[Cantsurf]

790 guys,
My S has a wicked head shake in the mid to upper 40's mph.
I'm talking if you let go of the bars and don't get back on, you will crash!
I told the dealer about it (I'm not sold on these guys skill set yet) and the claimed the front tire was over-inflated, which caused cupping, which caused shake.
First of all, I've never touched the TP on the front tire, and regardless, that's BS.
Anyone else having this problem? I've got a friction cruise thingy on my throttle so I can set the speed at 47 mph and get a hell of an adrenaline rush.
Let me know your thoughts or experiences.
Thanks

 

[Grizz]

I had a 2016 1290 SA basically same problem. It would develop the head shake when slowing or decelerating through the 45 mph range. I took it to the dealer and he said tires. At that time the bike came with Conti Trail Attack 2’s. I did some research and found that at those speeds there is an induced frequency that varies with tire size etc. if tires are not stable they will accentuate this problem basically letting the pulse build. So I pulled the front damper and filled it with 85 gear oil. This helped but it was still there. Finally got the dealer to change the front tire another Conti attack 2. The problem did not go away even with the front dampener with 85 gear oil. So I continued to bitch and had the dealer take off the Conti Trail Attack 2’s and put on some Michelin Anakee 3’s. The head shake was gone. I put some Michelin Wilds on for an off-road adventure I did and again no shake. So based upon my experience I got to believe it is the tires. This problem is exacerbated by the rake of most adventure bike geometry which makes the bike twitchy and more nimble but it also more vulnerable to these situations. It is what it is.


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[maurockstar]

Same issue on my ‘16 1190. After lots of back and forth with dealer they changed tires to contis attack 3 and it was gone. I still don’t know if it was that or something else they did and didn’t tell me. Hey even asked me to remove the top case, which of course was BS and unacceptable.

Sounds to me like a generic KTM issue on adv bikes, which is a shame really.

Do you have any waving at high speed? Mine starts to “float” in the front when I’m over 100mph. If I push down really hard the handlebar I can go up to 115 without the shaking but then it starts again.


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[Grizz]

Problem is that in order for bikes to be nimble of road the rake is so acute that even the slightest wave in the ply of the tire induced sway into the bars. Once tires are right is is good or at least noticeable. Also filled damper with 85 gear oil.


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[DaveAu]

Sorry to jump in...... (SDGT owner killing time on a hot afternoon.....), but have you checked the steering head bearings for correct tension?..... a couple of our guys found their headstocks hadn't been tightened down properly from the factory and the dealership's hadn't noticed it at predelivery.

Even with a steepish rake the bike should not shake badly if everything is set correctly (head tension/tyre pressures/wheel alignment/etc)...... i had a Kawasaki Z1000J1 way back in the 80's with super nervous steering geometry but I had everything set just right (and good rear shockie's) - it wouldn't shake the bars unless i hit a big enough bump.

It can be tyres (and pressures will affect how they wear).... I've had some brands wear really badly, yet others wear evenly - try to find the sweet spot for air pressures (not too hard, not too soft, for your weight/riding - a dedicated tyre shop should advise the best psi to use..... a KTM shop will just quote the owners handbook)..... but it can also be worn steering head bearings, shock absorbers, fork oil levels. A bar mounted fairing or hand guards can upset steering (usually at higher speeds). Any crash damage (twist in the forks)? Mismatched rear spring settings upsetting the forks.... eg measure the sag.

Go through the bike thoroughly - if it is new, the suspension damping might not be set up right from the factory, if it is older/high mileage, then something may be needing a refresh or adjustment. I've done a lot of this sort of stuff over the years and have always had great steering bikes as a result.

Best wishes for trouble shooting the issue...... maybe try another bike mechanic with a good reputation if your official dealership is clueless .

 

[BP Rider]

790 guys,
My S has a wicked head shake in the mid to upper 40's mph.
I'm talking if you let go of the bars and don't get back on, you will crash!
I told the dealer about it (I'm not sold on these guys skill set yet) and the claimed the front tire was over-inflated, which caused cupping, which caused shake.
First of all, I've never touched the TP on the front tire, and regardless, that's BS.
Anyone else having this problem? I've got a friction cruise thingy on my throttle so I can set the speed at 47 mph and get a hell of an adrenaline rush.
Let me know your thoughts or experiences.
Thanks

Hello, I’m wondering if you were able to fix your shake issue on the 790? I just bought an S and yesterday was the first “real” ride...I noticed the front tire wobbling back and forth about 1/4 inch or so...any speed over 35 or so and above...tried shifting my weight and even did a “super man” standing and leaning forward on the tank and it didn’t stop. At first it felt like it was jumping up and down like it had a knot or something...but after looking more closely it’s moving side to side creating the “hopping” feeling...any help would be appreciated, I plan on calling the dealer tomorrow but was hoping to get some real world insight. Thanks.

 

[Cantsurf]

Hello, I’m wondering if you were able to fix your shake issue on the 790? I just bought an S and yesterday was the first “real” ride...I noticed the front tire wobbling back and forth about 1/4 inch or so...any speed over 35 or so and above...tried shifting my weight and even did a “super man” standing and leaning forward on the tank and it didn’t stop. At first it felt like it was jumping up and down like it had a knot or something...but after looking more closely it’s moving side to side creating the “hopping” feeling...any help would be appreciated, I plan on calling the dealer tomorrow but was hoping to get some real world insight. Thanks.

BP,
I have just been living with the issue. I am lined up for a new set of tires soon, happy to get rid of the Avon's. They suck off road. I'll post again after new tires. If still apparent, I'll check pre-load on steering bearings.
Cantsurf

 

[DaveAu]

G'day BP Rider,

Your tyre shimmy reminded me of a tyre issue I had many decades ago - it was installed incorrectly by a dealer at the time (they were dodgy buggers way back then..... all promise and no care)..... that tyre had a visible shimmy because it was not seated on the wheel rim - check the tyre bead line, it should be evenly seated all the way around the rim.

It could be as the OP says, a bad tyre, but you should also check for a warped wheel rim (I assume you have spoked wheels on the R) as it's possible you may have hit a rock/bad pothole on your travels (was the R new or used? maybe the prev owner damaged a rim?).

 

[Grizz]

Had a similar problem on a 1290 SA.. replaced front tire and never returned.


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[BP Rider]

Thanks for the insight, I will look closely this evening!...it is a new 790S, 4 miles on it when I bought it, maybe 150 on it now. Thanks again!

 

[DaveAu]

I had one other thought (I know, it's rare, thinking is so unnatural......)....... do you have a top case mounted to your 790S ? And if so, how much weight is in it?

I only ask because a heavy load behind the rear seat can upset some modern sharp steering bikes with standard soft suspension. My cousin, the pro bike mechanic, once told me he had a customer with a GSXR750 sport bike complain of a really bad headshake issue. When he was given a look at the bike he saw that the guy carried very heavy work tools on the back seat & rack - the owner would not believe that was the cause until he removed the tools and went for a quick ride.......

You probably don't have a heavy load on the back so it's more likely lost wheel weights/bad tyre/steering head bearing tension/tyre pressure/bent rim issue. No one manufacturers bad handling bikes - they'd go out of business fast these days..... but they can suffer from assembly errors or a defective supplied product like tyres/batteries etc.

See if you can find out what the fork and rear shock settings are supposed to be from the factory...... maybe an assembly worker had a bad day and didn't set them correctly...... this has been noted on the SDGT forum, where an owner found his clunking steering head bearings were loose, and once torqued correctly (with the forks set at the proper height above the head clamps) he was very happy..... pity it took 2 years to find the cause of his slow steering and clunky forks........ no help from local dealers...... they just don't know the basics.

 

[BP Rider]

Well, yesterday dealer called with good news, they noticed the tire wobble instantly and said the spokes / wheel were not lined up correctly, they fixed it and were scheduled to deliver back to me today...now the bad news...30 min before delivery they called; a technician did a final test drive and noticed it's still not right, so back to the drawing board. I'm glad the dealer is paying attention (and not their fault), but not what I expected in a brand new bike purchase.

 

[BP Rider]

After a closer look, the dealer figured out there was an alignment issue between the axle and the wheel which was causing the wobble. KTM covered the fix/labor and I tested her out and so far it’s smooth as silk. Let’s hope it stays that way. Thanks all.

 

[Don Lopez]

I posed this in tire thread as well. My stock 790R had a slight head shake/wobble at very high speeds, but not enough to scare me to slow down. I just rode 122 mph (115 on GPS) and bike was very stable, zero head shake. Karoo 3 front (7,200 miles), new K60 Scout rear, Rade windscreen. K60 has more vibration at low speed (less than 30) than the Karoo 3 rear. K60 good off-road except for stopping.

 

[Cantsurf]

So,
I finally got new tires, Mitas E07's. The tires are fantastic, rock solid on the road (a bit noisy buy acceptably) and off/gravel road, Hell Yeah!
Also, the head shake is gone. Not sure if it was a balancing issue or just crappy tires.
Ride On!

 

[Grizz]

Crappy tires.


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[BP Rider]

Unfortunatlely my above “smooth as silk” comment was the cart in front of the horse...since then I’ve had the bike back to the dealer twice, and now it’s back in my possession and after an otherwise awesome 200 m ride Saturday it seems to be getting worse, or at least it got worse throughout the ride. Dealer says it’s because I’m used to a cruiser, adventure bikes aren’t as smooth. On a perfect paved road I’m experiencing front end gyrating (in some cases nearly hopping) up and down, most noticeable at 40-50 mph. It is a “rhythmic” up and down wobble, faster speed, faster rhythm...until at high speeds it becomes unnoticeable. They say the wheel and spokes are near perfect, both side to side and radial, and there are zero defects with the tire. I have the 620m service scheduled for the 16th and I’ve asked them to again try to resolve it...not sure what to do at this point. If anyone has any advice or more specific questions I should be asking the dealer please fire away, any help is appreciated. Aside from this nagging issue, I absolutely love this thing and can’t wait to get into some real adventures but it’s hard to Ignore how it moves on a perfectly smooth road.

 

[Don Lopez]

Your dealer is supposed to test ride your bike during the 620 mile service, so they should figure out the shake problem. I have heard of front brake rotors causing issues and out of round front wheels due to spokes not right. Maybe the fork triple clamps or steering tube bearings are not adjusted right. I’ve never had a motorcycle as smooth as my 790R at speeds over 100 mph. At really slow speeds I get some vibration on pavement since I put on the K60 rear tire, but I don’t feel it off-road or at speeds above 10 mph on roads.
I‘m close to needing my 9300 service and hope the recalled rear brake line get in so I can get both done together. My rear brake has been flawless, and it stays in “Off-road” mode.

 

[rsmith]

Has you dealer checked the head bearings? It is a new bike, so I should be good. However, over tightened or loose bearings sometimes cause this. JMO

 

[BP Rider]

Has you dealer checked the head bearings? It is a new bike, so I should be good. However, over tightened or loose bearings sometimes cause this. JMO

I will mention the head bearings when I take it in, can’t hurt to ask. Thanks!