Author Topic: Can't get fork tubes back in! (Read 8505 times)

drdreas · « **on:** June 30, 2009, 08:57:44 PM »

Hi all, I've done a few searches and didn't come up with an answer, so here's my problem.

I wanted to remove the stock headlight ears, as well as installing clip-ons above the triple tree, so I took my forks off the bike yesterday. I took the wheel off, loosened both triple trees and they popped off and slid down easily.

They were a bit rusty where the triple tree was clamped, so I polished them up, polished the lowers, and went to re-install them today, planning to push the tubes 2" through the top of the triple-tree and install my clip-ons above.

As soon as I put a tube through the lower tree and into the upper I could see the alignment was off by 1/16" or so, and the tube wouldnt slide through the upper tree. I put grease on the tube and a bit inside the tree clamps and tried again. After a bunch of pulling and cursing, I got it lined up and into both lower and upper tree.

Once in, I had to get a friend to pry open the upper triple tree clamp with a screw driver, while I twisted the tube and pulled up as hard as I good to get it to slowly slide up into place. I finally got it high enough above the triple tree to mount my clip-on to.

The other tube was just as hard, and once I got it flush with the top of the tree, I couldnt get it to go any higher!!

No matter how much I twist, with the triple clamp pried with a screw driver, I can't get it to budge any higher!!

How is this possible? They slipped out so easily, and I would imagine getting them out would be harder, with that rust/corrosion that built up in the clamp. Now they are cleaned up, greased, and they won't go in!!

Any ideas? Its a mystery to me, and I'd like to know if anyone experienced the same thing or is something seriously wrong?

Thanks a bunch.

pee wee · « **Reply #1 on:** June 30, 2009, 09:05:22 PM »

was there a little tab in between the slot where the bolt pulls the clamp together ?it has a flat side on it that has to be against the tube. mine was the same way until i move that tab flat side in. its like a little spacer on the top of the tree.

drdreas · « **Reply #2 on:** June 30, 2009, 09:32:54 PM »

Not quite sure I understand. I don't remember there being any sleeve or tab or anything inside the triple tree clamps. Just the clamp, and a bolt running through. I twisted the fork tubes 360 degrees as I tried to get them through and they were hard to push in no matter their orientation.

754 · « **Reply #3 on:** June 30, 2009, 10:04:13 PM »

I dont think 77/78 has those tabs, at least not on the F.

Is there a line or a ridge on the tube, at base of the lower tree.. a ridge of dirt or a crease from peviously bent & straightened tubes.. that is preventing it from sliding up/

drdreas · « **Reply #4 on:** June 30, 2009, 10:13:26 PM »

Not at all, they are perfectly smooth other than the minor pitting that I polished up. Is it normal for there to be so much resistance to get them to slide in? I got one of them up, but it took so much force and twisting over the course of 4 or 5 attempts. They second one I can't budge any more though.

Hush · « **Reply #5 on:** June 30, 2009, 11:22:46 PM »

Have you taken your wheel off?
Sliding the forks in individually should not be a problem but trying while they are part of the front wheel/brakes might be as they could be spread, also look down at the wheel its self, has the wee alignment notch on the inside of the forks poped out and now angling the forks inwards?

EDIT: Ok just reread your post, there should be no good reason for them not to slide straight back on!

750goes · « **Reply #6 on:** July 01, 2009, 12:24:46 AM »

Loosen the top clamp, it is possibly twisted a little bit, making the insertion a little hard.

make sure both the top clamp and lower clamps are loose, push a screwdriver into the top and bottom clamps while pushing the fork in.

If they wont go in, then something is bent..

do the forks without the wheel installed is also better than manhandling the wheel as well..

mystic_1 · « **Reply #7 on:** July 01, 2009, 04:44:04 AM »

Quote from: 750goes on July 01, 2009, 12:24:46 AM

Loosen the top clamp, it is possibly twisted a little bit, making the insertion a little hard.

make sure both the top clamp and lower clamps are loose, push a screwdriver into the top and bottom clamps while pushing the fork in.

If they wont go in, then something is bent..

do the forks without the wheel installed is also better than manhandling the wheel as well..

+1 Everything needs to be loose. Pinch clamps for the fork tubes, pinch clamp on the upper tree at the steering stem, and the steering stem nut should all be loose. Tap some flathead screwdrivers into the pinch clamps (not too far!) to hold them open.

mystic_1

drdreas · « **Reply #8 on:** July 01, 2009, 06:37:00 AM »

I'm doing it with the wheel off, one fork tube at a time. I lubed the tubes, the inside of the clamps, took the clamp bolts off completely, and evev pried them open a bit with a screwdriver. It seems to be an alignment issue. The steering feels ok, other than a flat spot when the steering is centered.

754 · « **Reply #9 on:** July 01, 2009, 09:03:19 AM »

Quick fork tube check;

Lay one complete leg assembly on table. Now hold the other againt it, so alum sliders are facing outwards, that is tube against tube.

Leave first one sitting still and pull the other up against it.(At this point the top cap on the tube should be near the seal area of other leg assembly).. now look for any gaps..then TURN THE TUBE 90 Degrees, observe for gap, then turn again and observe.
Then turn the other tube 90 degrees and check it.

You may have only 1 bent tube, if it is out 10 thou, you should clearly see it.

If they are bent, and you face them the same way (bend to front) they will probably go in.

mystic_1 · « **Reply #10 on:** July 01, 2009, 09:15:52 AM »

Quote from: drdreas on July 01, 2009, 06:37:00 AM

I'm doing it with the wheel off, one fork tube at a time. I lubed the tubes, the inside of the clamps, took the clamp bolts off completely, and evev pried them open a bit with a screwdriver. It seems to be an alignment issue. The steering feels ok, other than a flat spot when the steering is centered.

Did you loosen the pinch clamp where the upper tree meets the steering stem, and the steering stem nut?

+1 to checking your tubes for straightness.

mystic_1

754 · « **Reply #11 on:** July 01, 2009, 09:24:30 AM »

Lower the offending tube just below top triple, then lightly clamp, the turn 90 degrees and clamp again, you will see what is wrong..

drdreas · « **Reply #12 on:** July 01, 2009, 09:25:09 AM »

Tubes are definitely straight. I checked them when they were out. Also, they came out of the trees very easily. What is the pinch clamp where the upper tree meets the steering stem? I loosened both pinch clamps on the upper tree that clamp the tubes, but thats it. Should I also loosen another clamp?

754 · « **Reply #13 on:** July 01, 2009, 09:33:21 AM »

The 3rd pinch on top tree, should be right behind the stem nut.

If they pulled out fairly easy, and are not going back in, sounds like they are bent.

drdreas · « **Reply #14 on:** July 01, 2009, 11:00:13 AM »

I checked the tubes, and they are definitely straight. Both tubes, placed in either side of the lower triple did not align quite right in the top triple, and they were offset in the same direction no matter which way I spun the tubes, so I think that indicates the upper and lower triples are out of alignment.

I don't know how that happened since I took the fork tubes out, but would this explain the binding? If this is the case, how do I get the upper and lower trees aligned again? Is this why I should loosen the third clamp on the upper than holds the stem? Would this allow the upper tree to rotate freely and line back up with the lower?

Thanks

Patrick · « **Reply #15 on:** July 01, 2009, 12:07:05 PM »

You may know all this, but I will mention it anyway.

Your triple tree is not a solid piece. The top of the triple is a plate that is held on by the nut at the top of the steering stem. Loosen that bolt and loosen the pinch bolt on the steering stem and you should be able to rotate the top of the triple tree until it aligns with the bottom. If you did not loosen those bolts that would explain the problem getting the fork legs back in.

Patrick

Caaveman82 · « **Reply #16 on:** July 01, 2009, 12:29:12 PM »

Quote from: Patrick on July 01, 2009, 12:07:05 PM

You may know all this, but I will mention it anyway.

Your triple tree is not a solid piece. The top of the triple is a plate that is held on by the nut at the top of the steering stem. Loosen that bolt and loosen the pinch bolt on the steering stem and you should be able to rotate the top of the triple tree until it aligns with the bottom. If you did not loosen those bolts that would explain the problem getting the fork legs back in.

Patrick

What he said.

Did you lean your bike against something while you were cleaning the tubes? If so that's probably what did it.

drdreas · « **Reply #17 on:** July 01, 2009, 12:44:23 PM »

Quote from: Patrick on July 01, 2009, 12:07:05 PM

You may know all this, but I will mention it anyway.

Your triple tree is not a solid piece. The top of the triple is a plate that is held on by the nut at the top of the steering stem. Loosen that bolt and loosen the pinch bolt on the steering stem and you should be able to rotate the top of the triple tree until it aligns with the bottom. If you did not loosen those bolts that would explain the problem getting the fork legs back in.

Patrick

I didn't know this. Is it normal procedure to loosen the top triple tree before replacing the fork tubes? It makes sense, bc this ensures there isn't binding if the top and lower are slightly skewed from one another.

Patrick · « **Reply #18 on:** July 01, 2009, 12:48:04 PM »

Yes, it is normal to loosen the steering stem nut and the pinch bolt to put the fork legs in..That way you can make sure everything aligns before you tighten everything back down.

Patrick

mystic_1 · « **Reply #19 on:** July 01, 2009, 01:18:45 PM »

The tightening sequence is important, too. You want to make sure everything's square and aligned before tightening all the pinch clamps. Hondaman posted a procedure somewhere, anyone remember where it is?

mystic_1

Bob Wessner · « **Reply #20 on:** July 01, 2009, 01:31:09 PM »

Couldn't find Mark's but found this;

"FORK ALIGNMENT: Slick seals and trick fork oil will get you nothing if the forks are not aligned to prevent binding. The front fender must fit its mounting lugs on the fork leg. Use an adjustable wrench to bend the fender bracket around so that it is a slip fit between the fork legs; the mounting bolts must not have to force the fender out into contact with the threaded lugs cast into the fork legs. Similarly, the fender must slip between the fork legs without having to force it inward. Bend the fender stays so that, like the fender, they neither force outward nor inward on the fork legs. Completely assemble the forks, wheel and fender. Tighten only the bolts in the lower triple clamp and pump the forks vigorously 10 or 12 times. Tighten the top triple clamp bolts. Pump the forks again and torque the axle nuts and fender bolts. This procedure will ensure that the forks are in alignment and will operate as smoothly as possible. It should be performed anytime the fork is disassembled."

Part of the Motorcyclist Mag. article that Glenn posted here;

http://forums.sohc4.net/index.php?topic=38253.msg393997#msg393997

drdreas · « **Reply #21 on:** July 01, 2009, 07:07:24 PM »

Thanks for all the help guys. I loosened the steering stem nut and pinch bolt and the fork tubes slid right up. I must have bumped the bike and pushed the upper and lower triple trees out of alignment.

I followed the instructions to prevent binding when I reassembled and everything worked out.

mystic_1 · « **Reply #22 on:** July 01, 2009, 08:38:09 PM »

Excellent, glad you got is sorted.

mystic_1

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Author Topic: Can't get fork tubes back in! (Read 8505 times)