Ducati Monster Forum

Moto Board => Tech => Topic started by: darkduc7 on September 09, 2008, 05:35:47 PM

Title: spring for sachs shock
Post by: darkduc7 on September 09, 2008, 05:35:47 PM
hey, i'm looking to get a stiffer spring for my stock sachs shock (2001 M900). i've done a little research, but havent been able to find where to source one from. i know ohlins would probably fit, but i'd like a cheaper option if possible. looking for one good for a 200lb-ish rider, maybe a little stiffer since i might do some more 2up riding soon.

oh, and how about fork springs too, i have the non adjustable showas 50mm...

thanks for your advice in advance!!
Title: Re: spring for sachs shock
Post by: mmakay on September 09, 2008, 07:01:49 PM
Eibach or Hypercoil 2.25" ID springs are cheap.  6"-7" length should work.
Title: Re: spring for sachs shock
Post by: VisceralReaction on September 10, 2008, 12:22:03 PM
Here is where I got mine.
http://www.eshocks.com/hyp_make.asp (http://www.eshocks.com/hyp_make.asp)
Title: Re: spring for sachs shock
Post by: Ducatiloo on September 10, 2008, 01:17:21 PM
Quote from: VisceralReaction on September 10, 2008, 12:22:03 PM
Here is where I got mine.
http://www.eshocks.com/hyp_make.asp (http://www.eshocks.com/hyp_make.asp)

Wow that is cheep,  another winter mod [thumbsup]
Title: Re: spring for sachs shock
Post by: CairnsDuc on September 10, 2008, 01:39:50 PM
If you are going to respring, you should also consider a revalve.

The Shock was valved and setup for the spring you have now, why not send it to a specialist and have it serviced, revalved and resprung at the same time.

it will cost a bit more, but it will ensure that the rear of the bike handles correctly.
Also your rear shock is due for a good clean and service if has never been done from when the bike was new.
Title: Re: spring for sachs shock
Post by: darkduc7 on September 10, 2008, 04:33:25 PM
thanks for the advice and links guys. i definitly am getting the shock revalved at the same time, but i'm not sure the shop in my area would know where to source a spring for it either. i was just going to give them the parts and have them revalve and oil. if i were to get an eibach or hypercoil, what spring rate would i need for my weight? (200+) with some 2up riding?  ;D
Title: Re: spring for sachs shock
Post by: mmakay on September 10, 2008, 08:37:47 PM
Some 2-up?  650lb at a minimum.  Depends on how well you want it to work with a pillion ... and how much much your willing to give up riding solo.

You can find some good info here: http://www.ducati-upnorth.com/tech/suspensionspring.php (http://www.ducati-upnorth.com/tech/suspensionspring.php) 
Title: Re: spring for sachs shock
Post by: Speeddog on September 11, 2008, 01:42:23 PM
Section 8 spring chart is good.
Title: Re: spring for sachs shock
Post by: Smokescreen on September 11, 2008, 02:31:38 PM
I've got an 800lb Eibach I took off Julia's M900, PM me if you are interested.  If it matches the table for you plus one (it should be in between) I'm sure we can make a deal.
W
Title: Re: spring for sachs shock
Post by: darkduc7 on September 11, 2008, 05:27:57 PM
thanks for the replies, this is really helpful. if i'm reading the chart correctly, i would want a 10 nM spring. now, if i went with an eibach or hypercoil, they rate thier springs in lbs. what would be the equal to a 10 nM spring, and what legnth would i need? i know 5-7'' was mentioned, but what "exactly" would i need for my sachs?  ???
Title: Re: spring for sachs shock
Post by: mmakay on September 11, 2008, 06:39:51 PM
Quote from: darkduc7 on September 11, 2008, 05:27:57 PM
thanks for the replies, this is really helpful. if i'm reading the chart correctly, i would want a 10 nM spring. now, if i went with an eibach or hypercoil, they rate thier springs in lbs. what would be the equal to a 10 nM spring, and what legnth would i need? i know 5-7'' was mentioned, but what "exactly" would i need for my sachs?  ???

I don't think a 10 is heavy enough for 2-up.  Well, unless you only plan to ride with your 55# niece.....

The next chart down the page shows exactly what springs are equivalent in the 3 common measurements.
Title: Re: spring for sachs shock
Post by: Speeddog on September 11, 2008, 06:59:02 PM
For a 200# with no gear rider, that translates to 215# with gear, so the Section 8 chart says 10.5 kg/mm spring.
That's about a 590 lb/in spring.

You could go stiffer to compensate for riding 2-up, but you'll suffer when riding solo.
Title: Re: spring for sachs shock
Post by: ducpainter on September 12, 2008, 04:55:27 AM
The section 8 chart is correct IMO.

I have a 10 on my Ohlins and I weigh 180...no gear.

I've also noticed with the little amount of 2-up riding I've done the bike performs much better.

I don't think I'd compensate for 2-up if you primarily ride solo.
Title: Re: spring for sachs shock
Post by: darkduc7 on September 12, 2008, 05:05:02 PM
well, im not doing a lot of 2 up riding, but i just dont want to be bottoming out and having a crappy time when i do bring my 100lb girlfreind [thumbsup]. so, from what i'm gathering, a 11 nM spring would be a good comprimise?
Title: Re: spring for sachs shock
Post by: ducpainter on September 12, 2008, 05:09:07 PM
Quote from: darkduc7 on September 12, 2008, 05:05:02 PM
well, im not doing a lot of 2 up riding, but i just dont want to be bottoming out and having a crappy time when i do bring my 100lb girlfreind [thumbsup]. so, from what i'm gathering, a 11 nM spring would be a good comprimise?
I wouldn't bother....

my bike doesn't bottom with my SO and the correct spring.

Your choice.

If you don't ride 2 up much why not just give it more pre-load when you do?