From: owner-klr650-digest@lists.xmission.com (klr650-digest) To: klr650-digest@lists.xmission.com Subject: klr650-digest V2 #123 Reply-To: klr650 Sender: owner-klr650-digest@lists.xmission.com Errors-To: owner-klr650-digest@lists.xmission.com Precedence: bulk klr650-digest Saturday, March 13 1999 Volume 02 : Number 123 ---------------------------------------------------------------------- Date: Fri, 12 Mar 1999 22:59:57 -0500 From: "Stephen Rivett" Subject: (klr650) Another list possibly? I was wondering, since I'm one for a good debate, could we have a second message board where we can take the threads that won't die? It could also be used to discuss NKLR topics since I haven't seen a list for them either. Thanks, Stephen Rivett. ------------------------------ Date: Fri, 12 Mar 1999 20:08:57 PST From: "Juan Villarreal" Subject: (klr650) Helmet tail light (NKLR) >From: "Karl Huebner" >Juan: > >I e-mailed the helmet tail light guy and have not gotten a response as of >yet. Do you know how much the units cost? Karl, I spoke to a fella named Corey... He quoted me a price of $69.95, plus $6 for shipping and handling. They (Hercules JRP, Inc.) have a toll free number (1-800-800-4920), but it was always busy. I instead dialed their regular number (570-992-5754). They take only credit card orders or money orders (no personal checks). Part number is 3100, and their address is as follows: R.D., Box 1416 Stroudsburg, PA 18360 Best of luck to you. Juan Villarreal Get Your Private, Free Email at http://www.hotmail.com ------------------------------ Date: Fri, 12 Mar 1999 19:08:09 -0800 From: "Arne Larsen" Subject: (klr650) NKLR - Winnipeg to Victoria - -----Original Message----- From: Tom Clay To: Arne Larsen ; KLR650 List Date: Friday, March 12, 1999 6:26 PM Subject: Re: (klr650) - Driving MR. Michael NUTS >Congratulations on the bike. I think you will like it. I've travelled by >KLR from Winnipeg to Victoria and back in each of the last two years, with >absolutely no mechanical problems [I have a '97]. I didn't bother with the >extended warranty, but instead spent the extra money on Manitoba's bizarre >motorcycle insurance rates. Ironically, the Valkyrie was the other bike I >was considering before I bought my KLR. I never did test one and am still >curious. Good luck. > >Tom Clay >Winnipeg MB >Vive le KLR Give me a heads-up your next time through. I live 2 minutes away from the Tim Horton's on the west side of Abbotsford, BC. It's the one by the Automall and big clock. Right at the Mt. Lehman freeway exit. I'll meet you for coffee there. Arne ------------------------------ Date: Fri, 12 Mar 1999 23:39:02 EST From: FTabor231@aol.com Subject: Re: (klr650) Questions, Questions, Questions - KLR In a message dated 3/12/99 8:52:52 PM Central Standard Time, jlwalk@prodigy.net writes: << but I think that it is also important to note that the frictional force isn't dependent (coefficient of kinetic friction) upon the contact area of the brake pads >> Then a brake pad the size of the head of a pin would be the same? Maybe a pin head size brake pad would dissipate heat better like a four valve head instead of the conventional 2 (bigger) valve head It seems like it is easy to lock up the rear disc brake, but the rotor is about the same size, the force is greater because our leg is stronger than our hand. And a full floater stops better than a fixed rotor because it 'aligns' with the pads in the caliper better, allowing the piston to apply more force to the rotor I guess I don't think that bigger is always better, but I know that 50 % of the population probably does. ------------------------------ Date: Fri, 12 Mar 1999 21:03:09 -0800 From: Christopher J Beasley Subject: Re: (klr650) KLR Fork Brace??? K650dsn@aol.com wrote: > In a message dated 3/12/99 7:01:34 PM Mountain Standard Time, > robertlmorgan@worldnet.att.net writes: > > << Tim Bernard has something in the R&D phase. Stay tuned. >> > > So does Steve at Quality Engine R&D. Who will get done first? And will they be able to produce them in quantity before Moab?;-) b > > > Gino ------------------------------ Date: Fri, 12 Mar 1999 21:47:36 -0800 From: "Jeff & Lisa Walker" Subject: Re: (klr650) Questions, Questions, Questions - NKLR >Then a brake pad the size of the head of a pin would be the same? Maybe a pin >head size brake pad would dissipate heat better like a four valve head instead >of the conventional 2 (bigger) valve head Theoretically, but the heat would be localized on the head of that pin, not dissapated over a larger area. Also, this would wear quite the groove in the rotor. >It seems like it is easy to lock up the rear disc brake, but the rotor is >about the same size, the force is greater because our leg is stronger than our >hand. And a full floater stops better than a fixed rotor because it 'aligns' >with the pads in the caliper better, allowing the piston to apply more force >to the rotor Also, when you are stopping, your center of gravity has shifted forward, and the rear wheel gets "lighter", thus less normal force, and thus the friction between the tire and the road can turn from static friction to kinetic friction real easy. Jeff---working on a difficult inertial integral at the moment. ------------------------------ Date: Fri, 12 Mar 1999 22:05:58 -0800 From: "Jeff & Lisa Walker" Subject: Re: (klr650) Questions, Questions, Questions - NKLR When you squeeze the brake lever pressure is exerted on the brake pads via the >caliper. This pressure increases the friction between the pads and the rotor. >This frictional force is tangential to the edge of the rotor and in the direction >opposite of wheel spin. This force is NOT the same on the larger rotor as it is >on the stock rotor! Why? Because the frictional force is a function of the >molecular structures of the two materials (brake pad and rotor) AND of the speed >at which the two are passing. Outside edge of the bigger rotor goes further than >the outside edge of the smaller rotor in the same amount of time (for a given >bike speed) and therefore is moving faster to accomplish this feat. (If you're >not convinced of this e-mail me) So, we have determined that the frictional >force applied by the pads to the bigger rotor are greater than for the stock >rotor. > Can you please explain to me, via an equation, how the relative velocities between the pads and the rotor factor into computing the frictional force? As far as I know, contact friction is computed by multiplying the normal force (i.e. pressure of the pads on the rotor) by the coefficient of kinetic friction, which is a dimensionless scaler. The coeffecient of kinetic friction doesn't change, its experimentally determined by the nature of the compounds in contact, in this case, steel and brake liner. In this regard, the tangential frictional force on the rotor is determined only by the magnitude of the force of the calipers onto the pads. Say you have a kid sliding down a very long slide. There is a coefficient of kinetic friction between the kid's butt and the metal (or plastic, as new slides tend to be--caused quite the static charge!). The kid has a normal force that is determined by the angle of the slide from the ground, and the kid's weight. This normal force is a vector that points directly up from the surface of the slide, and is determined by the vector component of the kids force due to gravity, which points straight down. Follow? The force due to kinetic friction is the normal force times the coeffecient of kinetic friction. So this kid is still accelerating due to gravity faster and faster. Are you saying that the force of friction increases due to the increased velocity? I think that the only thing that would increase is the heat that the kid feels on his butt. But nothing has changed the equation, and thus the kinetic frictional force is constant. In this regards, the explaination of a longer moment arm explains perfectly why a larger diameter rotor works better. If I am wrong, let me know, but I can't find anything in my texts to contradict this. With other types of friction, like with fluids, it does increase with increasing velocity, like with wind drag. Jeff ------------------------------ Date: Fri, 12 Mar 1999 23:13:09 -0700 From: Richard Ohnstad Subject: RE: (klr650) Another list possibly? I vote to stick with one list. Richard Ohnstad Tucson, AZ '94 KLR ------------------------------ Date: Fri, 12 Mar 1999 23:11:00 -0800 From: "Vik Banerjee" Subject: Re: (klr650) Another list possibly? - NKLR Yes its called the DUST list, but it doesn't get much traffic. If you prefer not to read NKLR messages why not just filter them to your deleted items bin? Cheers, Vik - -----Original Message----- From: Stephen Rivett To: KLR650-List Date: Friday, March 12, 1999 7:59 PM Subject: (klr650) Another list possibly? >I was wondering, since I'm one for a good debate, could we have a second >message board where we can take the threads that won't die? It could also >be used to discuss NKLR topics since I haven't seen a list for them either. >Thanks, Stephen Rivett. > > ------------------------------ Date: Fri, 12 Mar 1999 23:12:59 -0800 From: "Vik Banerjee" Subject: Re: (klr650) Helmet tail light (NKLR) I spoke with them also. We can get them for $48.xx if we order them in quantities of 10 (which is a case). This is the wholesale price and I or somebody else with a business would have to do the ordering. Cheers, VIk - -----Original Message----- From: Juan Villarreal To: AlaOmega@columbus.rr.com Cc: KLR650@lists.xmission.com Date: Friday, March 12, 1999 8:09 PM Subject: (klr650) Helmet tail light (NKLR) >>From: "Karl Huebner" > >>Juan: >> >>I e-mailed the helmet tail light guy and have not gotten a response as >of >>yet. Do you know how much the units cost? > >Karl, >I spoke to a fella named Corey... He quoted me a price of $69.95, plus >$6 for shipping and handling. ------------------------------ Date: Fri, 12 Mar 1999 23:25:42 -0800 From: "Arne Larsen" Subject: Re: (klr650) Another list possibly? - NKLR >-----Original Message----- >From: Stephen Rivett >To: KLR650-List >Date: Friday, March 12, 1999 7:59 PM >Subject: (klr650) Another list possibly? > > >>I was wondering, since I'm one for a good debate, could we have a second >>message board where we can take the threads that won't die? It could also >>be used to discuss NKLR topics since I haven't seen a list for them either. >>Thanks, Stephen Rivett. >> >> I think you could do this on your own by filtering and NKLR postings to the place of your own choosing - ie. delete bin, or one you create yourself. Haven't done it myself so I'm not sure. Arne ------------------------------ Date: Sat, 13 Mar 1999 03:25:37 -0500 From: Tim Bootle Subject: Re: (klr650) Questions, Questions, Questions - NKLR Jeff & Lisa Walker wrote: > Can you please explain to me, via an equation, how the relative velocities > between the pads and the rotor factor into computing the frictional force? > If I am wrong, let me know, but I can't find anything in my texts to > contradict this. With other types of friction, like with fluids, it does > increase with increasing velocity, like with wind drag. > > Jeff Jeff, your first response was correct except that you confused the words kinetic and static friction. Brake pads under braking undergo kinetic friction. Tires when not slipping undergo static friction. You were right about the size of the brake pads. There is only so much force available and it will be spread out across whatever size pad is there. The coefficient of kinetic friction does change based on the size of the pad but the braking force does not. (when simplyfing by centering the braking force of each size pad the same distance from the center of the wheel.) As for your second e-mail, which I have copied a portion of above. Yes I can. The formula is F=ma. You are thinking in terms of F=mv. That is the force is equal to the mass times the acceleration. All other formulas needed can be derived from this one. You are thinking in terms of F=mv. This type of physics we are dealing with is called dynamics. It is the studies of bodies undergoing acceleration. A statics representation of this formula would be F=mv or F=md/t or where acceleration had been replaced by velocity and mass over time had been replaced by the coeficient of kinetic friction. The formula we need to use is F=ma or F=md/dt(d/t) where d/dt(d/t) is the derivative of or change in distance/time as a function of time. The torque exerted by the brakes IS a function of how fast the rotor is turning because it is a function of the frictional force. The frictional force is greater on a bigger rotor because it is turning faster. Why? Because there is more movement per revolution of the wheel. (the distance is greater.-more rotor passes the pads) Since the rotor under the pads is turning faster than the stock rotor would be, it is going further for a given MPH of the bike. So if you are figuring a torque why is the distance important? Because in an angular system you have to consider the angular force, which is a factor of acceleration (the change in the change in the distance as a function of time) Thinking about this from a statics viewpoint it does not make sense. But since the wheel is slowing it has an angular velocity which is decreasing. This is a negative angular acceleration. The torque that the brakes provide is not a static torque like that when using a torque wrench. It is a dynamic torque which provides negative angular acceleration. (In your defense, In my original answer to Frank's question I did explain it as if it was a static torque. You can't find any formulas for it because you probably don't have a dynamics book. The first 4 to 6 semesters of college physics don't cover dynamics. It is a specialty course for physics majors and engeneers.) - -I hope this helps. :-) Tomorrow's lesson, the molecular physics of semiconductor doping as an explaination for the long advertised life of LED tailights and brakelights and of insulating base materials as an explaination of their short street life. - -No, just kidding. I'll try to stay away from heavy physics from now on. I just could not resist today. -Tim ------------------------------ Date: Sat, 13 Mar 1999 05:11:49 -0600 From: "J.P.Zucht" Subject: Re: (klr650) Don't sweat it... Arne Larsen wrote: =20 > Thanks guys I think you're on the money. I can pull a wrench for most > stuff, and any manufacturers defects should rear their ugly heads withi= n the > first year anyways. I didn't think about the stolen bike scenario... t= hat > would bite big time... and hungree adds...The other side of the coin... Preface: I've never bought extended warranty for a motorcycle because the last time I bought a new bike it was still unheard of...but I HAVE bought extended warranty for several cars. There have been very good points made (against) so far, but: 1.. I've traditionally looked on extended warranty as good financial protection for 'one lousy extra payment, (maybe two?)'. 2.. It's 'insurance'...if I never needed it, I don't cry about money wasted, I'm happy that it only cost me that 'extra payment' for a REALLY GOOD, defect-free, car (bike). Someone recently had a cracked case near the drain plug (??). What if that happened about 2 years into his ownership? And...we may think in terms of 'one' major repair...what if one got a 'bad' bike that BROKE two or three times ?!?! Extended warranty is a bit like a cheap tire or a cheap chain - you can pay less NOW, but it *might* cost ya - BIG TIME - down the road. ch-ching...another 2=A2 (CDN) ------------------------------ Date: Sat, 13 Mar 1999 05:23:48 -0600 From: "J.P.Zucht" Subject: Re: (klr650) KLR fairing Arne Larsen wrote: > Do I dare ask what "stealth" edging is? > Arne (Gun-shy??? Me???) You just ask away! I've learned stuff from answers to your questions! That's a point that maybe gets missed...an answered question may benefit many more people than just the one who asked... hungree ------------------------------ End of klr650-digest V2 #123 ****************************