Basic Suspension Adjustments

[Baileyrock]

This is for after you have set proper SAG on your bike.

The Best way and what Most of use fail to do is to take the time to make changes (one at a time) a FEEL how that effects our bikes!

You should find a section of road (tracks even better) that has all the different types of turns and conditions that you would like you bike to handle better on. Ride the section at least once(maybe to & from a starting point) to get a base line feel for the bike. This is after you have set proper SAG and air pressures at home!!!

Now on most stock VFR's you really only have one adjustment you can make and that is the min. dampning adjustments on the rear shock. After you base run ride pull off the road and go Full Soft (CC) on this adjustment and ride the section again, feel how the bike feels now compared to before. Return and now set it at Full Hard ? and ride the section again, how does the bike feel/handle now? Better/worse than before? Which extreme felt better to you? Hard or soft or base? Whatever setting felt better is now where you start all over again. If it was the firmer setting, then work between the base and the full hard setting making 1 or 1/2 turn changes to dial in a feel that makes YOU most comfy on the bike! NOT what someone else does to their bike! <_<

With stock bikes you can try air pressure changes and Rake changes(raising or lowering the front or read of the bike "NOT SAG") by either shiming the rear shock or raising or lowering the the fork tubes in the triple trees. Raising the tubes(sliding tubes up) steepens Rake making for quicker turn in and left/right flicking of the bike. Tire type and profile can also make a huge difference.

Aftermarket suspension only adds more variables to set-up and that is why you should only make one change at a time so you can learn and feel what the change does to your bike. If you take the time to do this you will never be happier with your bikes handling. :thumbsup:

[Das Bone]

[fallzboater]

With stock bikes you can try air pressure changes and Rake changes(raising or lowering the front or read of the bike "NOT SAG") by either shaming the rear shock or raising or lowering the the fork tubes in the triple trees.

<{POST_SNAPBACK}>

Shaming the rear shock may make it feel low, but is just unkind. Be nice to your suspension, and it'll be nice to you.

[Trace]

Shaming the rear shock may make it feel low, but is just unkind.? Be nice to your suspension, and it'll be nice to you.

<{POST_SNAPBACK}>

Indeed. It's not nice to shame your shock. After all, you're the one who's screwing it one way and then the other..... :P

[Good post, good advice, BR :thumbsup: ]

[Baileyrock]

:lol: You guys are funny.

I really didn't mean to shame the shock, it's Honda that put them on our bikes!

I shamed the stock shock right off my bike! :P

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Cbr F3 Ohlins installed

[NVR2L8]

Good info for those of us who don't quite understand how to correctly set up the suspension. I do know setting it up for my size/weight and riding style should have been the first thing I did to my new VFR, but now that I've also lowered my bike, I'm probably way out of my league and should enlist the help of someone who knows what they are doing.

Maybe one or more of our SoCal VFR experts could offer to help...we could arrange some sort of "Suspension Day"? Thoughts???

[Guest SagaciousDupe]

Great advice!! Excellent point about the 'feel'. What is good for someone else may not be right for you. It's awesome when you get it dialed in...become one with the bike!

BR...hope you don't mind me adding one comment: If you start making changes make sure to take it easy the first time out! Check how it feels when braking etc. before getting on it!

[Baileyrock]

Great advice!!? Excellent point about the 'feel'.? What is good for someone else may not be right for you.? It's awesome when you get it dialed in...become one with the bike!

BR...hope you don't mind me adding one comment:? If you start making changes make sure to take it easy the first time out!? Check how it feels when braking etc. before getting on it!

Yes if we all weighed the same, rode the same and smelled the same than we could all use a standard setting on our bikes, but a guy who weighs 250lbs and a guy who weighs 150lbs will not have the same preload settings and even if they weighed the same their levels of skill or style of riding can require much different settings. Every bike and rider combo is unique and requires their own set-up to achieve optimal performance for that combo. Take to time to do this and enjoy a greater level of confidence on your bike in all situations.

Great point, I assume that people would do that automatically which I shouldn't !

This post is just a simple start to what could and should be done, add on!

[Trace]

I shamed the stock shock right off my bike! :P

Me, too!! (Thanks to BR for the spare shock bracket :thumbsup: )

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Comparing total length after making extendo-bracket. After all my measuring and worrying, it STILL ended up being about .5mm longer than needed. But it doesn't really matter, since the Penske has 12 mm of ride height adjustment available.

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Detail of bracket fab. Bolt head needs to be severely ground down to fit at top of shock.

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Reservoir hung on bracket w zip ties. I drilled holes in back of bracket webs for zips to go thru. (Holes are NOT thru the bracket to the front such that you can see them!!)

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My bracket is 32.5mm long. Your's won't be, so don't even try to compare numbers!! This is for a 954's Penske, so your numbers will definitely vary....

[ShipFixer]

Suspension tuning is relatively simple system dynamics. You shouldn't guess about feel with rebound damping from the extreme ends, the right way is to set it so that you're critically damped. This is the damping that will give you the shortest rise time while giving no oscillations. People change rebound according to whether they'd like the suspension to feel "firmer" or "softer," but rebound damping is really unable to alter those characteristics in a meaningful sense.

Set the damping soft. On the highway, bounce the rear a little with bumps or by going up and down on the seat a little. The bike should bounce down and come back up, without going back down again. If it does, this is oscillatory behavior. On the stock VFR shock, increase the damping one eighth to one quarter turn, and repeat. When the oscillation stops, your suspension is properly adjusted. (This may require someone riding alongside you to tell you if the oscillations have stopped.)

What are the risks if you just guess based on feel and SWAG it?

Too much rebound damping for a pseudo-firm feel only increases system rise time, not suspension firmness. What does that mean? The bike takes longer to return to equilibrium after you hit a bump...it doesn't resist the input from the bump any differently. How does that impact you? The suspension may not return to equilibrium soon enough to absorb the next bump...the only way your bike can react is for the tire to leave the pavement. This is one type of chatter over stutter bumps. We interpret this slow reaction movement as a "firmer" suspension, when its really just a maladjusted suspension.

Too little rebound damping has the obvious disadvantage of oscillatory behavior. You don't want that. The worst case scenario would be hitting expansion joints at the natural frequency for your combined mass, spring rate, and damping ratio...then you get resonance, which is a bad thing, and possibly the other kind of chatter. You can get wierd wallowing sensations in turns as your suspension is loaded and unloaded, which is another bad thing.

Real "firm" or "soft" feel can only properly be adjusted by spring rate, and somewhat by high and low frequency compression damping. Rebound damping gives you the feeling of "firm" or "soft," but not in reality. If you want a firmer suspension and the advantages it brings, you really have to change your spring rate...no other way to do it...

[Baileyrock]

Suspension tuning is relatively simple system dynamics.  You shouldn't guess about feel with rebound damping from the extreme ends, the right way is to set it so that you're critically damped.  This is the damping that will give you the shortest rise time while giving no oscillations.  People change rebound according to whether they'd like the suspension to feel "firmer" or "softer," but rebound damping is really unable to alter those characteristics in a meaningful sense.

Real "firm" or "soft" feel can only properly be adjusted by spring rate, and somewhat by high and low frequency compression damping.  Rebound damping gives you the feeling of "firm" or "soft," but not in reality.  If you want a firmer suspension and the advantages it brings, you really have to change your spring rate...no other way to do it...

All good,

But I'm Not trying to improve the book knowledge of anyone here about the suspension dynamics. Most people don't even set their SAG let alone anything else on there bikes, but when they do they can Feel a vast improvement in their bikes without knowing Dynamic Theory(or whatever the hell were talking about here). The Best racer/driver (doesn't matter wether it's a cage, MC, boat whatever) is the one who can FEEL what something is doing and how changes can effect that feel good or bad, this make's it much easier for the Engineers/team to improve the system for that driver. My use of extreme settings is to provide an obvious difference in FEEL that almost anyone could detect. This gives each rider a reference point they never had before and added skills that may allow them to pick up on the fact that their bike or any bike they get on isn't set-up right or that their rear shock is loosing oil/gas etc. It's all about gaining knowledge and for me "Feel" means much more than Theory when I'm rippen some twisties or doing a Track day. Now if I can add the understanding on top of the feel, it's a Bonus. I think for most of us it may be easier to feel what happens to the bike vs understanding system dynamics.

All my references to Firm/Soft are mostly related to a stock bike and the only adjustment (other than setting proper SAG) offered which is the knob that says "Soft--- Hard" on the rear shock, that's it. That is the soft or firm/hard I'm referring too and that little knob can make a major difference in how the bike Feels to every rider.

If my bike doesn't feel right I make changes based on some knowledge(not much) and lots of Feel experience, not a slide rule. :P

[vfrjim2002]

There are several treatises on suspension setup out there. I cant recall the links at the moment, but for those in need it would be worth the effort to hunt them down. Since the only adjustment we have available is rebound, a couple of quick tests can help with the setup. First, find a series of pretty sharp-edged bumps. Ride over them at speed. If each bump produces a secondary hit in the seat, the rear is under-damped on rebound (all we can muck bout with anyway). Add rebound (turn the screw toward "H") until sharp edged bumps produce only a single felt impact.

For the second test, find a stretch that's as close as you can get to a washboard. Now, ride this at speed. If the suspension feels increasingly harsh as you traverse the washboard section, the you have an excess of rebound which is causing the rear to "pack-down." The remedy is to reduce rebound until the bike feels the same at the end of the section as at start.

The fly in this ointment is that's the settings that generate the best result over one surface may be slightly over or underdamped for the other. If that's the case, setup for the one that best fits your favorite road.

Now if you have a rear/front with adjustments for compression damping, better still for hi and low speed compress damping the process gets more complicated. Complicated, but still doable.

Suspension set up can be a lot of fun. Put a bit of time into it and your bike will reward you. Have fun.

[teleskier]

gosh I can hardly wait to get the new Ohlins. Think I will start at factory settings and go from there unless someone has other ideas for my weight?

[ShipFixer]

But I'm Not trying to improve the book knowledge of anyone here about the suspension dynamics.

It doesn't require any real book knowledge I didn't give them the math behind it, just the end result.

The Best racer/driver (doesn't matter wether it's a cage, MC, boat whatever) is the one who can FEEL what something is doing and how changes can effect that feel good or bad, this make's it much easier for the Engineers/team to improve the system for that driver.

Yes, but they're part of a team with inputs from the engineers. They better understand what they're feeling, and know the difference between the harsh feeling of too much rebound damping and real firmer feel. This is why the systematic approach with a team works better than Max Biaggi using the force :goofy:

You see this all the time in all sorts of sports, particularly less well funded things like mountain bikes. Less knowledgeable racers jack up damping because it makes things feel firmer. But the guys who set theirs up as they're intended to be and get ridiculed by their friends for having a "soft suspension" go faster.

My use of extreme settings is to provide an obvious difference in FEEL that almost anyone could detect.

And that's usually used by teams to demonstrate the difference between those two feels. But that shouldn't be used to set the suspension. You'll put people down the wrong path this way, and increase the time before their bike is truly properly adjusted. They should adjust themselves to a properly adjusted bike, rather than one that they think "feels" right. Why put someone with no saddle time into the position of guessing at what's "good?" That's setting them up for tank slappers, chatter, wobbly mid-turn action, and all sorts of unhappiness.

[Baileyrock]

It doesn't require any real book knowledge   I didn't give them the math behind it, just the end result.

Yes, but they're part of a team with inputs from the engineers.  They better understand what they're feeling, and know the difference between the harsh feeling of too much rebound damping and real firmer feel.  This is why the systematic approach with a team works better than Max Biaggi using the force :goofy:

You see this all the time in all sorts of sports, particularly less well funded things like mountain bikes.  Less knowledgeable racers jack up damping because it makes things feel firmer.  But the guys who set theirs up as they're intended to be and get ridiculed by their friends for having a "soft suspension" go faster. 

And that's usually used by teams to demonstrate the difference between those two feels.  But that shouldn't be used to set the suspension.  You'll put people down the wrong path this way, and increase the time before their bike is truly properly adjusted.  They should adjust themselves to a properly adjusted bike, rather than one that they think "feels" right.  Why put someone with no saddle time into the position of guessing at what's "good?"  That's setting them up for tank slappers, chatter, wobbly mid-turn action, and all sorts of unhappiness.

You are so right on all accounts, what was I thinking? :goofy:

Thanks for your imput!

[hlf]

Suspension tuning is relatively simple system dynamics.  You shouldn't guess about feel with rebound damping from the extreme ends, the right way is to set it so that you're critically damped. 

<{POST_SNAPBACK}>

Do you have a reference that states that vehicle suspensions should be critically damped? I'd be very interested reading more. Thanks.

[VFR FLYER]

BAILEYROCK ROCKS! He is a very helpful and passionate rider who wants to share what he knows. we need more riders that are willing to help out! this time he was a little afield in thinking but not enthusiasim. he was the only one who mentioned the importance of tire pressure and that the pressure could very bike to bike, tire to tire, rider to rider. the best news is that we are all in this sport together and everyone wants to help each other. i was very glad that shipfixer jumped in and helped out, without being negative and flaming anyone. i wold like to here more of this subject. i for one thinks suspension comes after good safety gear and before performace mods! VFRD ROCKS! :P