Recently I had a mechanic friend install new fork oil seals and dust seals. Now the forks bottom out way too easily. Initially I thought that he didn't put in enough fork oil. I had given him two 16 oz. bottles of 15W, and now have approximately 6 oz. left over. Then I thought that he didn't install the Spring Preload Spacers. I took off the Fork Cap Bolts, and both Spacers are there. The Clymer shop manual says that I should have 4.7 inches of fork stroke, but all I seem to have is about 2.6 inches. What could be wrong??? I appreciate any help.
What Clymer means by 4.7'' of fork stroke is the measurement from full extension to the bottom of travel. Now, once the bike is off the centerstand and you have you're weight on it, about 1 1/2'' or so of the travel should be taken up by static sag. That should leave plus 3'' of travel, give or take, to soak up bumps. The fact that you have less than that is evidence that the stock springs are as inadequate as their reputation suggests. Try a search for Progressive Springs. :thumb:
The forks didn't bottom out prior to having this guy replace the seals. I just measured the distance from the bottom of the lower triple clamp to the top lip of the dust seal. I get 4-11/16 inches. I would appreciate others taking the same measurement and then post their results. Thanks!
make sure he hasn't pinched ya progressives, if ya had them in, and put stocks back in :nono:
No I didn't buy progressive springs for this GS. I sure would like to have several of you take and post the measurement between the lower triple clamp and the top of the slider. I really need some help. Thanks!
Quote from: knowlseymake sure he hasn't pinched ya progressives, if ya had them in, and put stocks back in :nono:
how in the F can you 'pinch' the progressives????
Main Entry: 1pinch
Pronunciation: 'pinch
Function: verb
Etymology: Middle English, from (assumed) Old North French pinchier, from (assumed) Vulgar Latin pinctiare
transitive senses
1 a : to squeeze between the finger and thumb or between the jaws of an instrument b : to prune the tip of (a plant or shoot) usually to induce branching c : to squeeze or compress painfully d : to cause physical or mental pain to e (1) : to cause to appear thin or shrunken (2) : to cause to shrivel or wither
2 a : to subject to strict economy or want : STRAITEN b : to confine or limit narrowly : CONSTRICT
3 a : STEAL b : ARREST
4 : to sail too close to the wind
intransitive senses
1 : COMPRESS, SQUEEZE
2 : to be miserly or closefisted
3 : to press painfully
4 : NARROW, TAPER <the road pinched down to a trail -- Cecelia Holland>
- pinch pennies : to practice strict economy
I think he was using pinch with definition 3 a.
matt
So far Gisser has been the most help, but no cigar. The rest of you guys are hilarious. Gisser, Knowlsey, Chessy and Jasco, each of you go to your GS and take those measurements. Now come back and post them here.
Quote from: BUZZINSo far Gisser has been the most help, but no cigar. The rest of you guys are hilarious. Gisser, Knowlsey, Chessy and Jasco, each of you go to your GS and take those measurements. Now come back and post them here.
one of my seals are blown, else I would do it for ya... but as of now my bike sits too low cause only one fork is holding it up
Mine is a little less than 5 inches while sitting on the sidestand.
The fork tubes, not my ..... ;)
BTW...This '93 GS500 only has 8,700 miles on it. I can't believe that the stock fork springs would behave this way as was suggested by Gisser, indicating that the stockers need to be replaced. Also, I don't believe that either one of the springs are broken, since I had both of the top caps off, and I can feel spring preload pressure trying to reinstall the caps.
I can only conclude that the mechanic reinstalled something wrong while redoing the fork seals. Please post your measurements. The real measurements, as longer doesn't necessarily mean better. Does anyone have any suggestions???
Quote from: cheesyhow in the F can you 'pinch' the progressives????
Just a note, in the UK & Oz "pinch" means "to steal", not squeeze an item between something.
He was warning him to make sure the mech didn't rip him off and swap his springs. :o
Most likely when you had the forks service it reduced the STICTION which was not allowing the forks to operate smoothly.
I measured 5 and 1/8th inches from the base of the dust seal to the lower triple, but realize that is with proper static sag (sans rider) for my weight, 130#'s; and the forks moved down 1mm in the triples; Progressives with 3/8th inches of preload. Rider sag (with rider) is supposed to be 1.4 to 1.55 inches (this is to allow travel in the downward direction so the spring can push the tire down to maintain traction with the road when you crest a hill or over rough road surfaces, also helps eliminate headshake when the front end gets light).
26 oz. converts to 768cc's, or 384cc's per tube; recommended amount is 377ml (cc's) per leg (tube); so I think you're ok, there.
Static sag merely means with the bike at rest. Whether that means with rider aboard or not depends on who's setting up the suspension. I can't think of a reason for separating the two. But, yes, can't determine if BUZZIN has a problem if he doesn't clarify what measurement he's taking to get his numbers. :dunno:
Quote from: cheesyQuote from: knowlseymake sure he hasn't pinched ya progressives, if ya had them in, and put stocks back in :nono:
how in the F can you 'pinch' the progressives????
sorry i meant it as a joke (Pinched) stolen,,,,,,,,,,,,,,,,me from england. speak with Fn fork tongue
I took my measurements static (without a rider), on the right fork leg, while the GS is resting on the kick stand. It would be great if someone with Progressive Springs would take some measurements, as well as someone with stock springs. Thanks for your help!
QuoteIt would be great if someone with Progressive Springs would take some measurements, as well as someone with stock springs
Done already. You say 4-11/16'' for yours.
Jasco says
a little less than 5'' [per fork measure, not his unmentionable] and
scratch says a tick over 5'' with Progressive Springs. These measurements are all within the seal stiction margin of error. You might as well take your measurement on the centerstand with the fork fully extended and then another measurement with the bike off the stand and with rider aboard. You can take that measurement using a zip tie around the fork tube to mark the total sag. If the difference between the two measures is more than 2'' then you know the front is drooping too much. :cheers: [/i]
Quote from: knowlseysorry i meant it as a joke (Pinched) stolen,,,,,,,,,,,,,,,,me from england. speak with Fn fork tongue
No need for an apology! I dig intelligent regional phrases. Of course I've watched enough Brit TV to pick up a few terms.
I still haven't had a good defintion for a "toad in a hole" (a food item). :dunno:
Progressive springs installed by previous owner. ;)
5 1/8th between triple clamp and fork seals. Didn't do the centerstand sag trick noted above, but I could tonight if need be. Let me know.
Done already. You say 4-11/16'' for yours. Jasco says a little less than 5'' [per fork measure, not his unmentionable] and scratch says a tick over 5'' with Progressive Springs. These measurements are all within the seal stiction margin of error. You might as well take your measurement on the centerstand with the fork fully extended and then another measurement with the bike off the stand and with rider aboard. You can take that measurement using a zip tie around the fork tube to mark the total sag. If the difference between the two measures is more than 2'' then you know the front is drooping too much. :cheers: [/i][/quote]
We measured another GS with stock springs last night at 5 inches. Gisser, thanks, I'll give your suggestions a try tonight. I hope that you were right when you said that the stockers are probably shot. I ordered Progressive springs from Motorcycle Accessory Warehouse, and can't wait till they arrive. :)
Quote from: drvmystckProgressive springs installed by previous owner. ;)
5 1/8th between triple clamp and fork seals. Didn't do the centerstand sag trick noted above, but I could tonight if need be. Let me know.
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Mike, thanks for taking the measurement, and also for the personal e-mail message. I appreciate it.
"Toad in the Hole" If i remember mt childhood days right is a british sausage (kinda like our hot dog but better) stuck in the middle of yourshire pudding (kinda like bread not like our type of pudding)
for more info check out this link
http://www.uktvfood.co.uk/index.cfm/UKTVFoodpreview/recipes.newrecipe/ID/517456.shtml
Well I finally got new Progressive Springs in the bike, and it does ride a whole lot better without bottoming out. I believe the previous bottoming out problem is due to some extent to the junk stock springs, but mostly to the oil level. The Clymers shop manual calls for a volume of 382 ml (?), and also a measurement from the top of 3.9 inches. Since I didn't take the fork legs out of the triple clamps, I can only estimate a measurement of 11 1/2 inches from the top. Based on what was left in one of the bottles, I would say the mechanic put in approx. 13 oz. in each fork leg. Why the difference? Which one is correct?
The instructions with the Progressive Springs states not to exceed 5 1/2 inches from the top. I added some, and would guess that I'm at about 9 1/2 inches now. I'm using 15W fork oil. To me it seems like it could still be somewhat firmer. I was thinking of adding the balance of the open bottle to each leg, but not exceed the 5 1/2 rule. Should I go higher?
These measurements are usually taken with the spring removed and the fork fully compressed, which could make a BIG difference. If you try to use the same measurements on an extended fork you might end up popping a seal or something.
Quote from: KerryThese measurements are usually taken with the spring removed and the fork fully compressed, which could make a BIG difference. If you try to use the same measurements on an extended fork you might end up popping a seal or something.
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Thanks, I did have the springs out and propped up the front end to compress the tubes, and still had an initial measurement of about 11 1/2 inches from the top. Now I'm at approx. 9 1/2 inches, but think that the ride could be a bit more firm. Does anyone with experience think that I should add more oil?
First, I want to make sure that I understand how you're compressing the forks. They're still in the triple clamps ... I guess that's OK.
Have you removed the front wheel so you can compress the forks one at a time, or are you doing it some other way?
I have helped two different people install Progressive springs the "non-lazy way" by removing them from the bike, etc. The first guy (richard) is a pretty hefty kid, so we filled his spring-less, fully compressed, vertically oriented forks up to the 99mm level (same as for the stock springs; the 3.9" value you got from the Clymer manual).
For the other bike we filled to the Progressive-recommended level ... 139 or 140mm if I recall correctly. (Which translates to 5.5 inches.)
The only thing I can't remember for sure is how much oil we needed for the job. But I don't think we used more than 1 bottle for either bike.
So yeah, something is fishy. Maybe your mechanic swigged a few ounces by mistake? :dunno: Either that or there's a fundamental problem with the on-the-bike method of compressing the forks....
Quote from: KerryFirst, I want to make sure that I understand how you're compressing the forks. They're still in the triple clamps ... I guess that's OK.
Have you removed the front wheel so you can compress the forks one at a time, or are you doing it some other way?
I have helped two different people install Progressive springs the "non-lazy way" by removing them from the bike, etc. The first guy (richard) is a pretty hefty kid, so we filled his spring-less, fully compressed, vertically oriented forks up to the 99mm level (same as for the stock springs; the 3.9" value you got from the Clymer manual).
For the other bike we filled to the Progressive-recommended level ... 139 or 140mm if I recall correctly. (Which translates to 5.5 inches.)
The only thing I can't remember for sure is how much oil we needed for the job. But I don't think we used more than 1 bottle for either bike.
So yeah, something is fishy. Maybe your mechanic swigged a few ounces by mistake? :dunno: Either that or there's a fundamental problem with the on-the-bike method of compressing the forks....
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I did take the front wheel off, as my intention was to compress and measure the oil without spring one leg at a time. However, the the fork brace screw heads were starting to strip out, so I decided to compressed both legs together. I propped them up as high as they would go, unless it requires the compression of the rebound spring. If thats the case, then I have a measurement problem. Otherwise the only difference between vertical and lazy is that the oil level is not perpendicular to the sides of the tubes due to the fork angle. This only inhibits my ability to take a very accurate measurement, but it does get me in the ballpark.
Maybe the mechanic did take a swig of the fork oil. He is a little weird. This is probably why I haven't heard from him looking for payment for the work that he did.
Nope, compressing the rebound spring is NOT part of the procedure.
Are you measuring with something like a stiff wire? Theoretically you could take measurements along the highest and lowest slopes of the tube and average them, but it may not work very well in practice.
Anyway, if richard like his Progressive-based ride with the oil level at 99mm, I'm sure you can stand to add some more. You're close to twice, aren't you?
Just empty the bottle and call it good. ;)
Well, I just got done pulling the caps and springs again. Then jacked up the front end to compress the tubes and sliders. Took an initial measurement of about 9 1/2 inches from the top. I then found that I still had almost 7 1/2 oz. left from the second 16 oz. bottle of fork oil. This really tells me that the reason for bottoming out was due to low oil level. I raised the level to about 5 1/2, which is the maximum recommended by Progressive. And I still have 2 1/2 oz. left over. When you get this high in the fork tube, 1 oz. appears to raise the level by about 1.6 inches. I used the engine dip stick to measure. Just carefully point it down the center of the tube until the bottom side of the cap touches the top of the tube. Then measure down to where it's wet on the stick.
I put zip ties on each fork leg touching the top of the dust seal, and then went out for a ride looking for some bumps. I never bottomed it out, but I wouldn't say that the ride is stiff or hard at all. Actually I was looking for a stiffer ride. It's still too soft. The zip ties say that I compressed the forks 3 1/8 inches, so I must have come close to bottoming out.
Does anyone have any other ideas on how to make the ride more firm???
More firm? Or, more resistant to bottoming?
Remember, Progressive Springs are progressively wound
-or at least dual rate -to give a compliant ride over minor bumps and firm up after an inch or so of travel.
IIRC, you mentioned using 15-weight fork oil -which I find to be very firm.
If you add a bit more oil the fork will be more resistant to bottoming and won't affect the stroke much otherwise
due to the math involved in compressing air.
There's always heavier oil and if that doesn't provide a satisfactory result
the next step you could cut coils to increase the spring rate
and you wouldn't want to do that until after you've at least set your sag
and have thoroughly tested the setup.
Plenty of options, just on step at a time.
Quote from: GisserMore firm? Or, more resistant to bottoming?
Remember, Progressive Springs are progressively wound
-or at least dual rate -to give a compliant ride over minor bumps and firm up after an inch or so of travel.
IIRC, you mentioned using 15-weight fork oil -which I find to be very firm.
If you add a bit more oil the fork will be more resistant to bottoming and won't affect the stroke much otherwise
due to the math involved in compressing air.
There's always heavier oil and if that doesn't provide a satisfactory result
the next step you could cut coils to increase the spring rate
and you wouldn't want to do that until after you've at least set your sag
and have thoroughly tested the setup.
Plenty of options, just on step at a time.
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Gisser, is that what it is, the air gap is more compressable than the oil? So if I raise the oil level (less air) the ride should become progressively more firm. I calculate that if I empty the balance of my fork oil evenly into each leg (16 oz. in each), I should be at approximately 3 1/2 inches from the top. This is less than the stock recommendation with wimpy springs and spacers, and a lot less than Progressive recommends. Is there a chance that the seals will blow out? Would anyone recommend going this high?
Quote from: BUZZIN
Gisser, is that what it is, the air gap is more compressable than the oil? So if I raise the oil level (less air) the ride should become progressively more firm. I calculate that if I empty the balance of my fork oil evenly into each leg (16 oz. in each), I should be at approximately 3 1/2 inches from the top. This is less than the stock recommendation with wimpy springs and spacers, and a lot less than Progressive recommends. Is there a chance that the seals will blow out? Would anyone recommend going this high?
____
No harm in experimenting. Just suck out the excess if it doesn't suit you. Seals won't blow. I used to run 10 lbs. of air pressure in each leg of my older GS with no problem.