Join Date: Jun 2005
Bikes: khs flite 100, cannondale r800
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Originally Posted by centexwoody
Pardon my question but that chart looks wonderfully official & quantitative but I'm unable to understand what it actually means. Would the wise ones kindly point towards documents/books that would help me understand? What does the skid marking from this thread have to do with? Burning rubber on a really fast bike? Is this off-roading or some form of cycling that is simply unknown to me? I'm not even sure why a 14, 17 or 18 makes a difference in terms of braking...is this sheer velocity and momentum achieved vs the pressure required to apply the brakes?
This is gonna be my last question since it appears that I am woefully unprepared to even READ this messages...
The top chart is a list of skid patches. Most people have there cranks in the same position every time they skid. If you have a ratio of 48x16 which is a 3x1 then one crank rotation will create three full rotations on the wheel (and it will end up with the same part of the tire facing down).
If you have a 48x17 ratio the two numbers are relativly prime which means you can't break it down further than 48x17 which means you have 17 skid patches (or 17 different positions that the tire would be relative to your cranks).
If you have 1 skid patch you can burn through your tire in one position and end up with a hole in it.
The bottom is straight ratios and shows you that 42x14 will feel the same as 48x16. And if you know that you have a ratio of 3.0 and you want to move down to 48x18 you can also see that 43x16 is the same ratio. You can look at the chart based off of what you have now/know, and use it to help you find a better ratio. This is similar to gear inches, just a different measurement.
Hope that helps.