Fork alingment

I just got done rebuilding the front end of my bike. New head bearings, repainted triple trees and hand controls including master cylinder with new viewing window. Also installed a new EBC brake rotor with new pads. Now I'm not sure if the fork tubes are aligned to each other. If I go full lock to the right the acorn on the top triple tree almost hits the gas tank. When I go full lock to the left the acorn nut clears the tank by about a quarter inch. Is there a way measure to make sure everything is lined up?

 

You can lay a flat piece of glass across the fork legs. If the glass wobbles like an old wooden chair. The forks are out of alignment.

It is possible that the forks have become slightly bent with age. You can turn them in the triple tree to try to get them lined up again.

Ghost

 

Loosen the axle and bounce the front end a few times. That gives a little bit of self alignment. Anything going on in the area where the forks hit the stops on the frame?

 

Are you talking about the steering alignment?
These guys seem to think you are talking about the straightness and orientation of the fork tubes themselves.

 

I'd agree with Adrian that it could be down to wear/damage on the lock-stops on the frame/bottom yoke. If the bike's been crashed in the past & the bars slammed violently to one side it can indent the lock stop & cause what you're seeing even if everything is now straight on the bike...

Edy, this-:

Bent/misaligned fork tubes could cause this too if the bend is in the right (wrong?) place... Or of course a tank that's not sitting right for some reason (damaged/missing rubbers)

 

The top yoke can be twisted too. After my accident, I thought my forks were bent because they weren't level (using glass plate). However, upon disassembly, I found that they straight. The top yoke must have twisted in the impact and just releasing the nut probably would have fixed the alignment.

Also, are you sure your tank is symmetrical? Maybe one side is a 1/4" higher than the other. Definitely check with some plate glass or something very flat.

 

Tighten the top and bottom clamps on one side(I do the throttle side) of the forks. Leave the other side just a little loose as well as the axle. With the front wheel off the ground, jackstand under the frame, handle bars straight, quickly spin the front wheel backwards by hand and let the wheel make atleast one turn before a helper jams on the front brake and holds it until you tighten the other side of the forks and the front axle. You will be able to easily ride no hands every time after you do this.

 

jim123 I will give this a try. I might have to let the wife in the garage to help, I guess.

 

Here's how I true-up my forks:

put everything in place and tighten everthing up til it is just strong enough to hold everything in place but can still be easily nudged.

Get two perfectly straight broom handles or other two thin but perfectly straight pieces of wood about 3-4ft long (the longer the better......)

fit one of the pieces through the wires, brackets, whatever you need to do so that the piece is perfectly flat against the fork upper tube. tie it in place at both tubes, but be careful not to tie it so tightly that it now bends...keep it perfectly straight across.

Fit the other piece through the rim, on the front side of the lower fork tube. Now, simply roll the rim back til it holds the wood stick in place (making sure you don't have one side of the stick up on a bump or anything). tie the rim so it can't rotate and loosen the stick--or just tie the stick like you did at the top--

so far, that should have take you about 5 minutes

Now, go back to the top, and sight down the forks but you're looking at the two wooden sticks to see if they are parallel to each other. If they are dead parallel, you're all set. If they are not parallel, simple nudge, tap, the top clamp which ever ways you need to go til the sticks are dead-on parallel.

Once there, tighten the top triple clamp nut while making sure the sticks stay parallel. Once that's tight and sticks are still parallel work your way through the tube clamps to snug them down while keeping the sticks parallel.

Once all is tight and sticks still parallel, you're done. Now, just pull the sticks out.

Takes usually only a few minutes to do all that.

It's really a simple process......if the sticks are perfectly parallel, then the forks MUST be perfectly parallel at 90 degrees to direction, regardless of whether one or both of the sticks is inclined along the tube. If you are looking for parallel sticks from out in front of the bike, that won't work. It doesn't matter if they are perfectly parallel to the floor or not.

What IS important is that they are dead-nuts parallel when sighting them straight down from the top if the triple tree. It is INCREDIBLY easy to see if they are not parallel, because an end of the bottom stick will be visible. If perfectly parallel, the bottom stick will be perfectly hidden by the upper stick.

YMMV

Dave F

 

Do that a few times before you tighten everything down. You'll hear the forks and axle squeak as they move into place. After a few times doing this, you won't hear things moving around when you jam the front brake on. That's when you tighten everything up.

I was following a friend on his gs500 and he was leaning off the left side f the seat as the bike went straight down the road. It was a very windy day and I thought the wind was blowing him around. We made a 90 degree left turn to due north, and he was still leaning. Strong wind out of the north west I thought until another 90 degree left turn and wound up going back the way we came. Still leaning left. I tried the bike and it just felt weird. Couldn't let go of the handelbars as the bike wanted to go right. Anyways, we did this trick and all was fine afterward. It was easy to let go of the handle bars at any speed.