[colombo]

I've experiences this several times... a low speed head shake/wobble when on the gas and above maybe 70 mph and hitting a bump. Also it happened once on a tight twisty transitioning from left to right. Startled me a little. I'm thinking more and more about putting that heavier weight oil in the damper and see if that does anything.

 

[fredaroony]

I'd be looking at the sag setting on the shock first

 

[colombo]

I'd be looking at the sag setting on the shock first

Right, steering geometry is a culprit. But seeing as how the suspension is not adjustable, I just want to know if anyone else has seen this. I did set the rear sag to 5mm/37mm free/loaded, but it didn't make any difference. The wobble always resolves after a sec or so.

 

[Donnstar]

IMO I don't believe you will find your solution in the damper. Try the shock first and see what that does.

 

[Donnstar]

Sorry, I forget about the lack of adjustment. My suggestion won't do you any good.

 

[colombo]

IMO I don't believe you will find your solution in the damper. Try the shock first and see what that does.

Yeah, the shake is pretty low frequency. It was a shot in the dark... still might do it tho.

 

[barbagris]

Check Head bearings!

 

[colombo]

Check Head bearings!

Will do.

 

[Motosupial]

I've experiences this several times... a low speed head shake/wobble when on the gas and above maybe 70 mph and hitting a bump. Also it happened once on a tight twisty transitioning from left to right. Startled me a little. I'm thinking more and more about putting that heavier weight oil in the damper and see if that does anything.

Just out of curiosity what do you weigh (no gear) and how many clicks up did you go on the preload?

 

[colombo]

Just out of curiosity what do you weigh (no gear) and how many clicks up did you go on the preload?

I weigh 195 lb and I went to setting 9 of 10.

 

[colombo]

Check Head bearings!

Done. Handlebar motion is smooth and light. No free play then I push/pull on the forks. All this done with the wheel off the ground of course.

 

[L8-apex]

In my experience, preload has more effect on ride height than it does on sag (only the right spring can get your sag correct). Cranking up preload has probably raised your rear height, thus decreasing fork rake (just as raising forks in triple clamp would). This would make the bike more prone to headshake.

 

[colombo]

In my experience, preload has more effect on ride height than it does on sag (only the right spring can get your sag correct). Cranking up preload has probably raised your rear height, thus decreasing fork rake (just as raising forks in triple clamp would). This would make the bike more prone to headshake.

Interesting... I'll play around with the preload and see what happens.

 

[QCS]

Had that on the OEM bike. Completely gone after the suspension upgrade. I would also check rear preload. With very little settings available on the OEM shock, dialing this out is not really an option.

 

[DaveNZ]

I think the problem enlies with the suspension (after checking tires, balancing etc, head steering bearings etc) the variable weight springs are very soft initially then go into a harsher part of the spring travel. i never had any stability issues with the stock suspension, i just didn't like the floaty feel when transitioning the bike from fast left to right, I'm 86kg and had set the rear sag on the 3rd ramp from the hightest point down. The front end of the 790 has very large rider sag numbers (54mm from memory) so too much rear preload will take too much rear free sag out, so id sugest dropping a few clicks lower in the rear preload. you weigh about 88kgs, so thats 10 more than me, i was happy on the 3rd or 4th click down. The thing with putting to much preload is, you reduce the free play/static sag, and your getting a mismatch from front verse back. There is a little trick that could be done with the stock suspension and that would be try different weight oil in the forks, stock is 5W, could try 7.5 etc if you had the time and ability to try this. This was going to be my first port of call but after feeling the amazing difference with the Nitron shock, i went down the Matris route but have quite got the front end perfect yet.

 

[fredaroony]

Sorry, I forget about the lack of adjustment. My suggestion won't do you any good.

You weren't wrong, the shock has preload adjustment

 

[fredaroony]

I think the problem enlies with the suspension (after checking tires, balancing etc, head steering bearings etc) the variable weight springs are very soft initially then go into a harsher part of the spring travel. i never had any stability issues with the stock suspension, i just didn't like the floaty feel when transitioning the bike from fast left to right, I'm 86kg and had set the rear sag on the 3rd ramp from the hightest point down. The front end of the 790 has very large rider sag numbers (54mm from memory) so too much rear preload will take too much rear free sag out, so id sugest dropping a few clicks lower in the rear preload. you weigh about 88kgs, so thats 10 more than me, i was happy on the 3rd or 4th click down. The thing with putting to much preload is, you reduce the free play/static sag, and your getting a mismatch from front verse back. There is a little trick that could be done with the stock suspension and that would be try different weight oil in the forks, stock is 5W, could try 7.5 etc if you had the time and ability to try this. This was going to be my first port of call but after feeling the amazing difference with the Nitron shock, i went down the Matris route but have quite got the front end perfect yet.

Thought you weighed 76kgs!! Lockdownitis?

 

[fredaroony]

Had that on the OEM bike. Completely gone after the suspension upgrade. I would also check rear preload. With very little settings available on the OEM shock, dialing this out is not really an option.

I am super tempted but keep changing my mind. Initial first 1000klms is the bike handles pretty decently stock but I haven't had it on a fast road yet. Also don't want to spend so much on this bike where it bridges the gap to a 890!

 

[Motosupial]

I weigh 195 lb and I went to setting 9 of 10.

Looks like youve found the limit for reduced trail on the front end.
Im 97kilo and I only went up 3 clicks. Stock is 5, Im at 8. And I probably wouldnt want it to steer any quicker.

 

[colombo]

Looks like youve found the limit for reduced trail on the front end.
Im 97kilo and I only went up 3 clicks. Stock is 5, Im at 8. And I probably wouldnt want it to steer any quicker.

Fair enough. I'll back it out a couple of clicks, we'll see what happens!