Quote from: Jeff PI was planning on doing it without removing the forks.  I'm thinking I can use a jack to compress the forks while the bike is leaned back on the rear wheel.

You won't need a jack to compress a fork without a spring, you can slide it with your pinky finger. I would imagine that it is possible to undo both fork caps at the same time, but I am not sure how far forward the bike would lean and still be firmly planted on the center stand. It would be worth a few minutes to try to support in a manner to do it this way since you can do both forks at the same time.


It seems that checking the oil level with the forks still on the bike would be difficult at best. Just keep in mind that if the fork tube is not vertical, your reading may be off a little bit if you are not measuring exactly at the center* of the oil surface.


*Not meaning to start a debate as to the nature of surface tension and fluid dynamics of fork oil. Simply a reminder that if the fork isn't vertical, the fluid isn't horizontal.  

Ok I need some mid-job help!

Since I have the day off, I decided to go ahead and remove the forks completely.  Right now they're on the floor of my garage, with the end caps, seat washers, and stock springs and spacers out.  I've got two 0.75" pvc pieces to use as the new spacers.  The old fork oil is drained out.  I'm ready to go.  Except I'm not quite sure what to do about the new oil level.  The Haynes book says 99 mm, the install sheet from Progressive says 140 mm.  I'm assuming I should go with the latter?  The Progressive directions are really poorly written, you get a big bold disclaimer that it's just a "recommendation", but after that it definitely sounds like a solid instruction.  I'm gonna go ahead and fill it to 140 mm, but some feedback would be great.  Thanks,

jeff

Definitely go with what the haynes book says.  I'm not certain if those progressives are specific to our bike or not, but I do know that I did 99mm and it works great.  

info on how Kerry and I got the height correct on my forks is found Here

Uh, pardon my ignorance. Maybe this is a stupid question, but is that 99 (or 140)mm measure from the top of the fork to the surface of the oil, or from the bottom of the fork to the oil level?

Top edge down to the surface of the oil.

ok the bike is back in one piece.  I'll be taking it for a ride later today.  

I filled it up to 140mm, as the Progressive instructions said.  Getting an exact measurement was really easy with them off the bike.  I used a shish kabob skewer with a mark at 140mm.  Sounds like you got a good result by going with 99 mm richard, any idea how they'll act differently with 140 instead of 99?  Now that it's all assembled and back on the bike I figure it'll be easy to top it off if I need to.  

jeff

I can't say for certain, but I suspect you'll find that less fork oil == less dampening power on the front fork.  Since you've got it done that way, pay special attention to see if it seems to be "giving" too easily.  For instance, if the front springs bottom out going on or off a driveway, you need to add more oil.

Everyone I know who's reported doing it has used the 99mm number... never heard 140mm before.  let us know how it works!

(oh, and if you decide to top off, remember what Wrencher mentioned about it being a little inaccurate to do it with the fork slanted)

Just a note to say that I got the forks off and they are upside-down in a plastic bowl draining.  Some notes:

Total time to remove everything and lay the parts out on cardboard labelled "Left" and "Right" was 1 hour, 40 minutes.  But I was being very cautious.

It's hard to work on the fork caps without a friend to hold the handlebars out of the way.  I used bungy cords to pull them up towards the ceiling.

The Haynes manual says to remove the wheel, then the mudgaurd and brace, then loosen the upper pinch bolts and remove the caps.  It was about at this point that I realized my brakes were still attached to the right fork, and it was a bit dicey to remove those big hex bolts with the fork all loose.  I suppose that the Haynes manual says to remove the brakes as part of removing the wheel, but I have never needed to do that for wheel removal, so I hadn't thought of it.

The top pinch bolts were too hard to loosen using just a hex wrench.  I ended-up using a 6mm hex socket attachment and a large socket wrench on them.

The bottom pinch bolts were a tad difficult to loosen, without being able to brace on anything (no wheel, no handlebars, etc.).  But I used a long torque wrench and that worked well.

There wasn't nearly so much for oil as I thought:  it a gallon icecream pail, it only filled up about 2/3 inch counting both forks.

Keep track of approx how much fork oil you put back in...  if you feel like you put in much more than you took out, you were pretty low!

Just an interesting question.  I know one of mine was really low, and it was amazing to see how much better it felt after replacing it.

then after fixing the low tire pressure and removing the wrench from the back shock, it felt and turned like a whole different bike!  had to learn to corner all over again.

Quote from: richardKeep track of approx how much fork oil you put back in...  if you feel like you put in much more than you took out, you were pretty low!

I took out total 725ml out of both old shocks.  But maybe a few more ml. stuck to the springs.  I put in 400ml. per side to get the level up to where Progressive suggested (140mm below the top, compressed).  So I took out about 70ml less than I put back.

Quote from: richardI know one of mine was really low, and it was amazing to see how much better it felt after replacing it...then after fixing the low tire pressure and removing the wrench from the back shock

Man, the previous owner must have really abused and ignored that bike

BTW, my Haynes manual doesn't list any torque settings for the fork caps.  I've got them finger tight: using thumb and ring finger on only 4 inches of the wratchet.  If I had to guess, I'd say it's like 1 Nm of torque now.  Should I go tighter on those nice fine threads?


EDIT: I meant 1kgf, or about 10Nm.  NOT 1Nm.

If by fork caps you mean the caps on the very top of each fork (which would make sense, now that I think of it) Kerry and I measured the first time we removed the caps abt 30-35 Nm with a Tork wrench.

Quote from: Rema1000[ If I had to guess, I'd say it's like 1 Nm of torque now.

Oops, I meant 1kgf, or about 10Nm... about what I do for sparkplugs.  So it sounds like it should have been snugged down a bit tighter.  I've got the handlebars back on already, so I guess I'll just have to watch for leaking out the caps for a few rides.

By the way, I cut-down the stock spacers to 18mm (just shy of 3/4"). With the bike supported from underneath, and no weight on the handlebars, I was able to screw-in the caps without assistance.  It seemed easiest to press down on the cap with both thumbs, then rotate the cap, and stop if you feel any resistance (cross-threading).  You will not feel the resistance well enough if you're using a big 1/2" breaker bar on it!  It was difficult to tell if the threads were engaging: the first time they didn't, so when I let off the pressure after the about a full turn, the cap popped up.  But the second time, they engaged fine.  The threads gave almost no resistance to being threaded.

As Srinath has suggested, this may be easier with one person pushing down and another turning. But I had no trouble by myself, and I'm a lightweight.

My experience with the caps was that when I first tried it (when I installed progressives, but hadn't replaced the oil) it was a little bit difficult at first 'til I got the hang of it, then they weren't too bad.

the second time I tried it, I had the forks off the bike, and it was a piece of cake.

it's all in the angle and technique.  you really only need one or the other. =]

Huh? You can cake the caps off with the forks off?  The Haynes manual instructed loosening the top fork caps with the lower pinch bolts still tight... then before you pull the forks off, it says to remove the caps.  Then, the installation is the reverse.  

So I pulled the caps before I pulled the forks, and then inserted the oil-filled forks without any caps (!).  I was a little worried about crud falling down into the open forks during installation, so I got everything squeaky clean first.  

Sounds like maybe I should have just pulled and installed them with the caps loose, but still on the forks.

Yes, always loosen while they are still there... we made the mistake of forgetting to do that, and had to put it partly back on. =]  but to put them back on, it's easiest to put them finger-tight while it's off the bike, then put it on and tighen.

I just ordered a set of progressive springs and I'm trying to get a couple of things straight. The clymer manual says to measure the oil with the spring out and the shock compressed and to fill it to 99mm from the top. The progessive instructions say to fill them to 140mm from the top. If I go with 99mm, won't the larger springs displace more oil than the smaller stock ones?
Which measurement should I use?
Also, I'm planning on leaving the forks on when I install the springs. If I measure the oil at the lowest point, then measure the highest point, add the numbers then divide by 2, shouldn't that give me close to the same measurement as having the fork vertical?

Quote from: ekimIf I go with 99mm, won't the larger springs displace more oil than the smaller stock ones?

Yes.  Definitely.  I coudn't specify an amount in cc's or anything, though.

Quote from: ekimWhich measurement should I use?

Up to you.  We went ahead and filled to the 99 mm mark on Richard's bike.  The difference is 41 mm, or 1.6 inches.  That's a lot of oil to leave out!  (It's also a lot to put in, if it's truly "extra".)  If you're a lightweight you might split the difference.  Richard's a "healthy" kid weighing 200(+?) lbs and I think he likes the front just as it is.

Quote from: ekimI planning on leaving the forks on when I install the springs. If I measure the oil at the lowest point, then measure the highest point, add the numbers then divide by 2, shouldn't that give me close to the same measurement as have the fork vertical?

Makes sense to me!  The main "downer" with this method is that you won't be able to get the old oil out this way.  (How old IS the oil, anyway?)

When I put Progressives in my bike (this was before Richard came along and wanted to do it right on his bike  :x ) I just removed the top caps, exchanged springs, added a PVC spacer, and put the cap back.  Didn't measure the oil or anything.    But now that I've got a slight oil leak on one side I plan to take the forks off and perform "the works".  I'll probably change to 15W oil while I'm at it.  Besides, now I have THE TOOL....

EDIT: Changed link from sisna.com to bbburma.net.

Do replace all the oil, you should remove the forks. Check the modification manuals at www.bikepower.net for more info on installing progressive fork springs.