rear tube emergency question

[Jeffrey]

The heavy counterweights are designed to offset the stock heavier piston; not the aftermarket lighter piston. But, heck if I went to all the expense and trouble to do the big bore kit, I would probably try and create a reality distortion field, too.

[Horton Oliphant]

But what if Kawasaki didn't try to make their big single as smooth as possible? Motorcycle manufacturers do a lot of fine tuning of sound and vibration to what they think will be the ideal levels to sell the most bikes. Alan Henderson A13 Iowa

On 4/7/2012 11:34 AM, Jeffrey wrote: > > The heavy counterweights are designed to offset the stock heavier > piston; not the aftermarket lighter piston. > > But, heck if I went to all the expense and trouble to do the big bore > kit, I would probably try and create a reality distortion field, too > > > [Non-text portions of this message have been removed]

[David Nichols]

As I understand it (Disclaimer: I'm a Mechanical Engineer, but I've never designed an internal combustion engine), the reason Kawasaki used a chain driven (with doohickey) balancer in this engine is because the piston was so large they would need a very heavy crankshaft counterbalance weight to balance out the reciprocating mass. This would make the flywheel effect very slow revving. As a compromise they designed the balancer system, which quells vibration but doesn't cancel it out completely. Not knowing the exact constraints the engineers were using, I'd guess they made it just enough to prevent any failures at normal operating parameters. Rider comfort was probably a second consideration (this isn't a Gold Wing, some felt vibration was more than likely deemed acceptable). Another fact: a perfect location for the counterbalance weight would be on the crankshaft, placing it out of plane like they have done makes it less efficient at eliminating vibration. This would explain why a lighter piston feels smoother than the OEM. -David ________________________________ From: Horton Oliphant To: klr DSN_klr650@yahoogroups.com> Sent: Saturday, April 7, 2012 1:23 PM Subject: Re: [DSN_KLR650] Vibration big bore But what if Kawasaki didn't try to make their big single as smooth as possible? Motorcycle manufacturers do a lot of fine tuning of sound and vibration to what they think will be the ideal levels to sell the most bikes. Alan Henderson A13 Iowa

On 4/7/2012 11:34 AM, Jeffrey wrote: > > The heavy counterweights are designed to offset the stock heavier > piston; not the aftermarket lighter piston. > > But, heck if I went to all the expense and trouble to do the big bore > kit, I would probably try and create a reality distortion field, too > > > [Non-text portions of this message have been removed] [Non-text portions of this message have been removed]

[beachmike1]

Concerning the post on flywheel weight and vibration. With no counter balancer a single is a seriously bad vibrator . This is due for the simple view. First that if a rough approach to balance the piston at 100 % ( where the counter weight is 100 % of the weight of the piston) the unbalance of the up and down piston movement can be mostly accommodated and cancelled out for about 25 degrees of each side of top dead. Enter and bottom dead center. This is not perfect. The acceleration of the piston is governed by the occulting influence of the rod throw ratio and gereanl non perfect sinusoidal action against the pistons liberal motions. The forces produced by the counterweight are perfectly sinusoid auto in nature. The result is as follows. The piston motion is somewhat balanced by the counter weight as stated. The crank however from about plus and minus ten degrees on each side of THC to the same at BDC starts to produce an uncompensated force creating vibration. This force is max at plus ans minus ninety degrees from TDC. The dual counter balance system reduces this a lot but not perfectly. First is reduces the overall vibration in the same way the counter weight does. However by splitting the piston counterbalance mass into two and turning them in opposite directions a good portion of the vertical component of the piston forces are removed but instead of inducing a single force with a maximum at plus or minus 90 degrees from TDC these forces are split into two smaller forces acting in equal and opposite directions canceling each other out. However again the action is not and cannot be perfect due to the circular nature of the crank motion and the none perfect clocking of piston forces with an additional issue with the piston forces not the same at the top and bottom of the stroke. This is a common final project for third year mechanical engineering student. Back many moons ago I wrote a program foe an HP 41 CV to run this problem. It took fifty five lines of code for the simple counter weight problem and another 35 lines to add the effect for the counter balancer. It was in HP basic. In 1980. In about 1998 we hired an intern who when to the same school took the same course and has the same teacher and was given the exact same final exam. I was not happy. I did not help him on the work except point out programming mistakes and help with prob Em definition. I did go to the college to see why a prof would be so lazy to do this and not correct the darn mistakes in the test to start with. I was humbled when I found out this was such a pure test of dynamics understanding that it was used to compare classes over the years. And compare schools. A more interesting problem is to layout the second third and fourth order evirbarations that gets ugly and requires a lot of programming.

[mark ward]

No tube issues TODAY, BUTT (pain in the A** so 2 t's intended) Just a heads up to AVOID a possible ISSUE. I went to check my air pressure and could'nt get a reading, just a very tiny pst. the tire seemed firm but I tried to put a little air in and still NOTHING....HUUUUH ?????? Gota little mirror and looked inside the stem, and found an Oring. Last yr. I bought the "GOOD" $2. steel, stem caps that have the O'RING seal in them. It went right inside the stem stopping me from checking or filling the air. On the road with low pressure, & I would have been there a while, scratching my head AND KICKING THE TIRE,..... NO MIRROR OR DENTAL PICK to remove it. Back to good old PLASTIC.

--- On Thu, 4/12/12, Jim Fortner wrote: From: Jim Fortner Subject: Re: [DSN_KLR650] Re: Rear tube emergency question To: "Jud" Cc: "DSN_KLR650@yahoogroups.com" DSN_KLR650@yahoogroups.com> Date: Thursday, April 12, 2012, 6:14 AM Thanks everyone. The Harley tube did indeed get the KLR the 65 miles home. The KLR rear heavy duty tube didn't stand much of a chance against a piece of one inch pointed iron shrapnel. It put a one inch slice in the tube after going in Near the base of a Kenda 270 knobby. I had just come off 5 miles of gravel road and pulled onto 455 a paved road when the KLR went wiggly shifting from second to third. That is such a sickening feeling. Luckily I rolled to a stop in the driveway to a farm that also had one of the best private shops I've ever seen. I started checking the tire and didn't see anything. About that time Kathy came by and invite me to use the shop after we ran to town to get patches and some gas for her mower. I rolled the bike about a quarter mile down a gravel road to the shop. Kathy and Steve specialize in Harley repairs and builds. From the looks of the client bikes Steve must be very good. He had about 6 jobs going and more waiting. These were some really nice custom bikes. Steve at his second job but the Kathy opened up the shop for me and allowed me the use of tools and a lift. It took several tries to get the old Kenda bead to break. It also took five times airing the tire up and down with some lube to get the bead to seat. I haven't dis mounted and mounted KLR tires lately and was remembering a particularly difficult Metzler Karoo stiff sidewall bead dis mount problem. I don't think I will be leaving home without spare tubes and tire tools again. That Murphy fella is a real but kicker. Jim Plano, TX On Apr 11, 2012, at 10:17 PM, "Jud" wrote: > That will get you home, much as a 21" tube in the rear tire will get you home. As Fred suggests, the tube will fold, and the bottom of those folds will be the weak spots. The tube might actually last a couple thousand miles, but eventually one of those creases will fret through, so you might as well get it out of there early and change it at a time and place of your choosing. Ride easy to avoid heat build-up and increase your chances of getting home. > > --- In DSN_KLR650@yahoogroups.com, Jim Fortner wrote: > > > > I've ripped a tube while on the road. I don't have my replacement tubes. Murphy loves me. I have a Harley 40502-06 which is a 17 inch center metal valve tube marked for 150-160 70 17 tires. Will this work to get me home 50 plus miles away? > > > > Jim > > Slidell, TX > > > > [Non-text portions of this message have been removed] [Non-text portions of this message have been removed]