arcticflipper Posted June 16, 2006 Share Posted June 16, 2006 Is there anything that could co wrong with the fork dampening? How do I test to see if it is still working fine? I've read about valving, is this something that could pop out under heavy riding? Reason for the Q, the front feels like it's coming back up way too quickly. Maybe I'm imagining stuff, but is there anything I can check just to be sure? I've also noticed a scratching noise from the right front fork, when ever it is used. Any ideas? Quote Link to comment Share on other sites More sharing options...
Redbird Posted June 16, 2006 Share Posted June 16, 2006 Damper rod may have come loose from the fork cap. Possible, but not likely if it was assembled correctly. The problems wouldn't only be on rebound, but there would certainly be problems, and probably more severe than you describe. How old is the fork oil? BTW, it "damping", not "dampening", unless you're talking about washing the bike or something. edit- that should have read "wouldn't" only be on rebound, as it does now. Quote Link to comment Share on other sites More sharing options...
arcticflipper Posted June 16, 2006 Author Share Posted June 16, 2006 Thanks RedBird.. I just dropped the front forks out to see if there's a difference. The one feels more oily than the other one, and also softer. Not a lot but still softer. There's no oil pushing out that I can see through the oil seal. If I replace a fork seal, do I do both at the same time or just the damaged one? I will check the air space now, and see if the one has less oil in it than the other. Could this perhaps also be the cause of my tank slapper? not really a tank slapper, but rather a serious vibration on the handle bars. I changed the fork oil about 15 000 km or 9322 miles ago - when I had the forks done. Would track riding cause more and quicker wear on the fork oil and also perhaps be the cause of the one fork being more oily? The track I normally ride is mainly right turns, which is also the fork that feels more oily and is also softer than the other. Quote Link to comment Share on other sites More sharing options...
G2 Posted June 16, 2006 Share Posted June 16, 2006 Thanks RedBird.. I just dropped the front forks out to see if there's a difference. The one feels more oily than the other one, and also softer. Not a lot but still softer. There's no oil pushing out that I can see through the oil seal. If I replace a fork seal, do I do both at the same time or just the damaged one? I will check the air space now, and see if the one has less oil in it than the other. Could this perhaps also be the cause of my tank slapper? not really a tank slapper, but rather a serious vibration on the handle bars. I changed the fork oil about 15 000 km or 9322 miles ago - when I had the forks done. Would track riding cause more and quicker wear on the fork oil and also perhaps be the cause of the one fork being more oily? The track I normally ride is mainly right turns, which is also the fork that feels more oily and is also softer than the other. Remove the fork caps, check to see if the rod is still screwed into the cap and the jam nut isn't loose like Tim suggested. If all is good, loosen the jam nut and unscrew the caps from the rods and remove the spacers and springs. Fully compress the forks and measure and compare fork oil height. I think 142mm to the top of the tube is stock. At this time you can compare the "feel" of the damper by pushing in and pulling out on the rod. There should be much more resistance on the rebound stroke. (if there is enough oil ) I'm guessing if a fork seal is leaking then you aren't compressing any air in the fork (and may have lost some oil) and that is the reason for the soft feel. Who did your forks? Quote Link to comment Share on other sites More sharing options...
dunedain Posted June 16, 2006 Share Posted June 16, 2006 Thanks RedBird.. I just dropped the front forks out to see if there's a difference. The one feels more oily than the other one, and also softer. Not a lot but still softer. There's no oil pushing out that I can see through the oil seal. If I replace a fork seal, do I do both at the same time or just the damaged one? I will check the air space now, and see if the one has less oil in it than the other. Could this perhaps also be the cause of my tank slapper? not really a tank slapper, but rather a serious vibration on the handle bars. I changed the fork oil about 15 000 km or 9322 miles ago - when I had the forks done. Would track riding cause more and quicker wear on the fork oil and also perhaps be the cause of the one fork being more oily? The track I normally ride is mainly right turns, which is also the fork that feels more oily and is also softer than the other. Track riding will indeed wear your fork seals, bushings and oil more. There is really no connection with the right turn track and right fork having trouble. Since they are bolted together in the tripple and you got a hard axel then it becomes a signle system. Thats why the pro's often times put a 0.90 spring in one tube and 0.95 spring in the other so they can get to a 0.925 spring rate. If your hard riding it's time for new oil. When you had the "forks done" did they work on the valving for you? Vibration in the bars? I'd check tires, steering head bearings but you could have some suspension issues adding to this problem. I think you'll have to buy fork seals as a pair so might as well replace them both. I doubt if you blew shims off the stack. When you say one feels more oily than the other does that mean you got oil on the slider tube? If so then you got a leaky oil seal which should be evident by poppig the dust seal off. So when you push down on the fork tubes do they spring back the same? When you turn them upsidedown and listen to them as the oil trickels to the other side. Do they each sound the same? Have you lost a lot of weight lately? Quote Link to comment Share on other sites More sharing options...
arcticflipper Posted June 18, 2006 Author Share Posted June 18, 2006 I checked the oil level and airgap on both - 143mm exactly. Cleaned off the forks and checked to see if there's any oil deposits after some riding. Nothing. I'm now not sure anymore if it is the front or the rear that is causing the problem. I completely lost it today in a high speed corner. Doing 260 + kph turning right the rear stepped out, started of feeling like a speed wobble, and then it just kept running wider. Dropped a knee out to try and get the bike to keep it's line, nothing changed. Also counter steered completely, with no improving the line. It's a corner I know very well, and have run previously at much higher speeds than I did today. The guy behind me said it looked like the shake came from the rear, but I'm not sure? I think I will change the front fork oil just to be safe, and also have teh rear shock checked. I do know that I 'm due for a rear tyre, which might also contribute to the problem? Pumping the dampning rod on both the shocks felt very similar, but once everything is assembled the right fork feels spongy, springy in a way. As if the dampning isn't there. It returns quicker with no visible slowing down to the original position. I'm not getting any bottoming out on the front or rear. Turned the dampning on the rear OEM from hardest out 2 turns. Seems a little bit better with holding the line, but still gets the arse wobbling. Tyres? Pressure is 2.9 kpa front and rear, checked the wheel bearings - seems fine, checked the steering bearings, and torqued to the correct settings. Weight is still the same as before - 70 KG's about 155 pounds I think. Is it possible that the dampning spring could be worn out? What does this spring do? Quote Link to comment Share on other sites More sharing options...
arcticflipper Posted June 18, 2006 Author Share Posted June 18, 2006 So now after all this testing and checking etc. It struck me that I never checked the load and static sag on the bike. I know fucking newbie.... :icon_doh: So after checking this I found that the current setup is so way out that an elephant could ride the bike and it might be closer to what it's supposed to be. I've changed the majority to get it as close as possible, but still need to do the rear OEM shock. That thing's a bitch to try and turn. How do you guys turn the spring in or out? Clamp the spring and then turn the rings in? I tried the hammer and drift thing - I know fucking animal :icon_duh: but that became too painful for me to do, so I rather left it. I could still not get the rings o turn in any case. End result - front is sitting on 43mm with the rear at 38mm. Front sounds ok, I could possibly still drop the front yokes about 2mm to help bring it further into spec, but I first want to ride and test it again. This is most prob the reason for my gt stipes down my pants this morning.... I Quote Link to comment Share on other sites More sharing options...
bartonmd Posted June 18, 2006 Share Posted June 18, 2006 260kph!! That's like 150mph right??? No thanks man. BTW, to adjust the rear preload, what the majority of people I know had to do was take the shock out of the bike and put it in a bench vise and use a hammer and drift on it (preferably a brass drift) to get the lock ring loose, then it the other ring just turns with a spanner like most other shocks... Remember that it's something like a 5:1 ratio, so if you need to have 5mm less sag, you only need to move the spring preload up about 1mm to get the desired effect. for the front, you just add washers on top of the spring to add preload, but if I recall, it's not quite a 1:1 either, but possibly like a 2:1 (this is just what I've heard, I put mine together and happened to have the right amount of spacer the first time following Race-Tech's directions, so I've not had to adjust mine. BTW, did I hear you say that there was to much sag on the hyperpro springs out of the box, without setting the sag, even on a 150lb rider?? COUGHhelvet COUGHhelvet Mike Quote Link to comment Share on other sites More sharing options...
arcticflipper Posted June 19, 2006 Author Share Posted June 19, 2006 Nope sorry, not on HyperPro's here. OEM's Got hold of a second fork set, and tried these - looking to trade the current XX in on a newer one, well one with lower miles on. Haven't been able to find something else to replace the XX with yet. My usual forks is setup with wilbers springs and valving. Much better, but these I'm transferring to the newer XX. No fucking way I'm selling those!!! What is the normal figures for the sag? Front and rear? Actually is it better to have it closer to the beginning numbers, like 35mm front and 30mm rear or more towards the end? What have you guys found works better? Quote Link to comment Share on other sites More sharing options...
bartonmd Posted June 19, 2006 Share Posted June 19, 2006 "standard" sag is usually 1/4 to 1/5 of the total suspension travel, so on the XX, ~25-35mm is what I've heard... Mine is set up around 30mm... Mike Quote Link to comment Share on other sites More sharing options...
OZDave Posted June 19, 2006 Share Posted June 19, 2006 I'd go as far as a third of the travel on the front (fast road, not track). Mine is set for about 37mm. However I have 1kg Eibach springs and valving changes too. This changes everything when setting up suspension, compared to stock. About 35mm on the rear, but I have a Wilber shock set up for my riding contitions. Quote Link to comment Share on other sites More sharing options...
arcticflipper Posted July 5, 2006 Author Share Posted July 5, 2006 This has been bothering me a bit, and after another trackday I found that the front tyre wore excesively. It cupped way to fast on the track. So I then turned back to the front suspension and stripped the forks completely, even the valving. Cleaned everything with a fine comb and check everything 3 times. The valving was clogged up by fine dirt and some metal chafings. No wonder the suspension wasn't feeling right. Managed to clean everything out, and also managed to put it all together the same way it came appart. Feeling pretty chuffed with myself, and I can say that there has been a major improvement in the bikes handeling. I went with the 7.5W fork oil, instead of the 10W Honda OEM fork oil. The bike feels like it is gliding, no more hard knocks or bumps. Did another trackday, and checked the wear pattern on the front wheel - no uneaven wearing down anymore, did notice that the rear spring was set a tad too hard - to compensate for the panniers. Guess this will have to do, or I need to do the trackday with the panniers fitted... :icon_doh: Quote Link to comment Share on other sites More sharing options...
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