Good shock for my GRiSO??

This comes from a Aprilia RSV mille R, can get it cheap. Needs a clevis type bottom connection.
Eye to eye is 325mm at the moment.

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Would this be a good shock for my GRiSO?

There's another thread going at the moment about a Stelvio shock upgrade that has lots of technical advice about the RSV4 shocks.
Basically, yes it has been approved by Ghezzi .

What year did it come from, which model is it & what spring is on it ?

Thanks Nobleswood, the shock has been offered to me for 150 euro so I bought it, emailed the owner for more info.

The spring:

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Ghezzi will have to identify that one for you, I can't tell what weight the spring is rated for

Klaas123,

Check out this thread

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Thanks! I see a problem, the clevis mount used in that thread is for people with long legs, I'm 174cm high (or short).

Klass, stock GRiSO shock is 318mm +/-.
Ohlin is adjustable in length, usually +/- 8mm. If it hasn't been tampered with from stock you would be able to adjust it back to 318mm. Although the GRiSO will handle/turn better with shock lengthened 10mm.

Ohlin have a short and long clevis mount available, both are adjustable.

Waterbottle did this mod with a Tuono Factory shock, contact him for a few tips on spacers etc.

Your spring:
01093 = 150mm free length.
59/150 = 15.3kg/mm spring rate (for fat bastards) Actually, it indicates a higher rate rocker ratio and longer wheel travel on the Aprilia.

PLEASE CHECK STROKE LENGTH OF SHOCK IS SAME AS SACHS! (SHAFT TRAVEL)

Depending on your weight, a 36/105 might be more suitable, = 10.71kg/mm. GRiSO spring is 9.6kg/mm.
A stiffer spring correctly set will have your ass higher as well.

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Elton John shoes !

Ghezzi,

I pulled the trigger on a 2009 Aprilia RSV4 1000R Ohlins shock with a 01091 - 31/95 spring. Following your recommendation.

Cheers

Thank you Ghezzi!!!

I will need a different spring for sure, I'm 82kg without riding gear... Hope the travel will be long enough

Don't know how much Nob weighs, keep us posted on your experience.

Klass, a 34/100 could be a good match for your weight, all depends on total bike and ACCESSORY weight, riding style and personal PREFERENCE.

A WORD OF WARNING!
Before we purchased the 2015 Tuono Factory 1100 Ohlin shock for Waterbottles bike, I was able to bring it home and check it against my Bellagio & Matris for clearance issues.

Purchasing any shock that has been specifically produced for another make/model, can be fraught with hidden dangers.
1. Clearance issues, ie. fixed/remote reservoirs and hydraulic pre-load adjusters.
2. Mounting issues, ie. clevis/eye mounts.
3. Stroke length, ie. corresponding to rocker ratio and total rear wheel travel.

Will order a 34/100 if travel is equal or better then stock Sachs, thanks Ghezzi.

Some questions:

- What is the stroke length of the Sachs?
- What is the inside size of the original clevis mount?
- Size of mounting hole in original clevis?

klaas123 wrote:

Will order a 34/100 if travel is equal or better then stock Sachs, thanks Ghezzi.

Some questions:

Q1 - What is the stroke length of the Sachs?
Q2 - What is the inside size of the original clevis mount?
Q3 - Size of mounting hole in original clevis?

Dunno, but I'll go and measure it for you ............................

A1 - 48mm (without 24mm rubber bump stop)
A2 - 25mm (from memory - Ohlin clevis is wider, you may need 2 x 2mm (?) thick washers
A3 - 10mm (same as Ohlin)

Now I'll try not to bore you all with my mathematical theory .......................
We have a rising rate linkage setup, topped out it is approx 3:1, bottomed out its 2.3:1 = av ratio of 2.65:1 (2.65mm wheel travel / 1mm shock movement)
Ron put a shock without spring in a press, with a fare bit of pressure the 24mm thick bump stop rubber would squash down to about 6mm.
That would give shock shaft travel of 42mm, multiplied by the average rocker ratio of 2.65:1, means a GRiSO only has 110mm of wheel travel.

Aside from alterations to geometry, the potential "compliance" gains of a longer shock are two fold.
1. If it has longer shock shaft travel, it will equate to more rear wheel travel. = less bottoming, feels more compliant
2. Longer shock means the starting point (topped out) has the rocker and linkages moved further around their respective arcs. So in respect to the rising rate, the starting point could theoretically now be 3.2:1. This adds an even greater feeling of compliance.

Those who have installed a Stelvio shock in a GRiSO, confirm this.

Not boring at all to me Ghezzi, and thanks for the answers! Now I don't have to remove the Sachs 'till the Ohlins is ready Will update this thread with my findings.

Ghezzi,

I weigh in at 70 -75 Kg, so according to the spring chart, the 01091 - 31 will be the same rate as the OEM spring on the Guzzi. Which I think is a close enough place to start.

After reading several threads here on GrisoGhetto I took away the idea that the Tuono/RSV4 shocks could be made to work on a GRiSO.
Mind you Aprilia changed specs frequently so I'm not going to be worried about some re-working needed. Bottom line is the shock cost $360 US, a good price, if it doesn't work, I'll sell it on. No worries.

Next problem; I can't find a damn Ohlins parts catalog that lists the clevis pins.
So I'll have to wait for the unit to arrive, on my Birthday Wednesday, to measure the shaft & call around.

Should the spacers be metal or nylon or delrin or high densityplastic something ?

Nobleswood wrote:

Bottom line is the shock cost $360 US, a good price, if it doesn't work, I'll sell it on. No worries.

Exactly my thinking, paid 150 euro for mine

I live in a little country town called Brisbane, population 2.3 million. We got all manner of tech heads that rebuild motorcycle suspension for a job. Ok there are 2 specialists I trust within 20km. More if I wish to travel further.

I get the impression from various forums that they are few and far between in the US, like you have to ship your suspenders across country for specialist work. Here we just ride down the road. Maybe our roads are really shit?

In AUD$ terms $500 - $700 gets your stock shock re-valved and re-sprung.
$1100 will buy you a quality brand shock with basic comp & rebound adjusters.
You can pay $2000 + for bells and whistles varieties. So if you only pay $300 for a 2nd hand Ohlin don't just flick it in the bin after a simple test ride, develop it into what you really need.

Even if you buy brand new, NOTHING comes pre-set to perfection, you have to adjust it to your own personal needs.
My Matris has something like 20 Lo-speed compression settings, 20 Hi-speed compression settings and 30 rebound settings.
20 x 20 x 30 = 12,000 possible combinations. Only 1 of those 12,000 is perfect, 125 setting combinations will be in the ball park (5x5x5), and that is before I select the correct spring and add in the infinite variable of spring pre-load. So that leaves about 11,875 different damping settings that will be fucked up and give me a terrible riding experience. Get it?

My Matris R was purchased 2nd hand (unused) from the states for USD$1200. I'm now on my 3rd spring ($200 each) and I've had it stripped and internally modified 3 times (about $300 a go).
OK, some of that was to keep up with other bike development, like carbon wheels, losing 40kg and shifting C of G etc. Every time Scott has rebuilt the shock, measured sag and set the spring pre-load with me on it. He then bounces the bike and sets all three damping adjusters according to all his race bike set-up experience. Now its in the ball park 125.

From here it is up to me to ride it and adjust for my preferences. I don't ride smooth race tracks, I ride motocross tracks that have a thin coating of bitumen, in places.
First up, I add an extra 2 clicks of rebound to stop the bike booting me up the arse after every bump. Race bikes need to return to full ride height ASAP, I need comfort.
I also keep a little log book in my pocket, recording Scotts settings. Then I mess with each compression adjuster, one at a time I go +/- a click or 2 to see if it feels better or worse.
Then I record my impressions in relation to each of those individual changes. If I get bamboozled by the results I ring Scott and he tells me what direction to head in ......................

Whack an Aprilia shock in ya GRiSO mate, she be apples.  Yeah right!

Disclaimer: I'm not an engineer nor an engineers son, but I'll keep on fettling Guzzi's until my day is done.

ghezzi wrote:

So if you only pay $300 for a 2nd hand Ohlin don't just flick it in the bin after a simple test ride, develop it into what you really need.

That is the intention Ghezzi, I'm not a quitter by nature Do you have a starting point for compression/rebound settings for this shock?

OOPS! I edited my post while you were asking ...................

Klass123, A proper suspension tech will set your sag and bounce the bike each end and then in the middle (back of tank). Each end of the bike should squat the same distance, and rebound at the same speed. That's your ball park.

All I can suggest is find the appropriate Aprilia factory settings for the model the shock came from, or count the number of clicks from fully closed (clockwise), to fully open. Then set the adjuster in the middle.

Nobleswood, you may have to find an Ohlin dealer to order the clevis, only took a day for the Brisbane dealer to get one up from Sydney for Ron. He made his own alloy spacers, you may find steel washers of the correct dimensions.

ghezzi wrote:

Whack an Aprilia shock in ya GRiSO mate, she be apples.  Yeah right!

Disclaimer: I'm not an engineer nor an engineers son, but I'll keep on fettling Guzzi's until my day is done.

You are a great source of knowledge about suspension, thanks man!

ghezzi wrote:

OOPS! I edited my post while you were asking ...................

Klass123, A proper suspension tech will set your sag and bounce the bike each end and then in the middle (back of tank). Each end of the bike should squat the same distance, and rebound at the same speed. That's your ball park.

All I can suggest is find the appropriate Aprilia factory settings for the model the shock came from, or count the number of clicks from fully closed (clockwise), to fully open. Then set the adjuster in the middle.

I will write down the present settings of the shock and use them as a starting point before visiting a suspension specialist.

My comment about 'selling it on. ' Was to put your mind at rest that you had talked me into buying something that might not work.

I'm wearing big boy pants now & realise that, it might not fit. Ok. It's not a calamity. I'll find one that does.

Then there will be something on the bike that has a possibility of working. Then we can start tweeking & testing.

It does seem you have access to more suspension guys in your neck of the woods.
I live in the capital of Ohio with a population of 860,000 & haven't found a suspension guru yet. Some names I've picked up but haven't used are RaceTech, 100 miles away & someone near Indianapolis 170 miles.

I appreciate the education & the time it takes to clearly explain the details of working on the suspension. But it's a simple task.

Thanks for taking the time. I owe you beers , many, for your help so far already

Any recommendations for for static sag and sag with me in the saddle?

We will make it work with the great help of Ghezzi Nobleswood, any pictures of your Ohlins shock?