Stelvio shock on a GRiSO riding impressions

So the shock has gone on and i have just gone 30 miles down roads i know well that also have some nasty bumps.

Here is what i found

1/ Just do it! why Moto Guzzi just didn't fit one in the first place i don't know
2/ Where did the ground go! its now a long way down, great if in the future i want to lower the pegs
3/ Ground clearance is no longer a problem, didn't go mad, but normally my boots would be all over the road, while trying to keep them tucked in, they didn't touch down at all, bodes well for sidestand and pegs
4/ Wow, real suspension!!! over some crap roads with big whoop type bumps no bottoming out at all, fantastic! The ride quality is also a lot better, see note below on spring rate.
5/ The stand works as well as it did, i was worried it would be too short, but its not

Set up. The front i left the same, with the forks dropped 5 rings through the forks, Preload is showing 5 rings and compression is 2 full runs out and rebound 1.5. To be honest i have not spent a lot of time on the front end, given how rubbish the back is. The rear i have set to 10 turns in for preload, and i cannot adjust the rebound at the bottom without someone on the bike as the adjuster is obscured. The spring rate is 11kg/mm and if i was being really picky i would try a 10.75kg/mm but am happy with what's on it as i sometimes take a pillion.

If that doesn't make you change, then i will get to the best bit. The front end. It is now a differnent bike, it almost feels slightly slower steering, but i am guessing that the extra weight on the font end has worked wonders. The bars never move, honestly its like a bloody sports bike, or someone has fitted a steering damper, the difference is night and day!

For all guys who have recently bought maxtrx shocks and are having problems, i would get a shock of 10.5kg/mm to 11.0kg/mm (i am 13 stone without bike gear), raise the ride height as high as it will go and then play with the damping, if you only get it as good as mine now is, it will be a revelation.

Along with Mark's maps its the best £165 i have so far spent on the bike, very very happy, feels like a new bike

Fantastic to hear you've cracked it Keith; sounds like a major step forward from Matris bullshit about tailored shock (and BTW getting stiffed by them for £705 in the process.) but that's my current problem as you well know...

....All we need now is to buy out a bulk order of stelvio shocks.....if I didn't feel so screwed over by Matris/biketorque, I'd be thinking a straight stelvio replacement (rather than GRiSO) should be same as OEM or better - but as they say 'once bitten, twice shy'...

Either way thanks for sharing some key knowledge; hopefully we all move forward (without shocking bumps)....

Paul, i think that with the correct spring you should be able to get the Martis shock to work, what is the spring weight and do you have the adjustable length version?

CLICKY HERE :-)

No....trying to change the spring as it is the 13.5 kg/mm (135N/mm) standard...after that agree I'll be in a better place

"Along with Mark's maps its the best £165 i have so far spent on the bike, very very happy, feels like a new bike."

Agree, and I got mine from Pinwall for $75. So Happy!

The damping on my Matris set up is superb, it's just the spring that is the issue. The shock will be up for a rebuild soon so I'll address that then but even with a stiff Spring it's streets ahead of the original Sachs unit.

Pete

The Matris shock that Pete put on my bike is just right for me. I'm 90kg without bike gear and the ride is fantastic thanks to Pete. I don't know what the spring is rated at but Pete could tell you.

I have available for those who may require;

1. Eibach 333060 spring (0500.225.0650) 11.61kg/mm
For you Pete if it suits. Off my Matris, free length 127mm -ID 58mm - wire 11mm - 3 coils

2. A complete GRiSO shock unmolested. Plus another stock 9.6kg spring

3. A Bellagio shock body - 310 mm eye-to-eye.

4. Bellagio 9.0kg spring FOR YOU SKINNY BLOKES - 188mm free length. will fit straight onto GRiSO shock.

5. Matris L133 K120 - 12.24kg/mm spring. Free length 133mm - ID 58mm - wire 11mm - 3.25 coils.

6. Ohlin 01092-69/170 L336 - 17.23kg/mm off a Honda Blackbird.
Free length 172mm - ID 56mm - wire 14mm - 5 coils

7. Hydraulic pre-load adjuster off Bellagio, machined to fit stock GRiSO Sachs shock.

I'd love to give it a go Wayne, thanks.

Pete

I'll send it down.
Being do some research on different brand spring rates. They all use different measurements.
Matris K120 I assumed was 12kg. No its N/mm which isn't to a simple factor of 10.
It equates to 12.24kg/mm

Eibach .0650 is lbs/inch, = 11.61kg/mm, yet both springs have very similar dimensions.

Interested in the common observation that the Stelvio shock makes the bike sit noticeably higher at the rear. Does this not increase the risk of the suspension topping out over undulations, noting the relatively short range of travel?

Stelvio shock is basically 10mm longer (330mm eye-to-eye) than a GRiSO Shock.
Ride height (measured vertically from axle) will be approx 30mm higher, rake will be reduced by approx 1 degree.

If there is greater shock shaft travel, this well equate to longer rear wheel travel, but topping out shouldn't be any different from standard GRiSO, considered all other things being equal.

Brent S wrote:

Interested in the common observation that the Stelvio shock makes the bike sit noticeably higher at the rear. Does this not increase the risk of the suspension topping out over undulations, noting the relatively short range of travel?

The shock is longer and has a longer stroke, so in my case i can actually set it up to have some sage which should help with it topping out. One the original GRiSO shock i had it set up without any static sage, for reasons explained earlier and didn't have too much topping out over undulations, mainly bottoming out. I guess the only time i may now have this problem is because of the increase in spring rate but my short earlier yesterday would say it all looks good.

Piaggio never seemed shy of trying to save a dollar, so wonder why they just didn't fit the Stelio shock to every GRiSO as standard, rather than having 2 different specs for the Stelvio and GRiSO respectively?

Probably because the cost to them was the same. As you state the bean counters are so tight they can peel and eat an orange without taking their hands out of their pockets. If there was a saving to be made they would of grabbed it, strangled it, stomped it and then locked it in a (cheap!) box for posterity!

Pete

I think they were making some hipster cruiser with the GRiSO, until everyone saw it and they realised how well it went. i read somewhere that when it was tested at the factory they raised the foot pegs an inch as they were wearing them away as it handled so well. By that stage, they were probably already committed to the shock and there would have been other changes to make, lowering the pegs again, longer side stand and as Pete says it is built to a budget.

Seat height as well. Years ago I loaned my buddy my stock '09 GRiSO for a month and he loved it except he was on his toes at a stop. Riding a +500 pound bike without solid contact with the ground was a bit unnerving for him.

All seems a bit perplexing this shock and spring rate thing. The Matris rear for example, you get charged an arm and a leg for a "customised" product, and it appears that you get the 135N spring whether you're 65kgs dripping wet, or heavier than the GRiSO itself. I'd be pretty pissed if I'd shelled out for that. However, I've got new Matris front forks, so god only knows what's in those. They feel good though, if slightly stiff, but even if they filled the fork tubes with wet cement it would feel better than stock.

I've got the Wilbers rear shock, and the only thing I'm kicking myself for is not measuring the ride height before and after, as I'll be damned if the bike isn't a bit lower now, post the Wilbers shock going in. Spring on mine is a 95N which is essentially the same spring rate as stock supposedly, although the spring coils looked thinner than on the original. No idea if this means anything or not. If Matris go "heavy" on their springs, Wilbers may well tend to go lighter. Heard at least 2 others mention this on various forums. Nonetheless, had a turn or two more preload added which seemed to have helped a bit, so can only really give it more time on the road to see if I have any issues with it bottoming out or not.

If I knew that the Stelvio shock was such a good match, I may well have gone for that and saved the cost of a whole aftermarket setup. Will keep watching these threads with interest.

Brent, i only went the Selvio route as i dont like spending money and wanted to see if it was the right way to go. Everyone seemed to point in the direction of an increase in ride height and harder spring, too be honest you could guess that after riding the bike for a bit.

The rear suspension now does what it is supposed to do, it is a huge improvement. I will see what the handling is like after giving it the berries, at the moment it has changed the front into something a lot more stable and make take some getting used to (probably 100 miles!).

I am then going to start on the front. If i am still unhappy then i will upgrade to something more expensive, now i know what difference it makes.

The problem sometimes with suspension is that everyone rides a bike differently and like different feedback.

It certainly looks as though its sitting higher at the back with the Stelvio shock

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These are the shocks for comparison

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No Easy Adjustment unless you get someone to sit on the bike

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Its an Ohlins.........honest!!!

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sidrat wrote:

These are the shocks for comparison

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Looks like the GRiSO shock is serviceable (separate gas tank with refill valve) while the stelvio is not (unless you fit a valve on the body which is possible).

Take a look at this.
It's an alternative solution to higher the back keeping the stock shock

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