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Discussion Starter · #1 ·
I posted as a follow up post in another tire thread, but want to really get input and therefore more views for answer.

I just installed a TKC80 front replacing a Heidenau K60 front. I went from a front that was really good on the tarmac, a bit of road noise, to now with the TKC80 having a very unnerving high speed oscillation occurring above 70 mph. And yes, where I'm at the freeway speed to keep up with traffic is 70 plus a lot. A reason I got the AT. I've rechecked mounting and alignment. I've changed tire pressure from between 28 and 35 (what a friend runs on his 950 with TKC80 front) It was installed at a dealer with machine balancing. So I doubt that is the issue. The fellow rider I mention above has the TKC80 on his KTM 950 and has never seen the issue on his bike. I see that in the other thread that maybe this has happened for some with other tires.

Anyone specifically had this issue with the TKC80? Solutions?
 

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Maybe it’s a duff tyre, explain all this to the place you bought it from and hopefully they will replace the tyre for you.
 

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I'm running a TKC80 front with a K60 rear for over 4000 miles and have not had this. Maybe a wheel weight fell off after balancing. I would take it in for a re-balance.
 

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Discussion Starter · #4 ·
Thanks, I think you guys are right that it seems I'm going to have to pull it and take it back to the dealer and least re-balance it. The tire was deeply discounted as OEM removal from another bike they sold. And it showed absolutely no wear so I'm pretty sure it hadn't even seen outside of showroom so I don't think the other bike owner had them pull it because he felt something with it. I just don't think they're going to replace it. But, if it continues I'll certainly ask....
 

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If it's side to side oscillation it's known as headshake. The front fork is packing because of the knobby, just add a couple turns fork preload and/or go a couple clicks faster on the rebound damping on the forks. Change one thing at a time, test, repeat. Should be able to dial that right out of there unless the tire is badly out of round.

If it's an up and down or balancing type issue it could be a number of things. Defective tire, idiots couldn't follow directions and put the weight in the wrong place, damaged tire during installation, shop didn't bother balancing because it's a "slow bike", etc. Personally I've never balanced a wheel for the AT and none of them have ever shaken. But sometimes a tire just has a heavy spot, you could take your front wheel off and do the ol' axle stand wheel balance check, fairly easy way to verify.
 

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Discussion Starter · #6 ·
If it's side to side oscillation it's known as headshake. The front fork is packing because of the knobby, just add a couple turns fork preload and/or go a couple clicks faster on the rebound damping on the forks. Change one thing at a time, test, repeat. Should be able to dial that right out of there unless the tire is badly out of round.

If it's an up and down or balancing type issue it could be a number of things. Defective tire, idiots couldn't follow directions and put the weight in the wrong place, damaged tire during installation, shop didn't bother balancing because it's a "slow bike", etc. Personally I've never balanced a wheel for the AT and none of them have ever shaken. But sometimes a tire just has a heavy spot, you could take your front wheel off and do the ol' axle stand wheel balance check, fairly easy way to verify.
Coast to Coast; Yes, it is the side to side oscillation you speak of first. Your latter explanation makes sense to an out of balance condition which is why I was hesitent to believing that as the problem.

Will what you describe typically only occur at high speed? Which is what is happening to me. At 60mph is not an issue. Or at least not noticably so. It is only after I get to 75mph or more.

At any rate; I will do your suggestions on the rebound first, and then preload if that doesn't work. I have never experienced this phonomenon before in all my years of tire changes. I very certainly appreciate your response and hope I can get this solved as I did like the off-road traction and character of the TKC80.
 

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Discussion Starter · #7 ·
I hesitated to call it headshake because I did roadracing and have had headshake. The kind where you almost lose control. But usually that is from an inadvertant side load accelerating aggressively out of a corner, the front wheel gets light, and when you set it down or aka load it up again it goes into a headshake.

This is a slow speed weave (what I'm calling oscillation per what others have described) where I have diffuculty maintaining my position within the lane on the freeway at a steady high speed.
 

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Check if it's a uni-directional tire, and see if the installer has it rotating the right or wrong way. There's usually an arrow on the sidewall, maybe this got overlooked.
 

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My TKC 80s are new to me, 1st set. I lowered pressure to 20 ft and 25 rear for off road riding and back onto the pavement it seemed fine, I rode the 400 miles home at the same pressures. It cornered fine and had a smoother ride than the 29/36 that I started out at. Just my take on them FWIW.
 

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No problem with the TKC80 front. Rock solid. Just don't run 20psi in the front on gravel forest service roads at higher speeds (80-100kmh) else the weak sidewalls will get you a tweaked rim.
Had a TKC80 rear and now a Mitas E-10 Dakar.
No head shake, no oscillation at sustained 130+ speeds with or without Wolfman bags on Touratech racks.

Check your steering head bearings. Check front axle pinch bolts are properly adjusted and forks are parallel.
Check tyre is not out of round and bead is fully seated. A spin balance is good but tyre can still not be properly mounted or OOR.
 

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I hesitated to call it headshake because I did roadracing and have had headshake. The kind where you almost lose control. But usually that is from an inadvertant side load accelerating aggressively out of a corner, the front wheel gets light, and when you set it down or aka load it up again it goes into a headshake.

This is a slow speed weave (what I'm calling oscillation per what others have described) where I have diffuculty maintaining my position within the lane on the freeway at a steady high speed.
I've not had the slow weave you describe on the AT. For me it is the same as you describe in your first paragraph. I forgot once to reduce the rear preload when I removed my luggage and noticed it shaking a bit right away, later on when I passed a semi going down hill I let off the throttle and almost went into a tank slapper, worst I've ever experienced it. I get milder cases of it once in a while when the setup was off but it's usually on dirt that I notice it.
 

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Discussion Starter · #12 ·
I've not had the slow weave you describe on the AT. For me it is the same as you describe in your first paragraph. I forgot once to reduce the rear preload when I removed my luggage and noticed it shaking a bit right away, later on when I passed a semi going down hill I let off the throttle and almost went into a tank slapper, worst I've ever experienced it. I get milder cases of it once in a while when the setup was off but it's usually on dirt that I notice it.
As of yet I haven't felt anything like it was going into a tank slapper. It's more annoying than anything and somewhat disconcerning that I have to work so hard to maintain my lane position. I almost felt that a cop behind me would pull me over for drunk driving :-( Especially since it was at higher speeds and shall we say not quite at the speed limit, but with the flow of traffic so....

I look forward to trying some of the suggestions I've been given. Just haven't been back in the garage and on the bike (**** job). I'm going to start with taking everything loose and basically starting over. Then work forward with the suspension adjustments that have been suggested to me.
 

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my tkc80 front doesnt oscillate ... but it sure feels weird. or at least felt weird when i first put it on. Ill say ive never had dirt tires on a big bike before. But it handled a great deal differently than the stock tires did. its easy to get the bike out of shape with the TKC front.

i chalked it up to the difference in shape between the E-07 rear and never having ridden a big bike with dirt tires.
 

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Anyone specifically had this issue with the TKC80? Solutions?
Yes, and I ride the same SoCal stretches you do. Generally with this tire I felt the issue at 80+ and even worse at 90+. I did not feel this issue with the bike heavily loaded with passenger on stock suspension.

My experiences:
Stock tires, no issues
Shinko 805, no issues
TK80, high speed drifting/wobble especially on grooved surfaces
Shinko 705, stock wheels, Hyperpro heavy springs, tubeless conversion.. no high speed wobble yet, pretty bad deceleration head shake from 45-25.
 

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I had the same wandering lane feeling with the TKC-80 on my KTM 950SE. The only thing that finally helped it was a Scott's steering damper. After that add-on, the bike felt rock solid on SoCal freeways and of course in the Mojave.
 

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The TKC80s aren't BAD but they are probably the most over rated tires out there and their looks is probably what helped them sell so much. If you put ridding in slippery mud aside, the Shinko 805 are better in every way, at a fraction of the price. Had the TKC80s on my Urban GS and they vibrated, were noisy, the rear wore flat in under 3000km...never again.
 
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