klr650 :exhaust

DSN_KLR650
LDHunter
Posts: 55
Joined: Sat Jul 05, 2008 11:58 am

gak!!! head shake? wobbles? new tire issue!!!

Post by LDHunter » Fri Aug 22, 2008 6:46 am

KLRistas, I had a new Kenda 270 put on the front of my KLR yesterday and took it for a test drive and everything seemed normal. It has a fairly new (2K Miles) OEM Dunlop 750 on the rear and the bike has a total of 8K miles on it. I took it out for a ride yesterday afternoon and on the way home I passed a slow mover on a highway I've driven hundreds of times. After I passed I glanced at the speedometer and realized I was going 80 in a 55 zone so I let off the throttle and YIKES!!! The front end starting doing a little dance that reminded me of what they term as "head shake" common to sport bikes but it wasn't nearly as bad as what I've seen in videos. My best description I can give is it seemed to "wobble" with a slight side to side motion detected in the handlebars. Is this common with this tire? I never had this issue with the very well worn factory front tire. Frankly I'm "shaken" (pun intended) and now am worried about riding one of the most stable bikes I've ever owned. $bob$ [Non-text portions of this message have been removed]

Spike55
Posts: 267
Joined: Thu May 11, 2006 2:22 pm

gak!!! head shake? wobbles? new tire issue!!!

Post by Spike55 » Fri Aug 22, 2008 7:09 am

It seems that you don't have enough miles for the steering head bearings to wore out but a 'de-acceleration wobble' is a symptom of that condition. Maybe the bearings (two) only need adjusted. Do you hear any noise from there when getting on / off the front brakes or going over rough road surfaces? This would be good thing to fix if it is occuring. If all is well with the bearings then it must be the new tire. I had a Metzler ME33 get cupped of two years and it acted like that as I coasted down thru 45 mph. New tire, now more problem. Don R100, A6F
--- In DSN_KLR650@yahoogroups.com, LDHunter wrote: > > KLRistas, > > > > I had a new Kenda 270 put on the front of my KLR yesterday and took it for a > test drive and everything seemed normal. > > > > It has a fairly new (2K Miles) OEM Dunlop 750 on the rear and the bike has a > total of 8K miles on it. > > > > I took it out for a ride yesterday afternoon and on the way home I passed a > slow mover on a highway I've driven hundreds of times. > > > > After I passed I glanced at the speedometer and realized I was going 80 in a > 55 zone so I let off the throttle and YIKES!!! The front end starting doing > a little dance that reminded me of what they term as "head shake" common to > sport bikes but it wasn't nearly as bad as what I've seen in videos. > > > > My best description I can give is it seemed to "wobble" with a slight side > to side motion detected in the handlebars. > > > > Is this common with this tire? > > > > I never had this issue with the very well worn factory front tire. > > > > Frankly I'm "shaken" (pun intended) and now am worried about riding one of > the most stable bikes I've ever owned. > > > > $bob$ > > > > > > > > > > [Non-text portions of this message have been removed] >

Jud Jones
Posts: 1251
Joined: Wed Mar 03, 2004 2:52 pm

gak!!! head shake? wobbles? new tire issue!!!

Post by Jud Jones » Fri Aug 22, 2008 7:41 am

--- In DSN_KLR650@yahoogroups.com, LDHunter wrote:
> > > My best description I can give is it seemed to "wobble" with a slight side > to side motion detected in the handlebars. > > > > Is this common with this tire? >
Not at all, but the flexy knobs may have brought out some undesirable aspects of your setup. By all means, check your steering head bearings. But my best guess is insufficient rear spring preload for your load. Were you carrying anything on the rear rack? Have you set your rear sag by adjusting preload? What fork springs do you have?

smthng else
Posts: 65
Joined: Sat Apr 19, 2008 8:43 am

gak!!! head shake? wobbles? new tire issue!!!

Post by smthng else » Fri Aug 22, 2008 8:13 am

On Fri, Aug 22, 2008 at 7:46 AM, LDHunter wrote:
> After I passed I glanced at the speedometer and realized I was going 80 in a > 55 zone so I let off the throttle and YIKES!!! The front end starting doing > a little dance that reminded me of what they term as "head shake" common to > sport bikes but it wasn't nearly as bad as what I've seen in videos.
It's possible that you don't really have a problem... Of course, you should check all the other suggestions to be sure and safe (head torque, etc). But, my '08 has done this since day one, but only under very particular conditions. There's one spot on my commute home coming off a bridge that will trigger the same behavior every time if I'm not paying attention. Basically, I've found that if the front end is loaded up (either by sudden deceleration or by braking) and I'm not point dead-straight ahead AND I manage to hit a slight dip in the road (even 1 cm is sometimes enough), the front will compress slightly and upset the frame causing a nasty headshake. That immediately gets transmitted through the rest of the frame and feels like it's gonna get real ugly real fast. Whacking the throttle or leaning forward both pull it right back out of it with no ill effects. Given enough time (10 seconds or so) it'll sort itself out by itself, but I prefer to fix it like right NOW! ;) Happens with both the stock tires and my new Gripsters (front and rear). It's very similar to a high-speed "bobble"... get up to about 70 or so and just wobble the bars a bit. That'll start the same behavior, but no where near as badly. The scenario described in the previous paragraph is about 10 times worse. I've tried just about everything to get rid of it, but nothing seems to make a difference. I've just attributed it to the tall forks and frame geometry. As long as you know it's there and don't fight it, it's not too big of a deal. I'm not saying that they all do this, but don't loose too much sleep over it if it happens occaisionally, just control it and get out of it as soon as possible. Do NOT clamp down on the bars and muscle it... that doesn't work and just transmits the wobble through the rest of the frame, making things worse. --Jonathan "smthng" Kalmes Springfield, VA 2005 Yamaha FJR1300ABS - "Blue Bayou" 2006 Jeep Unlimited Rubicon - "Teflon" 2008 Kawasaki KLR 650 - It's here, but it hasn't earned a name yet. ;) http://smthng.info "If I'd known it was harmless, I would have killed it myself."

Jeff Saline
Posts: 2246
Joined: Fri Oct 10, 2003 6:02 pm

gak!!! head shake? wobbles? new tire issue!!!

Post by Jeff Saline » Fri Aug 22, 2008 11:09 am

On Fri, 22 Aug 2008 07:46:22 -0400 LDHunter writes:
> KLRistas, > > I had a new Kenda 270 put on the front of my KLR yesterday and took > it for a > test drive and everything seemed normal. > > It has a fairly new (2K Miles) OEM Dunlop 750 on the rear and the > bike has a > total of 8K miles on it. > > I took it out for a ride yesterday afternoon and on the way home I > passed a > slow mover on a highway I've driven hundreds of times. > > After I passed I glanced at the speedometer and realized I was going > 80 in a > 55 zone so I let off the throttle and YIKES!!! The front end > starting doing > a little dance that reminded me of what they term as "head shake" > common to > sport bikes but it wasn't nearly as bad as what I've seen in > videos. > > My best description I can give is it seemed to "wobble" with a > slight side > to side motion detected in the handlebars. > > Is this common with this tire? > > I never had this issue with the very well worn factory front tire. > > Frankly I'm "shaken" (pun intended) and now am worried about riding > one of > the most stable bikes I've ever owned. > > $bob$
<><><><><><><><><> <><><><><><><><><> $bob$, Have you checked all the front end fasteners to make sure nothing is loose? If you have I'd go with a possible steering head bearing, rear shock preload or improper tire inflation pressure as possible causes. Maybe Martin Earl will see this and add some input as he mounted two new K270s on his bike this week and rode home last night. Of course he as usual was putting 1 1/2 gallons in a 1 gallon bucket by carrying a pressure washer home with him so he had some interesting wind catching characteristics. I've used K270s exclusively for the last 23,800+ miles without issues. Best, Jeff Saline ABC # 4412 South Dakota Airmarshal Airheads Beemer Club www.airheads.org The Beautiful Black Hills of South Dakota 75 R90/6, 03 KLR650, 79 R100RT ____________________________________________________________ Click for information on obtaining a VA loan. http://thirdpartyoffers.juno.com/TGL2141/fc/Ioyw6i3m3mWYgXh0irYcPHCjBB4SROpOd2IJopvCbdqDJSdU3VCp8Y/

boulder_adv_rider
Posts: 115
Joined: Tue Aug 19, 2008 12:08 pm

gak!!! head shake? wobbles? new tire issue!!!

Post by boulder_adv_rider » Fri Aug 22, 2008 11:43 am

Dear shaken and stirred - It's a dreadful condition called 'tank slapping' common with high output bikes. It's often reduced/eliminated with a steering damper. Considering it just happened with a new tire install, I'd look to make sure both tires are properly high-speed spin balanced, tire inflation is proper, and wheels are aligned. You might consider checking the tire for dish/run-out but I suspect it could be simply new rubber up front combined with deceleration that caused instability. I've had no problems with my race bike until letting go the handlebars at 140mph and it shook like a mad cow. So perhaps you momentarily allowed the bars to do their thing...bad juju. Seeing the problem just occured with new tires, so I wouldn't go nuclear checking stearing bearings, wheel bearings front and rear, swing arm pivots, front fork alignment/wear/oil, and rear shock. Most of the time this happens when slowing down and the momemtum shifts and center of gravity changes (e.g., weight comes off the seat). The KLR's 21-in front wheel offers good gyroscopic stability (until it goes out of control and works against you) so most likely the tire, road or you not maintaining control of the bars initiated the condition. Watch this guy in the video...notice his feet and center of gravity change. His feet actually compound the horror. This is the next level after bar shake when the moto actually oscillates in harmonic means. Had his feet been glued to the pegs and he hit the rear brake, it's likely he could have recoverd. That's why when this condition happens you have to get on the rear brake to get things corrected. Personally, I've gripped the bars and pulled straight back hard if memory serves me. But I've never been crazy enough to clamp the front when this happens at 150mph to see/test what happens. ;) Note this guy is going a lot faster than the video suggests. I'd estimate well over 100 mph on exit. http://www.youtube.com/watch?v=xUBwCX_Mv2Q
--- In DSN_KLR650@yahoogroups.com, "smthng else" wrote: > > On Fri, Aug 22, 2008 at 7:46 AM, LDHunter wrote: > > After I passed I glanced at the speedometer and realized I was going 80 in a > > 55 zone so I let off the throttle and YIKES!!! The front end starting doing > > a little dance that reminded me of what they term as "head shake" common to > > sport bikes but it wasn't nearly as bad as what I've seen in videos. > > It's possible that you don't really have a problem... Of course, you > should check all the other suggestions to be sure and safe (head > torque, etc). But, my '08 has done this since day one, but only under > very particular conditions. There's one spot on my commute home > coming off a bridge that will trigger the same behavior every time if > I'm not paying attention. > > Basically, I've found that if the front end is loaded up (either by > sudden deceleration or by braking) and I'm not point dead-straight > ahead AND I manage to hit a slight dip in the road (even 1 cm is > sometimes enough), the front will compress slightly and upset the > frame causing a nasty headshake. That immediately gets transmitted > through the rest of the frame and feels like it's gonna get real ugly > real fast. Whacking the throttle or leaning forward both pull it > right back out of it with no ill effects. Given enough time (10 > seconds or so) it'll sort itself out by itself, but I prefer to fix it > like right NOW! ;) > > Happens with both the stock tires and my new Gripsters (front and > rear). It's very similar to a high-speed "bobble"... get up to about > 70 or so and just wobble the bars a bit. That'll start the same > behavior, but no where near as badly. The scenario described in the > previous paragraph is about 10 times worse. I've tried just about > everything to get rid of it, but nothing seems to make a difference. > I've just attributed it to the tall forks and frame geometry. As long > as you know it's there and don't fight it, it's not too big of a deal. > > I'm not saying that they all do this, but don't loose too much sleep > over it if it happens occaisionally, just control it and get out of it > as soon as possible. Do NOT clamp down on the bars and muscle it... > that doesn't work and just transmits the wobble through the rest of > the frame, making things worse. > > --Jonathan "smthng" Kalmes > Springfield, VA > 2005 Yamaha FJR1300ABS - "Blue Bayou" > 2006 Jeep Unlimited Rubicon - "Teflon" > 2008 Kawasaki KLR 650 - It's here, but it hasn't earned a name yet. ;) > http://smthng.info > > "If I'd known it was harmless, I would have killed it myself." >

mechanizeinc
Posts: 53
Joined: Fri Aug 22, 2008 10:49 am

gak!!! head shake? wobbles? new tire issue!!!

Post by mechanizeinc » Fri Aug 22, 2008 11:49 am

Don't sweat it. Check everything if you haven't, as regular maintenance & proper tire pressure are things you should always stay on top of. Suspension rebound/dampening settings/sag will contribute as well as rider/weight position. At freeway speeds (over 70mph) I slide back an inch or two on the seat for stability. Slowing in heavier traffic or to exit the freeway I slide back to normal riding position. On the technical stuff through the trails I occasionally end up damn near on the tank. Every time I've mounted a new rear tire that is not 100% street profile, regardless if the front is new or well worn, I've gotten some shake at various speeds over 65mph. Aggressive knobbies exasperate the issue & it shows up sooner, 65mph or so. A milder knobbie like the Continental TKC-80 I currently run does it around 70+. When I run enduro/trail tires that incorporate a more blended/overlapping tread design like a truck AT tire, the wobble doesn't start 'till 75+mph. In all these cases, after the tire has a couple hundred miles or more on it, the wobble goes away. Well, a true knobbie will still cause an occasional sphincter pucker tank slap when you get to 80mph and/or cross the paint when changing lanes. Shannon 2006 green one (well, more central Texas mud colored right now... we haven't had rain in a while)

Reverend
Posts: 66
Joined: Thu Jun 26, 2008 9:55 am

gak!!! head shake? wobbles? new tire issue!!!

Post by Reverend » Fri Aug 22, 2008 12:18 pm

No idea about the tire, but with the knobbies ojn mine, it was scary over 65 indicated. With the new less knobby tires, its 'floaty' around 80mph and up. I think the KLR is a very unstable bike, but that's probably due to geometry and frame flex etc. I come from years of riding sport bikes and sport tourers. I'm getting used to it though. I've checked suspension and bearings (bike barely turned 5K) so I know it's not a serious fault. Perhaps a fork brace and different tire pressures would help?
> -----Original Message----- > Behalf Of LDHunter > My best description I can give is it seemed to "wobble" with a slight > side > to side motion detected in the handlebars.

DORN
Posts: 2
Joined: Wed Aug 20, 2008 8:48 pm

gak!!! head shake? wobbles? new tire issue!!!

Post by DORN » Fri Aug 22, 2008 4:21 pm

--- In DSN_KLR650@yahoogroups.com, LDHunter wrote:
> > KLRistas, > > I had a new Kenda 270 put on the front of my KLR yesterday and took
it for a
> test drive and everything seemed normal. > It has a fairly new (2K Miles) OEM Dunlop 750 on the rear and the
bike has a
> total of 8K miles on it. > I took it out for a ride yesterday afternoon and on the way home I
passed a
> slow mover on a highway I've driven hundreds of times. > After I passed I glanced at the speedometer and realized I was
going 80 in a
> 55 zone so I let off the throttle and YIKES!!! The front end
starting doing
> a little dance that reminded me of what they term as "head shake"
common to
> sport bikes but it wasn't nearly as bad as what I've seen in videos. > My best description I can give is it seemed to "wobble" with a
slight side
> to side motion detected in the handlebars. > Is this common with this tire? > I never had this issue with the very well worn factory front tire. > Frankly I'm "shaken" (pun intended) and now am worried about riding
one of
> the most stable bikes I've ever owned. > $bob$ >Check the rotation and balance marks on the tire if is has them and
make sure it is mounted on the rim correctly. Lift the front end and slowly spin tire to check for balance and run out, wheel should spin true and stop at different spots on each spin. Also make sure the bead is seated correctly all the way around the rim and the tire does not have an excessive up and down motion look when you spin the tire. If all looks good you might just be pushing the tire to its road perfomance limits. If it's P rated you are 14 MPH short of it's recomended 94MPH max sustained speeed limit. I think any road rated knobby tire is going to give you some negative feedback at those speed's and this tire is a lot less road friendly than the OEM you were used to. Also consider you may have changed the steering geometry depending on the tire profile of the Kenda VS the OEM. They say you should not mix and match different tire's between the front and back and this may be the case here or it's just the price of compromise between road and trail performance. If it works well in the dirt and you get good mileage out of it and it only has this quirk at 80 MPH on deceleration I am impressed. After eliminating any mechanical issues you are just pushing the bike to it's limits which is where all of the fun is!!!

LDHunter
Posts: 55
Joined: Sat Jul 05, 2008 11:58 am

gak!!! head shake? wobbles? new tire issue!!!

Post by LDHunter » Fri Aug 22, 2008 5:50 pm

I want to thank everyone for the EXCELLENT discussions and analysis of my "wobble issue". I have many things to check now and will inform you all when I figure it out. I watched the technician carefully balance the wheel and tire after he mounted the tire so that's not likely the problem. I'm thinking that since the issue appeared on the same day that I had the new tire put on it's probably a combination of the suspension not being set up just right and the new tire with it's long skinny knobs that was showing me just how poorly it IS set up. I suspect that I'll order new TKC-80 tires for it Monday and if the problem completely disappears on the first test ride after that I'll be happy and satisfied. If that was it I'll discount the Kenda to one of the guys that gave me the advice if they want it. Now if that dang tropical storm will just pass through without washing Tallahassee into the Gulf of Mexico I'll be happy. $bob$ [Non-text portions of this message have been removed]

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