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 Rear Sachs shock

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stevie1
Carlotto
Carlotto


Posts : 43
Join date : 2014-05-18

PostSubject: Rear Sachs shock   Tue Jun 03, 2014 11:46 am

Reading through posts, it appears a viable option to replace the stock spring with an Ohlins 1093 around 800 pounds/inch, I'm ok with stock spring but my wife is most unhappy with the harsh suspension.
Does anyone have a write up to do this, or is it beyond the home mechanic without a full workshop!???.
I'm not after track day performance, just a bit more comfort for my wife.
Thanks
Stevie.


Last edited by stevie1 on Wed Jun 04, 2014 2:56 am; edited 1 time in total (Reason for editing : different info wanted)
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guzziownr
Biondino
Biondino


Posts : 220
Join date : 2013-12-23

PostSubject: Re: Rear Sachs shock   Tue Jun 03, 2014 2:29 pm

I had a local shop swap the spring as I do not have a spring compressor or the desire to MacGyver one out of innertubes and scrap lumber.

I did the de and re-installation with nothing more exotic than allen wrenches and the usual metric suspects from the toolbox.

Battery tray and muffler came off, the airbox was tipped up but not totally removed. It took longer than it should have but that is the way of it when I am in the garage.
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stevie1
Carlotto
Carlotto


Posts : 43
Join date : 2014-05-18

PostSubject: Re: Rear Sachs shock   Tue Jun 03, 2014 3:47 pm

Shock removal no problem, removed it last week to grease swing arm & shock bearings, spring compressors no problem, im actually after a method to do the spring changeout, or advice to practicality.
Thanks
Stevie
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stevie1
Carlotto
Carlotto


Posts : 43
Join date : 2014-05-18

PostSubject: Re: Rear Sachs shock   Wed Jun 04, 2014 2:54 am

Can anyone confirm spring lengths please, i have read in this site that an Ohlins spring 1091 or 1093 are suitable replacements, i see Guzziownr has replaced his stock spring with a 1092 (in picture he posted), i have looked at an Ohlins chart-this gives the following-1093=150mm, 1091=160mm 1092-170mm, i thought the 1093 would be longest??, but the chart has it as the shortest of the 3, i suspect the chart may be wrong??.
Also what is the actual lenght of the stock rear spring, i cannot find it written anywhere.
Many thanks
Stevie
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Grisodude
Tiradritto
Tiradritto


Posts : 312
Join date : 2013-07-02
Age : 55

PostSubject: Re: Rear Sachs shock   Wed Jun 04, 2014 3:49 am

Hi stevie1
I just had my shock rebuilt, the spring number as I see it is 01091-39-110.
Weight was 85 Kg for wife geared up and 90 kg for me + 20 kg for gear.
Re-valve as well (racetech)
I also made some rear pegs which help my wife move around easier.
See my post GRiSO rear pegs in GRiSO inspiration.

Harry
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guzziownr
Biondino
Biondino


Posts : 220
Join date : 2013-12-23

PostSubject: Re: Rear Sachs shock   Wed Jun 04, 2014 7:23 am

The 1092 was not quite long enough and needed to be snugged down with the adjuster.  It was cheap and available so in it went.

I am 102 Kilos in my Spongebob p.j.s and my wife goes on the GRiSO only under duress.
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stevie1
Carlotto
Carlotto


Posts : 43
Join date : 2014-05-18

PostSubject: Re: Rear Sachs shock   Thu Jun 05, 2014 12:57 am

Thanks form the replies gents, out of interest, how did the pillion passengers find the suspension after the respringing??
Thanks
Stevie
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Grisodude
Tiradritto
Tiradritto


Posts : 312
Join date : 2013-07-02
Age : 55

PostSubject: Re: Rear Sachs shock   Mon Jun 09, 2014 1:58 am

Stevie
Leanne and I liked it as the bottoming out of the shock took away the jarring in our backs.
All up it's a good investment.

Harry
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stevie1
Carlotto
Carlotto


Posts : 43
Join date : 2014-05-18

PostSubject: Re: Rear Sachs shock   Mon Jun 09, 2014 8:34 am

Thanks Harry, its on the to do list, once i locate a spring.
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Hacky
Tanabuso
Tanabuso


Posts : 93
Join date : 2016-01-07

PostSubject: Re: Rear Sachs shock   Sat Mar 12, 2016 4:40 pm

Grisodude,
In 2014 how much did the work on your shock cost and where did you have it done at?
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guzziownr
Biondino
Biondino


Posts : 220
Join date : 2013-12-23

PostSubject: Stelvio shock   Sat Mar 12, 2016 5:28 pm

I have a Stelvio shock in my GRiSO. Better spring and more travel. See if Mr. Roper has the one from the wreck. DW
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Hacky
Tanabuso
Tanabuso


Posts : 93
Join date : 2016-01-07

PostSubject: Re: Rear Sachs shock   Sat Mar 12, 2016 10:11 pm

Think I read under another thread that the shock from the wreck has been sold or at least promised to another forum member. Is that the case Pete?

Regardless details on the Ohlins upgrade still interest me Grisodude.
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Pete Roper
GRiSO
GRiSO


Posts : 3783
Join date : 2013-05-29
Age : 59

PostSubject: Re: Rear Sachs shock   Sun Mar 13, 2016 1:01 am

Not that I'm aware but if that is the case I'm sorry. Nobody has picked it up yet..... Nor has anybody given me any money.

I'm basically trying to help people out with their experiments because I can. This isn't part of my 'Business', I won't be getting rich by selling off bits of wrecked out shit. I'm sure that there are people who think my business is a licence to print money? If so anyone who wants to buy it can. Make an offer.

Pete
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Oz1200Guzzi
Don Abbondio
Don Abbondio


Posts : 1783
Join date : 2014-03-13
Age : 62

PostSubject: Re: Rear Sachs shock   Sun Mar 13, 2016 1:03 am

commonly called "first in, best dressed"
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Brent S
Carlotto
Carlotto


Posts : 39
Join date : 2015-10-19

PostSubject: Re: Rear Sachs shock   Wed Mar 23, 2016 4:50 pm

Gents, if I could jump onto the tail of this thread for a moment.......

Just had the rear sag measurements taken on my GRiSO at a local workshop this morning. Took the bloke about 30 seconds to say that the spring is too soft. Sag is around 35mm even with the factory-set preload wound down a long way. I was told that if the preload is tightened further, it may help with the sag, but the ride may get worse. I'm 78kg weight, so god knows how bad the stock Spring is for the larger lads amongst us.

Does anybody have a recommendation for a spring brand and specification that may work. Needs to be available in Australia. As much as this topic seems to pop up, I've had trouble finding recommendations from people who have swapped out their rear spring and who are happy with the result.

Thanks.
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ghezzi
Fra Cristoforo
Fra Cristoforo


Posts : 1699
Join date : 2014-05-22
Age : 59

PostSubject: Re: Rear Sachs shock   Wed Mar 23, 2016 5:28 pm

I would question those results as in most suspension is built around rider weight of 75 -80kg.
Was the 35mm static sag or rider sag? How much pre-load (in mm) has currently been placed on the stock spring? It will need to be removed first to measure this.

Go to your local suspension guru in Melb, there must be experts there.
Ohlin, Eibach, Penske springs approx $200. One of the brands will have a spring with correct free length and internal diameter.

From memory, stock GRiSO spring is rated at 9.6 kg.

But while you have the shock out for spring replacement, have the guru re-vlave it, approx $350.
This will net you the best value for money as the stock Sachs suffers from hydraulic lock, as in, it cannot flow oil fast enough for "hi-speed" compression damping (big/harsh bumps). The adjuster on the shock primarily controls low speed damping, or squat in corners.

I used these guys years ago for my Cali Stone.
[You must be registered and logged in to see this link.]

or .... [You must be registered and logged in to see this link.] have a good rep
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Brent S
Carlotto
Carlotto


Posts : 39
Join date : 2015-10-19

PostSubject: Re: Rear Sachs shock   Wed Mar 23, 2016 6:29 pm

Ghezzi, I thought it was odd too. The measure was the difference in height between the suspension at almost full travel (off the bike with me lifting the rear as much as I could) and then with me on the bike in normal riding position.

No idea how much exact pre-load had been dialled-in as the spring would have to be taken out to do this, and to be honest, the bloke assisting me didn't appear to have the time nor inclination to do that there on the spot.
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ghezzi
Fra Cristoforo
Fra Cristoforo


Posts : 1699
Join date : 2014-05-22
Age : 59

PostSubject: Re: Rear Sachs shock   Wed Mar 23, 2016 7:23 pm

Well there you go, he only did half the job and will sell you parts and labour based on his mis-information.

A. Measure topped out, or fully extended.
B. Measure static sag, the suspension at rest under the bikes own weight.
C. Measure rider sag, you on the bike in full battle dress in your normal riding position.

The following numbers may not be gospel, just an example for the explanation.
If A minus B = 10 mm (was considered to be normal)
If C = 30% of maximum rear wheel travel, then you have the correct spring and sag set up.

30% if GRiSO has 120 mm rear wheel travel = 36 mm. You are on the money here.

Now here is my theory.
If A minus B = Zero (or significantly lower than 10 mm) it would indicate the spring is too soft and heaps of pre-load has been wound on to maintain a rider sag near to our theoretic ideal of 36mm.

If A minus B = 25 mm (or significantly higher than 10 mm) it would indicate the spring is too hard and pre-load has been wound off, so it settles the the right height when you climb aboard.

When a spring is fitted to the shock, a degree of pre-load needs to be added to keep it all together. If the spring could float things like spring retainers would fall out.
I would suggest the standard Sachs shocks are a parts bin special for the Guzzi and a short spring has been used, hence the appearance of lots of pre-load on your spring. Bella was the same.

Compression damping re-valving will get you the best bang for buck with the Sachs, if you want better sex Sachs, buy a new shock.
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Brent S
Carlotto
Carlotto


Posts : 39
Join date : 2015-10-19

PostSubject: Re: Rear Sachs shock   Wed Mar 23, 2016 8:34 pm

Ghezzi, thanks. One thing I did notice was that when I attempted to lift the rear end to get to the top of the suspension travel, the thing barely moved. It was like there was zero 'upwards' travel. Would support the commonly held view that the standard Spring is too soft and has a heap of pre-load wound in.
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ghezzi
Fra Cristoforo
Fra Cristoforo


Posts : 1699
Join date : 2014-05-22
Age : 59

PostSubject: Re: Rear Sachs shock   Wed Mar 23, 2016 8:58 pm

We are only talking 1/4" of vertical movement of the chassis/seat measured directly above the axle.
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Brent S
Carlotto
Carlotto


Posts : 39
Join date : 2015-10-19

PostSubject: Re: Rear Sachs shock   Wed Mar 23, 2016 9:43 pm

One of those links you sent me (ProMech) is only around 25 minutes ride from where I live, so I might give those guys a try.

Thanks.
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guzziownr
Biondino
Biondino


Posts : 220
Join date : 2013-12-23

PostSubject: Re: Rear Sachs shock   Thu Mar 24, 2016 7:26 am

I really like my Stelvio shock...
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Ralf z
Tiradritto
Tiradritto


Posts : 315
Join date : 2014-01-02
Age : 49

PostSubject: Re: Rear Sachs shock   Thu Mar 24, 2016 4:26 pm

Am I thinking the only Avantage for the Stelvio shock in a GRiSO is the heavier spring and length?
As I thought it only has rebound adjustment and preload no compression adjustment and no extra reservoir like the GRiSO shock
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PostSubject: Re: Rear Sachs shock   Today at 1:41 am

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Rear Sachs shock
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