Warp11XX Posted August 11, 2010 Share Posted August 11, 2010 This is actually about a GL, but is general enough to apply across the board... Removed forks for bushing, seal, and dust cover replacement. Cleaned them, wiped dry, reassembled, and measured out the oil by volume...377cc's right leg, 372cc's left leg. Used the measurement markings on the Honda Pro bottle, so I'm estimating a tolerance of +/- 5cc's. Pumped the forks quite a bit to fill the valve chambers. Measured height is supposed to be 7.6 inches...I'm getting 6 1/2" and 6 5/8" respectively. What gives here? Is the critical factor volume or height in the tube? Secondary to that, my fork springs have been upgraded by the previous owner to what I believe is Progressives. As opposed to the stock drawings, I have two springs instead of one. They are not under the same load since the inside one is significantly shorter. The fork cap in place would leave an approximate free air gap of two inches. Should I shim the inside smaller spring to the same static compression height as the larger one when the caps are in place? Quote Link to comment Share on other sites More sharing options...
Zero Knievel Posted August 11, 2010 Share Posted August 11, 2010 Having just done it last winter, my 2 cents. Just go by volume measurement IF you are completely draining and cleaning the tubes. By the time you follow the instructions to get the air out, the height measurement is so close to specs it's irrelevant to worry about it. Quote Link to comment Share on other sites More sharing options...
Warp11XX Posted August 11, 2010 Author Share Posted August 11, 2010 The tubes and sliders were disassembled and drained 24 hours or more into a container. I did not disassemble the damper rods and oil lock mechanism, but wiped and dried throughly with clean rags. Very, very little residual oil was present at reassembly. Quote Link to comment Share on other sites More sharing options...
Zero Knievel Posted August 11, 2010 Share Posted August 11, 2010 The tubes and sliders were disassembled and drained 24 hours or more into a container. I did not disassemble the damper rods and oil lock mechanism, but wiped and dried throughly with clean rags. Very, very little residual oil was present at reassembly. If those are the parts I'm thinking of (cartridge inside the tube), you might be good to go. Just remove the bolt and take them out and clean them off. I tried to pump a bit of brake cleaner in them to wash out the old oil. Let them sit vertically overnight to drain any residue out. Quote Link to comment Share on other sites More sharing options...
Redbird Posted August 11, 2010 Share Posted August 11, 2010 If volume and air gap disagree, go with air gap. Quote Link to comment Share on other sites More sharing options...
Warp11XX Posted August 11, 2010 Author Share Posted August 11, 2010 So, I can pull the caps back off and remove the springs again to adjust the level to 7.6" by sucking out an inch worth of fluid. Not a biggie since I haven't put them back in the tree yet...but I'm not finding anything related to the spring setup I have in place. All the drawings and websites I've found show a single spring in each leg. Mine has two, one slipped inside the other, but the inner one being 5" to 6" shorter than the outer (Progressive?) at full expansion. When assembled, the inside spring would have approx. 2" of free space above it with the cap threaded all the way down. Would adding a CPVC shim that covers this gap be advisable? I just can't understand why there would be "free" space in the tube that isn't contacting the spring all the time. How about the extra displacement of oil from the "helper" spring? Is that a factor to consider in regard to oil level? Quote Link to comment Share on other sites More sharing options...
Zero Knievel Posted August 11, 2010 Share Posted August 11, 2010 So, I can pull the caps back off and remove the springs again to adjust the level to 7.6" by sucking out an inch worth of fluid. Not a biggie since I haven't put them back in the tree yet...but I'm not finding anything related to the spring setup I have in place. All the drawings and websites I've found show a single spring in each leg. Mine has two, one slipped inside the other, but the inner one being 5" to 6" shorter than the outer (Progressive?) at full expansion. When assembled, the inside spring would have approx. 2" of free space above it with the cap threaded all the way down. Would adding a CPVC shim that covers this gap be advisable? I just can't understand why there would be "free" space in the tube that isn't contacting the spring all the time. How about the extra displacement of oil from the "helper" spring? Is that a factor to consider in regard to oil level? I'd say forget about it. The fluid level is to cover the cartridge, not the springs. I doubt it makes any meaningful impact. Quote Link to comment Share on other sites More sharing options...
Redbird Posted August 11, 2010 Share Posted August 11, 2010 If I'm understanding your description correctly, it sounds like the second, internal spring(s) are kinda like helper springs on a truck- they don't come into play until the suspension is compressed enough to engage them. Never seen a set up like that on a bike, but I'd probably just assemble as it was and not sweat it, or remove them entirely. The volume of the extra springs will indeed affect the final air gap if they are not OEM- I have no idea what the math would be to correct for them. Maybe drop them in a graduated cylinder w/water, then do the math depending on how much of them are submerged in oil? Or you can just figure it's a freakin' GL1500 and quit sweating the details- it's gonna handle like a boat either way. Quote Link to comment Share on other sites More sharing options...
Warp11XX Posted August 11, 2010 Author Share Posted August 11, 2010 :icon_lmao: True dat ! It's even amazing how much it looks like a Jet Ski on steroids with the forks removed. You're correct in the helper spring idea...it makes contact after a little compression I'm sure. I'm guessing that it probably makes contact in static position parked. My guess is that they only lose contact when in full rebound ie: on a jack or front lifted. Maybe I'm trying to fix a problem that doesn't even really exist since I really had no complaints before the seals started leaking and I was ignorant of what was inside the tubes. Sooooo I'll set my oil to 7.5" in both legs tonight, put it back together, and call it the SS Minnow from now on... Thanks guys! I may be riding the rolling sofa again by the weekend... Quote Link to comment Share on other sites More sharing options...
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