Wilsons Sandbox

Thanks to all who replied to my question a few weeks ago regarding handlebar oscillations at highway speeds with new TKC80's. For the benefit of those who reported the same symptoms, work is still in progress but these steps have reduced the effect: 1. Removed plastic handguards. 2. Reduced preload on the shock to minimum. 3. Pulled the chain guide for better access and fine-tuned alignment of rear wheel in swingarm. Can't really say this had noticeable benefit, but of course I've convinced myself it 's a positive thing. 4. Straightened misaligned handlebars. They were off by a few degrees since I bought the bike used, but I never bothered lining them up perfectly as the D607s made the bike handle so well. Evidence on the fender and fairing suggest the previous owner had been down a time or two and I'm guessing the off-center handlebar was a result, but I mainly straightened it to possibly correct any uneven forces acting on the front tire through the forks. All appears straight after the adjustment but it did take quite a bit of torque on the bars to line things up before re-tightening the clamps. Tip: A broomstick slipped through the front wheel in the right spot with the end poked into one of the holes in the aluminum bash plate works quite well to hold the wheel roughly straight with the frame while you make your adjustment. The end result is that instead of consistent onset of handlebar wobble at indicated 70mph (GPS says 65.5) into a headwind, it now starts less abruptly, closer to 75mph, and is less severe. On the downwind leg of my highway test loop I reached 85 indicated with less wobbling than used to be present at 70 indicated going into the wind. Still not ideal, but definite improvement. A very light grip on the bars tends to reduce the oscillations and removing one hand works even better. From the earlier responses, steering head bearings are often a suspect in these situation, but with the KLR mounted on the bike jack and the front end suspended I could detect no movement or clunking as I tried to shake the lower end of the forks. Have not tried to tighten them a smidge but will look into it soon. There is one other thing I'd like to try if the remaining wobble can't be eventually adjusted out - a slightly less aggressive front tire. Would be nice to retain the big lug TKC80 in the rear but wonder if something like a Duro, GP1 or Mefo might give enough traction for general off-road use and offer better stability on the highway. Anyone needa a verra nass set of low-mileage D607s? Steve Norman, OK

--- In DSN_KLR650@yahoogroups.com, wrote:

> Thanks to all who replied to my question a few weeks ago regarding

handlebar oscillations at highway speeds with new TKC80's. For the ...

> 2. Reduced preload on the shock to minimum.

This is baffling. Usually this will cause the bike to weave in the same way that overloading the bike will cause it to weave, because it shifts too much weight to the back and the front doesn't have enough weight on it to keep it loaded and in contact with the pavement. When I had the stock spring I had my shock preload turned up all the way. One thing you *may* need to do, if you do this (add preload in the back) however, is to add some preload to the front. Experiment by putting some air in the front forks. I am wondering -- what air pressure are you running in these TKC-80's? And what kind of inner tubes? I've found that the super-heavy-duty inner tubes tend to make handling unstable at high speeds on the highway, my last set of TKC-80's I ran a regular "heavy duty" tube up front and a "regular" thin tube in the back when I was doing high speed runs, and pumped the back up to the max on the sidewall (35psi if I recall correctly) and pumped the front to 28-30psi.

> The end result is that instead of consistent onset of handlebar

wobble at indicated 70mph (GPS says 65.5) into a headwind, it now starts less abruptly, closer to 75mph, and is less severe. With TKC-80's my KLR is stable up to around 80mph (actual GPS), above that the handling starts getting a bit skittish (front starts feeling really light with it reacting too much to imperfections in the pavement with a slight wobble) to warn me that I'm going way too fast for what the KLR is. My KLR is very well set up with custom springing to my specifications front and rear, perfect wheel alignment, head bearing spot on, etc., and completely stable at all speeds with non-knobbie tires, so it's clear that the TKC-80 on the KLR is never going to be as stable as a D607. But I think you have some ways to go to reach what the TKC-80 is capable of on the KLR. -E

--- In DSN_KLR650@yahoogroups.com, wrote:

> > > Thanks to all who replied to my question a few weeks ago regarding handlebar

oscillations at highway speeds with new TKC80's. For the benefit of those who reported the same symptoms, work is still in progress but these steps have reduced the effect:

> > 1. Removed plastic handguards. > 2. Reduced preload on the shock to minimum. > 3. Pulled the chain guide for better access and fine-tuned alignment of rear wheel in

swingarm. Can't really say this had noticeable benefit, but of course I've convinced myself it 's a positive thing.

> 4. Straightened misaligned handlebars. They were off by a few degrees since I bought

the bike used, but I never bothered lining them up perfectly as the D607s made the bike handle so well. Evidence on the fender and fairing suggest the previous owner had been down a time or two and I'm guessing the off-center handlebar was a result, but I mainly straightened it to possibly correct any uneven forces acting on the front tire through the forks. All appears straight after the adjustment but it did take quite a bit of torque on the bars to line things up before re-tightening the clamps. Tip: A broomstick slipped through the front wheel in the right spot with the end poked into one of the holes in the aluminum bash plate works quite well to hold the wheel roughly straight with the frame while you make your adjustment.

> > The end result is that instead of consistent onset of handlebar wobble at indicated

70mph (GPS says 65.5) into a headwind, it now starts less abruptly, closer to 75mph, and is less severe. On the downwind leg of my highway test loop I reached 85 indicated with less wobbling than used to be present at 70 indicated going into the wind. Still not ideal, but definite improvement. A very light grip on the bars tends to reduce the oscillations and removing one hand works even better.

> > From the earlier responses, steering head bearings are often a suspect in these

situation, but with the KLR mounted on the bike jack and the front end suspended I could detect no movement or clunking as I tried to shake the lower end of the forks. Have not tried to tighten them a smidge but will look into it soon.

> > There is one other thing I'd like to try if the remaining wobble can't be eventually

adjusted out - a slightly less aggressive front tire. Would be nice to retain the big lug TKC80 in the rear but wonder if something like a Duro, GP1 or Mefo might give enough traction for general off-road use and offer better stability on the highway.

> > Anyone needa a verra nass set of low-mileage D607s? >

Now try setting the spring preload where it belongs, which in all likelihood is stiffer than where you started. Lowering the rear by softening the spring will slow your steering down, but any stabilizing effect will be overcome by the tendency of the front wheel to "hunt" as it is unloaded. Shoot for about 3" sag. The world is full of KLRs running on wide variety of tires that do not wobble at any speed, because they are correctly assembled and adjusted.

Jud, You need to sit on my KLR. I'm 210 lbs and the fella who sold to me was an easy 100lbs over that. I suspect he swapped out the spring as I can barely get any usable sag at the lowest preload setting. My 170 lb riding buddy took one short 2-lane highway run on my KLR (before I swapped out the tires) and complained bitterly about the stiff, non-compliant ride. Yeah, I know... I should have completely rebuilt all the suspension to match my weight before bothering the list with my tire questions, but I have to do my part to keep the list traffic away from lifestyles, religion and politics. Steve --------------- Now try setting the spring preload where it belongs, which in all likelihood is stiffer than where you started. Lowering the rear by softening the spring will slow your steering down, but any stabilizing effect will be overcome by the tendency of the front wheel to "hunt" as it is unloaded. Shoot for about 3" sag. The world is full of KLRs running on wide variety of tires that do not wobble at any speed, because they are correctly assembled and adjusted.

--- In DSN_KLR650@yahoogroups.com, wrote:

> You need to sit on my KLR. I'm 210 lbs and the fella who sold to me

was an easy 100lbs over that. I suspect he swapped out the spring as I can barely get any usable sag at the lowest preload setting. Ouch. One thing you might try, then, if you're not yet in the market for a softer rear spring, is some 1" lowering links. These will put the bike a little lower to the ground and by changing the rising rate on the shock will cause the suspension to be softer. Downside is that you'll need to relocate your license plate because the TKC-80 *will* self-clearance your rear inner fender bottom where the license plate is mounted, probably relocating your license plate to the trail behind you at the same time. Slide your front forks tubes up in the triple clamps a little at the same time and you should have a much more stable ride, albeit one that is an inch closer to the ground. Not a factor usually if you have stiffer springing at the same time (which apparently you do) -- if you sag 2" rather than 3", you end up with the same total suspension travel at the end of the day. Also: Some KLRistas swear by fork braces. Some swear at them. And some have no opinion. I'm in the latter. I've tried my KLR with and without fork brace and frankly didn't find that it made any difference. Others swear that their steering was always unsteady until they put a fork brace on their bike. (Shrug). YMMV. Worth a try, I suppose. _E

Here is a link to the mod thread. http://www.advrider.com/forums/showthread.php?t=130172 Jeff Haldin Elk Point, SD -----Original Message----- From: DSN_KLR650@yahoogroups.com [mailto:DSN_KLR650@yahoogroups.com]On Behalf Of Steve Strader Sent: Wednesday, May 28, 2008 1:51 AM To: DSN_KLR650@yahoogroups.com Subject: [DSN_KLR650] Footpeg relocation methods I recently saw on this list where someone posted links to a footpeg mod. It showed how to use angle iron and square tubing to move the pegs back and down. I've literally spent hours searching this forum and others for the post. Can anyone help me out? Also, does anyone produce a bolt on relocator any more? I know there was a guy who had what appears to be a great setup but he skulked off into the night with a lot of peoples $$$. Anyone else out there making such a thing? Thanks, Steve Strader, Ukiah, CA '06 Greenie (of course) [Non-text portions of this message have been removed]