75 Z1B weird frame issue

trying to find out why one side of the front tire is wearing more than the other side,I discovered a weird frame issue.
If you look at the bike from the front,with the bike being straight/vertical,the forks/wheel is tilted to the left, meaning instead of having the the fork coming down completly vertical, the top of the forks is at 1 and the bottom at 7.
it look like the steering head is not coming down straight.
I looked at all the welds and it certainly don't seems that the bike was crashed and repaired.
BTW, i have owned the bike for 10 years and i have never noticed this problem.
The bike handle normal and track straight and true.
Could the bike steering head not having been welded straight from the factory?
Anything else that could be responsible for this tilt?

I'd recommend replacing the steering head bearings with tapered rollers. It's possible that your stock ball bearing races have become worn. Have you checked the torque on the steering stem nut under the top triple clamp?

If the bike had come from the factory with this problem, which it didn't, you'd have noticed this problem a long, long time ago.

How many miles on your bike?

I would recommend checking fo play in the bearings. With the help of a friend, jack the bike up with either a floor jack and a 2x4 across the bottom of the frame, or the correct bike jack. straddle the front tire and gently lift. If you have ANY play the issue needs to be addressed before you ride again.

Might also want to measure the length of the forks on each side to see if you have a difference.

I recall hearing that Kawasaki actually lisaligned them on perpose and that most drag and road racers actually cut and reweld the stem area "straight" to track, with speed, correctly. Like I said this is something that I heard, I think here. Search it.

The bike has about 40,000.
Like i said i have owned the bike for over 10 years and never noticed the issue.
I'm going to check for bearing issues

misaligned in purpose?
That an interesting idea.

luc wrote:

misaligned in purpose?
That an interesting idea.

Yeah, first I've heard of it...

checked the for play, nothing, and the forks are the same lengh on both side

Have you done any work on the fork, like changing the seals?

i changed the dust shields a few years back.
I think that i will have to pull the steering stem to look at the bearings/races.
I shoud also be able to see if the steering tube/head is straight or not

I'd go ahead and order the tapered roller bearings from Z1 Enterprises, it's an upgrade.

If you don't see any broken welds or stress cracks around the steering head, I seriously doubt that the frame is crooked.

Another thought... If the back wheel is out of alignment, it'll cause the front to track crookedly. How are your swingarm pivot bearings?

I would change the fork oil and measure the oil that comes out. Roy