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Thread: Preliminary Suspension setup on 2017 TF

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    apriliaforum Member bigrog's Avatar
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    Preliminary Suspension setup on 2017 TF

    Just to set the scene, I have recently bought a 2017 Tuono 1100 Factory, but for import duty reasons it isn't wise to bring it over to Malta until it is at least six months old. So I went to visit it earlier this month where it is kept in the UK, because I just couldn't wait that long to jump on it. Well the first ride was a bit of a disappointment, because the suspension set up was so off that the bike was like a pogo stick on the road. Back in the garage my son and I set about adjusting the pre-load. We found that the rear had zero preload (shame on you Aprilia) and the front had a bit too much. So I thought it might be of interest to give the results here.

    The theoretical basis on which I set the aims for the Rider sag front and rear were 30% of the full suspension travel. I was then looking for a Free sag (bike only sag) expressed as a percentage of the respective rider sags of 70% front and 25% rear. I used 112mm as the full front suspension travel, and 124.1mm on the rear, which I think is correct if the 2017 workshop manual is correct. (No doubt there will be different opinions on what the theoretical basis should be, but these figures worked very well for me on my Triumph Tiger with Andreani re-valving in the front and a Nitron shock on the rear).

    This results in the following theoretical aim numbers for the respective sags:
    Front: Rider sag = 33.6mm, Free sag = 23.52mm
    Rear: Rider sag = 37.23, Free sag = 9.31mm

    So we went about this by setting the Rider sag (I weigh around 92Kg), and then measuring what the Free sag turned out to be. This made sense to me since if you do the theory (it is also a bit intuitive) then it turns out that if the Free sag is too big, then the spring constant is too big and vice versa. So the Free sag is a direct indication of whether the spring is too stiff or not stiff enough. Being a new bike, the suspension is tight so stiction was quite high. We did our best to get a mean value for the sag by first lifting the suspension and letting it settle, then compressing it and letting it settle. But even so I would say that the measurements were not as accurate as the numbers would suggest, but they are Ok as an indication of what is going on.

    So we set the preloads to achieve the aim measurements for the Rider sag, and these were the measured results:
    Front: Rider sag = 34mm, Free sag = 28.5mm
    Rear: Rider sag = 38mm, Free sag = 10

    So it looks like the rear spring is pretty close to my theoretical aim, but the front is too stiff (and it felt so). It surprised me, but plugging the front theoretical aim and measured numbers back into formula 5 below, it turns out that the spring rate is 1.9 times what it should be (always assuming that my maths is correct)

    The effect of setting the pre loads was an immediate improvement on the road. I started backing off the damping on the rear, but because of the poor weather and limited riding time, I really didn't get to optimum. I guess that the front springs will need to be replaced at some stage, but I will contact Ohlins to get their take on it, before doing anything. Any one happen to know what the OEM spring rate is on the front?

    For the Curious

    Regarding no load sag, this is probably a simplified statement of the theory, because it ignores possible effects of air gaps and top out springs:
    If k is the spring constant Sf, is the Free sag, Sr is the rider sag, Mb is the bike mass, Mr is the rider mass and Mp is the preload mass. Then the balance equations
    For the Free sag is :
    Mb=Sf*k +Mp Ö..(1)

    And for the Rider sag:
    Mb + Mr =Sr*k +Mp Ö.(2)

    Substituting Mb in (2) and rearranging
    Sr=Mr/k + Sf ....(3)

    Hence for any Sr that is a constant (the desired rider sag), the Free sag is proportional to the spring constant, i.e. if Sf is too big then k is too big, If Sf is too small then k is too small.

    From (3) it also follows that k = Mr/(Sr - Sf) ....(4)
    Given an ideal spring rate of ki and ideal theoretical sag aim values of Sri and Sfi, then with the actual spring rate of ka, we set the Rider sag to Sri and measure a free sag of Sfm. It follows from equation (4) that the ratio of the actual spring rate to the ideal is given by:

    ka/ki = (Sri-Sfi)/(Sri-Sfm) ....(5)
    The Third Law of Human Dynamics: For every opportunity to communicate there is an equal and opposite opportunity to misunderstand

  2. #2
    apriliaforum prov-nov
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    Wow! And here I was thinking I fell into the rabbit hole of suspension.

    I agree, the front is stiff and ive been progressively dialling numbers and sag settings trying to find the optimal range. The rear should be in range considering we're both in range for weight and it is sprung a little heavier at the rear for pillion carriers.

    Can you advise how many turns of preload were required to achieve the numbers front and back ?

  3. #3
    apriliaforum Junkie ampj8's Avatar
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    Hi and welcome
    For my weight Iíve found it good for the road even with preload zero.
    The Sachs RR has some preload but there I assume different components.

    Reading the manual it is the basic setup.

    I did rode on race track with this setting which was good for a first contact with the factory and the track.

    No poggo-Ing at all neither rear or front. Have my GoPro facing front and can see forks working well in range during these rides.

    Anyway setup is a personal adjustment so thanks for this great explanation!


    Sent from my iPhone using Tapatalk

  4. #4
    apriliaforum Member bigrog's Avatar
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    Quote Originally Posted by Mikey666 View Post
    Wow!

    Can you advise how many turns of preload were required to achieve the numbers front and back ?
    No Sorry, we did it by adjust and measure until we hit the rider sag values that we were after. I can say that the front was close, maybe a turn on each leg, however the rear was quite a few turns of the adjuster ring. The difference was night and day better, but still not exactly as I would like it to be. Ohlins seem to have a reputation for being on the stiff side, maybe because they are more race focussed? However I prefer to think that they are quality products and incorrect user set up is the more likely cause.
    The Third Law of Human Dynamics: For every opportunity to communicate there is an equal and opposite opportunity to misunderstand

  5. #5
    apriliaforum prov-nov
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    After reading the above thought i would tinker into the realms of wizardry called suspension setup today.. Totally new in this area so thought it would be fun.. Must say a tad difficult working on my own and what with interruptions from er in doors didn't get too far.. BUT!!! This is what i have established thus far . All comp front and back set as per manual (standard road) Rebound on front was at 8 click instead of 12 so made a change there.
    front static sag is at 20mm , so would seem preload is wound in from factory/dealer. Rear Static sag is also at 20mm seem spring is at its max length, so that would also need a tweak.. Well thats it ,, not had chance to try with new front rebound and will probably wait until i get the sag sorted. Any tips welcome.. As i said new to this dark art and getting most info from the old youtube, but happy to take any advice from the masters out there.

  6. #6
    apriliaforum Member bigrog's Avatar
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    Quote Originally Posted by freddy871 View Post
    After reading the above thought i would tinker into the realms of wizardry called suspension setup today.. Totally new in this area so thought it would be fun.. Must say a tad difficult working on my own and what with interruptions from er in doors didn't get too far.. BUT!!! This is what i have established thus far . All comp front and back set as per manual (standard road) Rebound on front was at 8 click instead of 12 so made a change there.
    front static sag is at 20mm , so would seem preload is wound in from factory/dealer. Rear Static sag is also at 20mm seem spring is at its max length, so that would also need a tweak.. Well thats it ,, not had chance to try with new front rebound and will probably wait until i get the sag sorted. Any tips welcome.. As i said new to this dark art and getting most info from the old youtube, but happy to take any advice from the masters out there.
    Unfortunately since I don't have my bike here I didn't go any further with the suspension tuning so can't add any more actual experience with the Tuono. I generally start by getting the static rider sag where I want it to be. I then set the rebound in the ball park by winding it all out then pressing down on the suspension and letting it spring back up. It should just rebound up to the top and stay there. If it is underdamped then the it will go over the top and start compressing again. If it is overdamped then it will stop too abruptly or take time to get to the top. With my bike being so new, it was difficult to set this because of the stiffness in the suspension, so I erred on the underdamped side. I then set the compression to stock.
    Next stage is out on the road, I pick a quiet stretch of road which has a rough surface. I also make notes of every setting and how it feels, so that I can get back to it at any time. I only tune one end of the bike at a time, front first then rear. I would adjust the rebound one click at a time from under damped to over, and should be able to feel where it best suits me. I also check the rebound on the front by braking hard then releasing it and finding the point where it feels most stable, hopefully that coincides. With the compression damping I use the same under to over damped one click at a time technique, looking for the suspension to absorb the bumps without bottoming out (under damped) or throwing me out of the saddle (over damped).
    This process takes me quite some time to get right and even then I continue to tune for handling in corners and on different road conditions.
    The important thing is that there is no real right or wrong setting; it is right when it feels right for you and gives you confidence in the way the bike handles. Of course it is important to know what affects each aspect of the handling so that you can home in on the relevant setting. This is a good step by step guide
    The Third Law of Human Dynamics: For every opportunity to communicate there is an equal and opposite opportunity to misunderstand

  7. #7
    apriliaforum Member bigrog's Avatar
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    I recently emailed Harris Performance, who are one of the leading Ohlins distributors in the UK and provide support at race tracks. I expressed my concern that the front springs are too stiff for my weight but this was their reply
    "Our Ohlins technicians have read your email and feel the current springs are correct but suggest running 12-13mm static sag on the rear.
    We also suggest running the standard damping settings as specified in the users manual. "

    I am further confused by the Dave Moss thread post #14. Those sag figures seem to me to be too big, i.e. not enough pre-load. Mike06 weighs 100kg, but if the sag was set closer to 30% of full travel, that spring would look to be just about right for his weight. Dave Moss's Suspension Tuning Masterclass suggests 1.5" to 2" rider sag at the front which is 38mm(34% full travel) to 50mm(45%), but I am constantly reading that 30 to 35mm is the norm for a road bike. So who is right?
    The Third Law of Human Dynamics: For every opportunity to communicate there is an equal and opposite opportunity to misunderstand

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    apriliaforum expert plocky's Avatar
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    Hey there bigrog, I get the impression you are starting to over think this, any set up is just a base & you need to adjust to your individual riding style as Dave Moss's Suspension Tuning Masterclass suggests.
    Try looking simpler at first like in this vid, Dave Moss - https://www.youtube.com/watch?v=mK3flKxf41U

    When it comes to spring rate, this little bit of info is a gem.

    Suspension should not "top out" harshly. "Topping out" occurs when the suspension extends to its limit.
    It should barely have enough force to top out without the rider on board.

    Too Little Free Sag = When static sag is correct and the free sag is less than the minimum recommended, (e.g., it tops out hard), a heavier spring rate with less preload is needed.

    Too Much Free Sag = When static sag is correct and the free sag is more than maximum recommended a lighter spring with more preload is needed.
    www.totalcontroltraining.net/Suspension101eBook.pdf
    2015(16) RSV4 RR Ascari Black 201HP

  9. #9
    apriliaforum Member bigrog's Avatar
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    Quote Originally Posted by plocky View Post
    Hey there bigrog, I get the impression you are starting to over think this, any set up is just a base & you need to adjust to your individual riding style
    Not so sure I am, I have personally rebuilt/installed springs and Andreani valves in my Triumph Tiger plus a Nitron shock on the rear with great results. I agree that tuning the suspension is down to preference and rider style but that is generally within certain well established empirical parameters. As you say one aim is to avoid bottoming and topping out the suspension and the key parameters in this are down to science, with the spring rate and rider sag settings being the major factors.

    However a word of caution on rider preference over theory and observation, and this was provided by Dave Moss himself in this article. He set up a range of bikes and everyone agreed that the difference was night and day. At the end of the article he secretly set all the damping to minimum and after riding it, there was a slight majority who thought that it was better, when clearly it could not have been so.

    What I have found interesting is Dave Moss's observation of tyre wear patterns and I just looked at my Tiger yesterday. Despite being happy with the way it is set, there are definite indications that I have a rebound setting problem. Sorting that out may or may not translate into a noticeable difference but I like that tangible evidence exists which can be directly translated into corrective actions.

    Quote Originally Posted by plocky View Post
    When it comes to spring rate, this little bit of info is a gem.
    That is exactly what I said up front to emphasise the importance of the free sag in relation to the correctly set (generally accepted range) of the rider sag. It looked complicated because of the theory bit (yup I am an engineer so like theory, but not so keen on black art), but the outcome was :
    When the rider sag is set then free sag will be what it is, and in general too much free sag indicates too strong a spring, too little free sag indicates too weak a spring.

    What I am having a problem with is that Dave Moss seems to like a lot of Rider sag, 38% of the front suspension travel on Mike06's bike and up to 45% from his masterclass. I just need to understand why you would throw away so much of the compression range at the outset, which would promote the possibility of bottoming out?
    The Third Law of Human Dynamics: For every opportunity to communicate there is an equal and opposite opportunity to misunderstand

  10. #10
    apriliaforum newb
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    Something that might be helpful is the Ohlins Setup App.
    Here are the middle of the road Sag settings for the 2017 Tuono Factory (21% Rear, 33% Front):
    Click image for larger version. 

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    Last edited by JNG; 12-07-2017 at 09:26 AM.

  11. #11
    apriliaforum Member bigrog's Avatar
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    A good summary of essentially Dave Moss's analysis to reading tyre wear. Its part of this missive which I have not read but looks to have a wealth of information for long cold winter nights.
    The Third Law of Human Dynamics: For every opportunity to communicate there is an equal and opposite opportunity to misunderstand

  12. #12
    apriliaforum Member bigrog's Avatar
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    Quote Originally Posted by JNG View Post
    Something that might be helpful is the Ohlins Setup App.
    Here are the middle of the road Sag settings for the 2017 Tuono Factory (21% Rear, 33% Front):
    Thanks JNG, that is interesting. Just dowloaded it and had a little play. I found it doesn't like decimal points in the masurements which is not really a problem, but took a bit of figuring out why it wouldn't calculate the sag.
    The Third Law of Human Dynamics: For every opportunity to communicate there is an equal and opposite opportunity to misunderstand

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    apriliaforum Member bigrog's Avatar
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    Quote Originally Posted by bigrog View Post
    I recently emailed Harris Performance, who are one of the leading Ohlins distributors in the UK and provide support at race tracks. I expressed my concern that the front springs are too stiff for my weight but this was their reply
    "Our Ohlins technicians have read your email and feel the current springs are correct but suggest running 12-13mm static sag on the rear.
    We also suggest running the standard damping settings as specified in the users manual. "
    I think I found the missing link on the front spring rate thing. The theory that I put up front is not correct for the Ohlins because of the top out springs. I found this by Peter Verdone in which he provides rule of thumb starting figures for rider and free sag. However he says "Complications in sag setting results in the use of top-out springs, such as Ohlins' use in their modern shocks and several companies are now including in their forks. These typically increase the free sag while having no effect on rider sag." Which is exactly what I was seeing, the free sag was about 5mm bigger than expected.

    Sorry if I am flogging this subject to death but I am using this as a bit of a jotter pad for my thoughts while also getting some useful feedback from you guys who have much more experience than I. One thing about the Ohlins App is that they are using sag to adjust for ride height, but they are keeping the geometry within some design criteria since the sag front and rear are not varying by the same increments.
    The Third Law of Human Dynamics: For every opportunity to communicate there is an equal and opposite opportunity to misunderstand

  14. #14
    apriliaforum expert DaveNZ's Avatar
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    Quote Originally Posted by bigrog View Post
    Just to set the scene, I have recently bought a 2017 Tuono 1100 Factory, but for import duty reasons it isn't wise to bring it over to Malta until it is at least six months old. So I went to visit it earlier this month where it is kept in the UK, because I just couldn't wait that long to jump on it. Well the first ride was a bit of a disappointment, because the suspension set up was so off that the bike was like a pogo stick on the road. Back in the garage my son and I set about adjusting the pre-load. We found that the rear had zero preload (shame on you Aprilia) and the front had a bit too much. So I thought it might be of interest to give the results here.

    The theoretical basis on which I set the aims for the Rider sag front and rear were 30% of the full suspension travel. I was then looking for a Free sag (bike only sag) expressed as a percentage of the respective rider sags of 70% front and 25% rear. I used 112mm as the full front suspension travel, and 124.1mm on the rear, which I think is correct if the 2017 workshop manual is correct. (No doubt there will be different opinions on what the theoretical basis should be, but these figures worked very well for me on my Triumph Tiger with Andreani re-valving in the front and a Nitron shock on the rear).

    This results in the following theoretical aim numbers for the respective sags:
    Front: Rider sag = 33.6mm, Free sag = 23.52mm
    Rear: Rider sag = 37.23, Free sag = 9.31mm

    So we went about this by setting the Rider sag (I weigh around 92Kg), and then measuring what the Free sag turned out to be. This made sense to me since if you do the theory (it is also a bit intuitive) then it turns out that if the Free sag is too big, then the spring constant is too big and vice versa. So the Free sag is a direct indication of whether the spring is too stiff or not stiff enough. Being a new bike, the suspension is tight so stiction was quite high. We did our best to get a mean value for the sag by first lifting the suspension and letting it settle, then compressing it and letting it settle. But even so I would say that the measurements were not as accurate as the numbers would suggest, but they are Ok as an indication of what is going on.

    So we set the preloads to achieve the aim measurements for the Rider sag, and these were the measured results:
    Front: Rider sag = 34mm, Free sag = 28.5mm
    Rear: Rider sag = 38mm, Free sag = 10

    So it looks like the rear spring is pretty close to my theoretical aim, but the front is too stiff (and it felt so). It surprised me, but plugging the front theoretical aim and measured numbers back into formula 5 below, it turns out that the spring rate is 1.9 times what it should be (always assuming that my maths is correct)

    The effect of setting the pre loads was an immediate improvement on the road. I started backing off the damping on the rear, but because of the poor weather and limited riding time, I really didn't get to optimum. I guess that the front springs will need to be replaced at some stage, but I will contact Ohlins to get their take on it, before doing anything. Any one happen to know what the OEM spring rate is on the front?

    For the Curious

    Regarding no load sag, this is probably a simplified statement of the theory, because it ignores possible effects of air gaps and top out springs:
    If k is the spring constant Sf, is the Free sag, Sr is the rider sag, Mb is the bike mass, Mr is the rider mass and Mp is the preload mass. Then the balance equations
    For the Free sag is :
    Mb=Sf*k +Mp …..(1)

    And for the Rider sag:
    Mb + Mr =Sr*k +Mp ….(2)

    Substituting Mb in (2) and rearranging
    Sr=Mr/k + Sf ....(3)

    Hence for any Sr that is a constant (the desired rider sag), the Free sag is proportional to the spring constant, i.e. if Sf is too big then k is too big, If Sf is too small then k is too small.

    From (3) it also follows that k = Mr/(Sr - Sf) ....(4)
    Given an ideal spring rate of ki and ideal theoretical sag aim values of Sri and Sfi, then with the actual spring rate of ka, we set the Rider sag to Sri and measure a free sag of Sfm. It follows from equation (4) that the ratio of the actual spring rate to the ideal is given by:

    ka/ki = (Sri-Sfi)/(Sri-Sfm) ....(5)
    Looking at your settings, for me, id remove some front preload, id aim for 38mm rider sag, and your rear with 37mm sag seems too much sag, and with only 10mm free sag, id say your rear spring is possibly too light. i would have thought you would be looking for 30-35mm (max) rider sag with around 15-17mm free sag. BUT, we all have our own ways as to how our bike is set up.
    It used to be "Rock around the clock" now its "limp around the block".................................In the shed...... Multistrada 1200, Termi full system with matching ECU, and ohlins SCU. KTM 640 supermotard, with full titanium system and a shit load of spares. (track bike) and a Bran spanking new 1290 GT. Torque monster.

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    Quote Originally Posted by DaveNZ View Post
    Looking at your settings, for me, id remove some front preload, id aim for 38mm rider sag, and your rear with 37mm sag seems too much sag, and with only 10mm free sag, id say your rear spring is possibly too light. i would have thought you would be looking for 30-35mm (max) rider sag with around 15-17mm free sag. BUT, we all have our own ways as to how our bike is set up.
    It is possible that a heavier rear spring may be needed. The OEM spring rate is 0.95 which is said to be “generally good for riders upto 180lbs”. (OEM fork spring rate is 1.05)
    Last edited by JNG; 12-07-2017 at 05:01 PM.

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