trapezeartist Posted January 22, 2018 Report Share Posted January 22, 2018 I want to try softening off the front forks of my 200. Unfortunately the manual doesn't go beyond telling me how to change the fork oil and I can't find a drawing of the forks anywhere. Can anyone enlighten me so I don't get any surprises when I open it all up? Are standard springs identified in any way? Are alternative spring rates available? Is the preload adustable? If so, what is recommended? What weight of oil is recommended? Should there be an air gap above the oil, and how much? Thanks in advance. Quote Link to comment Share on other sites More sharing options...
b40rt Posted January 22, 2018 Report Share Posted January 22, 2018 Try aft, anything between 190 & 220 ml. Quote Link to comment Share on other sites More sharing options...
trapezeartist Posted January 23, 2018 Author Report Share Posted January 23, 2018 14 hours ago, b40rt said: Try aft, anything between 190 & 220 ml. Presumably that's the same quantity in both legs. Does that leave an air gap at the top? Behaving as an airspring? Is there any preload adjustment? Quote Link to comment Share on other sites More sharing options...
pschrauber Posted January 23, 2018 Report Share Posted January 23, 2018 The least amount of fork oil is 20mm above the inner fork piston which has to be covered completely when the fork stanchions are completly pulled out. Good compromise for viscosity is SAE 7.5. There is no preload setting, but you can make your own shaft to place inside the fork to preload the spring. Complete adjustable fork suspension by inserts can be aquired throug HFS forks in Spain. Quote Link to comment Share on other sites More sharing options...
trapezeartist Posted January 23, 2018 Author Report Share Posted January 23, 2018 Thanks P. That was the sort of info I was hoping to get. I feel an evening in the mancave coming on. Quote Link to comment Share on other sites More sharing options...
b40rt Posted January 23, 2018 Report Share Posted January 23, 2018 (edited) 6 hours ago, trapezeartist said: Presumably that's the same quantity in both legs. Does that leave an air gap at the top? Behaving as an airspring? Is there any preload adjustment? Yes, each leg. On very hot days I usually vent the forks to avoid "air spring" As Patrik said, use steel / alloy spacers to adjust sag. New springs are probably a good idea. ATF is about 7.5 at. Edited January 23, 2018 by b40rt Quote Link to comment Share on other sites More sharing options...
trapezeartist Posted January 23, 2018 Author Report Share Posted January 23, 2018 New springs may well be on the cards. First I need to establish that there is no other reason for the forks feeling too stiff (air spring effect, too heavy fork oil, etc) and then I will need to know what the rate of the existing springs is. I'm hoping they may be marked in some way. I've heard good things about Magicals. Quote Link to comment Share on other sites More sharing options...
motopelli Posted January 25, 2018 Report Share Posted January 25, 2018 Here is a formula and explanation of how to calculate your spring rate: http://www.bluecoilspring.com/rate.htm I've developed the habit of starting off with 10wt in one leg and 5wt in the other. Effectively yielding 7.5wt, then if you want to go up or down in weight you only need change one side 1 Quote Link to comment Share on other sites More sharing options...
trapezeartist Posted January 25, 2018 Author Report Share Posted January 25, 2018 Thanks Motopelli. It's about 40 years since I last did that sort of calculation so a reminder was most definitely needed. Most large springs I have known in the past (ie suspension springs) have either been stamped with the rate or colour-coded (in which case you need to find out the code). It's the 4th power of wire diameter that makes the measuring process rather finicky. Quote Link to comment Share on other sites More sharing options...
cangy1000 Posted January 26, 2018 Report Share Posted January 26, 2018 Stiff folks? Totally opposite to what I found on my 200 when I first got it. Maybe just way too much oil of too thick, big spacers in there. Careful the tops might hit you in the face when you undo em. I replaced the(what I assumed)originals with Magicals and put enough 10w oil to stop the folks topping out, bit of trial and error required. If you get Magicals you will need the adjustable preload spacers they sell at the TY majesty place, or make some big spacers. I've set mine with little of no preload and are quite bouncy now in comparison to the old setup.I find it much easier to pick the front wheel up now, I'm liking it so far. Quote Link to comment Share on other sites More sharing options...
trapezeartist Posted January 30, 2018 Author Report Share Posted January 30, 2018 Well I finally got out to the garage tonight. I drained the fork oil and replaced it with 200ml of 5W in each leg. It now feels a lot softer and bouncier though the front is still stiffer than the back when pushing down on the seat. I don't know if there are any spacers under the springs as I didn't remove the fork tubes from the bike. I did take the opportunity to measure the springs. Free length = 508mm 57 active coils (surprised me a bit) Mean diameter = 23.5mm Wire diameter = 3.75mm The springs protrude 30mm out of the top of the legs. Does that mean I have a spacer down at the bottom? Does anyone know if that is the standard spring? Quote Link to comment Share on other sites More sharing options...
cangy1000 Posted March 1, 2018 Report Share Posted March 1, 2018 My standard springs were about the same with no spacers. Quote Link to comment Share on other sites More sharing options...
trapezeartist Posted March 1, 2018 Author Report Share Posted March 1, 2018 13 minutes ago, cangy1000 said: My standard springs were about the same with no spacers. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.