Weave at speed - now weave all the time

[Snow]

Hi all,
I have had a slight weave that appeared mostly at speed around 40-50mph that didn't really bother me because I usually just putt around town, but being that I plan on going motorcycle camping soon, I need to get the bike right.

So, I decided that the most likely culprit was a too-loose steering stem from when I replaced my steering stem bearing awhile back. So, I loosened the three nuts holding the top triple tree clamp down and pulled out the center bolt (too give myself a little room) and then proceeded to tighten up the steering stem - first by loosening the locknut and then by tapping the bottom nut around with a screwdriver and mallet.

I kept checking the movement of the front end to make sure I didn't make it *too* tight, and then put the lock nut back on and put everything back together. Well, to sum things up, she now weaves all the time. Not good.

What have I done to myself? What have I done to my bike? The air pressure is good in the tires. Perhaps I need to make sure my fork tubes are clamped in correctly, starting from the top clamp while being suspended by a jack?

Help!!!

- Stranded in a Cage

[scalded dog]

You may have already checked it, but it sounds like the forks are not tight enough, in the clamps. I just replaced my front forks with a pair off e-bay, and it rides a lot better. I had run into the back of a pickup truck and bent my old ones. Later 'Dog

[Snow]

I'll check the book to see if there is a recommended torque and if not, I'll *make sure* they are all tight enough after I double check the position of the forks then

Sorry to hear about the pickup problem, hope all is well aside from the forks!

[skids]

Re: Weave at speed - now weave all the time

Does she feel as though it won't hold a straight line? Kind of like a balancing problem as if you are walking on a plank? If so, your head bearings are just a bit too tight or are binding a little.

Originally posted by Snow
Hi all,

I kept checking the movement of the front end to make sure I didn't make it *too* tight, and then put the lock nut back on and put everything back together. Well, to sum things up, she now weaves all the time. Not good.

[Snow]

Kinda, feels like I am riding drunk to tell you the truth.

[sixtysix]

Sounds like they are too tight to me as well.

[Snow]

Ok, I am going to ride out to the garage now and loosen 'em up a bit - will post results here when I get back. Thanks for the advice guys

*edit*

And its about this time that Snow realizes he let his woman borrow his winter riding gloves tonight to ride to class with over her normal gloves b/c she doesn't have any yet...doh!

Well...I'll let everyone know when I know at least.

[TopCatGr58]

Head Too Tight.

Okay, I have to remember this is NOT the PLUS Site!!

Snow, I used to have an old '67 Yam 350 2 stroke twin street bike, and it had this knob on the center steering head that you could tighten to stiffen up the steering head action for when you were driving on the highway, to help it stay straight against wind blasts from oncoming cars, etc.! However, if I forgot to loosen it when I got to slow speeds, it made it very difficult to manuever because it was too stiff and I couldn't make those quick steering actions needed at lower speeds.

But this is contrary to how your bike is handling, cause you say that it weaves at higher speed. What I'm thinking is also that it is too tight, and so you have the bars set at a certain position and it's very hard to change that position, so the bike continues to follow that direction....not exactly where you want it to go until you make a sizeable input effort and correction, but then it's usually too far, and so the bike then goes in that overcorrected direction until you try to correct it again, hence the "weaving" type action you described. The bikes steering head can't move in those little subtle amounts to allow it to maintain a straight path with just slight variances in steering movement.

With it on the center stand, put something under the front of the engine/frame so that the front wheel is suspended off the ground, and then as you make your adjustments, see if you can make the bars move from far left to far right with just the littlest pressure, where it almost flops over from left to right. If it stops when you give it a push from one side to the next, then it is too tight, it should be a smooth action, but also not a stiff one!! Good luck.
T.C.

[Snow]

When you say just the littlest of pressure, you mean just a little tiny baby push? If that's the case..well..then..yeah...I may have overtightened it just a *wee* (translation: WAYY overtightened) bit.

[skids]

Make sure that you test it AFTER you tighten the keeper bolt. That bolt can somehow exert some pressure on the adjuster rings and change the overall adjustment. At least that has been my experience! BTW, you might want to check out the trailing arm adjustment after you readjust the steering, if you still have some wobble.

Originally posted by Snow
When you say just the littlest of pressure, you mean just a little tiny baby push? If that's the case..well..then..yeah...I may have overtightened it just a *wee* (translation: WAYY overtightened) bit.

[Snow]

Well, looks like I did overtighten it - she is being much nicer to be now that I've loosened her up and gotten closer to where she is supposed to be. I won't say I've gotten it right on b/c I don't have the correct tool for the job, but she swings from one lock to the other with a gentle push with the adjuster bolt taken out.

My first test ride proved to be scary as I managed to loosen the stem too much...very scary, but now it seems pretty close to dead on.

Thanks for all the advice!

[John]

I had a problem with the bearing races in the steering head. It seems that after all these years of going straight down the road, the races will develop a worn spot in the front and back side from the constant load in that area. They way to check is to raise the front wheel of the ground, slowly move the bars side to side, and check for a little binding when the steering goes through the 'center' position. If so, replace the bearings and races. They can be found at any bearing supply store for 1/2 the price a dealer would ask. My local rip off artist, I mean dealer, wanted $22 per set, upper and lower, and I was able to get them for $20 for both. Just get the part number from the bearings and races. It is stamped on them. On the bearing itself, it will be on the inner race that rides on the through bolt. You may have to look hard, as it won't be very big, but it is there. Most bearing manufacturers use the same part number, as there seems to be an industry standard for part numbers. The ones I bought were Timkin brand, but there are other brands available. I don't recall the part number, and I didn't think to write it down in my manual. Just make sure that you pack them with grease before installing them.

[Snow]

I replaced mine about a 9-12 months ago, got the parts at a decent price from partsnmore.com. I think it was about $30-33 US for the whole she-bang.

[pgg]

After adjustments, stringline the wheels too. You may discover the swingarm bearing nuts need tweaking left or right.

[pgg]

Here's how to stringline the wheels. You need 2 lengths of thin string, a flat concrete floor, a felt-tip pen and 2 weights. Start by sitting the bike perfectly upright ( block under the sidestand ) and have the front wheel pointing dead straight. 2 feet or so behind the rear wheel lay a 2 inch thick board or book on the ground and weight the 2 lengths of string the rear tyre width apart. Kneel or lay in front of the front wheel and pull the string taut so it lightly grazes the rear tyre sidewalls. Keep the string dead straight.

Mark a dash on the ground below the front axle. Do the same both sides. End result is 2 marks on the ground either side of the front wheel. If the wheels are perfectly aligned, the marks are identically spaced from both front tyre sidewalls. If not; you need to prise off the pivot nut covers and tweak the pivot nuts.