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 Suspension fore and aft

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guzziownr
Biondino
Biondino


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PostSubject: Suspension fore and aft   Thu May 01, 2014 12:34 am

I managed to change the rear shock without shedding too much blood.  I winkled it out the top after removing the airbox and battery tray.  Here is what I replaced it with, a low miles used shock and an Ohlins 800 lb spring:
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Now that is settled I turn my attention to the front:
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Spring preloading is nut 3?  The more it "protrudes"  the more preload, yes?

TIA, DW
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Guzziboy66
Grignapoco
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PostSubject: Re: Suspension fore and aft   Thu May 01, 2014 11:53 am

I would think that the LESS it protrudes, the greater the preload. By screwing the nut into the fork, I think you are mechanically pushing down on the top of the spring. In essence you are loading the spring before (pre, prior) to it doing any actual work. Am I making any sense here?

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Pete Roper
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PostSubject: Re: Suspension fore and aft   Thu May 01, 2014 12:12 pm

Exactly.
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guzziownr
Biondino
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PostSubject: Re: Suspension fore and aft   Thu May 01, 2014 8:15 pm

Guzziboy66 wrote:
I would think that the LESS it protrudes, the greater the preload.  By screwing the nut into the fork, I think you are mechanically pushing down on the top of the spring.  In essence you are loading the spring before (pre, prior) to it doing any actual work.  Am I making any sense here?

Yesss, but the instructions say start adjustment from the fully closed, most rigid position (all the way clockwise). I will fiddle with it tomorrow and report.

DW
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pauldaytona
Fra Cristoforo
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PostSubject: Re: Suspension fore and aft   Thu May 01, 2014 8:25 pm

The shock looks just like stock? why not an ohlins from the breaker, here they go under 400
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Guzziboy66
Grignapoco
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PostSubject: Re: Suspension fore and aft   Thu May 01, 2014 10:29 pm

guzziownr wrote:
Guzziboy66 wrote:
I would think that the LESS it protrudes, the greater the preload.  By screwing the nut into the fork, I think you are mechanically pushing down on the top of the spring.  In essence you are loading the spring before (pre, prior) to it doing any actual work.  Am I making any sense here?

Yesss, but the instructions say start adjustment from the fully closed, most rigid position (all the way clockwise).  I will fiddle with it tomorrow and report.

DW

OK - I see what you read. I believe that they are referring only to screws 1 and 2.
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Uzidzit
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PostSubject: Re: Suspension fore and aft   Thu May 01, 2014 10:40 pm

this has some pics of the guts that make it easy to understand how the front fork adjusters work
[You must be registered and logged in to see this link.]

The valving on your stock with an 800lb spring will not feel awful turn the compression about 2 turns out, and close the rebound and then open about 15 clicks for the first run at it....spring rate is really the key in re-bound valving and the rebound stack in the stocker is way too slow so with a higher rate spring it starts to get better.

the 1/4 to 1/2 turn out most folks run the compression with the stock rear shock is due to the flaccid noodle of a spring the factory uses...you will need less and it will be a LOT less Harsh this way....

you may want to start at about 7mm preload on the spring and see how it looks
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guzziownr
Biondino
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PostSubject: Re: Suspension fore and aft   Fri May 02, 2014 1:26 am

pauldaytona wrote:
The shock looks just like stock? why not an ohlins from the breaker, here they go under 400

My stocker was $65 including shipping. When I got it I did not know about the possibility of a longer travel shock working. Perhaps next season.
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guzziownr
Biondino
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PostSubject: Re: Suspension fore and aft   Fri May 02, 2014 1:36 am

[quote="Uzidzit"]this has some pics of the guts that make it easy to understand how the front fork adjusters work
[You must be registered and logged in to see this link.]

So tightening the spring compression (#3) makes the center stick up more? In the workshop PDF it says to back off the spring compression before disassembly and the picture seems to show the center fairly flat.

Quote :
The valving on your stock with an 800lb spring will not feel awful  turn the compression about 2 turns out, and close the rebound and then open about 15 clicks for the first run at it....spring rate is really the key in re-bound valving and the rebound stack in the stocker is way too slow so with a higher rate spring it starts to get better.

So, close the compression clockwise and then open two turns? Then rebound as prescribed.

Quote :
the 1/4 to 1/2 turn out most folks run the compression with the stock rear shock is due to the flaccid noodle of a spring the factory uses...you will need less and it will be a LOT less Harsh this way....

you may want to start at about 7mm preload on the spring and see how it looks
Done, thanks. DW
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Uzidzit
Tiradritto
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PostSubject: Re: Suspension fore and aft   Fri May 02, 2014 11:42 am

The more of the silver stalk on the fork sticks up the Less preload on the fork, it pushes down on 3 pins in the fork cap which push down on a washer and load the fork spring.
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guzziownr
Biondino
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PostSubject: Re: Suspension fore and aft   Fri May 02, 2014 10:35 pm

Thanks, mine is currently showing two lines. I was doing the Guzzidiag thing today and then went for a ride on the the bumpy local roads. The heavier rear spring made a huge difference and I will start adjusting on Sunday when I have more time.
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guzziownr
Biondino
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PostSubject: Re: Suspension fore and aft   Tue May 06, 2014 12:00 am

I did a rough check of the sag front and rear and then did a baseline for the front and rear.  I will have to ride some to get used to the bike again after the winter.  The roads were clear and my favorite back road got a fresh coat of asphalt.  Good times.  See obligatory fuzzy cellphone picture below.[You must be registered and logged in to see this image.]
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DungeonMaster
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PostSubject: Re: Suspension fore and aft   Tue May 06, 2014 4:37 am

I was talking to a brother rider from work.
He was telling me how he was at the races talking to a guy from Lindemen Suspension.
The red head guy that owns the Laverda SFC - Kirk.
Kirk's recommendation was to balance out the front and rear.
Set your compression and rebound the same front and rear.

I have some adjusting to do!!!!
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guzziownr
Biondino
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PostSubject: Re: Suspension fore and aft   Tue May 06, 2014 1:55 pm

That's what I did as a base.  We are blessed with many tar strips, pot holes and frost heaves in my area so it is easy to go from smooth road to WTF in a local loop.
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guzziownr
Biondino
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PostSubject: Re: Suspension fore and aft   Tue May 20, 2014 8:37 pm

O.K. the front seems fine now.  Good feel for the road and no weird moments on our rough Spring roads.

In the rear I did as suggested and went two turns on compression and rebound.  Mine does not "click" so I just turned it closed and then opened it two full turns.

At normal speed and on normal bumps the rear is fine, I can fell it compressing and absorbing shocks.  At high speed the same bump hits super hard and abruptly.  It will also do this if two small bumps come one after the other.

What next, suspension sages?

Sunday's ride:  View of the Catskill Mts. from the Shawanagunk Mts.

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ghezzi
Fra Cristoforo
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PostSubject: Re: Suspension fore and aft   Thu May 29, 2014 11:28 pm

From reading this I take it you are more of a suspension novice than myself. Uzid (with the) zit is fairly switched on in these matters but a local suspension technician (read specialist) will be worth their weight in gold to you. I sometimes need my "guru" to draw me pictures with a red crayon from my Ronald McDonald colouring in set.

Somebody said "Balance" your compression and rebound front and rear. This doesn't mean same number of "clicks" or turns of an adjuster. Rather you need to hold the bike vertically and push down very quickly with both hands at the back of the tank. Both ends of the bike should squat and rebound the same distance and speed. The "guru" will determine much from this.

After he has set all your adjustments, this is just a base line. Then you play with minor adjustments one at a time.

A good experiment is to right down his base settings (so you can return to them later).
Then wind off all the rebound at the rear and ride a short test track of bumps.
Then wind on max rebound damping and ride the same bumps again.
With your new found knowledge of "extremes" and how bad it feels, return to your base setting.

It is good to record you thoughts immediately after each test loop.
Now from your base setting add +1 click of rebound, test ride and record how it feels
Then from your base setting go -1 click of rebound and repeat your test ride.

Its the only way us noobs to the black art of suspension can make any head way.

My suspension has approx. 12,960 possible combinations of damping, to me that just means 12,950 will be absolute shite, 9 will be somewhere in the ball park, and 1 will be spot on.
Actually the spot on '1', just means the best compromise for handling and comfort on our goat tracks.
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ghezzi
Fra Cristoforo
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PostSubject: Re: Suspension fore and aft   Thu May 29, 2014 11:50 pm

My experience with the GRiSO shock is the compression damping can go from "too soft" to "too hard" by moving it less than a cats whisker. My guru drew a picture of a hole with a blunt needle almost the same diameter approaching the rim of the hole. Massive oil flow and nothing changes in the damping as the blunt needle approaches. Then with in a very tiny range of movement the hole is blocked off.

A long tapered needle will ultimately give you much finer adjustments and finite control over your damping needs. I enquired about modifying the stock GRiSO Sachs shock but cost verses benefit ratio was very poor compared to spending less money for a better piece of equipment, as in the Matris.
My experience thus far for your benefit;
2nd hand GRiSO shock from Swaggz $100, new spring $200, re-valve/re-shim internals $350. (Modifying Bellagio hydraulic pre-load adjuster to fit GRiSO shock was extra). Still no good!
2nd hand but new Matris R still in the box, $1150, new spring $200, re-valve/re-shim twice $500. (This came from a heavy but previous GRiSO owner in the States.)
So far I've spent $2500 chasing rainbows & modifying other equipment not designed or built for me or my bike. If I just bought a brand new Matris R custom built for me and Bella, it would have cost less than $2000 incl shipping and taxes.
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guzziownr
Biondino
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PostSubject: Re: Suspension fore and aft   Fri May 30, 2014 1:56 am

We are just rounding in to peak riding season here in New York. I will be trying out your adjustment strategy as I enjoy the cool mountain air. No chance of me spending thousands on replacement parts -- you can't spend what you don't have.
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wardest
Grignapoco
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PostSubject: Re: Suspension fore and aft   Sat May 31, 2014 6:44 am

I just rode 450 kms round trip.
On the "B" roads full of bumps the factory setting is awful. I feel like I am riding a mobile rocking horse. My ass has never left the seat so many times on a ride. It feels like the front and back are just fighting each other.
I am 90 kg or 200lb. I am not breaking any speed records.
There has got to be a better setting for the stock equipment ? I don't have the budget for a new shock (yet). My bike suspension experience is limited so I don't want to make it worse.
what is a good starting point for sag height etc
But it sounds like I need a guru. Can anyone recommend someone in SYD area

Mike

Mike
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ghezzi
Fra Cristoforo
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PostSubject: Re: Suspension fore and aft   Sat May 31, 2014 7:39 am

You could do a lot worse than these settings:
Remember, your sag height will be achieved with less pre-load but compression/rebound will be in the ball park for you.

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Dave is a Qld'er, bought the first GRiSO in town 2007.
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Pete Roper
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PostSubject: Re: Suspension fore and aft   Sat May 31, 2014 9:59 am

Terry Hay at 'Shock Treatment' is the go-to bloke in Sydney. I used to have a bloke up here but he vanished to the US and hasn't returned.

Of you don't want to be 'Off the road' I think I've got a shock in the workshop you could use as a rebuilder and then send me your one when you swap it out. I'd imagine that a new spring and some re-valving work wouldn't be more than $4-500. Cheaper than a new shock.

Pete
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DungeonMaster
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PostSubject: Re: Suspension fore and aft   Mon Jul 14, 2014 3:25 am

A while back I got tired of getting hammered to death on concrete freeway expansion joints by my heavily damped front forks so I unscrewed the dampers all soft. And I left them that way.
Until this week.
I decided that the advice I heard about matching the front and back was Good and my back is heavily damped sooooo
I set the front rebound and compression All Hard.
Then I went riding to Newcombs on Hwy 2 today.
First stop I backed out both rebound and compression a half turn.
Next stop opened another half turn.
Now the front is feeling pretty good up in the twisties. I am thinking another 1/4 turn open and I should be good.
I will just have to stay off those Infernal freeways.
Or take my bike to Lindeman Eng.

DM
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mark111
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PostSubject: Re: Suspension fore and aft   Mon Jul 21, 2014 5:03 am

After riding my new to me GRiSO (2010 Tenni) with the stock supension I remembered why I had the rear shock rebuilt and the forks revalved on my old and now dead 2008 8v.
The roads north of Sydney are a great test and have again accentuated how harsh the stock damping is.

I am currently running 0 compression damping front an rear and it is still harsh over the crap rural roads we are provided with. Spring preload is appropriately softened and with suitable rebound damping setings for my 80kg in riding gear weight. The general suspension comnpliance on smoother surfaces is ok and the handling is good but sharp bumps continually anoy as the suspension struggles to deal with them.

I note a number of people have fitted a Matris rear shock (not worried about the forks as I will have them rebuilt locally) my dilema is do I spend a grand+ on the rear shock or spend around the same money to do forks and have the rear shock rebuilt.

To keep it simple, is the Matris (K model) shock a quantum leap and worth the outlay.
My previously rebuilt shock with racetech components performed well, much better than stock but was not a magic carpet ride.

My second question is do matris do a good job of matching spring rates for individual rider weights, in my new slimed down version I'm currently around 80 kg in riding gear.

70% of my riding is one up with the remainder split between a pillion and other times loaded with bags and rack. Obviously the default should be towards one up riding.

Feedback would be appreciated.
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ghezzi
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PostSubject: Re: Suspension fore and aft   Mon Jul 21, 2014 8:17 am

Started on my Bellagio with stock shock, rebound and hydraulic pre-load only. Compression was non adjustable and always felt like hydraulic lock (too harsh).

Bought second hand GRiSO shock off forum member, as you know it has compression and rebound adjusters but only lock rings for the pre-load.

I had the GRiSO shock re-sprung for my weight, modified the Bellagio's hydraulic pre-load adjuster to fit, and also revalved to suit. STILL TOO HARSH.

I was searching for compliance to absorb the bumps and handle, not be rigid and bounce off line on anything bigger than a cigarette butt. Actually, in QLD we don't have bumps any smaller than a house brick.

My suspension tech is Scotty Heyes (son of Roger Heyes). He commented that our Sachs damping needles are very 'blunt'. My experience with GRiSO compression adjuster is, there are no "click" positions, it just turns like a screw on a thread. A fraction of movement can go from too soft to too hard.

All that experimentation became a WOFTAM. My next "cheap arse" alternative was to buy an unused Matris R, built for a heavier rider with a GRiSO, which is heavier than my modified Bellagio. So again I had to re-spring and re-valve. Should have just bought the best for me and my bike the FIRST TIME.

My advice, get the Matris R. My bike is 217kg full wet weight and I am 100kg in battle dress.
Currently using a 105N/mm Eibach spring. Getting my head around both Hi & Lo speed compression damping, and how they work in sync has taken awhile. But it is worthwhile.

Be aware that Italy closes for August, their summer holiday. Matris are used to building high end RACE equipment, racetracks are SMOOOOTH compared to Aussie roads. So don't tell them you're a track day junkie and "You can pass Biaggi round de left hand side"
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Lenz9753
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PostSubject: Re: Suspension fore and aft   Sun Jun 21, 2015 10:43 am

Gentlemen ..... and others , I confess I bought my 2010 GRiSO based on the forgiveness that lust will do to a man. On reflection my choices in women and boats have an alarming similarity ...... HOWEVER the suspension on this beast is a deal breaker.

HARSH AND UNCOMPLIANT IS A GROSS FUCKING UNDERSTATEMENT  !

I've zeroed the preload on front and rear to establish a minimal preload baseline and also set compression damping at minimum to establish the static and dynamic sag. I'm @ 94kg min (look away children) and maybe 97 / 98kg with riding gear on. Static sag (rider + bike) on the front is 27% (89mm) of full suspension travel (122.5mm) and after an aggressive ride there is still 30.7mm left of unused suspension.

These observations suggest the existing front spring rate needs to be reduced by between 20% - 25% to reach the ~ 33% full static sag recommended for non-race usage on average roads. I haven't measured the full static sag at the rear wheel yet as a percentage of full rear wheel travel but I suspect the reality will be similar or much less than the 27% observed on the front. The rear suspension bears a remarkable similarity to my late grandfathers heavy duty, horse drawn dray.

It appears the std spring rates - unless the previous owner was 130+kg and changed springs - are significantly greater than my mere 98kg can justify on real life roads ...... another fucking project
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