Why does my bike suddenly wobble?

[Raux]

dude after you made your monster a superbike did you add a steering damper?

[flynbulldog]

I'm assuming you put the clip-ons above the triple? You could try putting them below the trip where they belong and raise the trips back up to stock. That may be enough to do the trick  

[stopintime]

I've resprung a few bikes for guys weighing 215-260#, with 11.6 and 12.5 (650 & 700 lb/in) rear springs.
No complaints back from them, and they know my phone number. 

But, SoCal roads are not your roads.
My customers are not you.
I respect that your tuner will have local knowledge of the roads you ride, and likely has talked at good length with you about what you want.

It is a concern when a suspension change results in an instability.

This wobble you experienced, was it a slow weave of the whole bike?
Or was it a faster wiggle, mostly in the bars?

Time will tell if my guy has managed to make my bike as good as it can be for the money - and for me.
Can you tell from the new rates how they relate to stock - I mean, did my guy stiffen up the rear more than the front (percentages)?

How fast is "fast"? It was much slower than for example the vibration you would get from an unbalanced car tire.
At first I thought it was because I was on the small lines/dots dividing lanes - the frequency could be similar, +/- 5 per second?
It wasn't strong enough to move the bike around - I really couldn't say if I felt it through the bars or the seat/tank.


BTW: the rear is now almost an inch higher than stock at free sag (12mm) - riders sag 36mm

[stopintime]

dude after you made your monster a superbike did you add a steering damper?

Nope - I'll have to wait to know if the bike has become generally unstable or if it's something that can be done to
correct a mistake or careless work (like on Spidey's list). If it's a thing from his list, a damper would just cover up, not solve, a problem.

Your previous comment is backwards, isn't it? "Superbiking" me over the tank will add weight to the front, making the front more stable??
I know that an inch at the rear and lowered front (just 5mm or so) will make the bike more twitchy, but other than the wobble it felt very stable and far from too "easy".

My clip ons are mounted below the triple and have 3.5" risers on them - still the grips are two inches lower than stock.
It's the SpeedyMoto top triple that required the front to be lowered.

One of the intriguing parts of the puzzle is still why the wobble apparently only occurred in left turns.

[Statler]

one thing to look at is rider input.   with the new clipons you may possibly be stiffarming on lefts (but not rights where your arm is bent more due to twisting the throttle).   this can cause a weave.   can you take your left hand off the bars once turned in?  (please check that carefully).

[stopintime]

one thing to look at is rider input.   with the new clipons you may possibly be stiffarming on lefts (but not rights where your arm is bent more due to twisting the throttle).   this can cause a weave.   can you take your left hand off the bars once turned in?  (please check that carefully).

I'll even try both arms and legs, if you think it would help 

In fact I checked my arms regularly, most of the time I noticed better leg/core work and loose elbows - which was one of my goals with the clip ons mod.
I'm not 100% sure if that was maintained when the wobbles happened. I was tucked in at the time and couldn't have had straight arms, but going that fast I might have had stiff arms.

Tell me more about the "one hand off the bar" exercise - sounds educational....

[Statler]

sorry...wouldn't take my hand off the bar on a weaving bike.....just making sure you're not tightening up and transmitting more wobble.  I was stunned at the end of my fourth track course when I was raising my left hand to signal I was slowing and pitting in while still cranked over with my knee on the ground.     There were some areas on the track the bike felt unstable and it turns out it was me getting tense and gripping the bars hard....the bike's natural little corrections were being screwed up by me.   I relaxed and the front moved a little but the bike overall was like a rock after that.   (also s4rs with clipons and its ass in the air a bit...and BSTs..and steering damper which can't fix my input weave)


I like all the other suggestions here more.....just a thought in case nothing else pans out.

[flynbulldog]

Superbiking" me over the tank will add weight to the front, making the front more stable??

No - Wrong - You loose stability, you gain front traction and you gain steering quickness both at the cost of stability.
You've gone too far. I was just at a race suspension seminar, many of the riders raise the rear a little at a time untill the bike becomes unstable ( like yours)
Then they lower it back down till it settles in. Your scenario is very typical but if you want to chase geese feel free 

[Roscoe]

Remember to change things in small increments, one at a time. I agree this is a geometry issue.

You say it's only in the left at that speed, is there an identical corner going right, with the same imperfections and bumps?

[DLSGAP]

hmm raised an inch in the back.. that does seem high...

ducs are so finicky.. lol

[Speeddog]

Just to clarify...

He didn't raise the rear, per se.
It's been resprung, so it's more the case of the rear end being back to where it should be.

[mitt]

Just to clarify...

He didn't raise the rear, per se.
It's been resprung, so it's more the case of the rear end being back to where it should be.

And According to the OP resulting in +1inch - so it is the chicken or the egg.

mitt

[stopintime]

And According to the OP resulting in +1inch - so it is the chicken or the egg.

mitt

Not a chicken, not an egg - I ride at the rear height the Monster is meant to be, and it's just a "little" lower up front. It's different from before, but before was too low. The geometry is not very different from that of many/most Monsters.

Remember to change things in small increments, one at a time. I agree this is a geometry issue.

You say it's only in the left at that speed, is there an identical corner going right, with the same imperfections and bumps?

I will have to wait for a suitable opportunity to check if I experience any right hand wobbles. If I do, it might narrow the possible scenarios.

[BK_856er]

Not a chicken, not an egg - I ride at the rear height the Monster is meant to be, and it's just a "little" lower up front. It's different from before, but before was too low. The geometry is not very different from that of many/most Monsters.

I will have to wait for a suitable opportunity to check if I experience any right hand wobbles. If I do, it might narrow the possible scenarios.

Sounds like you have the bases covered from all the good input.

I have no FHE with your swingarm type, but is it possible that with the gear/chain swap you ended up with less swingarm length (shorter wheelbase) and/or more rear ride height than you expected?

I think you indicated 36mm rear rider sag.  What is your front free/rider sag?  Your static geometry might not be so different than most monsters out there, but with such a heavy rear spring you might not be loading it up much in a gentle sweeper, so the attitude of the bike through the turn could remain too aggressive.  Just speculating out loud here.

BK

[TiAvenger]

5 mm drop is *very* aggressive.

I took mine down 2 mm, and anymore was totally unstable. Without raising the rear.