Wilsons Sandbox

>Is there a book for idiots like me who think they'll be ready for such a >ride in 5 years time? How about similar events in the U.S.

> I think we should get Kawi to sponsor a team from this list for the > next P-D. No wonder we never get any press, we're not visible > enough! Lets' do it the KLR way, though. No fancy support trucks or > crews to work on the bikes while we sleep. Just a gas card and a > saddlebag full of spares. Yeah, it'd be cool. I'll bring the beer. >

>Is there a book for idiots like me who think they'll be ready for such a

On Fri, 16 Jun 2000 01:47:08 EDT, InWoods13@... wrote: :) Will find out Dakar registration requirements & get in touch off list with results. Getting late, rambling again...All best Scott A14 "thunderdog - tha underdog" Sorrento >> Thanks Scott, I've already bookmarked the Dakar website but don't let that stop you from seniding any info or inspiring words my way (always willing to accept info and inspiration). My race experience to date is nil but I plan on changing that quickly (or should I say "fast"?). Hence my questions about new forks, etc. I was thinking KTM also or maybe a KLX for sentiment but probably KTM. I don't have the legs or the money - yet - but I do have an unhealthy dose of ambition and an even unhealthier dose of balls. I doubt I'll be able to cut down to part time work but I'm trying to accomplish that this summer (without sacrificing too much paycheck). As far as the motorcycle gods go, well I can only pray for a smile at the right time. Maybe that's why they've been so mean to me lately, so they can feel ok about giving me the thumb's up in 2005. Don't know if you have what it takes til you give it all you've got. dat brooklyn bum _______________________________________________________ Get 100% FREE Internet Access powered by Excite Visit http://freelane.excite.com/freeisp

----- Original Message ----- From: Jim & Shannon Morehead To: Chris Krok Sent: Saturday, June 17, 2000 7:23 AM Subject: Re: [DSN_klr650] NKLR contact patch velocity > I believe the original discussion was on the subject "Why do my tires cup?". > We could also agree that the tires on most lister's bikes would fall into > the general category of "knobbies". > > I couldn't care less about drag racing tires, Goodyear Aquatreads or other > non-motorcycle tires in this context. And , BTW, anti-lock brakes are not > tuned to react to the miniscule amounts of tire movement we are discussing > here. > > So, even if you didn't intend to, I'm glad you finally agreed with my point. > Although, you did take quite a long time to say so. There are indeed areas > on the tire that do squirm on the road and wear the tire. AKA cupping. > > Jim > > ----- Original Message ----- > From: Chris Krok > To: DSN_klr650@egroups.com> > Sent: Friday, June 16, 2000 8:38 PM > Subject: [DSN_klr650] NKLR contact patch velocity > > > > > > > > > > Consider the source. I think this is from the same genius who claimed > that > > > rolling motorcycle tires have zero velocity relative to the pavement. > While > > > it may be true if one assumes perfect conditions, no tire or tread flex, > > > clean and perfect pavement, etc., it doesn't take much imagination to > see > > > that a tire contact patch could easily deform and move relative to the > > > pavement as the tire rolls. > > > > I'm not the original posting genius, but I'm afraid that this is true, > > without the assumptions. Remember, the coefficient of static friction > > is much higher than that of dynamic/sliding friction. (Non-engineers: > > put a book on a table and push it. Notice that it takes a certain > > amount of force to start it moving, but less force to keep it moving at > > a constant speed. Also note the difference between this "break free" > > force and any acceleration force.) If your contact patch was moving > > relative to the pavement, in any direction, then the (lower) sliding > > friction would be in effect. If you took a turn, you'd wipe out. Also, > > your brakes stop you faster when they are not locked up. That's how ABS > > works. As soon as it detects lockup, it frees the brakes, so the wheel > > can begin turning, regaining its "zero velocity" contact patch and hence > > its traction before reapplying. Also note that if you are driving a car > > and go into a skid, you turn the wheels in the direction of the skid. > > The purpose is again to get the wheels turning and regain traction. In > > a more extreme case, watch drag racing. Before lining up, they do a > > burnout to warm up the tires and make them stickier. When they launch, > > consider that if the tires broke free, they would just sit there and > > smoke, considering the amount of power they are putting down. Someone > > also took high-speed films of top fuel dragster wheels on launch. Tons > > of wrinkle, but the bottom stays still. > > > > If that's not enough, watch the Goodyear "Aquatread" commercial, where > > they show a tire going through water, shot through glass on the > > underside. > > > > Also, if you plot the trajectory of a point on the wheel, you will see > > that it takes a "bouncing" path. There is a cusp where it hits the > > ground, where it undergoes a 180 degree change in velocity direction. > > (In fact, this is on the cover of my calc text.) Therefore, it must > > pass through zero velocity. Of course, this is perpendicular to the > > pavement, but if you want assumptions, how about a bike going straight, > > with symmetric tires? (which they all are.) The centerline of the tire > > has no reason to "slide" to either side due to symmetry, so it is at > > zero velocity. I am reluctant to refer to this as a "slap," though, as > > the tire is a continuum, and the motion of the tire itself is better > > described as a wave. (i.e., in tire-fixed coordinates.) > > > > Granted, with tires like knobbies, the outer knobs will roll in as the > > tire flattens. However, I guarantee you that the center of the patch is > > stationary. > > > > Chris > > > > > > -- > > Dr. J. Christopher Krok Project Engineer, Adaptive Wall Wind Tunnel > > Graduate Aeronautical Laboratories, California Institute of Technology > > MS 205-45 Phone: 626.395.4794 > > Pasadena, CA 91125 Fax: 626.449.2677 > > > > ------------------------------------------------------------------------ > > TRAVEL FOR PENNIES ON THE DOLLAR! Get dozens of the best travel agents > > competing for your business with our new FREE service. > > http://click.egroups.com/1/5571/5/_/911801/_/961204689/ > > ------------------------------------------------------------------------ > > > > Visit the KLR650 archives at > > http://www.listquest.com/lq/search.html?ln=klr650 > > Support Dual Sport News... dsneditor@... > > Let's keep this list SPAM free! > > > > Visit our site at http://www.egroups.com/group/DSN_klr650 > > To unsubscribe from this group, send an email to: > > DSN_klr650-unsubscribe@egroups.com > > > > >