Adjusting Forks

[DenzComp]

Hello-


I recently rebuilt my bike.

I read the brochure for the 78 on this forum. It states that you can adjust the forks using only a screw driver.

Where exactly do you do this at? Right at the top under the rubber caps? I didn't want to start messing with stuff until I knew for sure.

And if that is the correct location how do I do it? Just turn it with a screw driver?

On my old forks...the screw was almost flush to the top...on these ones...they're down in aways.

It rides rougher than it did... so I'd like to put them where the old ones were.

Thanks in advance,
-Dennis

[DenzComp]

Also....what setting would be recommended for a single rider....180.

Thanks.

[Pat Kelly]

Under the rubber caps at the top of the forks is where the adjustment is. It takes a very large screwdriver. You press down then turn the screw to change the preload on the spring. There are three sholders on the adjustment (much like on the rear shocks) and each one compresses the spring a half inch or so. Adjust both to the same setting.
As far as the setting, it would depend on how much the springs are worn (they've been holding-up the bike for 30 years), your weight, load weight (have a fairing?), and your personal taste in the feel of the bike.
If it is needed, you can upgrade to Progressive Forksprings (can be found at www.denniskirk.com). These give a nice feel to the front end and along with a fork brace (www.tkat.com) will adress most front-end issues that are inherent with these bikes.
It could be that they are already adjusted to the max preload which could make for a harsh (stiff) ride.

[DenzComp]

Okay....thanks.

I was pretty sure that's where they were supposed to be adjusted...just wanted to be 100%.

[DenzComp]

I just went out and got them to move. I turned them so they were all the way up like my old ones....

I'm still having a problem....I push down on them and they stay half way down...I have to pull up on the bars to get them to raise...

What would be causing this problem? Worn out springs?

They feel fine going down..just don't wanna come back up...maybe its just from sitting....

[Pat Kelly]

That is called "stitchion", something is making them grab. Looks like it's time to rebuild the forks.
It is possible that the bushings are worn but I don't recall anyone on this board having to replace them.
Search the forum, the subject has been discussed at great length. The main topic is getting the allen bolt out on the bottom of the forks. I personally have had sucess with the broomstick method .
Drain the fork oil (drain screw near the axle). Remove the fork cap. Remove the lower fork leg (see allen bolt refrence above). Replace the fork seal (consensus here is that OEM fork seals work best, YMMV). Reassemble, refill with new fork oil. Enjoy.
The repair (not owners) manual describes the proceedure quite well (you have a manual, right?).

[DenzComp]

Yeah...I have a Clymers....that's what you get when you buy forks off eBay I guess...

[DenzComp]

Would the tubes that the headlight is hooked to be enough to grab?

I forgot to put in those rubber gasket things that are at the bottom of those tubes...

I tested the forks before I installed them and they worked fine...

Maybe they are catching there....

[DenzComp]

The clymers said all I have to do is remove the top nut...and open the drain screw on the bottom. Push up and down a few times to get all the old fluid out....close the drain and refill with 7.17 oz of SAE10W fork oil.

And replace fork seals....they're just the rubber dust cover things on the top where the tube enters the bottom part right?

It doesn't seem like my drain is an allen...it's a Phillips head...
Is that all there is to it? That should fix the problem?

[Erik the Red]

Originally posted by DenzComp
And replace fork seals....they're just the rubber dust cover things on the top where the tube enters the bottom part right?

It doesn't seem like my drain is an allen...it's a Phillips head...
Is that all there is to it? That should fix the problem?

You're just looking at the dust covers. Pull those off, and you'll see the actual seal underneath there.

Drain is a Phillips head screw; the Allen is inside the fork tube -it can be very stuck. I had to use this Fork Tool <--(click here) to get mine apart. Compressed air tool on one side in combination with the fork tool from the inside... Look at your Clymers and you'll see what I mean.

I'm thinking that it'd be best to take it all apart to make sure nothing is bent or dragging on the inside. Then replace any seals that aren't doing their job while it's apart.

[DenzComp]

Well I emailed the guy I bought them from on ebay. He sells a bunch of bike parts and said that he normally drains the oil before shipment.

I'm assuming that's all that's wrong. I'll pick some up tomorrow and fill er up.

[gixxer]

Now that I have my air cap back off of the roof...

My bike is an 81 H. It has standard forks with air caps on the top of the forks not just a rubber cap. After reading through a bunch of these posts I decided to have a look underneath the caps for the little screwdriver tension adjustment. I was unscrewing the cap when it let go and flew 50' in the air as the spring came out of the fork about 8" behind it! Shouldn't there be something holding that spring in there besides the air cap?

[Ken Talbot]

Re: Now that I have my air cap back off of the roof...

Originally posted by gixxer
Shouldn't there be something holding that spring in there besides the air cap?

Gravity maybe? No, as you have discovered, there's nothing else holding the spring in there.

As you have probably guessed by now, getting the cap back on with the spring in place is a bit of a chore. You will need to block up the front end to take all weight off of the front wheel. Then, getting the fine aluminum threads of the cap to bite into the steel threads of the top of the fork tube, without cross threading, is tricky.

You'll want to push against the spring while slowly turning the cap counterclockwise. Listen and feel caefully to detect when the cap drops just a hair, indicating the start of the cap thread has just passed by the start of the tube thread. Keep an even pressure against the spring, and begin turning clockwise to get the two threads to engage. If it feel at all like it is binding, back it off and try again.

It is a good idea to practice this before you put the spring in. Work the cap slowly CCW until you feel the drop, maybe even use a sharpie to mark the magic spot. Turn CW to feel how the thread should feel so you can look for that same feeling with the spring in place.

BTDT...

[gixxer]

Weird setup, certainly makes me not want to take it apart again. I did finally get it back together but not without a struggle! Thanks Ken. I'm thinking that maybe what I should do to change the fork oil next time is just remove the core from the air valve and squirt the fresh oil in there instead of having to retrieve the air cap from the roof.

[Ken Talbot]

Here's how I change fork oil . No parts on the roof!