d606

[revmaaatin]

Jeff, Thanks for the reply. As a point of reference-- Gen 1 forks come with a schrader valve; Gen 2 forks do not. Some (in the past) suggest adding 5psi to both forks to accomplish the same thing you postulate by adding oil and decreasing the air volume; adding air pressure to speed up the rebound. AFAIK, Mother Kaw says the Gen 1 schrader valve is to relieve pressure due to change of altitude. Interesting what the tin man-tinker can push the limits with just a small amount of adjustment of oil and air. which begs the question-- What caused the engineer to choose the OEM oil level; was it performance divided by forkseal life. head scratch. It would seem to me-- The weak point/failure point in all this is the fork seal; the unknown is how does it react to the increased air pressures.... At this point, it appears you have found a sweat spot between a little more oil and not to much increase in the airpressure. Speaking of fork seals, IMO the best replacement seal is the OEM seal; not the cheapest, but the best. We changed out a set the PO installed (previous to ~27K miles repair) and the height of the seal/contact patch was 1/3 less than the OEM. 20K miles later, still going strong. 35K on the other KLR; no leaks. Paul Streeter was here last week; his KLR blew a seal the weak prior and when he bought sthe 'replacement' equivalent available locally, he opted NOT to install it and to let Fred send him some OEM immediatly. revmaaatin.

--- In DSN_KLR650@yahoogroups.com, Jeff Khoury wrote: > > As I understand it, increasing the amount of oil within the fork decreases compressible (air) space in the top of the shock. When the shock compresses, it has two effects: > > 1: Pressure builds faster above the oil, causing a stiffer "bottom" to the shock, sort of like a progressive spring, but less pronounced. > > 2: The increased pressure speeds up the rebound of the shock, in part compensating for the heavier oil (ATF) that I put in to increase compression damping. > > The problem is on traditional forks is that compression and rebound are controlled by the same orifice. If you slow down compression, you slow down rebound at the same time. Cartridge forks do not have this problem; they have separate orifices for each. > > The increased pressure "assists" the springs in pushing the fork back out after compression. > > ...that is how it was explained to me by an old school motocross racer. > > I chose 10mm because it was a conservative overfill. I figured I would try more if it didn't have the desired effect. It felt fine when I was done so I didn't mess with it. > > -Jeff Khoury

[Jeffrey]

Yeah the aftermarket fork seals obviously aren't as good as the OEM. When one of my aftermarket seals recently started leaking, I just changed the fork oil and at the same time I added a few CCs of TransX power seal and tranny seal expander to each fork. IT HAS WORKED FOR $5K MILES! j#3

[Ron Haraseth]

My old 1980 KDX 400 came with a comprehensive maintenance manual. It included two whole pages of front suspension tuning information which included charts and graphs which showed changes of dampening action, preload, etc. based on changing oil viscosity, height, and air pressure. I used to run between 8-12 #s pressure. Wish I still had that manual...and the bike for that matter. The front suspension was a life saver...couldn t say as much about the rear suspension, however. When your front forks get hot to the touch, you know they are working hard for you. Ride safe. I'm heading out this morning for a 10 day back country adventure in central west Idaho and SW MT starting today. A good test for my '02 loaded for camping, which by the way, has progressive front springs with Ricor Intiminator cartridges set at 130 mm oil (5 weight) level with 1/2 inch of extra preload spacer and a Ricor IAS rear shock with the heaviest spring (I push 250# plus by myself). Ron -----Original Message----- From: revmaaatin Sent: Thursday, July 19, 2012 11:23 PM To: DSN_KLR650@yahoogroups.com Subject: [DSN_KLR650] Re: front suspension upgrade? Jeff, Thanks for the reply. As a point of reference-- Gen 1 forks come with a schrader valve; Gen 2 forks do not. Some (in the past) suggest adding 5psi to both forks to accomplish the same thing you postulate by adding oil and decreasing the air volume; adding air pressure to speed up the rebound. AFAIK, Mother Kaw says the Gen 1 schrader valve is to relieve pressure due to change of altitude. Interesting what the tin man-tinker can push the limits with just a small amount of adjustment of oil and air. which begs the question-- What caused the engineer to choose the OEM oil level; was it performance divided by forkseal life. head scratch. It would seem to me-- The weak point/failure point in all this is the fork seal; the unknown is how does it react to the increased air pressures.... At this point, it appears you have found a sweat spot between a little more oil and not to much increase in the airpressure. Speaking of fork seals, IMO the best replacement seal is the OEM seal; not the cheapest, but the best. We changed out a set the PO installed (previous to ~27K miles repair) and the height of the seal/contact patch was 1/3 less than the OEM. 20K miles later, still going strong. 35K on the other KLR; no leaks. Paul Streeter was here last week; his KLR blew a seal the weak prior and when he bought sthe 'replacement' equivalent available locally, he opted NOT to install it and to let Fred send him some OEM immediatly. revmaaatin.

--- In DSN_KLR650@yahoogroups.com, Jeff Khoury wrote: > > As I understand it, increasing the amount of oil within the fork decreases > compressible (air) space in the top of the shock. When the shock > compresses, it has two effects: > > 1: Pressure builds faster above the oil, causing a stiffer "bottom" to the > shock, sort of like a progressive spring, but less pronounced. > > 2: The increased pressure speeds up the rebound of the shock, in part > compensating for the heavier oil (ATF) that I put in to increase > compression damping. > > The problem is on traditional forks is that compression and rebound are > controlled by the same orifice. If you slow down compression, you slow > down rebound at the same time. Cartridge forks do not have this problem; > they have separate orifices for each. > > The increased pressure "assists" the springs in pushing the fork back out > after compression. > > ...that is how it was explained to me by an old school motocross racer. > > I chose 10mm because it was a conservative overfill. I figured I would > try more if it didn't have the desired effect. It felt fine when I was > done so I didn't mess with it. > > -Jeff Khoury ------------------------------------ List Sponsors - Dual Sport News: http://www.dualsportnews.com Arrowhead Motorsports: http://www.arrowheadmotorsports.com List FAQ courtesy of Chris Krok: http://www.bigcee.com/klr650faq.html Member Map: http://groups.yahoo.com/group/DSN_KLR650/app/peoplemap/view/map Group Apps: http://groups.yahoo.com/group/DSN_KLR650/grouplets/subscriptionsYahoo! Groups Links

[dooden]

Bingo thats what i did. Love the 606 and the K270 on rear works for me.. Dooden A15 Green Ape

--- In DSN_KLR650@yahoogroups.com, "Jud" wrote: > > $95 seems like a lot, but that's about what they cost these days. For a front, I'd use another D606. If you are going to mix brands, use the Dunlop on the front and the kenda on the rear. > > --- In DSN_KLR650@yahoogroups.com, Tam a'Rack wrote: > > > > I have a chance to pick up 2 new D606 for $95 each, seems like a deal to me. > > And as I have a KLR650 and a DR650 (both use the same size tires) I think I should get them. > > > > Any thoughts as to a front tire to match with them? > > > > I will be riding mostly off pavement (most of the time I have a 20 mile run to reach the dirt roads) > > I have a Kenda 270 on front of the KLR now and it seems to work well. > > > > > > Thanks for the input so far. > > > > Tam (west central Arkansas) > > > > 2007 DL650 (Wee-Strom) > > > > 2003 KLR650 > > 2000 TW200 > > 1997 DR650 > > > > > > [Non-text portions of this message have been removed] > > >