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Discussion Starter · #1 ·
I just received the rest of my order of suspension parts from Stoltec. In my case the hassle of having to disassemble the forks was a bigger deal than the cost, so I figured why not go whole hog. I ordered the 25mm cartridges and the Penske triple clicker, but I'm a little apprehensive about setting it up properly. I don't doubt I can identify gross errors in adjustment, but after getting it half way to where it should be, it's the last few clicks I have no confidence in. Most of the bikes I've owned have lacked adjustable suspension and the few recent ones that did, worked fairly well with the default settings. I had hoped base line recommendations would have come with the parts, but while the Penske did include generic instructions that suggested starting from mid range, no instructions came with the cartridges. I'm assuming that rebound damping should be directly proportional to the strength of the spring pushing against it and since I'm using relatively light springs I decided to start with settings about 2/3 way to full soft. Compression damping, while not directly related, sort of is. The heavier AND taller the rider, the more tendency to transfer weight during braking and acceleration and since I'm a relatively small, light weight rider, I decided to start with settings for compression also about 2/3 toward full soft.

I realize that both compression damping in front and rebound in the rear affect weight transfer during braking and likewise both rebound damping in front and compression in the rear affect it during acceleration out of a turn, how do I know if I should adjust front or rear or a little of both? How do I know if I have the right front and rear balance?

I hope Nick chimes in with suggestions, but I welcome any help from those of you with suspension setup experience.

In one post by triplethreat he said "Looks like you need to back off the rebound just a bit.....you got a slight bit of raised area on the trailing edge of the tire grooves."
Please elaborate on that; the reason doesn't seem obvious to me.

One final thing, a single separate O-ring came with the cartridges. If both sides don't need one, where do I use it?
 

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In case of a doubt, less damping won't get you in too much trouble. The less damping you can use, better it is.

Trying to have the ultimate set up for the street is like impossible. Road condition/weather change all the time. Just make sure the bike stop, accelerate and ride over bump without popping your eyeball out LOL
 

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Discussion Starter · #3 ·
Trying to have the ultimate set up for the street is like impossible. Road condition/weather change all the time.
I'm aware of the extreme variability of public roads. I figure if I can get it to behave reasonably well in some of the bumpier turns (where the stock suspension totally fails), it will be more than adequate in smoother ones.
 

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I'd like to commend you on an extremely articulate post. Some great questions there which I will also look forward to the responses from others well versed in the art of suspension tuning.

I think this could be worthy to be a sticky thread as I have no doubt when the pros chime in they will provide some valuable information.
 

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In one post by triplethreat he said "Looks like you need to back off the rebound just a bit.....you got a slight bit of raised area on the trailing edge of the tire grooves."
Please elaborate on that; the reason doesn't seem obvious to me.
Rebound dampening will show itself on the tire as it wears. Triplethreat had it backwards there though. He and I ironed it out and we're both on the same page now. It goes like this: if the trailing edge of your sipes have a raised edge you are lacking rebound. Conversely, if the leading edge of your sipes has the raised edge you have too much rebound dampening. If you have neither, congrats, you're rebound adjustment is pretty damn spot on (or you just don't ride hard enough to get the wear to show).
If you rode the OEM shock with some enthusiasm you may have noticed the raised trailing edge as I did. Even with the rebound screw turned to full hard I still had trailing edge ridges. With the Penske I have in there now I'm able to make adjustments before I hit the twisties to firm things up and get more even wear.
 

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Discussion Starter · #6 ·
Since I really don't know what I'm doing, I'm proceeding slowly. The only things I've done so far is pull my ECU and send it off to be reflashed while I install the new suspension, and to check what the sag is with stock suspension. I wanted to be sure I wasn't making any significant changes to steering geometry if I set the new stuff to 30mm rear and 35mm front, but I got surprising numbers, With default preload, I had close to correct sag out back (33mm), but in spite of my light weight, I had a whopping 43mm in front, so it looks like I will be making a slight change to the geometry.
 

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The rear is fine IMO, just preload the front few turn to get you in the 38-40. To be honest sag numbers are no magic numbers... try it as it is now. go from there.

I use F37/R33 for the track. If you ride in bumpy road your number is very close to what Nick use on his bike if I remember well (F43/R36)
 

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Discussion Starter · #8 ·
Thanks Marthy for that info. I'm not sure if I really want to go all the way to F43/R36, but I'll definitely set it somewhat higher than I had originally planned (need to think about that some more).

All I accomplished today was removal of the stock shock which turned out to be a bigger hassle than expected. Could Yamaha have designed a more difficult fuel line connector? The front bolt for the shock was then easy to remove, but the bottom end was a different story. I even bought a couple new wrenches, to no avail. The only part of the lower linkage I had good access to was the front pivot bolt, so I removed it and then I was able to rotate the rear bolt upward where I could get a socket wrench on it easily.
Then I compared it side by side with the Penske and it looked like the Penske was just slightly longer. As I understand it the minimum length of the Penske is supposed to be the same as stock, but the length adjustment wasn't quite bottomed out. I'm not talking about a big difference (somewhere between 2.5 and 3 mm). Did Nick intend it to be that way? Maybe I need to email him about that.

Also, Ive been thinking what makes the triple clicker special is that it has separate adjustments for high speed and low speed compression damping. There is slight interaction, but generally the low speed adjustment mainly affects squatting under acceleration and the high speed mainly affects bump compliance. I realize that there's a limit to what you can accomplish, but since I'm trying to set it up for highly variable streets, shouldn't I start with somewhat more low speed compression and maybe even less hi speed damping to compensate (trying to have the best of both worlds). Isn't that the point of having separate Low and High speed adjustments?

I already received notice that my ECU is on it's way back. I will probably get it before I'm finished with installing the new suspension.
 

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Sounds like removing the tank isn't a great help to shock removal. The top bolt is doable with the tank in place. Remove the bolt accessed through the hole in the swingarm first, then the bottom shock bolt, then the top shock bolt. Reverse the procedure to install.

I would approach compression damping adjustment in the way you describe. Do Penske shocks not come with a base setting applied? Ohlins, Wilbers, Nitron etc do - pretty much fit and forget.
 

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Discussion Starter · #10 · (Edited)
Do Penske shocks not come with a base setting applied? Ohlins, Wilbers, Nitron etc do - pretty much fit and forget.
Perhaps it was, but the paperwork did not make that claim. High speed compression was at full soft and low speed a lot stiffer than I was originally thinking of starting. Rebound was also somewhat stiffer than where I had planned to start and preload looks like it's fairly close to maximum (maybe there's much more range than expected to ever be used). Or maybe that much adjustment is to make changing springs easy.
 

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I backed off the compression quite a bit from as-delivered on my Penske as well.

I just noticed you're one of the few Tucson riders on here. I'd be interested in seeing those forks whenever you get them set-up. Maybe we can go for a jaunt up Mt Lemmon to really test them out.
 

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The approach I suggest is this: set sag first. Set rebound via the 'bounce method'. Look on YouTube for some Dave moss videos, seeing him do it is easier than trying to explain. Try to get the rebound so the front and rear react the same. Set compression at midpoint both front and rear and ride some on your typical roads. If the bumps seem too harsh back compression off until it is tolerable. If it seems fine tighten up a bit till you feel harshness and then back off a smidge. Make sure your tire pressure is not set at stock (40# is absurd, run in the mid 30s front and low 30' rear; unless you are 250+). Too high tire pressure will make the cracks in the payment feel harsh. For street riding this will be fine. The compression will be too soft for the track this way and the rear will squat a bit on acceleration. If the squat bothers you tighten compression up in the rear. Realize that the track guys will obsess over this and tell you this is all wrong and they are correct. But for street riding this will get you in the ballpark. On smoother surfaces and spirited riding adding compression both front and rear will result in a more settled chassis and work much better.
 

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Usually anything over 5"/sec is consider HS. The goal here to to get away with as minimal damping as possible. If you're not sure open the knobs all the way and start from there.
 

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Perhaps it was, but the paperwork did not make that claim. High speed compression was at full soft and low speed a lot stiffer than I was originally thinking of starting. Rebound was also somewhat stiffer than where I had planned to start and preload looks like it's fairly close to maximum (maybe there's much more range than expected to ever be used). Or maybe that much adjustment is to make changing springs easy.

Quite possibly they don't then. Seems odd is all.
 

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Discussion Starter · #15 ·
Penske on, forks off and disassembled.

I lucked out in that on one fork leg, I was able to completely unscrew the bottom allen head bolt before disassembling the cartridge assembly itself, thereby allowing me to remove the entire cartridge. The other leg was a bit less cooperative. The cartridge wanted to turn with the bolt, but after adding full preload and jamming a pry bar under the top cap for another half inch of preload there was enough pressure to hold the cartridge while I unscrewed the bottom bolt. I then was able to also remove the entire cartridge assembly from that fork leg as well.

In a previous post here I said the Penske high speed compression was set to full soft, but that was wrong. When I rechecked it was set to full firm. Also there seems to be a slight discrepancy between the booklet and the actual shock. The booklet says there are 18 steps of high speed damping. I don't want to force it, but it doesn't want to go more than 8 clicks.
 

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Re releasing the bottom allen head bolt - I have often used an impact driver to loosen spring loaded bolts. Is this a bad practice? Could any damage result?
 

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I've read motorcycle shop manuals that recommend using an air impact driver if the internals turn with the allen wrench screw instead of the allen screw coming out.
 

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On motocross forks it is almost mandatory to use an impact wrench to break it loose, but I used a T-handle hex key with a cartridge rod holder that I had to make out of 3/4" pipe that was long enough to hold the cartridge to break mine loose. The FZ has longer than average fork tubes. I think that it was the only bolt on the bike that was not overtorqued from the factory. It was a breeze. The trick is really when you reassemble it to make sure that the copper washer is seated, thus the need for a rod holder.
IMG_3118846864994.jpg
 

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No problem using air wrench to remove bottom bolt, common practice. Don'use air tools to tighten however. Like Doug said tight enough to seat copper washer. Otherwise she will leak fluid. On the brakes.
 

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Discussion Starter · #20 ·
Although it looked easy enough to make a home made fork spring compressor, it appeared to require two hands for the compressor and a third hand to insert a wrench on the jam nut. I thought it would be easier to compress the light weight top out spring if I could get a hold on the shaft. I planned on tying a cord around the end of the shaft and screwing a nut on top of that to hold it. Since I wasn't able to find a nut that fit in my spare hardware, I waited till today to get one at the local nut & bolt outfit, but, to my surprise, even they, didn't have a 12mm nut with such fine threads. Then I thought, maybe if I put a piece of tubing over the threads to protect them I can clamp a needle nose vise grip on it and pull up on that, but there just wasn't room for all that. The tubing I tried was a very tight fit on a dry shaft (I had to screw it on), but then it gripped so well no vise grips were required during a test before assembling the forks.

When it came time to actually assemble the forks I discovered that if the threads on the shaft had a little fork oil on them the tubing inserted much easier and I feared it would just pull off, but when pulling on the tubing it contracts gripping the threads very tightly and it worked. However the wrench I tried to use for the jam nut was beefy, requiring near perfect alignment before it would slip into place and that proved difficult. When I finally switched to a cheap pair of pliers with narrower jaws, it was easy and after getting the top cap finger tight, I was able to switch back to the fixed size wrench for final tightening.

My ECU arrived and is installed, but I'm going to be busy with other things for much of tomorrow, so it will likely be Thursday before I can give the bike a good test.
 
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