Bike leaning to the left and random handle bar shake.

[Monkeytofu]

Just as the title says my bike seems to lean to the left although it drives straight. it feels like the bike tipped over, but I have no problems turning or steering the bike although I always find myself trying to correct the lean. This was happening before my recent crash but I can't remember when it started.

My handle bars are also randomly vibrating. I find it happens around 40-50 mph but I've seen it at lower speeds and higher, but it's and issue. I can stop it just by holding the handle bars but the front shakes a lot of I take my hands off.

My tire pressure is good, I've loosened the triple clamp, tightened to spec and tried to correct any twisting that may have happened from my low side, and replaced my handle bars.

I might buy new tires (recommendations?) soon so I might be able to rebalance, but I'm at a loss as to what can cause the lean or the shake.

Should I take it to someone more experienced at this point?

[Jim Moore]

The shake is caused by a worn out and squared-off rear tire. I recommend Pirelli Sport Demons.

[csmith12]

Check pressures too. Since you are looking in that area, inspect your brakes while your there. Lift the front tire and spin it, check rotor straightness and for a dragging brake pad.

[bdavison]

There are multiple reasons that this could be occuring.

1. Unbalanced tires due to some damage in your low-side.
2. Bent or out-of-round rims (again due to your low-side)
3. Squared off rear tire, or triangles front tire.
4. Internal damage to tires (if they are radials)
5. Tweaked front forks.
6. Wheels out of alignment.

[Lychee]

have you done this:
start at 3:00

Link to original page on YouTube.

[alex.s]

i think if you are completely straight up and it tries to turn it means one of two things, rear wheel is compleeeeetely out of alignment (in which case your chain would be all but annihilated) or your forks are crooked in the triples (one higher than the other) or your headstock is bent to the side.

[GeorgeRYoung]

All bikes have a resonance around 45 mph and whether this is perceptible as a wobble depends on the input (how dynamically unbalanced is your front tire?) and damping (hands on the bar, steering bearing tight, steering damper).

Most recommend tightening the steering head bearing until there is no play and a bit of drag. I personally prefer the steering damper approach.

http://web.ncf.ca/ag136/frontWheelWobble.htm

[austexjg]

Would need to look at the bike to get a better idea - take some measurments to determine if back tire is aligned properly.

[Jono]

My bike does this too. Pretty sure it is from one of my forks being slightly bent. But possibly front tire wear. Don't BT45's wear kinda weird. Idk. My solution: I just leave my hands on the bars. Haha.

[alex.s]

Originally Posted by GeorgeRYoung

All bikes have a resonance around 45 mph and whether this is perceptible as a wobble depends on the input (how dynamically unbalanced is your front tire?) and damping (hands on the bar, steering bearing tight, steering damper).

Most recommend tightening the steering head bearing until there is no play and a bit of drag. I personally prefer the steering damper approach.

http://web.ncf.ca/ag136/frontWheelWobble.htm

uhh. i'm pretty sure not all bikes' wheels wobble. i ballance my wheels myself very carefully and have 0 wobble at any speed. i can go from 85, hands off the bars down to 25 with clutchless downshifts and have no wobble at all (i have tried this) if your front wheel is wobbling you need to rebalance it. as tires wear down they can get out of balance. your link even says the wobble is caused by an out of balance tire

[EsrTek]

Originally Posted by Lychee

have you done this:
start at 3:00

Link to original page on YouTube.

Good info to know

[Monkeytofu]

Thanks for all the advice everyone, I'll be going through all the suggestions once I get back home. Clutch cable gave out today and I need to replace it.

[GeorgeRYoung]

Originally Posted by alex.s

uhh. i'm pretty sure not all bikes' wheels wobble. i ballance my wheels myself very carefully and have 0 wobble at any speed. i can go from 85, hands off the bars down to 25 with clutchless downshifts and have no wobble at all (i have tried this) if your front wheel is wobbling you need to rebalance it. as tires wear down they can get out of balance. your link even says the wobble is caused by an out of balance tire

What I said was all bikes have a resonance, meaning a frequency at which the response is a maximum. The front steering assembly has both mass and a restoring force, so it has a resonance point.
http://www.vf750fd.com/blurbs/vibmode.html

A wobble is a perceptible motion at or around the resonance point due to dynamic tire unbalance and lack of damping. I guess your bike and setup is an example of a bike which has no wobble at the resonance frequency.

When you say you balance your wheels carefully, what you probably mean is you statically balance them with weights until there's no 'heavy point'. This cures the wheel's tendency to bounce up and down at speed, it does nothing for dynamic balance. Dynamic unbalance is when the wheel weight is not symmetric about the vertical plane. Think of putting two 100gm weights on the top left and bottom right. The wheel would still be statically balanced, but would tend to wig-wag left and right when rotating. It is this dynamic unbalance which acts as input to cause wobble.
http://www.balancemaster.com/_privat..._explained.htm
When you're going 80kph/50mph this wig-wag is occurring at a frequency of 5.6 Hz (times per second).

I have no idea how to dynamically balance a wheel in a frugal, home setup. So I use a steering damper to squelch the wobble instead.
http://web.ncf.ca/ag136/steeringDamper.htm