SystemSix feels unbalanced while riding (Need Help)
 

I just returned from a two week vacation and I left my SystemSix Cannondale sitting in my AC garage for the duration. Upon returning and beginning to ride again I began to feel the bike wobble to the left every 3-5 seconds.

This is the list of things I have done:

Wheels are perfectly trued (Krysium ES)
Changed Wheels out for a different pair
Had LBS check it over (Only found a little bit of a loose headset)
Wheels are seated properly
Bars are aligned correctly
I've had two different riders ride the bike and feel this slight wobble (Everyone understand how they are in tune with their own bike)
Checked for cracks in the frame (NONE)
Also, I rode my fianceè's bike with no issues and could ride a perfect line and felt in control

Symptoms:
Wobbles to the left every 3-5 seconds then returns to the line I am taking (While not pedaling/While Pedaling)
Bike feels like it is controlling me instead of me controlling it (Very uneasy at 30+)


Does anyone have ANY ideas of what this could be?

Only thing I could of is that the bearing pressure nut isn't tight and your wheels have wobble from left to right, this happened on mine, but you said you tried different wheels.

Could it be cracked, or the slip locks are separating :/

I have checked both sets of wheels for the bearing =/
Also, my wheels do ride perfect on another bike. Where in the world could their be a crack that would cause this? The bike hasn't been through any trauma or damage. =(

Have an LBS ride it?

That's one of the next options but everything on the entire bike has checked out clean so I have no idea what it could be. It's not like I have a wheel way out of true

Ummm this might be kinda weird, have you checked your saddle for straightness or that one of the rails hasn't come lose?

Nope, just rechecking and my fizik seat is still all connected. This problem has been driving me nuts. I took it out a little while ago and it just feels like the bike wants to wiggle just enough to drive me insane. On hard efforts I really feel like I could lose control because the wheels honestly don't feel like they are moving straight. I also tried walking with the bike while holding the seat and it rolls in a straight line =/ I'm out of ideas, I truly hope someone reads this and can help me pick at straws at finding the problem.

I'd say check the headset...

Headset is fully tight and everything has been checked

I'd agree with Pete, god I wonder what else it could be... so it's definitely bike related and not wheels, you tried other wheel sets and still had the problem?

That's bizarre

Different wheels and everything and still having that problem. I also looked everywhere on the frame to make sure there wasn't a crack and NOTHING. Not even scratches

It's probably haunted by a rider with a huge left quad and an atrophied right quad.

pull the fork out and check the steerer tube, you sure someone didn't ride your bike while you were away

you're a hypochondriac?

+1, I think your a head-case....BF handle says it all.

Bring it back to the LBS and see if someone else notices.

How about JUMBO quads? Sprinter build

You didn't squeeze your top tube right. Tell me you didn't.

Nope, I honestly wish this problem would be obvious and I could get it fixed. I am going to go out in a little for another ride with another rider and see if they can notice anything different. It's something just a smig off.

This would be my thought as well.

What exactly do you think should be there if this would be the cause? Scratch? Bent? Crack? Any Damage?

Was anyone else home? Maybe someone moved it, (or banged it against something.)

No one else has touched it even. Not a soul even home

using the wrong crown race for a given headset can produce similar effects

It HAS to be something with the headset. If you're at your wit's end, get the whole headset replaced.

have your fork checked. Some of the cheap carbon forks are out of line. Check your cables, if your cables are too long they can put pressure on your h-bars and make the bike wobble. And check your headset again.