Sorry guys but I have to resurrect this extensively discussed subject again.

During the recent airing of the Le Mans GP there was a graphic showing the angle of lean of Danny Pedrosa which appeared to peak at 61 degrees which is very close to the 58 degrees that I have been preaching about for a number of years. Does anyone know whether this is the angle of the bike to the vertical (which I suspect it may be) or the angle of the CofG of the bike/rider combination to the vertical.

If it is the latter then he is pulling in excess of the 1.8 G which the angle of 61 deg would suggest.

For those of you who may, of recent times, have missed me on these boards (Zoot, Rolfo, etc!!!) I would mention that I am not having an easy time reading the posts as printed in white on grey. I had a serious eye problem manifest itself about 18 months ago where I was losing my vision at a rate where I would probably have been unable to read within 6 months or so. Fortunately for me I discovered Dr. Rosenfeld at the Bascom Palmer Eye Institute and after a number of injections into the eye I am back to 20/20. I do however somewhat lack contrast, hence my problems with white on grey. It does seem to be improving though which is why I am back (collective groans!)

There are multiple programs out there which can read web pages aloud to you. If you have a Mac its built in and you can select it under preferences.


Here are some for the PC:

http://www.browsealoud.com/page.asp?pg_id=80004

http://www.naturalreaders.com/?gclid=CP2j-sHdy5MCFRcZsgodNEcDiA

Some are free, some are not. Some have the option of downloading as an MP3 then you can listen to them on an iPod. Just imagine hearing a computer voice read King Kenny's posts as you walk along. Gads.

Anyway, best of luck but I hope these things can help you out a bit.

r60man - 29 May 2008 07:43 AM

There are multiple programs out there which can read web pages aloud to you. If you have a Mac its built in and you can select it under preferences.


Here are some for the PC:

http://www.browsealoud.com/page.asp?pg_id=80004

http://www.naturalreaders.com/?gclid=CP2j-sHdy5MCFRcZsgodNEcDiA

Some are free, some are not. Some have the option of downloading as an MP3 then you can listen to them on an iPod. Just imagine hearing a computer voice read King Kenny's posts as you walk along. Gads.

Anyway, best of luck but I hope these things can help you out a bit.

Thanks for the concern R60. I'll certainly keep that in mind for if it deteriorates. Right now I can read the posts OK but it would be easier if they were printed as black on white, ie what has been accepted for hundreds of years to be the best. Why mess with the traditional colours? Next thing is they'll probably try red on green which will sort out all those with classic colourblindness!

With no comments whatever on angle of lean I have reinforced the conclusion that I came to before which is that virtually no riders understand the relationship between cornering speed and angle of lean.

heritage32 - 30 May 2008 09:26 AM

Thanks for the concern R60. I'll certainly keep that in mind for if it deteriorates. Right now I can read the posts OK but it would be easier if they were printed as black on white, ie what has been accepted for hundreds of years to be the best. Why mess with the traditional colours? Next thing is they'll probably try red on green which will sort out all those with classic colourblindness!/quote]

Actually research has shown that a dark blue background with yellow lettering is best for people with vision problems.

Signature:

It will bring you so close to nausea, it will make you sick! - Big Al

My understanding is that motorcycles pull NO lateral Gs. If they did, even minutely, they would crash.

Having said that, the angle of lean is the one that offsets the Gs, and it offsets it to nil, IMO.

s2r

sin2rhyme - 06 August 2008 01:21 PM

My understanding is that motorcycles pull NO lateral Gs. If they did, even minutely, they would crash.

Having said that, the angle of lean is the one that offsets the Gs, and it offsets it to nil, IMO.

s2r

Any change in direction for a body in motion generates centripetal acceleration the net result of which is a centrifugal force (MVsquared/r where M is the mass of the object, V is the velocity and r the radius of the turn). The Vsquared/r component of this is an acceleration (ft/sec squared). If this is divided by 32.2 the acceleration is then in "G".

The fact that this "G" is offset by the shift in the position of the CofG from the bike heeling does not mean it has gone away! If it had then there would be no danger of the tyres ever sliding outwards on a corner.

The tangent of the angle of lean (measured as a line drawn through the CofG of the combined rider/bike and through the mean contact point on the road) represents numerically the G that the bike is subjected to, e.g. a lean of 45 deg would be 1 G, 60 deg 1.73 G. It is not possible to ride a bike through a corner at any angle of heel different from that dictated by the physics of the situation.

One thing - the contact patch of the tire when the bike is leaned over is not at the center of the tire, and the rider is slightly displaced to one side. The real angle you should measure, instead of that of the centerline of the bike, is that from the Center of Gravity of the bike/rider combination to the center of pressure of the tire's contact patch. How one can determine those is anybody's guess.

My guess is that the measurement you saw was the centerline of the bike, but I don't know for sure.

EDIT - Looks like you have those points down, already. I should have read your posts more clearly in the first place.

Hooray! Black on white - I can read it easily again.

Skater, I think you must be the only one on the m/c boards that understands what I am talking about

A "g" meter measuring horizontal g would give the tangent of the effective angle of lean which would be a very interesting figure to derive.

I guess the angle given on the race broadcasts is the actual angle of the bike versus the true vertical which doesn't, of course, take into account the points of contact with the road and the degree to which the rider is hanging off.