Forks update and a question

[11Rider]

Hi guys, I posted a few days ago that the forks on my '79 Special didn't seem to be operating too smoothly. I took them out, drained the fork oil and removed the springs. Once all the oil was pumped out thoroughly and the springs removed, each side of the fork worked very smoothly and quietly. I added 7.5 oz of fluid to each leg, and put the springs in and caps on. Both legs then got the original squeaky noise back - I'm assuming the springs are rubbing on the inside of the tube. Once the bike was reassembled they had quite a bit of stiction again along with the original noise. I checked the stanchion tubes for straightness too. Anyone else notice any significant squeak and or stiction? Is this anything to worry about??

[WMarshy]

How old are the seals in those forks? Maybe the need to be changed. How was the surface finish on the components, did the show any signs of metal to metal contact? If they were working correctly the shouldn't have any stiction...

[11Rider]

I didn't completely disassemble them but the tubes looked like brand new.

[79XS11F]

Is the flat washer or in some cases the plastic washer with the small hole in its center in place between the top of the spring and the fork leg cap?
Rob

[crazy steve]

The spring noise can be common, although are you sure you have the right springs? They should be only slightly smaller (about 1/16"+) than the inside diameter of the tube; POs have been known to do weird stuff, and if they're markedly smaller, you may be getting rattling.

As to the 'stiction'; if anything, used/worn seals should be loose. Remember though, these are also your front shock absorbers, so there should be some resistance to compression/rebound. Weight of the fork oil will affect this too; thicker-than-stock oil (10 wt is factory recommended) will stiffen up the forks.

Now, you say you didn't completely disassembled the forks. If you merely 'pumped' the old oil out, you may have left some gunk in there. Just pumping them won't always get all the crap out, so it's possible you may have something semi-plugged. Personally, if I don't know the last time a set of forks were serviced and the old oil is even slightly nasty, I'll fully disassemble 'em to be sure they're really clean.

Another issue; fork alignment. The Special forks are tough to get 'right' due to the setup procedure with the brakes, but if they're out of parallel to each other too much, you can get binding. If you need a lot of effort to compress the forks, check this. Sometimes a bike will be involved in a wreck and the forks get bent; they replace the fork tubes, but if the triple trees are tweaked, you'll have problems.

One other thing.... the factory manual only gives one fill amount, and doesn't specify if it's 'wet' or 'dry' (a shortcoming IMO). On some of my other bikes, they show the two different amounts, figuring that a simple drain will not get all of the oil out ('wet') while a total disassembly/cleaning will ('dry'). The difference on those is about 1-2 oz, and overfilling forks with oil will stiffen them up.

If the tubes moved smoothly in the lower sliders, you probably don't have any mechanical issues, so any problem is very likely to be an issue with oil flow/weight/amount.

'78E original owner

[11Rider]

To "79" - No, there is no washer of any type that was in the forks below the caps. I should be getting my manual any day in the mail and I'll check the exploded view. Thanks for that.

To "Crazy" - I was wondering about something similar, such as if there is a spacer missing or something on the axle. Again, I'll check when the manual comes in. Thank you very much

[natemoen]

7.17 US oz (212 cc) is what the book says for the amount of oil. So if you did not completely disassemble the fork and get everything out and then put 7.5 oz in it could be you just have to much oil in the forks.

[crazy steve]

....I was wondering about something similar, such as if there is a spacer missing or something on the axle. Again, I'll check when the manual comes in. Thank you very much

Here's a link to a fork alignment procedure that works every time...
http://www.xs11.com/forum/showthread...fork+alignment

The factory manual is completely silent on this too; another minor failing. An alternative 'check' for bent parts or binding can be done by getting the front wheel off the ground, removing the caps/springs, then moving the wheel up and down to see if it moves smoothly. On your Special, do this before you install the calipers. If it doesn't move easily, or you have 'sticky' spots, you have a problem.

'78E original owner

[11Rider]

^^^thanks!!^^^