dark side? abs friendly

[HansO]

no reason why it will effect the ABS as it is same as std size MC/Tyre diameter only slightly wider

 

[1olbull]

@CanberraR3
Very nice write up, Richard! The change in diameter when leaned is very critical to the handling characteristics of a motor and relatively nonexistent in a car tire.
Regarding ABS applications while turning, I think this be not so relevant because ABS functions at lock up. In a turn the friction circle would surely be exceeded at this point and one find themselves on their butt in short order. However, it must be pointed out that one or two motors are now coming out with ESC (electronic stability control) that is reportedly supposed to function in corners! This is pretty exciting stuff and I can't wait to learn more about it.

 

[1olbull]

no reason why it will effect the ABS as it is same as std size MC/Tyre diameter only slightly wider

@HansO
Richard was speaking of cornering performance where there is a tremendous difference in diameter.

 

[Wrecka]

 

[1olbull]

@nolton
Any tire is designated by cross section length, sidewall aspect ratio (percentage) and mounting diameter. A Stone Excedra Max is 240/55R16 means 240mm cross section width - the 55 is the sidewall aspect ratio (55%) - the "R" is radial - the 16 is wheel diameter in inches. Go figure this! Inches and millimeters used together?! WTF???

If you multiply the section width value by the sidewall aspect ratio you get the sidewall height. So, 240 X .55 = 132 mm 132 mm X .03937 (conversion factor for mm to inches) = 5.2 inches.

Now since there are two sidewalls in the total wheel diameter take 5.2 X 2 = 10.4 inches. Add this to the 16 inch diameter and you have a 26.4 inch total diameter.

Let's compare to a stock Metz 240/50R16. 240 X .50 = 120 mm. 120 X .03937 = 4.72 inches X2 = 9.45 inches + 16 = 25.45 inches total diameter or .95 inch smaller in diameter than the Stone.

Calculating a car tire is the same. 225/50R16 would be 225 X .50 = 112.5 mm X .03937 = 4.43 inches X 2 = 8.86 inches + 16 = 24.86 inches total diameter.

Hope this helps and I didn't screw up any math.

 

[HansO]

@HansO
Richard was speaking of cornering performance where there is a tremendous difference in diameter.

Believe me there is no major problem with cornering there is the optical illusion that most of the tyre is in the air but while at low speed that may be the case and that is the only time Richard would have been close enough to see my rear while cornering.
While applying power thru some of the faster twisty bit and sweepers I get tremendous grip with a DS and while the Bridgestone gets good grip I have felt it move under the same conditions, I have also followed another DSer thru twisty stuff before I went there (the Dark Side) and was amazed to see how big the contact patch actually was considering the amount of tyre that appeared to be in the air and he was getting better grip than my Metz was, Yes it takes a little extra counter steer to initiate a turn but it very soon becomes second nature, same applies to the need to counter steer the camber and while riding predominantly around city areas the the front tyres may wear more evenly even with the Bridgestone on the back there is noticeably more wear on the up camber side I would even say the wear right to left ratio is about even. remember I ride my wifes little Kawka 250gpx around town and many use my Rocket on the highways were there is more camber than town or city streets,
Yes you will while at walking or near walking pace feel the bike try to follow ridges and ruts in the road surface but if you are aware of this and are prepared to use a little body language it is not really a problem especially if you have ever done any dirt bike or trials riding.
The thing that is most important is to adjust the tyre pressure to suit your weight

 

[1olbull]

Believe me there is no major problem with cornering there is the optical illusion that most of the tyre is in the air but while at low speed that may be the case and that is the only time Richard would have been close enough to see my rear while cornering.
While applying power thru some of the faster twisty bit and sweepers I get tremendous grip with a DS and while the Bridgestone gets good grip I have felt it move under the same conditions, I have also followed another DSer thru twisty stuff before I went there (the Dark Side) and was amazed to see how big the contact patch actually was considering the amount of tyre that appeared to be in the air and he was getting better grip than my Metz was, Yes it takes a little extra counter steer to initiate a turn but it very soon becomes second nature, same applies to the need to counter steer the camber and while riding predominantly around city areas the the front tyres may wear more evenly even with the Bridgestone on the back there is noticeably more wear on the up camber side I would even say the wear right to left ratio is about even. remember I ride my wifes little Kawka 250gpx around town and many use my Rocket on the highways were there is more camber than town or city streets,
Yes you will while at walking or near walking pace feel the bike try to follow ridges and ruts in the road surface but if you are aware of this and are prepared to use a little body language it is not really a problem especially if you have ever done any dirt bike or trials riding.
The thing that is most important is to adjust the tyre pressure to suit your weight

Mate,
I thought he was referring to the change in the rolling circumference of a leaning motor tyre. A car tyre is not designed to lean so there is no reduction in circumference or diameter when it is leaned. The tire pressure dance youse all do (mentioned in your post) is an attempt to compensate for this. I did not take Richard's comments as hostile and thought they were erudite, hense my compliments.

I also do not take exception with your experience and comments regarding your use of a car tire. However well a skilled rider can perform with a car tire, does not change the science. I just watched a guy sail through mountains at high speed with an armpit and ****** kite suit strapped on. This sure doesn't mean it would be safe for the masses if they strapped on the same kite suit.

 

[ROCKETHEAD]

Took some long sweepers recently at the same rpm as going straight and my mph stayed the same.

 

[CanberraR3]

I was just talking mathematically, which is what I thought I was asked to do. As always, the mere mention of anything to do with car tyres, no matter how objective someone tries to remain, attracts the same old subjectivity and BS remarks about how much they improve handling etc. Even if that were partly true, which it isn't, I would spend maybe 1% of my riding with the bike cranked over in the way the evangelists speak about it. I'm far more concerned about the 99% thankyou.

Factually comments about sidewall height somehow get converted to contact patch and then there's a "accidental" bragging that no one with a proper tyre on their bike could possibly keep up with someone using a bloody car tyre. What I said was that the sidewall on a car tyre is taller than the sidewall on a motorcycle tyre. That makes no difference when the bike is running vertical but clearly throws everything out when it's leaned over. Of course a fellow would have to actually read the post to know that so I shouldn't be surprised at the reaction.

 

[CanberraR3]

Took some long sweepers recently at the same rpm as going straight and my mph stayed the same.

No, your speedo read the same. Your rear wheel speed/transmission speed wouldn't change unless your clutch was slipping. Sigh. Think about it.........Think a bit harder...... There you go. Got it now?

Maybe I should type slower and use a bigger font in these discussions.