Hyperpro shock for GRiSO 1100

Great. Once that it has worked for you it will be my starting point.

Hello Matias,

the European Song-Contest was so horrible I just went down into the garage and wrote down my setup:

preload: 1 cm of threads visible above upper ring
compression: 2,5 turns out from fully seated
rebound: 39 clicks out from fully seated

My bike is a 2006 with 45.000 kms. If your mileage is comparable the state of the old oil should be comparable as well and the setting should not be too far off.

In addition I found the settings of the German magazine Motorrad testing the GRiSO 1100 when it was new (fresh oil in the shock and the stock spring on the Sachs shock):

compression 1 turn out from fully seated (way more compression damping than my setting!)
rebound 9 "turns" out from fully seated (if they really meant turns instead of clicks this would be nearly fully open, which would correspond better to my "nearly open" setting. If this should be 9 clicks instead it would be way too slow from my experience.)

I´m curious to know where you finally find the sweet spot of your setup. Please provide feedback once you got it dialled in!

Best regards,
Matthias

Thanks for all the info Capitan !
My bike is the 2007 modelo and has 55.000 km on the clock.
But I am taking the oportunity to do a rebuild on the shock, including new oil.
For sure I will let you know what worked better for me, but I don't know yet when the spring will arrive, and I'm going on a bike trip on the 22nd off May. Probably I will only due it by the end of May.

Do you intend to service the shock by yourself or have it serviced? If you intend DIY have you got the tools to replenish the gas as well? It should be 170psi/11 bar and on the shock of my DR 650 I could use the MTB shock-pump for this purpose (Shrader valve). Refilling the oil worked after unscrewing the plate the compression-adjuster sits in on the reservoir. You just have to pump the shock until you feel no more air bubbles, then reinstall the plate with seal, apply pressure and mount the spring. If you don´t intend to do the internal seals this minimal approach could work on the Sachs shock as well. Shock oil usually is W2,5 or W3,5.

I'm going to have it done by a local service shop. The gas pressure is good information. You got that from Sachs documentation?
The guy told me he will use Motul Shock VI400 for the refill. Is it a good choice?

Any dedicated shock oil will do, they just differ in properties. Shock oil also lasts a lot longer than the usually heavier fork oil (heavier oil has longer molecule chains that break up during use, so it becomes thinner. Shock oil is thinner to begin with and suffers less).
The gas pressure is from my DR 650. As it has no damping or spring-tasks and should only keep the oil from cavitating the exact amount should not matter much. Usually Nitrogen is used, but as ordinary air also has 80% of Nitrogen I just refill my DR-shock with air – to no ill effect during the last 12 years.

The shock is back ....New seals, new oil, new spring. To refill it with gas the guy bad to install a schrader valve.
Still waiting for the damned swingarm bearings to proceed ....
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Why the hell did the company crank down on preload to the max? This is not necessary, in fact it will ruin the compliant part of the spring-travel!

Edit: The note from Hyperpro that came with my spring recommended a preload between 10 and 15 millimeters. Yours is about 40+ and way beyond manufacturer-recommendations and my experience.

Hi,
We were trying to follow the instructions that came along with the spring (pict below).
My understanding was that to get the required pre-load we should compress the spring 10-15 mm.
The spring had 170 mm in free condition (shorter than the stock one), so we left it with155 mm...
Did I got it wrong?
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I also have the SSB006 spring and have to confess that I never saw the springs side-by-side. I just told the mechanic swapping the springs for me to leave 10 mm of threads visible. As I installed the shock by myself I can assure you that my spring was really preloaded, not only mounted rattle-free.
This preload works both solo and with pillion (+65-80 kg total), is comfortable, but transparent in the faster sections. Compared to my previous settings I added 1/4 of compression and 1-2 clicks of rebound.

If you find your reworked shock too hard I´d recommend to reduce preload by quite a bit. This is much easier to do when not built into your bike though!

I was at the workshop when the mechanic was assembling the spring. He called me over so that I could test the shock hydraulics before assembling the spring.
I saw the springs side by side. The Hyperpro is shorter and I can tell you he was able to assemble it on the shock without the need of the spring compressor (with the adjusting rings completely unwinded there was space enough to insert the spring support disc on the other end of the shock(if you know what I mean). I didn't paid attention how much pre-load was applied on the spring with 10 mm of thread showing, but it couldn't be much...
Anyway, as soon as I will assemble the shock I will be paying attention to the sag. the Technical Datasheet says we should be looking for 15 mm of static sag...

Do you have any idea how much sag you are getting on yours (static sag, rider sag,...)?

Hi Matias and sorry for not replying earlier - I just happened to see your post. My sag should be right in the ballpark, at around 20% static and a good 25% with me sitting on the bike.

My spring definitely required the use of spring compressors, as the preload rings were touching the upper part of the shock body and the stock spring still had quite some preload. On the other hand the Hyperpro-spring with 10 mm of threads showing is definitely preloaded. Could they have swapped to shorter springs in the Netherlands while still keeping the same model number?

Have you put your bike back together and had an occasion for a test-ride?

Hi Capitan,
The stock spring had to be compressed to remove it from the shock, but the Hyperpro com be assembled without being compressed. It had 170mm length in free condition.

Unfortunately I am still waiting for the swingarm bearings to assemble the bike I ordered them from the UK (Stein Dinse didn't had them in stock) and they got stuck in Portuguese customs.....

I keep my fingers crossed for you receiving the parts before the riding season is over Once you got an occasion for a test-ride you´ll find out if your bike feels like a brick replaced the shock or everything is alright ...

BTW: I held my Hyperpro spring besides the shock and it definitely had a length that did not allow for installation without spring-compressors - weird.

Are you sure you got a stock GRiSO shock, not the longer Stelvio one?

Positively sure Capitan. I bought the bike brand new.

I was trying to find the SSB006 datasheet in the internet, but couldn't find it...
I came across this page from an Hyperpro shock.
Their definition for spring preload value is definitely (Free-lenght) - (Preloaded-lenght), and the instruction paper they sent along with the spring (posted somewhere in this thread) was mentioning 10-15mm of preload. For this preload they expect a 15mm static sag.
You say you are getting 22mm of static sag (considering a total wheel travel of 110mm), which confirms you spring has less preload. When you ride with passenger and luggage doesn't it get too low?

Anyway, as soon as I try it (please God, let it be soon!...) I will let you know how it feels like.
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From experience the rider sag is much more important than static sag and should be between 25 and 30 percent. Two-up I don´t feel too much sag and riding solo the bike behaves like I want it to: transparent on the quick stuff and at the same time as comfortable as possible. The progressive spring really is THE solution to reach this twin-goal.

You obviously installed your spring with 15 mm of preload, so you and I are not too far apart. If it feels too harsh you can easily take away 5 mm of preload to be in my ballpark. Notice, that at my amount of preload the shock NEEDS sufficient aid from the compression-damping not to wallow through it´s limited stroke. But I doubt that your amount of preload makes a lot of difference in this respect. An ideal adjustment of compression damping is – especially on a bike with such limited travel – key to a good riding experience and worth experimenting.

If our springs are the same, our adjustments are really far apart Captain...
Remember, you adjusted in order to have 10mm of thread showing, and I ajusted in order to compress the spring 15mm. Look at the picture below and imagine moving the adjusters 15mm up (no preload). How much thread would be showing?
Found also this other picture of a stock shock with an Öhlins replacement spring.
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hi everyone
i need a little help.
I decided to re-send my shock (which has an ohlins spring installed) back to the suspension center to do a check because i continued to feel it very harsh and hard.
Before repacking it, i measured the installed spring (printed codes are away so i cant read them).

Length: 190mm, ID=57mm, wire thickness=12,6mm
Original spring has same dimensions but wire thickness=11,4mm

Based on my little and far in the past experiences with springs, i'm not sure that this ohlins spring is effectively 110N/mm. Maybe the suspensionist confused the springs during last rebuild.

I also did some calculations and effectively it results in about 140N/mm despite the original one results about 96N/mm

Can anyone that has a similar spring measure the wire thickness and report the K of the spring here, to do a simple check?
Thank you in advance

In case it helps I measured my 6 inch (157mm) springs ... 135n/mm measures 12mm; 115n/mm measures 11.5mm & 85n/mm measures 11mm.

I've tried all three on Matris shock & never got great smooth ride. I'm currently running a Stelvio shock and it's OKish but still not great on rough roads - I tried softer spring on Stelvio shock & it didn't get better. I've sorted the front end by re-shimming the rebound & using extra light viscosity fork oil.

I followed your thread on 'the other forum where they charge you for advice' & looks like you are getting SAG in the right area (I can get in the range also). Maybe worth getting professional help; as I'm still looking for better rear suspension after 10 years of ownership - and wondering if it's just because it's long & heavy (& I am only 75 kg) !

I was not yet able to test my new Hyperpro spring because I'm still struggling to get my new swingarm bearings (it's a novel ....).
My spring has 170 mm lenght in free condition. I don't know the wire diameter now, but I will measure it next time I go to the garage. I don't know the rate of this spring either. I tried to look for the technical datasheet in the net but couldn't find it so far.
What kind of calculation did you do to come to the 140 N/mm? The ideal thing would be to do a Load/Deflection diagram, if you have the means for that.
It is also important to know if the rate of your spring is linear or progressive.
Hyperpro states this is a progressive spring. The rate value increases as the spring is compressed.
There are pictures of the Hyperpro and the Ohlins springs in my previous post. Hyperpo is progressive (distance beween the wire spirals is not constant), the Ohlins is linear.

@motografando: That spring weight must be way too hard for you, especially if there are threads above the locknuts showing. An Öhlins-spring for an STX-shock has the same inner diameter (57 mm), but only 160 mm of length [You must be registered and logged in to see this link.] A spring for a Breva is 10 mm longer and the Breva also got more travel to begin with.
I at 78 kg am in your ballpark weight-wise and would never try anything above 110 Nm – and even this spring would be at the minimum preload allowed for by the manufacturer.

@Mathias: In case you need further parts it would be easier to order from Italy, as it is still inside EU. I ordered my Hyperpro-spring from this shop [You must be registered and logged in to see this link.]

Matias wrote:

I was not yet able to test my new Hyperpro spring because I'm still struggling to get my new swingarm bearings (it's a novel ....).
My spring has 170 mm lenght in free condition. I don't know the wire diameter now, but I will measure it next time I go to the garage. I don't know the rate of this spring either. I tried to look for the technical datasheet in the net but couldn't find it so far.
What kind of calculation did you do to come to the 140 N/mm? The ideal thing would be to do a Load/Deflection diagram, if you have the means for that.
It is also important to know if the rate of your spring is linear or progressive.
Hyperpro states this is a progressive spring. The rate value increases as the spring is compressed.
There are pictures of the Hyperpro and the Ohlins springs in my previous post. Hyperpo is progressive (distance beween the wire spirals is not constant), the Ohlins is linear.

Thank you everyone for the support!

spring is linear.

this time i used this simple online calculator.
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many years ago, when i tuned up my previous bike myself, i used to calculate spring rates manually using mi physics textbook [You must be registered and logged in to see this image.]
based on vague memories of that i was suspicious because i remembered that, more or less, 12-13mm thick springs was very, very hard....

According to this calculator your current spring must be at least 124 Nm. This is even a lot for a 95 kg rider with luggage ... no wonder that your perception is "sitting on a brick".

el capitan wrote:

According to this calculator your current spring must be at least 124 Nm. This is even a lot for a 95 kg rider with luggage ... no wonder that your perception is "sitting on a brick".

Exactly.

A biker's ass doesn't ever lie

The only thing i can believe is that, because of on the spring there is no code, the suspensionist has made a big big mistake

motografando wrote:

The only thing i can believe is that, because of on the spring there is no code, the suspensionist has made a big big mistake

The unnecessary spring length of 190 mm would indicate this. Is there additional preload on that heavy spring? If so: take it out. The last thing you could try before swapping springs is a big reduction of preload and taking out compression damping step by step to see if things improve. But I fear with that spring installed these changes would only lead to minor improvements.