Ducati.org forum banner
1 - 10 of 10 Posts

· Registered
138 Posts
Discussion Starter · #1 ·
Looking for some guidance on where to measure from (exactly) and what number I should be shooting for. I'm using a corse dynamics ride height tool, TTX w/ DK linear link. I have the FGRT forks in CD 30mm triples set at 9mm to the cap showing, DK's recommendation. When I asked about rear number it's based off using the DK tool and at this point I don't know if there is any difference in the shape of the tools (they look pretty much the same in pictures but who knows).

I've read many of the excellent novela posts about chassis setup and was especially interested in the one that deconstructed ducati's intentions regarding the 848/1098 series' trail numbers and the relation to swing arm length. It was also interesting to hear that similar philosophies for setting up previous generations of superbikes applied just as well to the 848 generation chassis. I'm not going to pretend I understood most of it... But it all sounded pretty solid. Anyway, any help is appreciated. I'm going nuts not having ridden yet this season. I just want to get this done!

Also, when setting the rear height I'm guessing it's completely unloaded so I'll be putting the pegs on jack stand for this.
Motor vehicle Vehicle Tire Automotive tire Car

· Registered
2,127 Posts
Simply measure from the top of the tool to the center of the rear axle. I use a Race Tech sag tape measure, which is metric, works well.

I'm not a fan of DK's base numbers, he puts the bike too low to the ground and as a consequence, it has too much squat, which prevents front end traction. I've personally done many different configurations with that exact chassis and other Ducati Superbike's over the years, trying to find the best BASELINE setup and funny enough, I didn't need to do anything because the document below already does everything I did and explains why it's important to do.

So read this document and take your time. There are a lot of technical terms in it, which you can use google to translate for you. My suggestion is to go with what's written in this document as your BASELINE and then make adjustments from there.

http://madducracing.com/suspension/1098 geometry guide.txt

· Registered
7,504 Posts
Looking for some guidance on where to measure from (exactly) and what number I should be shooting for.

Also, when setting the rear height I'm guessing it's completely unloaded so I'll be putting the pegs on jack stand for this.
View attachment 86799
I AM a fan of Dan Kyle's set-up information.... here is some useful information....

#1Dan Kyle
Site Sponsor

Site Sponsors
2,936 posts
Joined: 28-December 06
Bike: 1098S 848 S1000RR
Posted 05 November 2009 - 09:44 AM
BEST setup for a 848 1098 1198

Kyle 30 MM offset triple clamps

Ohlins FGRT803 forks or
Comp 12 clicks out
Rebound 12 clicks out

Revalve of the OEM Ohlins forks to the same spec as the FGRT803 forks or
Comp 10 clicks out
Rebound 10 clicks out
Oil level with spacer installed 145 MM
Oil type Ohlins 1309 19 CsT @ 40 Degrees C

Ohlins 25 MM Cart kit for the Showa Forks
Comp 2 turns out
Rebound 12 clicks out
Oil level 165MM
Oil type Ohlins 1309 19 CsT @ 40 Degrees C

Height of forks using Kyle 30 MM offset triple clamp:
measured from the top of the triple clamp to the seam between the fork tube and the fork cap 6 MM to 13 MM.

The 13 MM will turn faster and be less stable.

Start in the middle 9 to 10 MM.

The heights will vary with rider preference and tire height differences.
Different tire brands have different diameters.

Kyle Track Link
Our track link requires the use of the DU788.
We mod the shock, making it shorter and changing the valve spec.
We have valve specs for the standard length OEM swingarm and the longer race swingarms.

With our track link and the OEM swingarm we start the damping settings at 10 click out for Comp and 10 clicks out on Rebound.

We also require a shortened Sato Height adjuster.
This will be set to about one thread showing on each end.
Using the ducati height adjustment measuring tool, we set the ride height at 235 MM, with a range of 230 to 240 MM.

Using the tool, this is measured with the rear of the bike FULLY extended, meaning there is NO weight on the rear wheel.
The measurement is taken from the top of the tool to the center of the rear axle.

Wheelbase length show be as long as possible.
The numbers measured from the center of the swingarm pivot bolt to the center of the axle should be as close to 504 MM as possible, with a range of 496 mm to 504 MM.

With the long swingarm the number is 510 MM with a range of 505 to 515 MM.

Rider sag with our Track Link should be:
Front 40 MM
Rear 30 MM.

In my opinion,
You have a number of things that are not so good on a stock 1098S.
They are in two parts.

The two can and do overlap, meaning that adjusting one can affect the other.

The one thing you want to be careful of is not adjusting one to fix the other.

The first thing to be corrected is spring rate and spring preload.

One more thing, IF you have the OEM 80 Nmm rear spring on your Ohlins shock and your Ohlins dealer told you to add preload, he does not know anything about the 1098S.
The OEM 80 Nmm spring already has too much preload on it.

The front fork springs are 10.0 Nmm
Depending on your weight they may be right, too stiff or too soft.

The same with the rear, but whatever the rear spring you use, you must reduce the spring preload by machining the preload nuts.

The OEM shock and forks are OK for street use, as far as the valving spec. But for ANY track use they are not any good.
You can revalve the OEM shock and forks.
Or replace them with the FGRT803 forks and the DU788 TTX36 Rear shock.

Here are rear shock spring recommendations with the OEM link.
To get the recommended 12 to 16 MM of spring preload the two spring preload nuts need to be machined. The plastic one on the 1098S will need to be replaced with an aluminum one.

1098 Shock Spring Recommendations
NOTE!!!!! This is with 12 to 16 MM of preload on the spring!!!!!!
Note weights are rider weight with gear, or take your weight and add 15 lbs for gear.

140-160 Lbs 80.0 Nmm
160-180 Lbs 85.0 Nmm
180-200 90.0 Nmm
200-220 95.0 Nmm
220-240 100 Nmm
240-260 105 Nmm
260-280 110 Nmm

For OUR Track Link stiffen rear spring by THREE 5 Nmm steps.So if you use a 90 Nmm spring with thye stock link we would go to a 105 Nmm spring with our track link.

These are the parts or mods I would recommend and the order I would recommend them.

If doing any of the items below, or all, saves you from crashing ONCE, you have paid for everything and more.

If you are going to ride your bike at a race track, track day, or race day, it does not matter,
Install the correct springs for your weight.

Set the sag.
This is with the bike suspension fully extended and with the Rider on the bike. The measurement is the difference of these two points.
For the street:
40 MM Front
30 MM rear

For the track:
Front 40 MM
Rear with the stock suspension link 20 MM to 30 MM
Rear with the Kyle Race Link 30 MM

Bikes with Showa forks

Revalve with 20 MM valves Good
Install Ohlins 25 MM Cart kit Better
Install Ohlins FGRT803 Forks Best

Bikes with Ohlins Forks

For the street the stock valving rides well, it will have a lot of brake dive, and bike movement. Good
Install Kyle Superbike valving Best
Install Ohlins FGRT803 forks Best

Bikes with Showa Shock
Respring the shock for your weight Good
Install Ohlins DU515 or DU520 Better
Install Ohlins TTX36 DU788 shock Best

Bikes with Ohlins shock
Install the correct spring for your weight, Machine the shock spring preload nuts to reduce the preload on the spring. OK for the Street Good
Install DU515 or DU520 Better
Install TTX36 DU788 Best

Steering damper
With Ohlins damper Best
With no damper (848) install Ohlins damper
With base damper Install Ohlin’s damper

Triple clamp
Stock 36 MM Clamp OK for street use, you will find for track use the bike does not have enough trail and tends to run wide on the exit of a turn under acceleration.
Ride height with the stock 36 MM triple clamps will vary with the tires you are using.
The rear ride heights at this time should remain stock.
The front fork height can be altered.

As you RAISE the front ride height you are adding trail, more trail will allow the bike to hold its line exiting a turn. This by the way is exactly what the 30 MM offset clamps do.
If the bike is running wide you can raise the front of the bike by pushing the fork tubes down. This should be done in very small step, I would try 2 MM at a time. You can continue to raise the front of the bike by pushing down the front forks until the forks are flush with the top triple clamp.
As you raise the bike up it will require more effort to turn the bike.
As you raise the bike it will tend to “feel” like it is falling into turns instead of rolling into turns.

You can install a Kyle 30 MM offset triple clamp, this adds the needed trail, and shortens the wheelbase which allows the bike to turn with little effort.
With our 30 mm offset clamps the fork height should be between 6 mm and 13 MM above our clamp. This again needs to be fine tuned depending on tires And rider preference. Again adjustments should be done in 2mm increments.
The 6 MM to 13 MM is measured from the top of our triple clamp to the seam between the fork tube and the fork cap.

Depending on the Tire you may have some rubbing if you are running 13 MM.

Suspension 101

Let me go over some basics on suspension. As if the basic stuff is not right no matter how much adjustment you do it will never work, Example it you front tire is at 10 PSI and the Rear 50 PSI do you think you can make the bike ever work right??
But everyone knows about tire pressure, the problem is everyone does not know about suspension, and must "gurus" do not bother to explain anything, a lot of times it is because the "gurus" do NOT KNOW.
My experience is if they cannot explain it to you, run away.

First always adjust your spring, do not tinker with the damping adjustments until the springs are right.
Front sag with rider 40 MM range 35 to 50MM
Rear sag with rider 30 MM range 25 to 40 MM.
Do not do anything until the springs and sag are right.

Now if, like in this case you are bottoming the bike, do not rely on a zip tie to determine this, if it is bottoming you will feel it.
The way NOT to stop bottoming, is more preload and or more compression damping, while this will slow down the dive it will make the bike ride harsh and not absorb bumps.

The way to stop it is by raising the fork oil level.
What does this do, the oil level does not have anything to do with the damping, as long as the fork valves are covered in oil they will work.
What changing the oil level does is REDUCE the amount of AIR in the forks.
Remember as you are compressing this air the PSI is building, just like more air in your tires, the more the forks are compressed the higher the PSI, the stronger the air spring.

This AIR is a powerful progressive spring, the less air the more powerful this air spring becomes. The great thing about the air spring is that is does very little in the first 75% of the fork travel, but when you approach bottoming out, this air spring acts as a second spring, holding the bike up. Without having to have a too stiff steel spring.

When adding oil to do this it MUST be done in very small amounts, usually 10CC per fork leg at a time. A very small amount of oil will make a big difference.
Rising rate suspension

What is it? Here is a good basic definition (taken from f1technical.net) with a few changes.

Rising rate suspension
A suspension system where the spring rate increases when the wheels move further in its travel. This action can be accomplished by configuring the geometric shape of the suspension, by using springs which change tension as they are compressed. The purpose of a rising-rate suspension is to maintain consistent ride and handling characteristics under a variety of situations: loaded or unloaded, straight roads or curves, and smooth roads or bumpy.

Ok, I will try and give a description on what is really does.

You have a rear wheel. This wheel has a travel usually around 120 MM on a Sportbike.

You have a shock, the shock travel is usually around 60 MM.

The two are connected by at least one link.

The link can have different designs allowing it to be Linear, meaning for each 2 MM of wheel travel the shock is travelling 1 MM, a 2 to 1 ratio.

Or you can design the link to be a progressive or rising rate link.

With a rising rate the options are endless. You can design it to do almost anything you want.

What we usually see is the travel, thru the first 50% (60MM) of wheel movement is very linear, meaning the for every 2 MM of wheel travel the shock is moving 1 MM.

Well what is happening in the next 60MM of wheel travel?? This is what is different.

What you may have is 60 to 70 MM of wheel travel the shock is moved 1.3MM
70 to 80MM of travel the shock is moved 1.6 MM
80 to 90 MM of travel the shock is moved 2MM
90 to 100 MM the shock is moved 2.5 MM

So what is happening, the shock and shock spring are moving more, they are moving at different ratios compared to the first 60MM of wheel travel.
So while it may take 60 lbs to compress each of the first 10MM wheel movements.
10MM 60 lbs
20MM 120lbs 60 lbs more
30MM 180Lbs 60 lbs more
40MM 240lbs 60 lbs more
50MM 300lbs 60 lbs more

Now it changes
60MM 78lbs more instead of 60 more 60lbs X1.3=78
70 MM 96 Lbs more 60 lbs X1.6=96
80MM 120lbs 60lbs X2.0=120

So what you feel on the bike is it takes more and more weight to compress the rear end.
This is great when you are selling a bike and have no idea how much weight is going to be on it, could be 120 lb rider 180 lb rider or a 180 lb rider with a 140 lb passenger. As this rising rate suspension can handle the different weights without bottoming out, which can cause a loss of control.

But when you know what the rider weights and it is say 180 lbs it works like crap as the rider does not weight enough to use all of the suspension.
As far as that 180 lb rider goes the suspension is pretty much doing the same as bottoming out, the suspension cannot use all of the available travel and stops moving, this causes a loss of traction and the tire, under acceleration, spins.

So what do we do, we make a new link that is more of a linear rate, less rising rate install a spring on the shock that is also a linear rate spring, and correct for that persons weight, and we get a more compliant suspension, that can use most or all the available travel, giving us more traction, hence the advantage at a track.

30 MM offset triple clamps

The advantage of these clamps is mostly at the race track, doing track days or racing.
The stock offset is 36 MM, these are 30 MM.
30 MM offset adds 6 MM of trail, this allows the bike to finish the turn better, allowing you to get on the gas sooner and hold your line better as well as better "feel" for what the front end is doing.
That same 6 MM change shortens the wheelbase making the bike turn faster and with less effort

53/53 MM Short stem

for 1098 Base, 1198 Base or any of the 1098/1198 series for use with the Ohlins Replacement R and T fork the FGRT803.

53/53 MM Long stem

These are for the 848 stock forks or the 848 using the FGRT803 forks.

53/56 MM Long stem or short stem.

These are for use with the FG511 Ohlins R and T forks.
This would be for the 1098S, 1098R, 1198S, or any 848/1098/1198 that you are mounting the OEM FG511 forks.

· Registered
235 Posts
BDC, I have a question about your CD 30mm Triples. Is that The Corse Dynamic triples? If so are you able to use them without modifying the frame and still use the Stock steering lock? I'm just starting to get the parts together and the info here is going to help a lot.

· Registered
138 Posts
Discussion Starter · #5 · (Edited)
BDC, I have a question about your CD 30mm Triples. Is that The Corse Dynamic triples? If so are you able to use them without modifying the frame and still use the Stock steering lock? I'm just starting to get the parts together and the info here is going to help a lot.
So the story with the Corse Dynamics 30mm triples is as follows: they were clearly designed for the original 848 and not the EVO. The top clamp will hit the frame piece for the the steering damper on the right before it hits those stupid little elliptical nubs that masquerade as steering stops. My temporary solution, for this riding season only, was to wrap the damn piece with duct tape until it stopped about 4mm from the frame. The future solution will be to have a shop machine new, larger stop nubs and swap them out.

Some bonus info about their compatibility with other parts I'm using may also help you. I use the Cox radiator guard, something else clearly not accounted for in design. I had to cut out some material from the top of the guard so the bottom clamp wouldn't hit it first; two U-shaped cutouts about an inch and a half wide on either side of the mounting brackets did it. I also picked up an Ohlins steering damper and the bolt that secures the damper bracket to the top clamp is not long enough because it's no longer threaded into the clamp itself, but rather a small bracket that now sits beneath. You need at least a 40mm bolt to thread in securely. I got lucky and found I could re-use one of the longer belt cover bracket bolts I ditched when I removed the charcoal canister and assorted junk from the right side of the bike. It was about 45mm and worked perfectly.

· Registered
138 Posts
Discussion Starter · #6 ·
Tuned/219R, thanks for the info. I have indeed read both of those thoroughly and that madducracing document was the one I mentioned. I'm going to start with 235 mm and see what kind of wheel base and trail numbers I'm getting with 14 tooth front sprocket and stock rear. I really just needed to know where to make those measurement with the tool (so top of the tool plumb down to centerline of axle is what I taking away from this).

In all honesty, I highly doubt I 'd even be able to distinguish better from worse at this point; that's just how much of a novice I am. I've only been a street rider and have yet to do first trackday... I just need it in the neighborhood of decent so I can start to get out, learn more and begin to understand what changes I need to make and how to actually evaluate them.

· Registered
138 Posts
Discussion Starter · #7 ·
So interestingly enough, it seems 245mm is the shortest I can set the ride height that's with the sato rod adjusted to nearly max. I could possibly get another 5 or so mm out of it but the lock nuts need some thread to tighten to.... Chain tension is also properly set at 32mm from center line of chain pressed against swing arm to hanging. I suppose 245 is not bad and it is a brand new spring, but I wasn't expecting to not even be able to hit the 235 baseline. Oh well. Time to button it back up and test ride. If I throw it down the road, I'll take it as a sign I did something wrong... Steering part Auto part Automotive exterior Steering wheel Vehicle
Finger Ruler Material property Measuring instrument Thumb
Auto part Fuel line Vehicle Engine Gauge

· Registered
268 Posts
Remember when you are setting the rear ride height, you have to have the rear wheel off the ground, but not using a pitbull stand. You need to support the bike from underneath. Like on the oil sump. The rear suspension has to be unsprung.

· Registered
2,127 Posts
Yea, most ride height adjusters are 14mm too long. If you grid or cut it down 7mm on both sides, that will give you the gap necessary to run a short ride height. However, if you read the document I posted, 245 is actually in the right range. Remember, swing arm angle is what your interested in, not some arbitrary Ducati numbers. The whole point of ride height is to prevent squat. Do a google search to understand what squat and anti-squat means, there are some good pages about it.
1 - 10 of 10 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.