Race Tech 5818 series spring for stock GRiSO shock?

Hello all!  I'm preparing to have my new GRiSO re-sprung, and wondered if anyone has used / can confirm the fit of Race Tech 5818 series springs on the stock Sachs rear shock?  Ohlins USA is proving to be a serious PITA to do business with, so I'm looking at the Race Tech which is listed as an alternate for stock applications that take the Ohlins 1095 series springs.  Specifically I'm looking at an SPRP5818116 58.2 ID x 178 OL  11.6kg-114N.  Have you used one and it fit?  Did you need any coil adapters, etc?

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Krag
'16 Moto Guzzi GRiSO 1200 8V SE in "I don't have enough tickets yet" red

It's a spring. If the specs are correct, why not?

I've played around with springs (on replacement Matris shock) & used Faulkners race springs which like the std one all seem to have same fitting ie no special adapters to fit them. Main thing is to get the right Inside diameter/Outside diameter/Overall Length/Rate within the range the Sachs base and the bike operating space allows .....  BTW Matris uses much shorter spring c.f. Sachs unit but only thing to watch is (for Faulkner at least) if you go higher rate spring, the internal diameter gets smaller - outside stays same.  Within normal range I doubt it has any impact.

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Just to follow up on this, got the RaceTech installed with no issues (with the spring at least, that upper shock bolt is a bitch). 5mm of preload got me up to 28mm of Rider sag, so looking good for an appointment next week with a tuner.

Good job, love to hear your comments post tuning.

I recently installed a Racetech SPRP 5818116 11.6kg spring on my 2011 GRiSO SE (after reading htis htrread) Test ride today and the rear end felt better for my weight (195 without gear). I had the rebound damping set to 40 clicks out. Dialed it back to 20 clicks. Preload adjusters basically where the I had them for the stock spring. So not set up; just basically winged it for now. Your experiences may vary, but increasing the spring rate a bit seemed to be an improvement. I was able to bottom out the stock setup on the potholed, frost-heaved roads.

I didn't (at this time) want to spend the $ on a new shock...and didn't find a Stelvio shock cheap.

BTW, removing the left side plate and supporting the bike with a steel rod through the frame allowed the shock to easily come out the left side.

89millegt wrote:

I recently installed a Racetech SPRP 5818116 11.6kg spring on my 2011 GRiSO SE

Are you running the stock fork springs? Seems they would need a bump up too?

Racetech 5818116 are $129.99. Eibach Coilover 0700.225.0650 are $70. Both 11.6kg/mm or 650lb/in.

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Eibach are used in Formula1 and Nascar. Their factory is just down the road from Racetech in Corona, CA. Not sure if that is what Racetech uses but would not be surprised.

I am running the stock front fork springs. I bumped the pre-load a bit. Seems like I’m getting full travel in the front (put a zip tie around the lower fork leg to see the travel) but never felt like the front was bottoming out.

Eibach spring seems to be the same and it’s even red like stock (racetech is blue) and it’s cheaper. I got my spring for just under $100 but would have gone with that Eibach spring and had beer money left over!

I should acknowledge, I took a guess at the spring rate. I'm not a suspension expert. New spring seems like an improvement for me.

From the "Reworkings Sachs shock" thread, the info I found when researching this was:

Source 1 - Bike sag = 11mm;  Rider sag = 27-33mm
Source 2 - Bike sag = 10mm;  Rider sag = 30-35mm
Source 3 - Bike sag = 3-5mm; Rider sag = 33-35mm
Source 4 - Bike sag = 10mm;  Rider sag = 30 mm

I targeted #4.  

So idea is, if the bike sags 10mm under it's own weight, then you sit on it and it goes to say 40mm (total, so the rider made it go down an extra 30mm) then your spring is way too light.

If it goes to say 20mm (total), then your spring is way too stiff.

For me, 155lbs, when I did the 95 N/mm shock spring the rear felt more stiff (spring wise) than the forks.  I'm just going on "feelings", so not very scientific.  

Seems stock fork springs and a 11.6kg rear spring would be imbalanced (unbalanced?).  

You could also check the bike & rider sag for the fork.  Hum, I have crappy notes on this ... seems like 5-10mm bike sag and 25-30mm rider sag on the forks.  Ok, here we go, I ended up with 7mm bike sag and 29mm rider sag on the forks.

But it all comes down to how you like it and how it works for you.

Did my rear shock and spring last week.

Rear shock length is 5mm long than stock mad by Wilburs so travel has increased

I have an Eibach 10.6 kg spring - 150 mm long
My weight without gear is 87kgs

Static sag - 10mm
Rider sag - 32mm

The preload on the spring is only a few mm . Few turns

Fork springs were also upgraded but not sure of the spring weight and gold valve mod.

Amazing difference in the ride.

If you are going for a 11.6kg spring I would be interested to know how you go getting your sag heights set ?

in case it helps I'm running a 115n/mm (11.5kg in your terms hopefully) on a matris with 15 mm static & 15 mm Rider sag (30mm total).....hence I'm looking to go lighter rate...

paulbrice wrote:

in case it helps I'm running a 115n/mm (11.5kg in your terms hopefully) on a matris with 15 mm static & 15 mm Rider sag (30mm total).....hence I'm looking to go lighter rate...

GDay Paul.

Interesting results. If its not too personal how much is the rider weight ? Is there a lot of preload on the spring.

Just trying to understand how this stuff works.

FWIW the tech was remove/install plus swap the spring on the rear shock in a little over an hour.
The shock was in out 4 times in a day.

The spring weight was always measured before install. The process ,the spring was compressed and force measurement was taken every 10mm. I guess an average of all 3 to check for spring weight.

I'm just under 80kg with kit on & not a lot of preload (I set preload to get to 30mm total SAG); I still don't feel any rear shock bottoming out.

Can do shock off and spring change in casual 1.5 hours - drop out below method preferred due to PITA getting inlet rubbers off air box & wiring/pipe issues for 'take out top' approach - but haven't got kit to check spring rate (I just use sealey VS1824, pic is on a stelvio shock)

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wardest wrote:

Did my rear shock and spring last week.

Rear shock length is 5mm long than stock mad by Wilburs so travel has increased

I have an Eibach 10.6 kg spring - 150 mm long
My weight without gear is 87kgs

Static sag - 10mm
Rider sag - 32mm

The preload on the spring is only a few mm . Few turns

Fork springs were also upgraded but not sure of the spring weight and gold valve mod.

Amazing difference in the ride.

If you are going for a 11.6kg spring I would be interested to know how you go getting your sag heights set ?

Might have something to do with the spring length you are running.  The Racetech spring referred to above and the Eibach is 7inch or 178mm long.  

You specify that yours is 150mm or a 6 inch spring.  Eibach does the 10.7kg/mm (600lb/in) in both 6inch and 7inch length.

Probably only Ghezzi can say whether the difference in length explains the sag question.  Does the 1 inch shorter spring mean you have reduced rear ride height?

Getting the shock out.
As i viewed it
Remove the seat and use 2 ratchet straps from a roof beam, kids swing,around each side the seat support frame adjacent the lugs that locate the seat.
Raise the rear wheel wheel 20mm off the ground .
Remove the (pork chop) frame piece right hand side that supports the rear wheel brake MC reservoir etc.
Beware the Brake light switch wire is attached with 3 p clips Allen screws. Remove the screws and support the part to keep the brake reservoir right way up.

Use a universal drive and socket to remove the upper bolt.
Remove the bolt from the lower end of the shock and remove adjacent bolt in the linkage
Raise the shock and tip the top of the shock left.
Out the shock will come on the left side of the bike.

45 min to remove and install.