2016 KLR Low Speed Off-road Front Tire "Wobble" - Page 3 - Kawasaki KLR 650 Forum
2008+ KLR650 Wrenching & Mod Questions For repair, maintaining or modifying discussions related to the newly updated 2008 and beyond, Generation 2 KLR650 Motorcycle.

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post #21 of 63 Old 07-02-2019, 09:50 AM
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Join Date: Aug 2010
Location: Kelowna, B.C.
Posts: 2,341
A couple thoughts;

- you have WAY too much rear sag....should be 25 - 33% or 1.83 - 2.41".....you have almost an inch more than the max. I'd try it at 2 1/4" or thereabouts.....if you can't get that then your spring is too soft (or you could try a set of EM raising links). Common wisdom suggests that the more you increase rake (by having the rear too low) the more stable the bike should be at speed but on the KLR it seems that unweighting the front end with sag and load can cause instability. I'm not surprised that someone dropped their forks and it helped.

- 5W oil is too light IMO, but you can ask Rick. I run 5W but only with the Cogent DDC's as they are designed for it.

- I don't think fork flex is your issue. ....as a matter of fact, the wobble/weave you describe almost sounds more like bad swingarm bushings, rear wheel bearings, rear wheel or a broken frame - none of which should be an issue on an almost new bike.


keep us posted and good luck,

Cheers,
Dave
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post #22 of 63 Old 07-03-2019, 12:23 AM Thread Starter
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Join Date: Nov 2018
Location: Elk Grove, CA
Posts: 76
Thanks, Dave!

Yeah, I measured the static sag and the springs are indeed not correct for my parameters. I get the proper springs and damping for every dirt bike I own....but I am going to figure this out before dropping that kind of coin on upgraded suspension. This problem feels to me like "something wrong" as opposed to "needs better suspension", for sure.

My initial plan was to try the 5W fork oil and raising the fork tubes as a means to encourage more fork compression to observe any changes in the oscillation characteristic.

I am starting with the forks and steering stem and working my way backwards. I will pull the forks apart, replace consumables, and check for bizarre parts (i.e. previous owner's work) and strange wear, and will put new bearings in the steering stem. (I will also doublecheck the front wheel bearings again).


I pulled the fork springs and spacers out today in preparation for rebuilding the forks. Before doing so, I placed 35.8# on each fork and measured 8/16" and 9/16" of compression. Not perfectly controlled, but did it several times with good reproducibility. If my math is right, that is a 1.14kg/mm to 1.28 kg/mm spring rate. (35.8#*1kg/2.2#*(9/16)"*25.4mm/in). I checked the scale with a barbell weight and it was spot on. The most definitive data I found was "sasquatch t" on this site at 0.52kg/mm for a 14.5NE fork spring. That is 42% of my measured rate! Yes, of course I will have friction losses in the fork and need to measure just the spring to get the true rate, which I will do, but that is a LOT of friction loss.

The fork spring wire diameter is 4.5mm thick, and the spring is 355mm long with 27 coils. The spacers are 295mm long. In this configuration there was only very light preload (~0.5") with the caps on. Do these dimensions jib with those you folks know for the stock units? In particular, I am curious if the 4.5mm spring wire diameter and 27 coils represents the stock size.

Please let me know if you know :-)

Thanks again, folks!

Last edited by Yeravener; 07-03-2019 at 12:49 AM.
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post #23 of 63 Old 07-03-2019, 08:30 AM Thread Starter
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Join Date: Nov 2018
Location: Elk Grove, CA
Posts: 76
The front wheel has sealed bearings (NTN 6202LU Right, NTN 6203LU Left)...earlier I was happy to see this but now not so sure. The Kawi parts manual (which I admit is a homologation of many years of KLRs, shows unsealed bearings in the bike (601B6202UG Right, 601B6203UG Left). I have the spec sheet on the NTNs, but not (yet) for the stockers.

From the manufacturers yellow QC paint dab on the right bearing circlip, it looks like the sealed bearings were stock.

Does anyone have these NTN bearings in their front wheel stock on a 2016 or NE?

Thanks,
James
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post #24 of 63 Old 07-03-2019, 08:55 AM Thread Starter
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Location: Elk Grove, CA
Posts: 76
Curiously, if you try to buy front wheel bearings now for a 2016 KLR650, at Kawi and the other three parts warehouses I checked, you get a 6202UC3 (Right, *Unsealed*) and a 6203UG (Left, Sealed). The 6202UG (Right, Sealed) in the bike now seems to not be available. This just gets more bizarre. Who would want one sealed and one unsealed bearing in their wheels? Unless the now-unavailable 6202UGs were defective? May be backordered...

If I can't get proper OEM replacement parts then investigating and fixing the oscillation is going to be difficult. The bike is only 3 years old(!). In 50 years of motorcycling I have not had these kinds of problem..more fun. 0653 in the morning and I need a beer already...hahahaha!

Last edited by Yeravener; 07-03-2019 at 09:00 AM.
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post #25 of 63 Old 07-03-2019, 10:38 AM
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Can't help on the NE spring sizing; I've never actually had one in my hand.

regarding the bearings; you should be able to go to any bearing house or good autosupply and just get the double sealed (-2rs) bearings. Factory is sealed one side only (or it is on the Gen1 anyhow) but I always replace them with double sealed bearings.



Dave
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post #26 of 63 Old 07-03-2019, 10:43 AM Thread Starter
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Location: Elk Grove, CA
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Thanks, Dave! Since I am doing this anyway, I'll do the doubles as well.
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post #27 of 63 Old 08-02-2019, 09:40 PM Thread Starter
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Join Date: Nov 2018
Location: Elk Grove, CA
Posts: 76
Update: I replaced the steering stem bushings, races, seals, and hardware. Also replaced the swingarm and rocker arm bearings, bushings, seals, and hardware. Torqued everything per the manual, including the castle nut on the stem under the upper triple clamp. Also lowered the fork tubes 20 mm as a test. Still have the oscillations with load or without, though worse with load, of course. All the bearings and bushings I pulled out looked fine, but I am eliminating causes. (peace of mind for $460 in parts all told, including fork parts).

Then I disassembled the forks...now checking the tube run-out and replacing all bushings, seals, dust covers, and circlips. Again, they all looked fine but I am eliminating causes.

I will then assemble the forks and fill with 5W in lieu of 10W in an attempt to get the egregiously over-damped forks to actually compress while riding. (I know the spring is still too stiff...this is just a test) Those of you who have the softer, earlier, forks that bottom....be glad. At least they compress:-) Also be glad you have a nut-shaped damper rod top that lets you hold the damper rod while unscrewing the bottom allen bolt. My 2016 has a round damper rod top, and the Kawi special tool for the purpose is square with sharp edges. You put the square against the inside of the round damper top, and, while it works to get the allen off if you push on the tool like he**, it also grates small pieces of metal out of the top of the damper rod. So I get to rinse the inside of the fork to get all the metal shavings out of it after I install the damper rods. This is a seriously ridiculous design, which will destroy the top of the damper rod over time and multiple removals/installations, or the new seal immediately from an errant sliver. What was Kawi thinking?? They had a great design with the earlier nut top!....oh yeah, it is likely cheaper to make the damping rod top round and not have to form the nut shape.....they probably saved at least 0.05 cents ;-) (Oh yeah, and I have to either use a welder or grinder to remove the bottom steering race because there is no room over the lower race to fit ANY tool above it to pop it out...including the Kawi special tool! As an engineer, these kind of design failures drive me crazy. But I tell myself the bike was $6K. Lots of room there to spend some $$ before I hit the price of other bikes. And they aren't perfect, either. 'Nuff on that.

Once back together with the wheel bearings, forks, stem, and the rear suspension eliminated as possible causes of the oscillation, I will check once more for a cracked frame and, if none, I will set the preload to get reasonable rider sag and ride the bike with *no* additional load other than me as the rider (so I have no geometry changes due to using the stock spring with a 100# camping load).

If it doesn't oscillate in this configuration, then I would be confident paying the cash for full cogent.

If it still oscillates in this configuration with just me then it came that way new from Kawi, since I just changed everything that could cause it. My choice then to use the bike would be to 1. change the springs front (softer) and rear (stiffer for camping load) (or go full Cogent damping and springs), toss the hard metal cases in lieu of lighter soft cases and lessen and distribute the camping load closer to the CoG, and hope that this all results in the oscillation at unloaded at least getting no worse when loaded. Choice 2 would be to get rid of the bike.

I know the super stiff spring and stiff damping in the forks is precluding any compression over softer bumps, with or without a camping load on the back, and this is sending high forces through the entire bike. I am of the same mind as dirt road that this is a primary cause of the oscillation, and that then putting a 110# camping load on the racks with most of the weight behind the rear axle (by pannier rack design) just exacerbates the problem tenfold.

Bottom line, I am looking for softer forks, lighter loads, and no change in location of CoG when fully loaded (i.e. load distributed so as to retain same front/rear weight ratio as when unloaded) to solve the problem. If it doesn't, then this bike will be a garden gnome and I will eat the carrots that my wife grows out of it! haha! :-D

Yes, full Cogent right out of the gate might just fix it all with proper spring rates and damping rates for camping loads...but I have to go stepwise like this because I don't want to spend up to $2K on Cogent suspension, only to find out that doesn't fix the problem, and that the real problem is the frame and engineered chassis system is just too weak. I am trying to get "proof of concept" with my tests before I drop any huge coin.

If I knew then what I know now, I would have purchased a 2013.

I will keep you folks posted.
Cheers!

Last edited by Yeravener; 08-02-2019 at 09:52 PM.
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post #28 of 63 Old 08-05-2019, 12:17 PM Thread Starter
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Join Date: Nov 2018
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It occurred to me......if anyone has stock fork springs from a 2008 to 2013 that they aren't using anymore, I would l like to buy them. Lowering the oil viscosity from 10W to 5W AND putting softer springs in the forks would be a better test than just changing the oil viscosity. I will put a WTB thread in the WTB section tonight.

Thanks!
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post #29 of 63 Old 08-06-2019, 02:24 PM
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Join Date: Nov 2009
Location: Lander, Wyoming
Posts: 5,531
Yeravener,
Even going back to your original posting I wonder if even your new steering bearings are adjusted TOO Snugly. This will cause the bike to Wander at low speeds, because the rider has to slightly over-correct because of the slight friction. You have always referred to it as "wobble", but I wonder if it isn't actually "wander"?
Too soft & spongy of front tire might even exaggerate the problem in dirt.

I once had a young dirt bike customer who went thru about 6 pair of handlebars, because he kept crashing in the corners. One trip down the alley behind my shop was all I needed to be able to feel his bikes problem.

I wish you were closer to Tom Schmitz, who is in Redondo Beach. But member 'campfire' is somewhere near the Bay area, maybe you could send him a PM and ask for a little personal assistance. Some members only need an excuse to go for a ride!

pdwestman
Modify at "YOUR OWN RISK"!

Still riding my 1987 KL650-A1. 85,000+ miles & counting
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post #30 of 63 Old 08-08-2019, 08:17 AM
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Yeravener,

I have a 2015 with 4k miles. I also get a weird hunt or wander in the front end. I just ordered the Cogent DDC and springs for the forks(they were wonderful to deal with BTW). I am hoping this is a drop in a solution I will let you know. After reading this thread I will check the steering head per DXKLR adjustment specs. Might as well check the front rim run out, spokes and balance. I will not get to it for about 3 weeks.

In your post, you mentioned a few times about stiffness in fork travel. I have ridden several different years on all kinds of terrain and I could never say the fork travel was stiff. You might remove the fork brace if you have not already and see if that helps. Please let s know as yo find things.

I am really hoping not to go thru all these gyrations in getting the bike correct.

Moto
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