Setting Proper Sag

[Guest ratchethack]

I agree with Ratchet!

Dave. Are you sure?!

 

I b'lieve you oughtta sincerely re-think this.

 

Don't you owe it to yourself and to the Forum to ensure that this kind of thing NEVER happens here?

 

No, no. I don't think this is a good thing a-tall. . .

 

Where's that outside-the-box, progressive, post-modern , unfettered-by-logic, unbound-by-reason, liberated-sphincter, dream-state-spawned, blue-sky, wishful thinking??!!

 

It's so liberating to ignore all boundaries between fantasy and reality. . .

 

Such walls are so artificial and so confining and -- well, so cruel. By all means, let's keep all such distinctions as amorphous and etherial as a gauzy, shimmering veil of pixiedust softly drifting down from the sky on a starry, moonlit night. . .

 

I mean, if such a thing as a "V11 Hayabusa eater" is "real" and the weight of the rear brake lever alone applies brakes going over bumps enough to initiate heat/drag cycles , etc., WHY NOT a rising-rate V11 rear suspension made of 2-part urethane polymers that you mix up in your garage?

[polebridge]

FWIW a whole lot of crap abought just go learn to ride a and stop making excuses for lack of control or lack of ability.

 

I have been riding for 30 years. It's not about learning to ride, it's about enjoying the experience. Before setting sag properly my bike felt a bit 'reluctant' to turn. Kind of like it just wanted to stand back up instead of track at the angle I placed it into. After setting sag properly it really transformed the bike. Now it stears in a more neutral fashion and just stays were I put it. In my case it wasn't about learning to ride. It was about learning something about suspension that I only wished I learned a long time ago.

 

For anyone out there who isn't happy with the way their bike is handling this may be (maybe not) a very simple fix.

 

You must think yourself a very splendid rider I am guessing? Guys like Hayden and Rossi are really great riders and they spend an amazing amount of time every week setting up suspension on their race bikes. I can only guess that they also have their personal machines set up to their liking also.

Same goes for brakes tires etc.

[g.forrest]

I have been riding for 30 years. It's not about learning to ride, it's about enjoying the experience. Before setting sag properly my bike felt a bit 'reluctant' to turn. Kind of like it just wanted to stand back up instead of track at the angle I placed it into. After setting sag properly it really transformed the bike. Now it stears in a more neutral fashion and just stays were I put it. In my case it wasn't about learning to ride. It was about learning something about suspension that I only wished I learned a long time ago.

 

For anyone out there who isn't happy with the way their bike is handling this may be (maybe not) a very simple fix.

 

You must think yourself a very splendid rider I am guessing? Guys like Hayden and Rossi are really great riders and they spend an amazing amount of time every week setting up suspension on their race bikes. I can only guess that they also have their personal machines set up to their liking also.

Same goes for brakes tires etc.

 

 

splended maybe the wrong description. above average will do. i guess like me you hadn't heard of sag setting until recent times! too stiff or too soft would have been it previous. 30 years riding how many times would you have changed springs in this time..[ or did you do some road racing] my point was all this talk of infinite fine adjustment theories. i have been riding 38 years and it's only the last three years that i've had adjustment other than rear spring tension. now the problem was allways ground clearance. i'm not knocking anyone trying to improve the handling of their bike, far from it. ''but'' when an endless discussion

supposedly in reply to a question of ''my v11 doesn't like cornering'' i felt the discussion became BS. AND my reply was not to you or most others on this forum!

[dlaing]

splended maybe the wrong description. above average will do. i guess like me you hadn't heard of sag setting until recent times! too stiff or too soft would have been it previous. 30 years riding how many times would you have changed springs in this time..[ or did you do some road racing] my point was all this talk of infinite fine adjustment theories. i have been riding 38 years and it's only the last three years that i've had adjustment other than rear spring tension. now the problem was allways ground clearance. i'm not knocking anyone trying to improve the handling of their bike, far from it. ''but'' when an endless discussion

supposedly in reply to a question of ''my v11 doesn't like cornering'' i felt the discussion became BS. AND my reply was not to you or most others on this forum!

Your crap is so full of BS! EDIT I should be above this crap...

Nobody is talking infinite fine adjustment.

It is quite the contrary, simply a disagreement over formulas for rough adjustment.

One school of thought is 15/30 front and rear in balance and the other is more of something like 5/25 rear and 20/30 front.

EDIT my numbers are actually 8/25 rear and 17/29 front

Perhaps a fine difference to some, but hardly BS

[polebridge]

splended maybe the wrong description. above average will do. i guess like me you hadn't heard of sag setting until recent times! too stiff or too soft would have been it previous. 30 years riding how many times would you have changed springs in this time..[ or did you do some road racing] my point was all this talk of infinite fine adjustment theories. i have been riding 38 years and it's only the last three years that i've had adjustment other than rear spring tension. now the problem was allways ground clearance. i'm not knocking anyone trying to improve the handling of their bike, far from it. ''but'' when an endless discussion

supposedly in reply to a question of ''my v11 doesn't like cornering'' i felt the discussion became BS. AND my reply was not to you or most others on this forum!

 

I understand your point but I think it's interesting that you say you have been riding for 38 years and only recently have you tinkered with various 'adjustments'. I am thinking that maybe it is only with experience that we start to notice that things aren't quite right.

 

I do not agree that the discussion is BS but this particular thread does have a hostile tone to it.

 

Unfortunate because I think that the two main protagonists here are both quite knowledgeable and have both helped me in the past with some really good advice.

 

No offense to either (or to you) is intended.

 

38 years! Keep up the good work!

[dlaing]

I understand your point but I think it's interesting that you say you have been riding for 38 years and only recently have you tinkered with various 'adjustments'. I am thinking that maybe it is only with experience that we start to notice that things aren't quite right.

 

I do not agree that the discussion is BS but this particular thread does have a hostile tone to it.

 

Unfortunate because I think that the two main protagonists here are both quite knowledgeable and have both helped me in the past with some really good advice.

 

No offense to either (or to you) is intended.

 

38 years! Keep up the good work!

The hostility part of many of the threads I get involved in bugs me.

Certainly a few have found me offensive, but aside from the retaliation that I often regretfully resort to, I endeavor to be polite and respectful when I question authority, and non-authority.

The reason I created this thread was to spare slow kitty and others from having to watch us hash out any BS and find TRUTH. The people that have contributed positively are helping move us further from BS.

I have been swayed in Brian's and Ratchet's argument's direction, and I hope they been swayed in the direction of my argument.

Maybe it is also healthy not to forget g.forrest's argument that we should just ride the bike and not fine tune infinitely, but I don't think we have forgotten that, although we must have somehow given that impression.

 

EDIT

Here are MY recommended percentages without aforementioned modifiers, translated to mm, for anyone who cares.

 

REAR Sachs

10mm unladen 8.3%

30mm laden 25%

FRONT

20mm unladen 16.7%

35mm laden 29.2%

 

I think maybe some get annoyed by the decimal point. It does not mean that you should set it to such a fine degree, it is just a result of the math that helped me arrive at these numbers, and omitting the numbers might compound errors in the future. But I am omitting the extending decimals...For example 8.3 is actually 8 and a third.

[luhbo]

... and the other is more of something like 5/25 rear and 20/30 front...

 

Here they recommend a static sag of 28-33/5-10 for sportsbikes and 25-30/10-15 for comfy chairs. Sportsbikes are mostly ridden solo, touring bikes with two passengers maybe.

 

Ladden should be one third of the total stroke, sports or touring, this would make 40mm for the V11 front and rear.

 

They say you should go for the correct ladden sag and then try to adjust the preload a bit to get the static figures, probably not without new springs.

 

Hubert

[belfastguzzi]

I am looking for clear, straightforward and accurate information on setting-up front and rear suspension. I can't remember where I found the sources of info when I set-up the V.11

 

I've done basic stuff on the Griso but I want to go through it methodically, according to recognised procedures. Surely someone can write a simple description of the process and it can be posted in the 'How To' or the 'FAQ' Forums? This is a key topic of interest for everyone and I'm surprised to see that it's not easily found here. On a search, this thread was the main one that I found. Maybe I've missed something else that is here. I would have thought there's a case for the topic being a 'sticky'? If there already is a useful, comprehensive thread here, what about a Mod making it a sticky?

 

What I found this time, were the Sport Rider articles, also mentioned in this thread. Are there other articles that people can recommend? Maybe the Sport Rider stuff is as good as anything else. What say you?

I should have made better notes, last time.

[Guest ratchethack]

I am looking for clear, straightforward and accurate information on setting-up front and rear suspension.

The following links have served me well:

 

http://www.racetech.com/articles/SuspensionAndSprings.htm

 

http://www.strappe.com/suspension.html

 

and for final fork setup, this page on setting air gap:

 

http://www.peterverdonedesigns.com/oilheight.htm

 

FWIW, the first link above is an article written by Paul Thede, Pres. of RaceTech, a US Moto Suspension specialty co that happens to be the foremost trainer of moto technicians in the US on suspensions. The second link offers greater detail and IMHO is a good supplement, providing slightly different perspectives here and there.

 

Hope this helps.

 

EDIT: Leave us not omit the following little gem from Docc, which I b'lieve nicely puts all the above into proper perspective:

+ =

EDIT (Part II): Leave us also not omit the following sage prognostication from Skeeve.

FWIW, I'm definitely coming down on the side of "if the forks are too soft, increasing preload is only like putting a Band-Aid on a sucking chest wound: it may make it survivable short-term, but you won't like it."

[belfastguzzi]

The following links have served me well:

 

http://www.racetech.com/articles/SuspensionAndSprings.htm

 

http://www.strappe.com/suspension.html

 

and for final fork setup, this page on setting air gap:

 

http://www.peterverdonedesigns.com/oilheight.htm

 

FWIW, the first link above is an article written by Paul Thede, Pres. of RaceTech, a US Moto Suspension specialty co that happens to be the foremost trainer of moto technicians in the US on suspensions. The second link offers greater detail and IMHO is a good supplement, providing slightly different perspectives here and there.

 

Hope this helps.

 

Very good. Paul Thede's method is also used in that Sport Rider process.

I think the basics are pretty straightforward, but they're lost in the confusing and contradictory detail in this thread.

 

As a starting point, my static sag front and rear, as best as I can measure it, is 30mm both front and rear. That is in the right ballpark according to the Thede recommendations... but did I read in this thread that it's not regarded as correct for the Guzzi, at least for the V.11, for some reason?

[Guest ratchethack]

Very good. Paul Thede's method is also used in that Sport Rider process.

I think the basics are pretty straightforward, but they're lost in the confusing and contradictory detail in this thread.

 

As a starting point, my static sag front and rear, as best as I can measure it, is 30mm both front and rear. That is in the right ballpark according to the Thede recommendations... but did I read in this thread that it's not regarded as correct for the Guzzi, at least for the V.11, for some reason?

On the surface, I don't know why this wouldn't be considered anything but right & proper, BFG.

 

Unless the unladen sags are out o' whack. In this case, it'd be an indication your spring rates aren't within target range.

 

If you spend some time at the links I provided to understand the relationships between laden sag, unladen sag, and spring rates, it will shorten up your process tremendously, also keep the back-and-forth posts shorter and more concise -- that's right, even Yours Truly.

 

EDIT: YIKES! I'd omitted the word, "but" in me first sentence above. Hope this didn't throw too much sand in the gears!

[belfastguzzi]

Ahh. I see that this subject was raised again just recently in the 'Hard hitting forks' thread.

 

I've kind-of repeated it. Well, it highlights that it would be useful to have this subject cleaned-up and knocked into a more permanent, definitive post on one of the tech. forums. If not that, even a post with relevant links to previous threads and the external links that Ratchet has given.

[Guest frankdugo]

does the factory set-up of the bike use a "average weight of rider"?

[belfastguzzi]

does the factory set-up of the bike use a "average weight of rider"?

Average weight of an athletic Italian rider maybe.

[Guest ratchethack]

does the factory set-up of the bike use a "average weight of rider"?

Frank, this is just me, but I've always assumed that there is no "factory suspension set-up", and that dealers do wotever they please, which could be lots o' things -- meaning, anything from nothing a-tall to just about anything you can imagine, and possibly some things you can't. Now I don't b'lieve I'm being too overly presumptuous here, but IMHO any GOOD dealer should at least attempt to get things roughly sorted, particularly for the weight and riding style of the novice who isn't likely to know how to do his own chassis setup (or more often, doesn't know it needs to be done!), just so's the guy doesn't bottom out over his first nasty pothole followed by a dismount via a flying vault over the bars in pike position with a half-twist into the path of an oncoming Kenworth.

 

Dealers typically sell bikes without concern about spring rates. 'Nother words -- one rate fits all. This is where all the problems begin. Unfortunately, it only gets worse from here. The typical response to typically undersprung suspension is to dial up more preload in an attempt to compensate. Unfortunately, there's no free lunch here, and no compensation to be had thereby. . . it's impossible to get the sags in an acceptable range with the wrong spring rate.

 

Seems to me that far too many harbor a false justification for dangerous inaction (read that confusion/ignorance/fear). It seems to give rise to the rationale that if they don't do anything a-tall with suspension that they're "safe" because they're riding on "normal" settings for "normal" riders. IMHO there is no "normal" suspension setting of any kind. Best assume that whenever you take delivery, regardless of whether its bog-stock spankin' brand-new, or PO'd, it sure as hell ain't set up for YOU in any case, and you need to start with the basics of spring rate, sags and preloads first and work thru damping rates and ride height (on both ends if adjustment is available) to finish it off.

 

You seem to be poking around the idea of wondering wot you got, maybe chassis tuning if it's out o' whack?

 

Now SOMEBODY's just gonna go wild with apoplexy here and insist this is all wrong. But pay no attention, the woods heareabouts 'r full o' at least a coupla delusional nut-logs besides meself. FWIW, here's a little something to start with:

 

Take a read of the laden and unladen sags at both ends. With the stock 120 mm travel at both ends, you should have ROUGHLY 30-40 mm laden sag and 15-20 mm unladen sag. If you're looking for softer settings, go higher in this range, but the laden/unladen sags should ideally be on a 2/1 ratio. If you're much outside of this range, you can SOMETIMES get both laden and unladen sags closer to your "target range" by adding (or subtracting) preload. Front and rear sags should match as closely as possible -- or at least not be wildly off, particularly in opposite directions. If you can't get close to this range by adjusting preload, your spring rates are not properly matched to your weight, and you're well advised to re-spring.

 

Another way to look at this is per my handy-dandy rule o' thumb. Assuming you've got 30-40 mm laden sag, you should have ~18 mm +/- 5 mm DIFFERENCE between laden and unladen sag at each end. If you're +3 mm on the fork, you want to be +(something close) mm on the shock, and vice-versa. If you measure too far outside this range on the high side at either end, the spring rate is too soft. Outside this range on the low side, the spring rate is too stiff.

 

Now most guys have no clue wotsoever wot rate springs they're riding on. But generally, for all practical purposes on the road, and for "normal" riding (throw in the rest o' the usual disclaimers) if you weigh 180 lbs. fully suited-up (and don't carry cargo or a pillion passenger), you will require about .9 kg/mm fork springs and a 95 N/mm rear spring. This will allow your sag settings to fall within the above guidelines.

 

Hope this helps.

 

EDIT! Egads! I just took a gander at the ancient history of this thread from about a year back. If somebody starts dreaming up definitions out o' thin air and fabricating their own rules again, I'm outta here. This stuff is challenging enough without a loose bucket o' venomous false delusions rolling around on a pitching deck. . . Good frickin' grief, ain't life way too short for blithering absurdity?!?! Come to think of it, based on past history, it's only a matter of time before it starts again. . . [sigh] . . .