Aprilia Tuono Rear Shock (Sachs)

[Nortwestrider]

Thank you sir.
I have the shock and will be ordering a spring soon.Do you know how much heavier the 180 spring is compared to the stock NC spring ??.I need a HEAVY spring.


Live life,be yourself !!!!.

 

[Ruggybuggy]

I have no way to measure the NC spring. What are your rider sag numbers on your stock spring. If my memory serves me correctly my rider sag was 54mm on the NC spring and now sits at 38mm with the 180mm X 120nm spring with my weight being 175lbs. Use those numbers to make an educated guess.

 

[Nortwestrider]

Mine is shot and I weigh 275# with gear so it doesn't work so well anymore.I'm doing some BIG mods to my NC this coming spring so I will need a very heavy spring.


Live life,be yourself !!!!.

 

[Ruggybuggy]

This shock will probably not work for you. The stronger the spring the length goes up (according to KFG racing). If the spring length is too long it would effect how far the spring could compress. Maybe someone else could build you a spring for your requirements. Damping with the Sachs could be a problem with a very heavy spring but you could roll the dice and see what happens.

Just thinking. If I have some time over the holidays I'll throw my wife on the back and see how much the bike sags with both of us on it (around 315lbs).

 

[Nortwestrider]

I had a spring made for my XT and my Vstrom and both worked pretty good and cost me around $125.On both of them I almost doubled the stock spring rate.


Live life,be yourself !!!!.

 

[Ruggybuggy]

I had a spring made for my XT and my Vstrom and both worked pretty good and cost me around $125.On both of them I almost doubled the stock spring rate.


Live life,be yourself !!!!.

If they can do an increase spring rate to about 150nm but still keep a length of 170-180mm It would probably work. When I turned in the damping screw on the Sach's shock it became very stiff so I would assume it coukd handle a heavier spring.

 

[Nortwestrider]

I was going to REspring the stock shock but I bought the SACHS shock in like new condition several months ago for $40.


Live life,be yourself !!!!.

 

[Ruggybuggy]

I wouldn't think you would be happy respringing the stock shock. Damping would be uncontrollable with the heavier spring.

 

[Nortwestrider]

That's why I jumped on the Sachs


Live life,be yourself !!!!.

 

[Ruggybuggy]

So I did some checks of the Sachs shock bottom bushing position with the suspension loaded and unloaded. My concern was that the bushing may fail if it was asked to rotate further than it was designed too. The stock NC shock uses a needle bearing assembly in the lower shock location. Comments on the result would be appreciated.

Before I loaded the suspension I marked the position on the shock/linkage relationship.

I loaded the rear suspension with a ratchet strap and compressed it to approx. 1/2 of the suspension travel. I could have gone further but I didn't want to do damage to the rear tail section by subjecting it to that kind of load.

This is the position of the shock before compression.

After compression. Doesn't really move to much.

Marked location of the shock/suspension linkage before compression.

Marked location of the shock/suspension linkage after approx. 1/2 compression.

This picture indicates the bushing location with rider compression.

I sure would like to compare this result to the Sachs shock installed in the Aprilia Tuono.

 

[LM15]

Again, a super writeup by Ruggybuggy...and with pictures!!!

 

[Antarius]

Yup, fantastic info in here.

 

[Ruggybuggy]

Yup, fantastic info in here.

Antarius, with you knowledge of suspensions what's your opinion on the amount of bushing twist? I did loosen the bolt, compressed the suspension to ride height then retighten so the bushing wouldn't be "twisted". You've been running yours for a few miles, how does it look?

 

[Antarius]

Antarius, with you knowledge of suspensions what's your opinion on the amount of bushing twist? I did loosen the bolt, compressed the suspension to ride height then retighten so the bushing wouldn't be "twisted". You've been running yours for a few miles, how does it look?

I've never had a problem with any shock that had either a rubber bushing or needle bearing. Ever. And I've swapped shocks on all sorts of bikes for years.

Mine on the NC looks absolutely fine and isn't falling apart or moving about. I've got roughly 5k on mine.

Mine is "twisted" when on the bike, by the way. I don't compress the suspension while I tighten the bolt.

 

[Ruggybuggy]

I've never had a problem with any shock that had either a rubber bushing or needle bearing. Ever. And I've swapped shocks on all sorts of bikes for years.

Mine on the NC looks absolutely fine and isn't falling apart or moving about. I've got roughly 5k on mine.

Mine is "twisted" when on the bike, by the way. I don't compress the suspension while I tighten the bolt.

Thanks for that post. Eased my mind!

 

[Nortwestrider]

Does anybody know what the stock NC rear spring rate is ???.
I just talked with RaceTech and they said the stock spring is 14.91kg/mm !!!.
This can't be right,my Vstrom 1000 was a 8.9kg/mm and it was a heavier bike.I bought a 15.kg/mm spring for the Vstrom and it was so stiff that my 275lb butt only moved it about 1" !!.


Live life,be yourself !!!!.

 

[Nortwestrider]

Well after talking with another suspension shop it seems that because of our rear linkage we have one of the heaviest rear springs out there !!.
14.9-14.5kg/mm !!!!!!!!!.


Live life,be yourself !!!!.

 

[Ruggybuggy]

Well I finally got a chance to ride the bike with the new shock installed. The 180mm X 120nm spring works very well. The ride is much more planted and when I hit the bumps that use to make me tense and think "this is going to hurt", nothing. Very happy with the result just choose your spring rate based on your weight. The 120nm spring works well for my 175lbs weight and I think it would work fine for heavier riders as well.

 

[Nortwestrider]

Do you know what the 120nm converts to in kg/ mm ??.


Live life,be yourself !!!!.

 

[Ruggybuggy]

Do you know what the 120nm converts to in kg/ mm ??.


Live life,be yourself !!!!.

Well just use a converter and translates to 12.23 kg-m.