Fork spring recommendations

[g.forrest]

i think you's all need to get out riding instead of all the BS analysis. one would think you's were riding for ranches. aint it riding season yet. all sounds more like cabin fever.

[docc]

Judging by the measurements, I think I was Wrong and the Ohlins springs would fit fine with longer spacers.

I would do what Ratchet said and just pull the springs.

 

 

No, really, I had the forks apart and the Ohlins springs don't fit. Something must be awry with the OD measurements on the springs They are a little funky to measure and I didn't retry as I was all anxious to get it back together to ride. Meeting some folks today for a painfully slow cruiser ride with a novice wife-rider in tow. But it is riding and her hubby is a fine fellow and a State Trooper. He actually let me go on a 64 in a 45 on the Sport before we met otherwise.

 

It is , as g.forrest has said, time to ride.

[Guest ratchethack]

. . .

I didn't like the Maxima 5wt oil I used. It was clear and colorless. Not hardly as interesting as the blue Silkolene I've used before. I'm looking forward to trying the synthetics. Are they more compliant?

 

I was surprised that the volume to set the 100 mm luftkammer varied from 355 ml to 300 ml from right to left. Made me feel like I'd screwed something up.

 

Before I'd used the volume measure ( to +/- 0.1 mL). I must have had much less air spring. Should that make the forks less harsh now ( with more air spring)?

Docc, I think you might be pleased with synth. 125/150 CARTRIDGE FORK FLIUD, as I've been, per many previous posts.

 

WRT 355 ml vs. 300 ml variance to get a 100 mm Luftkammer, I'd experienced much the same, therefore my many posts urging setting air gap vs. volume method. Hardly makes any sense to get accurate to +/- 0.1 ml when in practice, it makes you +45 ml and +100 ml over-filled, and 55 ml unbalanced right to left, eh?

 

Don't know HOW MUCH less harsh getting it right would make it, you'll have to give it a try. But I suspect A HUGE DIFFERENCE. You'll likely get at least as much an improvement as I did after discovering I was MUCH LESS OFF THE MARK than this and correcting it!!

 

Should be quite a positive change!

 

Gotta go ride a 500 km dingo fence now. . .

[docc]

Yeah,this is my fourth oil change and if I've overfilled them a little (or more) each time they've gotten progressively harsher with less and less air gap.

 

I've gotten somethng munted though. The rebound fork makes abit of a clunk when compressed and doesn't appear to be damping. I don't think I set the thread height above the blue lock nut correctly.I spun it all the way down then brought it back upto lock the cap.

 

Back to the shop now and try to sort it out.

[docc]

Less than a week to The Raid and I've had worse nightmares. Like when my high school girlfriend missed a period. Three times.

 

Indeed it appears the cartridge ( or some part of it) has 4 or 5 mm play up and down. The anchor bolt is tight. So tight , in fact, that it is no longer a hex drive. More of a round drive.

 

And 8mm is certainly bigger than a #5 screw extractor.

 

 

Where could the play be coming from and how in the world to get the thing apart now??

[Guest ratchethack]

. . .

Indeed it appears the cartridge ( or some part of it) has 4 or 5 mm play up and down. The anchor bolt is tight. So tight , in fact, that it is no longer a hex drive. More of a round drive.

 

And 8mm is certainly bigger than a #5 screw extractor.

Where could the play be coming from and how in the world to get the thing apart now??

Docc, I can't imagine wot's the cause of 4-5 mm play you've described.

 

But you've surely gotta have it apart now to investigate.

 

May I venture a guess that you've encountered the infamously destructive results of Craftsman notoriously undersized allen wrenches?

 

If so, my usual suggestion is to collect 'em all and pitch 'em in the trash and replace them with a properly sized, quality tool steel set.

 

Assuming your question "how to get it apart NOW?" is NOT rhetorical, I'd find a way to clamp up the fork and cartridge rod ass'y with bench vise -- and assortment of clamps if necessary -- and drill the head off with a 1/2" drill and sharp high-speed steel bit (of course). Since the bolt head's well buried in the recess in the bottom of the fork lowers, I reckon it's just about your only option.

 

Good luck.

[docc]

I was hoping to convert the thing to a Torx by hammering it in. A T50 is exactly 8mm so I'll have to go up a size. I'm not sure what that is in Torx. Even the body of the T50 I have is too large to insert in the fork's recess.

 

You're right about the Craftsman of course ( how'd you know that's what I used?)

 

Great Neck is even worse by far.

[docc]

I hate this. If it weren't for the internet I could have privately humiliated myself with my comedy of errors and never left the garage. Now the world knows. What a .

 

First, I'm not sure how the play got in the cartridge ( I don't remember ever breaking it down that far), but the foot valve was not seated in the bottom of the fork tube. Luigi maybe? But if so, what a Homer for me not to find it for 50,000 miles. Maybe it was tied down well enough and only recently rotated enough to start moving up and down the 4-5mm.

 

It gets worse. I don't care who makes your 8mm hex drive when the fastener actually is a T50 Torx. Sure the #6 screw extractor got it, but it was ugly.

 

And gets uglier. There's a set screw that keeps the anchor bolt for the cartridge. Did I say set screw? I meant SET SCREW. The screw doesn't show on the schematic and isn't mentioned in the manual's text. I'm sure any decent experienced technician would have known. Fortunately, I learned the delicate craft of tuning from the finest of sweaty, ham-fisted redneck tractor mechanics and got the thing apart in spite of how it was put together.

 

The Maxim oil looked really bad ( after 126 miles!!), so I'm glad it's gone and sorry it's still in the compression fork. The 5wt Silkolene is a synthetic, so I'm still uncertain about this whole "cartridge fork oil" thing.

 

So the Sport sits back on her own feet. Tomorrow I'll slip out and see how she feels.

[docc]

Judging by the measurements, I think I was Wrong and the Ohlins springs would fit fine with longer spacers.

I would do what Ratchet said and just pull the springs.

 

 

Dave,

 

Remeasuring with an alloy, analogue Vernier caliper I get the following values (not sure how they compare with what was posted before):

 

Outside diameter, Ohlins (Guzzi spec spring: 1.475 "

Outside diameter, Marzocchi spring ('00 Sport): 1.374 "

Inside diameter, Marzocchi fork tube 1.415"

 

As they say in gunsmithing,"go,no go."

 

I wish that they had worked. Now back to the archives for a source for good springs since my chance of losing 40 pounds is rather, ahem, slim .

[Guest ratchethack]

Hey Docc -- Glad to see you've rapidly moved well past anything like "analysis paralysis". Can't quite understand wot's going on, but sounds like progress, anyway.

 

It seems you'd mis-measured the Ohlins springs OD pretty substantially first pass. Your new ~+.100" larger measurement posted above clearly puts them outside of consideration for these forks. Too bad, but at least this is now understood and fairly well documented in case others may have the same inclination down the road.

 

My measurement of the Guzzi-issue Marz spring OD was within .005" of yours, which in my mind is well within an acceptable margin of mfg. tolerance for fork springs.

 

If y'er cooled off enough to think about this yet, I, for one, would appreciate a better understanding of this SET SCREW extravaganza you've encountered, which seems to've somehow become the object of y'er frustration. This may just be me, but I can't quite imagine how a set screw could have anything to do with the anchor bolt for the cartridge rod ass'y?

 

Not that I'm saying it doesn't exist -- please! -- I just don't recall a set screw from having my cartridges out several times, and certainly didn't either fiddle with one on the cartridges, nor would I have had any reason to, since I've been very pleased with the action of the Marz forks, an have developed no motivation a-tall for re-valving or mucking about with emulators.

 

It's encouraging that you seem to be gaining the upper hand here, my friend.

 

In the interest of furthering me own education, I'd certainly appreciate any further thoughts by way of clarification on wot the problem was WRT the set screw and anchor bolt situation, and an understanding of how a 4-5 mm slop came into play here -- that is, of course, if y'er up to it. . .

 

TIA

[docc]

The 'foot valve' is the bottom of the cartridge assembly which bolts securely (or not) into the bottom of the fork tube with an anchor bolt which is inserted from the underside, its T50 Torx head recessed up in the bottom of the fork strut (which is attached to the tube and mounts the axle and caliper). The foot valve has a hex head which drops into (or no) a hex recess in the bottom of the fork tube allowing the cylindrical case of the cartridge to shoulder securely (or not) to the bottom.

 

Apparently, this foot valve never dropped into engagement in the hex recess. Eventually it bounced about and rotated enough to line up and fall in which introduced the play. Perhaps this occured when I was monkeying around trying to remount the spring and spacer. Peering down into the tube it was apparent that there had been some banging about But probably not for more than the 126 miles of the morning ride. The hex on the foot valve is aluminum so it couldn't have stood up to those kinds of tolerances for long.

 

One of the mysteries is I don't recall removing the cartridge in the four oil changes I've done. If it was done by Marzocchi, you'd think my damping will be much improved.

 

The front fork diagram in the workshop manual at F26 does not show the bolt (or 'screw') which goes up into the bottom of the fork strut/tube (23), nor does it show the set screw which anchors the head of that bolt and inserts through a 5mm threaded hole inboard and above the axle. Like a dope I thought it was just a casting feature. Being inboard the hole was mucked in and the tiny hex head recesses probably 3 or 4 mm.

 

Even after forcibly turning the anchor bolt (gouging the head circumferentially) I had to drive the bolt out from the inside (marring the head longitudinally), such that I am certain the set screw does indeed act as a keeper for the head of that bolt.

 

The whole thing has been a menagerie of , , and

 

 

followed last night by and this a.m. by and

[Guest ratchethack]

Merdre!

 

Thanks for the explanation, Docc.

 

IMHO this is an important discovery, my friend. A careful review of all the procedures, drawings and photo's in the Service Manual, including a detailed engineering drawing of the entire fork, shows nary a trace of the set-screw -- as you said, no mention wotsoever.

 

However, looking very closely at the engineering drawing on p. F28 of my manual, there is shown a channel (not shown threaded) in cutaway view, and in a 90-degree view, a tiny hidden hole!

 

With inspection mirror and flashlight, I was able to find the bugger on both inboard flanks at the bottom of my fork lower castings, exactly where the drawing shows it.

 

I probably assumed as you did that they were a remnant of the casting process.

 

This explains why I recall a little difficulty with removal of the anchor bolts, though in my case, somehow it evidently wasn't as much of a problem as it was in yours!

 

I'm afraid wot we have here is yet another inexcusable omission from the Service Manual.

 

It will not be overlooked next dismantling!!

 

Thanks again!

 

EDIT: With a 2.5 mm long-handled allen wrench, I was able to tighten both of the set-screws -- one by 1/4 turn! Evidently, I'd worn the contact points on the set-screws down on the circumference of the anchor bolt heads. . .

 

EDIT #2 -- Good thing you discovered your foot valve wasn't seated after only very low mileage -- this could've got nasty.

[docc]

 

 

EDIT #2 -- Good thing you discovered your foot valve wasn't seated after only very low mileage -- this could've got nasty.

 

 

I'm not now entirely sure it was so recent. I rode to town to get an extra quart of oil and noticed a change pulling in the parking lot over a seam.

 

Always, well for as long as I can remember, the front end would make a 'plinck' when bumping a sharp edge at low speed. I never could find it and finally assumed it was play in the Heim joint for the steering damper.

 

It was so surprising today not to hear and feel it! I rode around town bumping through rough pavement before coming home.

 

The Sport is now sorted for the South'n Spine Raid. It's amazing what valve adjustment, plugs and a throttle body synch will do. Shifted into second at about 7000 rpm and she snatched the front tire off the road!