I see the tx650 and rd350 share same parts on the front fork and breaks . I have got the tube length cut to the size of rd and it is pretty much bolt on setup. My question is what is the fork oil grade to be used and oil capacity for each fork bottom
Cheers
The method I use is to remove the spring and make sure there is no oil remaining in the fork. Then add 6.5 oz of 20wt for oil, collapse the fork several times, working the slider all the way up and down, ending with the slider all the way up. Measure the height of the oil from the top of the fork tube. It should be six inches. Add oil if necessary. Look into the fork to ensure that the emulator (if used) or the valve is covered with the oil. If not, add oil until it is covered. Make the levels in both forks as close as possible but a little difference isn't important. This method was taught me by Matt Wiley of Race Tech for my RDs but should work in all forks.
Lyn Garland
Agree 100% with Lyn. Number of cc is only a guide to the "right amount". I tend to use a little higher oil level, but don't go too high. More oil means more air pressure when forks are collapsed ie stiffer springing effect. Too much and it pops or leaks past seals.
But you must set sag as well and you may need to add longer (or shorter) pre-load spacers.
When the forks are together on a complete bike, push down hard at the front and let it return. It should take about a second to compress and to rebound. If it slams down or back up, that indicates insufficient damping for the spring rates fitted. If it take a long time to compress or return, there's too much damping for those springs.
Stiffer springs require more rebound damping to balance forces than light springs.
Quote from: Yamaha 179 on October 30, 2019, 10:43:22 AM
The method I use is to remove the spring and make sure there is no oil remaining in the fork. Then add 6.5 oz of 20wt for oil, collapse the fork several times, working the slider all the way up and down, ending with the slider all the way up. Measure the height of the oil from the top of the fork tube. It should be six inches. Add oil if necessary. Look into the fork to ensure that the emulator (if used) or the valve is covered with the oil. If not, add oil until it is covered. Make the levels in both forks as close as possible but a little difference isn't important. This method was taught me by Matt Wiley of Race Tech for my RDs but should work in all forks.
Lyn Garland
Cheers bro will try that,
Quote from: teazer on October 30, 2019, 10:56:41 AM
Agree 100% with Lyn. Number of cc is only a guide to the "right amount". I tend to use a little higher oil level, but don't go too high. More oil means more air pressure when forks are collapsed ie stiffer springing effect. Too much and it pops or leaks past seals.
But you must set sag as well and you may need to add longer (or shorter) pre-load spacers.
When the forks are together on a complete bike, push down hard at the front and let it return. It should take about a second to compress and to rebound. If it slams down or back up, that indicates insufficient damping for the spring rates fitted. If it take a long time to compress or return, there's too much damping for those springs.
Stiffer springs require more rebound damping to balance forces than light springs.
Absolutely great ..in general how much oil might go into each tube .. i see my forks are a bit hard
yup. same here.
what springs are you using? hope they are the rd ones. tx ones may be stiffer due to the heavier bike.
yes rd springs
Quote from: Naveenreddy on October 30, 2019, 11:53:52 AM
Absolutely great ..in general how much oil might go into each tube .. i see my forks are a bit hard
Quote from: Yamaha 179 on October 30, 2019, 10:43:22 AM
working the slider all the way up and down, ending with the slider all the way up. Measure the height of the oil from the top of the fork tube.
I use the same method as Lyn. But just to make sure the terminology is not getting crossed up; 'the slider all the way up' means the upper fork tube is fully compressed into the slider (lower leg). If you use this method with the 'tube all the way up' you will get a fork that is very 'hard' if that is what you are experiencing.