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Discussion Starter #1
Hello All,

So recently I was at the track with this disaster of bike. Everything seems to be solved and I can move onto the handling characteristics of the 749.

One of the suspension experts at the track started talking to me about my rear shock being too soft for my wieght. That said, his immediate response was to either changet he spring or upgrade me to something that has a "top out" spring in it or do both change the spring and get a shock that has a "topping out spring" on it.

Now, I have some quetions... it is my understanding that having a shock with a top-out spring in it will HELP prevent the rear wheel from loosing some grip when the brakes are applied. However which shocks will provide such a feature? Presently, I have the so-called crappy Sach shock on my bike.

In terms of Sag this is what the bike is set up with:
-Front Forks (0.9kg springs Showa TIN) 35mm of rider sag and 30mm bike sag
-Rear shock with stock spring (don't know the wieght) was at 42mm sag in the rear which caused the bike to UNDERSTEER incredible and has been changed to 28mm sag. Note that the stock spring length is something like 164mm and mine is measuring 151 while the bike is sitting upright (on a rear stand) so i don't think that I Have OVER-PRELOAD the rear shock enough to warrent a new shock assembly in the rear.

Comments ?
 

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I don't know of any shocks that have a top out spring...I though that was a fork thing, but could be wrong on that. IMO, if a shock is set up right, it wouldn't give you that feeling anyways. As a side note, when I took the Sachs shock off the wifes bike and played aroudn with it with no spring on it, the rebound adjustment made zero difference anywhere between full fast and full slow. POS!! Your current set up probably gives you that feeling because 28mm of sag on the shock is not enough. Go up to at least 30mm and maybe closer to 32mm.
 

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Discussion Starter #3
Another quetion,

Would the handling characteristic of the bike on the road shine light on what the bike will handle like on the track?

Or would anything on the road be amplified on the track.
 

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I'm with galaxy here, I've never heard of a shock with a top out spring.

As far as road testing...no. Nobody can ride hard enough on the road to simulate racetrack conditions.
 

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rapter said:
Another quetion,

Would the handling characteristic of the bike on the road shine light on what the bike will handle like on the track?

Or would anything on the road be amplified on the track.
Hard to tell. Its such a different environment. At the track the bike feels like a very different animal.

At the track you are either hard on the gas or hard on the brakes. "Hidden" geometry or dampening characteristics/problems will become apparent at these much faster track speeds and when braking deep into corners. Also as you relax the bike will begin to feel looser, lighter and quicker to turn in. What might feel fine on the street or even beginner track group speeds, such as the compression damping you dialed out to soften the bumpy canyons or compansate for too stiff a spring will probably suck once you're going quicker. However until you get a track dialed in and can hit the apexes consistently it can be quite hard to separate what is you and what is the bike. That said, get the correct springs for your weight and spend $30 at the track to have your suspension set up and you will be a long way in the right direction. And yes there is a difference between shocks. The Race Tech technician at Buttonwillow drooled over my Penske 3 Way - not so much as to affect the handling mind you.

Good Luck
 

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Discussion Starter #6
Feels like I am going to have to wait until next season to figure out what what the correct set up is going to be for the bike.

Thanks for all your help!
 

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Yea, I agree... you need to ride it on the track to set it up. Even though I'm getting good lap times for a noob, I'm not pushing it hard enough to really feel the difference in the front end even on the track. Its depressing because its all set up properly and it is better, but my skills arn't there yet to feel a BIG difference. "sigh" like most of us noobs, its gonna take a while! heh. Hopefully you can contain yourself until the next track day!



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Rapter, do you still have the non-adjustable ride-height arm. It definitely sounds like the shock is too soft. I belive stock rate is 7.65kg/mm. Combine that with too little rear ride height and the front will want to run wide on accel. You can cheat the soft spring a little by jacking up the rear. Either way the OE Sachs is junk for the track and will not handle much of a spring change.

I'm about 155-160 geared up, have an OEM 999BIP (Showa) shock and it can just handle my weight satisfactorily on the track. However, it is pretty well balanced to my forks, so no issues. Bottom line: my overall setup could be better, but it works reasonably well, especially for my cheap suspension upgrades ($100 .90 fork springs and $15 shock)
 

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What's really really cool is when you get to the point that one click on an adjustment makes a noticeable difference. I heard guys talking about this phenomenon for years and never believed it existed...until you get some good components. That's also only on the track! I can take my same bike where a click or two is night and day on the track but 5 clicks riding back and fourth to work don't mean diddly squat.

Don't bother with this rapter...20 clicks on your shock wont change a thing;) :)
 

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shock spring and height adjuster

From what I know, Ducati still ships the superbikes with very stiff springs in the front and very soft spring in the rear. I have no idea why. It sounds like you've got the correct springs in the front already. I would get the correct rear spring for your weight and set the sag. A spring is about $100.
I would also buy a rear ride height adjuster. That's like another $100. The rear of the bikes are always set too low from the factory for agressive track riding and if yours is non-adjustable then your screwed until you can get the rear of the bike raised up. The soft rear spring is adding to the problem because the rear is going even lower (compresssing) under cornering load relative to the front which is being properly help up by the correct springs.

Put those two thing on the bike, then ride it and get the comp/rebound adjusters where you are happiest with them. Then start gradually raising the rear ride height to get the bike to turn. This has a huge effect.

I think you've got a spring rate/chassis geometry problem that you can cure for $200. Then you can still buy a fancy rear shock if you want to. I think you'll feel it is less necessary, though.
 

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I disagree. If you are going to change springs, put it on a real shock. A base Penske would be my recommendation, the two way. You don't need a triple adjustable shock, and the difference will amaze you.
 

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+1 with Chuck.

You don't do a custom paint job on an Chevy Vega. It's still a POS. Like what Jon said about one click difference, I can tell just that with my Ohlins/Penske shod SS. Makes all the difference in the world.
 

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And it just looks damn seeeexxy (in my best Fat Bastard voice:) ) Shoot Chuck...I didn't even want the tripple clicker. I'm scared of one of those things...I wouldn't know what to do. But I wanted the Penske, and then (NC) Rick told me about this one...This is a brand new shock this year for our bikes...only a double clicker (one rebound/one compression, just in case) with the piggy back reservoir. I had to wait almost 6 weeks for this sucker!!

I was gonna put the equivalent of this one on Misti's bike Brian but that one was a long wait also...so she decided to go with the Ohlins instead!! Women...what's up with this "her getting to choose her own shock" crap ;) :)

Just remember when it comes time to upgrade suspension, you can do it on a budget for sure, but this is one of those areas where you get out of it what you put in it. Not just paying for a name.

Ahh yea...Matt's right too...that thing doesn't have the rear ride heigth adjustment. That friggin 28mm of sag you had on there probably helped out a little because of that, but the ride sucks...not much of a trade off. This shock has its own ride heigth adjustment, so if you had one of these, you wouldn't need to do anything else. Does the D have the same linkage assembly where all you need to do is throw in an adjustable rod and you're done?? Not sure on that one.
 

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Discussion Starter #14
I definately agree that the compression and rebound adjusters on the rear Sach shock are not making much of a difference, which begs the quetion why are they even there???

I am able to get a couple of rear Showa shocks (off this forum) for pretty cheap, so I think that this may be a good option. This will be an over-the-winter project to change up the rear. If I am not mistaken the Penske shocks are going to be about $700.00 ???

Also, who carries these shocks?

I am going to double check what the ride height is set at later on today and will post it, may take a lot of fiddling before this is set right.
 

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rapter said:
I definately agree that the compression and rebound adjusters on the rear Sach shock are not making much of a difference, which begs the quetion why are they even there???.
Ahhhh...that my friend will not be answered anytime in our lifetimes!!

rapter said:
I am able to get a couple of rear Showa shocks (off this forum) for pretty cheap, so I think that this may be a good option. This will be an over-the-winter project to change up the rear. .
Excellent idea...:)

rapter said:
If I am not mistaken the Penske shocks are going to be about $700.00 ???.
Mine was just over that...and you wont beat the price from where I got mine. If you can, it wouldn't be worth it for support/customer service

rapter said:
Also, who carries these shocks? .
NC Rick...Cogent Dynamics

rapter said:
I am going to double check what the ride height is set at later on today and will post it, may take a lot of fiddling before this is set right.
Were we correct about your bike (D's) not having the rear adjustment rod?? Is it just a fixed rod back there or is the linkage differenct (from my pic above)
 

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Discussion Starter #16
galaxy said:
And it just looks damn seeeexxy (in my best Fat Bastard voice:) ) Shoot Chuck...I didn't even want the tripple clicker. I'm scared of one of those things...I wouldn't know what to do. But I wanted the Penske, and then (NC) Rick told me about this one...This is a brand new shock this year for our bikes...only a double clicker (one rebound/one compression, just in case) with the piggy back reservoir. I had to wait almost 6 weeks for this sucker!!

I was gonna put the equivalent of this one on Misti's bike Brian but that one was a long wait also...so she decided to go with the Ohlins instead!! Women...what's up with this "her getting to choose her own shock" crap ;) :)

Just remember when it comes time to upgrade suspension, you can do it on a budget for sure, but this is one of those areas where you get out of it what you put in it. Not just paying for a name.

Ahh yea...Matt's right too...that thing doesn't have the rear ride heigth adjustment. That friggin 28mm of sag you had on there probably helped out a little because of that, but the ride sucks...not much of a trade off. This shock has its own ride heigth adjustment, so if you had one of these, you wouldn't need to do anything else. Does the D have the same linkage assembly where all you need to do is throw in an adjustable rod and you're done?? Not sure on that one.
I am wondering myself if i can throw in the new linkage adjuster myself... as far as I am able to tell both the d and the regualar version have the same eye's mount.

BTW - that shock looks great in there.

Also, There may be something in the way that I have the front forks set (up at 4-lines), perhaps I should lower those babies back to 2-lines.

What would the differnce be between the two-way adjuster and the 3-way penske? From their web-site it appears that the only difference (although a rather large one) is that you have both low speed and high speed adjustment.

Chuck says that if I am going to spend the big bucks, that I should be looking into the two-way.

more to come...
 

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Yea...that three way is A-LOT of adjustment capability. Far more than what many mere mortals can take advantage of. Not I. It'll be more money too. A three way simply has a separate hi and low speed compression adjustment. Still only one rebound adjustment. That is the difference between a double and tripple clicker.

Taking your forks back to two lines showing will aggrivate any turning problems you have now. Remember we were saying how the rear is too low?? Raising the front is the same difference as lowering the rear (for the most part) and goes further in the wrong direction from where you are trying to go. You need to raise the rear or lower the front...but, if you have 4 lines (and remember the seam on the fork cap doesn't count as a line) you can't go any further.

Remember though...this is also another personal preference area. I run 3 lines, and up until my last track day, I still had the stock ride heigth in the rear. Don't get too wrapped up in "I need to run this setting" or "I have to run that setting" Learn what works for you, and don't expect it to happen over night.

The only problem with you (and this is no flames against you personally at all) is all the problems and crap you've had to deal with on this bike, you don't yet have a good foundation to work with. If I were you, I'd just get the basics down...get your problems sorted out first, then worry about some simple basic changes to the bike (decent, simple forks and a shock) then leave it alone for a while so you can go learn and have a frigging good time.
 

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A used shock may be in need of a service - hence cheap

On a 3 way shock, the high speed compression circuit allows the shock to dampen certain forces more effectively than a 2 way shock. It is there to dial out quicker bumps, seams and ripples. There is no reason to keep adjusting it - you can put the adjuster in a middle setting and it benefits. However using too much or too little dampening will start to effect/alter the low speed compression circuit, so you need to be judicious.

For me the point of getting good suspension is to help you go faster. And when you put the good stuff on you will. Will a 3Way Penske make you ride faster than a 2Way - it might.
 

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Solving the top out spring mystery

Here's my rear Ohlins shock with newly installed top out spring. Jason at Dept. of Suspension did the work for me. New valves, seals, main spring, and of course the top out spring.
 

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Discussion Starter #20
galaxy said:
Yea...that three way is A-LOT of adjustment capability. Far more than what many mere mortals can take advantage of. Not I. It'll be more money too. A three way simply has a separate hi and low speed compression adjustment. Still only one rebound adjustment. That is the difference between a double and tripple clicker.

Taking your forks back to two lines showing will aggrivate any turning problems you have now. Remember we were saying how the rear is too low?? Raising the front is the same difference as lowering the rear (for the most part) and goes further in the wrong direction from where you are trying to go. You need to raise the rear or lower the front...but, if you have 4 lines (and remember the seam on the fork cap doesn't count as a line) you can't go any further.

Remember though...this is also another personal preference area. I run 3 lines, and up until my last track day, I still had the stock ride heigth in the rear. Don't get too wrapped up in "I need to run this setting" or "I have to run that setting" Learn what works for you, and don't expect it to happen over night.

The only problem with you (and this is no flames against you personally at all) is all the problems and crap you've had to deal with on this bike, you don't yet have a good foundation to work with. If I were you, I'd just get the basics down...get your problems sorted out first, then worry about some simple basic changes to the bike (decent, simple forks and a shock) then leave it alone for a while so you can go learn and have a frigging good time.
I totaly Agree with you - i have not been able to ride this bike problem free. But I forget to make the post online earlier, and it is good news, I have sorted out all the issues with my bike. There is no bumps, humps or any of that crap. There is a new set of forks on the front and they work amazing! Amazing in the sense that there is nothing mysterious happening with this bikes riding characteristic (that is not set-up related).

So Here is what my forks are sitting at (15mm) they are at 3-lines, as I just learned that the top line does not count... Over the winter I will be moving them down another line (maybe)...


As for the rear height, I measured the rod from the top of the threads to the top of the threads on the bottom, that was 235mm. Now I believe that you add 18mm from the top of the threads to the get to the centre of "eye". Added together that should give me a rear ride height of 271. Not to confident on these measurments I will make another round when I am not in such a rush. Unfortunately, I did not have a wrench that was large enough to fit around the hieght rods locking bolt. So I was not able to see if it will loosen - even though it is listed in the service manual that the DARK has non-adjustable rear height, there still is a factory painted line (see pic below). Although, even if I was able to unlock this nut, there is really not all that much room to to move the rear up much...



Finnaly, with one of my last quetions about suspension, I seem to be unable to use the entire front fork travel. I have been told, by the same guy that wants me to BUY BUY BUY more stuff from him (i don't like this man), that I have either a HYDROLIC lock or a physical bump stop in my front forks that will not all the travel to go down. My understanding is that I want the forks to travel more for when I am on the track (this is not a street bike) so I am not too worried about metal on metal contact. I think that I may step up to either the penske... if I can get a reasonable price on it.. or maybe the Showa model since they are easier to get at a more budget price. See pic below



Thanks for the help
 
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