was that the exhaust or something you could hear scraping on every corner???.. that was NUTS... well, the famed corner that I used to have instability on at 12, I took at 150 (KPH) today, and had to have my feet tucked right in since they were dragging... it was WARM here today (28C) so the tires were nice and gummy, stuck like hell

as for the guy in the picture.. yeah.. i don't think he's making that corner... he's on the painted line on top of it...

 

Here's the sequence. First, this is with a stock bike, sag set at 7/8" rear and the front spacer length increased 5/8" to raise the front sag to 1 3/8" from the original 2 1/8" and fork oil level raised to 4 13/16" from the stock recommended 6 7/8" (? I think).

First, get rid of the centerstand or don't think about hard lefts. You can hit the peg bolts without any problem but there's very little room left, especially on the left with the centerstand.

Next to hit is the pipe covers, the pointy section at the very bottom just before it sweeps up to the rear. Remove those and you can get up into the brake pedal, then kiss the lower fairing plastic where it projects by the clutch cover, just below the oil fill on the right and the equivelent on the left. Shifter on the left doesn't hit like the brake pedal.

I never hit the pipes with the covers off but once you're into the brake pedal and fairing, there CAN'T be much left. If I had realized I was that far into it I wouldn't have done it but came in with those marks and still nothing on the pipes (covers removed).

Hope that helps.

 

can you describe the front spacers??? I take it they go on topof the fork spring to increase the spring force? as well as where you measure the oil level from.. pics would be really appreciated.. I am finding I'm getting pretty close to full tilt.. the wear on the tire is about 3/8th from the edge of the tire on the back, more on the front.. also, what is your wieght.. i'm a lightweight (145lbs in gear) so I might need less spacers, etc

 

I am talking about a '90 here so keep that in mind. The '90 and '91 are the same for sure, the '93 and up I'm not sure but might be, and the pre-90's are definitely different. They aren't cartridge shocks for starters. That was a first in '90.

The spacer goes on top of the spring and doesn't change spring tension but raises the height or sag. It can be said to increase tension but that's not the way to view it as it's only at the extreme bottom of travel. The original two inches of travel will have no more spring tension and the same force that caused two inches of travel before to add the spacer will still cause the same two inches of travel after the spacer, just starting from a higher point.

The point of setting sag is to place the fork travel in a position to optimize the available travel. In this case it also gains some corner clearance because it raises the bike but that's not the point of setting sag and technically not the place to set ride height. Because of the corner clearance issues though, it's a welcome side effect to the main point, optimizing available travel.

The raised fork oil is to increase the progressivity of the "spring" to aid in preventing bottoming on hard braking. It reduces the air volume that is captured in the fork and compressed as the fork travels towards bottom having the effect of making the "spring" more progressive. It has no effect on the damping or shock but aids the spring by progressively adding "spring" type force and more progressively than when there's a greater air volume from a lower oil level.

The fork oil level is measured with the spring out and the tubes fully compressed, bottomed out.

A search thru Racetech's site will afford much more detail to these principles.

The changes I made are just cheap tuning things that did make an improvement but are not optimum. I wasn't about to try to make a full on track hot rod out of this bike as it's got some inherent problems going in, not the least of which is the weight. I did the tuning things that helped but did not alter or detract from what it does well which is perform nicely in an all around fashion and all day rideable. It's still my favorite street bike for an all day mountain ride of 500 miles or more. And yes, it is an improvement when riding it hard but doesn't even approach a fully tuned race suspension.

BTW, my weight is 200#. Measure your sag and start figuring from there. The fork oil level you could raise as described as you won't overspring it with the stocks almost regardless of your weight. Read up on this stuff and only approach it when you think you've got the picture clearly. Record everything you do so you can go back or adjust as needed. Set the rear between 7/8" and 1", making sure that it's not topped out when the bike is standing upright but without you on it. That's the "free" sag number, BTW. NEVER run with no free sag at the rear. JUST topped out, where the force of a fingertip will start movement, or about an eighth inch should be considered minimum free sag at the rear.

Shoot for 1 1/4" to 1 3/8" static sag at the front. There should be ample free sag there, probably 3/4" or so. BTW, the difference between those two numbers, the "static" and "free" sag will tell you how close to correct your spring sizing is on just about any bike without knowing any specifics about the weight or spring rate. Those two numbers will indicate the appropriateness of the springs for their prescribed service. Again, review Racetech's site and maybe Traxxion Dynamics as well for more detailed information.

 

wow, quite a writeup, thank you for it..

one question about the rear sag.. considering it's the differance in ride hieght wiht oyu on it from the free sag level, how do you reduce/increase the sag without lifting the entire rear of the bike via preload... to me it sounds like you have to swap springs around

I'll have to mull this over for a bit still

 

Yes, that ride height thing can get confusing. Anytime you adjust your sag it has to change the ride height by the amount of the adjustment. There's no other way. BUT, consider it as what you've done is just put the bike back to the range originally intended by the designer. Once sag is set, the spring's proper, and the operating range (sag) is correct, leave it alone. It is optimized. Any desired ride height changes are now accomplished by sliding the tubes in the tree at the front or shimming the shock (preferred) or link length changes (whithout other options) at the rear. Get the sag right then leave it alone. Change the ride height by moving parts. Does that help?

And before to start any arguements, the sag settings can be used slightly to adjust height and to compensate for some different characteristics on different bikes but the base will not be moved much from considered ideals and there will be circumstances that are explainable that make those variations work. Those excursions can be messed with as experience with the standards are clearly understood and clear justifications for the excursions are also understood. Typical range for street use has rear static sag at 7/8" to 1 1/8" and front at 1 3/16" to 1 3/8". Hope that helps.

 

Thanks for pointing that out dad. Yesterday I scratched my left foot in a roundabout. After reading your comment and checking the distance to centerstand and muffler protectors, I'm glad I didn't had de foot backed off as usual and by that got an early warning. The balance of the bike felt very good though. I'll remove the center stand and the muffler protectors soon.

 

As long as you have the feeler bolts in the pegs, they will give the first warning without removing anything. If you're really pushing the bike, the centerstand is good to remove because it's not far behind the point where the peg bolt hits on the left side and if you overshoot the peg bolt and it hits, you've got a good chance of unloading the rear and skating. The pipe covers aren't nearly as rigid and while it's never good to hit any hard parts, those aren't likely to set you an your ear as they will give when they hit. While it will scratch the lowest part, hardly visible, it isn't so solidly mounted that it will lift the rear, unloading the tire. I only remove them for the track. It's the centerstand that I finally chose to leave off on the street for the reasons mentioned.

If you're regularly hitting the peg bolts on the street you might consider how wise it is to run that hard on the street. I use them as my warning to cool it a little when street riding. I hit them fairly often but just, and use it as a warning as mentioned. On the track, all bets are off... as are the pipe covers.

I hope that doesn't sound too preachy. Just trying to help. That's how I approach it. Also, moving your butt with the proper technique and/or raising the bike with appropriate springs and sag settings. Then maybe ride height. It will buy you more lean angle before to hit anything. I may get into this deeper than just the tuning items I've done and work with springs and ride height on my bike. Now that I've decided to go through it and prepare it for another 100,000+ miles of service it will be worth the effort. I'll post how that goes if I do.

 

No harm, I really do appreciate all this information and you have a very good point in using peg scratching as a cool down trigger.

 

I'll keep that in mind as well.. but with my size feet which always hang off the end of the pegs, I really have to work to tuck my feet in so tat something other than my foot is the early warning..

you should post all about how to move your butt with the proper technique as well

OK, so that's half a joke, half not