turn...

Oh it’s all too complicated I quit ..i so like thinking this shiite while riding

Yes you are correct to a point. Getting on the throttle will increase ground clearance on just about every properly set up/designed motorcycle due to chain pull. As you open the throttle the chain pull extends the rear suspension and so in theory will give you a very slight varying change in ground clearance depending on the lean angle and amount of throttle application. Older shaft drive bikes with a lot of jacking up and down at the back are more extreme and there was a riding technique for them where you tried to maintain a little throttle in the turn at high lean angles and avoid closing it at all costs especially rapidly to maintain better clearance.
Of course you can vary the angle required to negotiate a given radius turn at a given speed by hanging off the bike. That's part of the reason modern road racers started hanging off in the first place to reduce the lean angle of the bike for a given turn radius and speed. Other advantages followed to where we are today with elbows on the ground.

Ciao   

[Huzo]

Yes you are correct to a point. Getting on the throttle will increase ground clearance on just about every properly set up/designed motorcycle due to chain pull. As you open the throttle the chain pull extends the rear suspension

Just a question on that one Phil..
If the chain runs above the swingarm pivot (which it does), wouldn’t the tension tend to compress the shocks?
If you removed the rear shocks and started the bike on the centrestand then put it into gear and released the clutch, do you think it would move the wheel up into the guard or down towards the ground ? 
When is the last time you saw a drag bike lift it’s arse when the rider dumps the clutch and heads off down the strip....

[lucky phil]

Just a question on that one Phil..
If the chain runs above the swingarm pivot (which it does), wouldn’t the tension tend to compress the shocks?
If you removed the rear shocks and started the bike on the centrestand then put it into gear and released the clutch, do you think it would move the wheel up into the guard or down towards the ground ? 
When is the last time you saw a drag bike lift it’s arse when the rider dumps the clutch and heads off down the strip....

If the swingarm had no droop it would. As a general principle when the axle is below the swingarm pivot point the chain pull will extend the suspension under power. The amount is dependent on  the relationship between the countershaft and rear sprocket sizes the swingarm droop and the swingarm pivot centreline to the countershaft sprocket centreline. The combined relationship determines either squat or the opposite. It's what complicates final drive gearing changes for race teams and they just dont thrown on a smaller or bigger rear sprocket to fine tune the gearing or it upsets the handling on the throttle. It's also partly why modern GP bikes have adjustable swingarm pivot points, to tune the anti squat for different final drive combinations.

Drag strip squat? depends if its a bike set up for the strip or a modern sports bike or track bike that's set up well. A modern sports bike wont squat on the launch unless its been modified to do so. Thats why they want to wheelie off the line all the time and are difficult to get a good 60 foot time. A dedicated drag bike wont have any or little swing arm droop so the chain pull doesn't oppose the squat. Look at race starts for a modern WSB without mechanical launch control. They don't squat at all because the chain pull is overriding it so they tend to wheelie a lot so the rider and/or the electronic launch and anti wheelie control need to pull torque out or the rider uses rear brake. It's part of what a modern mechanical launch control does, lowers the rear suspension to lower the c of g and also help reduce the chain pull anti squat.

Ciao       

[Huzo]

If the swingarm had no droop it would. As a general principle when the axle is below the swingarm pivot point the chain pull will extend the suspension under power. The amount is dependent on  the relationship between the countershaft and rear sprocket sizes the swingarm droop and the swingarm pivot centreline to the countershaft sprocket centreline. The combined relationship determines either squat or the opposite. It's what complicates final drive gearing changes for race teams and they just dont thrown on a smaller or bigger rear sprocket to fine tune the gearing or it upsets the handling on the throttle. It's also partly why modern GP bikes have adjustable swingarm pivot points, to tune the anti squat for different final drive combinations.

Drag strip squat? depends if its a bike set up for the strip or a modern sports bike or track bike that's set up well. A modern sports bike wont squat on the launch unless its been modified to do so. Thats why they want to wheelie off the line all the time and are difficult to get a good 60 foot time. A dedicated drag bike wont have any or little swing arm droop so the chain pull doesn't oppose the squat. Look at race starts for a modern WSB without mechanical launch control. They don't squat at all because the chain pull is overriding it so they tend to wheelie a lot so the rider and/or the electronic launch and anti wheelie control need to pull torque out or the rider uses rear brake. It's part of what a modern mechanical launch control does, lowers the rear suspension to lower the c of g and also help reduce the chain pull anti squat.

Ciao     

That’s well worth considering.
I do understand and accept that it’s the direct line from the countershaft sprocket to the rear sprocket that determines whether the suspension extends or squats.
It’s a two minute job to take the shocks off the CT110. I’m interested to see what happens to the rear swingarm if I do that and pop it into gear then touch the throttle, like any half decently designed bike, the front sprocket, swingarm pivot and rear axle are very close to in line under load, there’ll be very few that aren’t.
Our earlier poster, suggested that it was a foregone conclusion that he would gain ground clearance under application of throttle due to torque reaction and on earlier shafties that’s more than likely.
My old XS750 Yamaha triple was a bastard for it.
However that will only be the case if at all, under acceleration, once the new speed is reached the suspension will have settled again.
I’ll leave that there for now..

[lucky phil]

That’s well worth considering.
I do understand and accept that it’s the direct line from the countershaft sprocket to the rear sprocket that determines whether the suspension extends or squats.
It’s a two minute job to take the shocks off the CT110. I’m interested to see what happens to the rear swingarm if I do that and pop it into gear then touch the throttle, like any half decently designed bike, the front sprocket, swingarm pivot and rear axle are very close to in line under load, there’ll be very few that aren’t.
Our earlier poster, suggested that it was a foregone conclusion that he would gain ground clearance under application of throttle due to torque reaction and on earlier shafties that’s more than likely.
My old XS750 Yamaha triple was a bastard for it.
However that will only be the case if at all, under acceleration, once the new speed is reached the suspension will have settled again.
I’ll leave that there for now..

Here's an Image of a Ducati Panagale road bike (albeit a special Superleggera one) The axle centreline is 75mm below the countershaft centreline and the arm pivot same as my track 1198. Bearing in mind the suspension will only compress around a further 40mmish with the rider on board and at max load in a corner you still have 35mm or so droop. This is a road bike as well and a race bike will be set up with more droop than this in all probability. I also forgot to mention the distance from the arm pivot and the countershaft centre also plays a part. Its easy to see how it can become a massively complex job extracting the last .5% from a racing motorcycle with all these dynamic variabilities in just the rear drive alone. And thats what separates Mark Marquez from the guy in 10th place in qualifying around .5%. Most race tracks are around a 100 second lap and .5 of a second separates the first 10 guys mostly. So you qualify 10th and you're 1/2 of a percent slower than MM. Kind of puts into perspective the whole MotoGP grid. They are all amazing riders.
If you study MotoGP footage(not so much now they have a rider operated squat device) or WSB when they occasionally have a under seat camera angle looking back you can see how the chain pull and suspension inter relate to cornering and power application. Suspension fully extended on the brakes and then compresses as the cornering load comes on then listen for the throttle to crack and the suspension extends a little as the throttle is fed in and the cornering loads diminish until you hear the throttle go wide open and the suspension fully extends and often goes out of shot as the chain pull comes into play. 

fascinating stuff, for me as you can probably tell.   

Ciao

[Huzo]

Me too. I’ll take the Panigale example on board and be looking at others.

[giusto]

I was just watching that on netflix this morning BRING OUT YOUR DEAD.........clang!!!!

"bbbut but I'm not quite dead yet" oh stop your whining!

[chuck peterson]

Thanks for all the technical!...great stuff

Huzo, rereading your post, I noticed how you put the bike on a BANKED curve..i was describing a flat horizontal landscape. I agree w you on the banking compressing the suspension there..

Ciao indeed! Here is the visual i have of adding throttle in a curve...front forks extended, up on the rear.

[Huzo]

Thanks for all the technical!...great stuff

Huzo, rereading your post, I noticed how you put the bike on a BANKED curve..i was describing a flat horizontal landscape. I agree w you on the banking compressing the suspension there..

Ciao indeed! Here is the visual i have of adding throttle in a curve...front forks extended, up on the rear.

I meant it in the truest sense. The bike is BANKED (leaned) on a flat surface, as opposed to remaining upright.
But I’m leaving it there for now.