Semi-retired Posted January 20, 2015 #1 Posted January 20, 2015 I try not to start quite as many posts as I used to with the fatal..."Am I going crazy, or....blah, blah, blah"......because as often as not, it turns out I AM going loopy. My latest conundrum, is that I've suddenly realized my front end hasn't had its forkoil changed in probably......well, EVER! Reading the post on the Venturers site, copied "here" by Freebird, at http://www.venturerider.org/forum/suspension-tires-handlebars-etc-/57207-changing-fork-oil.html, I see a notation that the original author planned to "up" his fork oil from W5 to W15. Now, THIS is the part where I would normally ask the proverbial question.......but I won't, because someone (I hope) is going to have a perfectly LOGICAL answer for me. Nonetheless, doesn't it seem a "little strange" that TRIPLING the viscosity of the oil in something as sensitive an instrument as a hydraulic fork tube would be even considered a suitable modification? I'm thinking that even DOUBLING it to 10-weight might be a bit radical.....but, tripling it? Comments?
BlueSky Posted January 20, 2015 #2 Posted January 20, 2015 My Kawasaki ZN700 called for 10W20 weight SAE motor oil. The second time I replaced the fork seals instead of buying the expensive fork oil, I just bought 5w30 Walmart engine oil and used it. Seems to work fine. The thicker the oil the slower the fork will react to a bump.
utadventure Posted January 21, 2015 #3 Posted January 21, 2015 A couple of years ago I installed Progressive springs and changed the oil and wanted a slower recoil. The oil was 10 weight but I wanted to step it up slowly. I mixed both 10 and 15 together for a 12.5 weight. I was happy with that call. The question how much change do you want?
BratmanXj Posted January 21, 2015 #4 Posted January 21, 2015 250 lb guy and ride somewhat aggressively, usually loaded or 2up. I went 15w to quell some dive and front wheel chatter. So far so good on this bike. The last bike (C10 Concours) I went from the factory 10w to 20w, and the HD Road King from 5w to 15w.
djh3 Posted January 21, 2015 #5 Posted January 21, 2015 I changed mine this fall. I went with the 10w oil and am happy with it. I can reduce to amount of air in front shocks now as the oil increases the compression.
Semi-retired Posted January 23, 2015 Author #6 Posted January 23, 2015 A couple of years ago I installed Progressive springs and changed the oil and wanted a slower recoil. The oil was 10 weight but I wanted to step it up slowly. I mixed both 10 and 15 together for a 12.5 weight. I was happy with that call. The question how much change do you want? I'm less concerned with "change" per se than I am in just making sure I've got sufficient QUANTITY of oil in there. It's when I started researching the correct emptying/measuring/filling procedures that I immediately came across the post from Venturers that was not only COPIED into our forum....but STICKY'd there.......so, I started wondering how "gospel" and/or widespread the concept of "tripling up" the viscosity had become......amongst other users. I'm a little guy (175lb) in comparison to many of us........and I always ride solo.....with a "modicum" of luggage........so.......I was thinking the factory spec should be entirely adequate for me. Yes/No?
Semi-retired Posted January 23, 2015 Author #7 Posted January 23, 2015 My only concern THERE would be that I know it's sometimes difficult (depending on the pump and or gage) to put in very low pressure readings.........and I figured it's hard enough to get SIX pounds accurately.......without whittling it down to THREE! (Course, I don't have the correct pump OR gage yet.....so, maybe it's easy! :-)
Rolltide Posted January 24, 2015 #8 Posted January 24, 2015 Changing the fork oil was on my list of "needs done" this winter. I went with 15w synthetic and I was looking to slow down the nose drive under braking. I run with 0 air in forks also. I'm very pleased with the results. As far as how much oil to refill with it takes 552cc in each fork. I bought a tool for this from Dennis Kirk and made it very easy.
BlueSky Posted January 24, 2015 #9 Posted January 24, 2015 Changing the fork oil was on my list of "needs done" this winter. I went with 15w synthetic and I was looking to slow down the nose drive under braking. I run with 0 air in forks also. I'm very pleased with the results. As far as how much oil to refill with it takes 552cc in each fork. I bought a tool for this from Dennis Kirk and made it very easy. 552 cc equates to 16.3 ounces so just use your wife's measuring cup!! Don't let her catch you!
Semi-retired Posted May 14, 2015 Author #10 Posted May 14, 2015 Just call me "Mike the procrastinator".......but, as it turns out, I am just NOW getting around to being in a position to actually change my front fork oil. The reason for NOW?? A new front tire has just been installed on my front wheel....and the wheel is yet to be re-installed on the bike....so it's kinda now or never (figuratively) for changing the fork oil. Do I ..........or don't I? Pros....(reasons TO do it) 1. The bike is 10 years old 2. It's got 55,000 kiloometers on it 3. "They" say it "should" be done 4. The wheel is off, providing optimal access to the drain plugs Cons......(reasons NOT to do it) 1. Someone stated that YAMAHA says it's not necessary 2. I've not had any "ride" issues such as bouncing, bottoming, plunging, whatever 3. It's a pain in the ass and will cost me a couple of days off the road, $20 in oil and probably a skinned knuckle However, I'm "leaning" toward doing it, so, a coupel of questions: 1. What percentage of people who HAVE done it (themselves) switched oil types rather than going with the stock 5 weight? 2. What household implement was used to feed the new oil into the tops of the forks. (or....in the event that the turkey baster's nozzle is too big.....which I suspect it is).......what can I buy........cheap, like me.....that will do the job? Thanks, guys.
djh3 Posted May 14, 2015 #11 Posted May 14, 2015 A large syringe from like fleet and farm they have for large animal vacinations.
wizard Posted May 14, 2015 #12 Posted May 14, 2015 I did not know about the drain plugs. Where are they?
Ace Posted May 14, 2015 #14 Posted May 14, 2015 I have changed oil in the forks in both my RSV's to a heavier oil. When I had my 06 I went up to 20 wt and found it just a tad stiff for my liking but the handling improved. On this 2000 MM Ltd I changed it to 10wt, I found it a bit better than the stock 5 wt but will be going to 15 wt on its next change.
Semi-retired Posted May 14, 2015 Author #15 Posted May 14, 2015 Anybody know the exact head size of those Allen bolts? I put the closest one I have up there and it felt just a tad loose. Some people are suggesting you wanna rap them a bit to loosen them up first......so, for SURE I don't wanna use an UNDERSIZED wrench (by half a mil or something) and strip the hole! Thanks for any info.
Prairiehammer Posted May 14, 2015 #16 Posted May 14, 2015 Anybody know the exact head size of those Allen bolts? I put the closest one I have up there and it felt just a tad loose. Some people are suggesting you wanna rap them a bit to loosen them up first......so, for SURE I don't wanna use an UNDERSIZED wrench (by half a mil or something) and strip the hole! Thanks for any info. "...6mm Allen head socket with a long reach to access the damper bolt itself." http://www.venturerider.org/forum/showthread.php?57207-Changing-the-Fork-Oil
Semi-retired Posted May 14, 2015 Author #17 Posted May 14, 2015 (edited) Thanks, Kev. And your recommendation for oil? Any point dicking with the 5 weight? I still find it hard to believe that folks on this forum figure TRIPLING the viscosity of a fork's oil is OK. Make any sense to anyone else? (I mean, Yamaha KNEW this bike weighed 869 lb when they built it. They built it for the North American market......therefore they KNEW the average rider would weigh 190...that his wife, sitting on the "included" rear seat would weight 150.....that THEIR combing luggage in the STOCK bags would weigh another 50 lb. Why would anyone think the engineers screwed up the fork oil viscosity requirement by a factor of 200%? Edited May 14, 2015 by Semi-retired
Motiv Posted May 16, 2015 #18 Posted May 16, 2015 Anybody know the exact head size of those Allen bolts? I put the closest one I have up there and it felt just a tad loose. Some people are suggesting you wanna rap them a bit to loosen them up first......so, for SURE I don't wanna use an UNDERSIZED wrench (by half a mil or something) and strip the hole! Thanks for any info. As noted previously it is a extended 6mm allen socket you will need. Those are NOT drain holes in the bottom of the forks, they hold the internal damper rod in place I can see them being used as drain plugs though and things should not fall out of place as long as you leave a few threads in the damper rod then remove the spring caps and push up on the bolts to let ALL the oil drain out. Consult the exploded view in your manual to see what I am talking about. I had to replace one of those bolts because it almost rounded out on me, ended up using an impact driver to remove it. My bike has 37K mi on it and the oil was very dirty as well as all the internal parts. This was done because I wanted to replace the fork seals as a preventive measure due to age. I also used a 500 ml graduated cylinder to add 553 ml of oil to each leg. I recommend taking the forks apart to do a full internal inspection but that's just me. If your happy with the dive in the front end use the same weight if you want to quell it a bit as I do step it up, your call in the end. Regards, Paul
ragtop69gs Posted May 17, 2015 #19 Posted May 17, 2015 I upped the oil to 15w , along with a set of sonic 1.2 springs. Much better ride now.
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