Another front fork thread

I've done a lot of reading and I think I'm ready to tackle my soft front end problem. Before taking it apart though, I have a few questions. First, how can I tell the cause of the excessive sag. Can it simply be because the fork oil is too low or is it more likely that parts are worn, such as the springs. There are no leaks from the forks.

Also, While I'm in there, is it worth buying emulators and new springs? I definitely cannot afford the race tech ones from 650 central, but it is possible that I could get the cheaper ones from Mike's. What are some opinions on them. I've already read a few but they were all somewhat inconclusive.

Thanks!

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I wouldn't do the emulators just yet. First, do the Minton Mods and use one ounce more oil than speced. If that's still too soft, replace the springs. I wouldn't buy the MyikesXS springs any more. They jacked the fucking price so high that now you can get real Progressive Suspension springs for about the same money. No sense buying third world produced copies which, by the way, are very crudely made.

+1 on 5twins' post, especially if you are on a budget. If it needs more help, go with Progressive springs for the simple fact that a spring is a precision tuned wire, and you just won't get the quality out of China that you get from Progressive, Traxxion Dynamics, or Race Tech.
Although I have Race Tech springs and emulators on both my other bikes, I'm not positive I'm going that far with the XS right now.

Yes, you can always do the emulators later if you're not satisfied with the Minton Mods. To install emulators, you drill the oil holes in the damper rods so large that they cease to function. The emulator does the job instead. With the Minton Mods, you enlarge the oil holes slightly. This changes the damping characteristics but doesn't stop the rods from damping the fork action. If you decide you want emulators, you simply go in there and drill the rods again, enlarging the holes even more.

If you are on a budget, putting in 3/4" pieces of pipe (heavy gauge PVC works) as pre-load spacers might be quite a satisfactory improvement. Just raise the bike so the forks are fully extended, remove the caps and install the spacers right on top of the springs...

^^have done the same thing in the past but with(oz) 10 cent pieces(for 34mm forks and 2 for each fork). for a quick fix it made a surprising difference

Don't just go stick a random dimension of pipe in your forks. This is how it's done safely and correctly.
(from Race-Tech's web site FAQ)
A: If you have a problem with bottoming, for example, it could be caused by either too soft of a spring or too little compression damping. The easiest way to get your spring rate in the ballpark is to do a "Valving Search" on our website. This will give you our recommendation for spring rate. Once you have the proper rate the rest is damping. That is what the Gold Valve® kits are all about, personal setup for you.

If your front end is diving, first of all, it should. If it dives too much or too little or if it bottoms you will need to do something about it. How much it dives can be affected by either spring rate or damping. When you hit the front brake, the front end dives. If you keep the brake on a constant amount the front end will dive and then oscillate around a certain height. Let's call this height the Dynamic Ride Height. This Dynamic Ride Height is totally determined by spring forces. How much it oscillates and how much it initially overshoots this height is affected by damping forces as well. Again the key thing is to do a "Valving Search" on the website.

Q: What is "Race Sag" (Static Sag)?
A: Static Sag or Race Sag is the amount the bike compresses from fully extended, with the rider on board.

Here's how to measure it.
1.First extend the forks or shock completely and measure from the wiper to the bottom of the triple clamp on forks or from the axle to a vertical reference point on the chassis. This is L1.
2.Take the bike off the stand, put the rider on board in riding position. Get an assistant to balance the bike or have the rider hold onto something, comress the suspension about 25mm (1") and let it extend very slowly (slowly is the critical term). Where it stops, measure the distance between the wiper and the bottom of the triple clamp or the axle and the reference point on the chassis again. Do not bounce. This is L2. (If there were no friction in the seals the bike would come up a little further.)
3.Next lift up on the suspension and let it drop very slowly. Where it stops measure again. Do not bounce. This is L3. The reason L2 and L3 are different is due to stiction or drag in the seals and bushings. (If there were no friction in the seals or the linkage the bike would drop a little further.)
4.Half way between L1 and L2 is where it would come to rest with no friction. Therefore L2 and L3 must be averaged and subtracted from L1 to calculate true Static Sag.
Static Sag = L1 - (L3 L2)/2
5.To adjust Static Sag make longer or shorter preload spacers or use the preload adjusters, if available.
It is important to note that there are no magic Sag numbers. However here are some guidelines to use as starting points. Please refer to the DVS Valving Search for specific guidelines.

Bike Type Front % Front (mm) Rear % Rear (mm) Rear Free Sag(mm)

Street Bikes 28-33% (30-35) 28-35% (28-37) (2-17)


All that being said, virtually any fork will take 10mm of preload without binding up.

double post

Thanks guys, I'm going to open them up tomorrow and drain the old fork oil and possibly do the Minton mods to the dampers. I'm a bit afraid to ruin them though, haha!

One more question. Is there any trick to getting the caps off? I don't think I have any allen key as big as I need.

Number one cap removal "trick" is to loosen the top triple clamp bolts FIRST.
Go buy the big allen socket. You can weld a nut to a bolt to make a remover but if you goober up the recess in the cap you will be kicking yourself.

+1 on that. A nut or bolt flats are not going to fit as well as a purpose built tool.

Great price on progressive springs here:

http://www.amazon.com/Progressive-S...gressive+Suspension+Front+Fork+Spring+11-1119

Here my 2 cents.Remenber the 70s dirt bike with air forks? The po of my 78 xs.Put air valves in the fork caps.After rebuilding my forks. I too had ft end dive.So I went a head and put some air in the forks The trouble is gone.The ft end is great.I run 15psi in each fork leg.I sit on the bike and it settles down about one inch.Push down on the ft end and it comes right back up. The fork are still holding air after 2 months no leaks.I know this may not be for you,but its working for me.Just some thing to think about.Thanks