Modern replacement shock absorber for GSX750ES

[GSX750ES junky]

I didn't.... but mine was off a very low mileage bike as well. I would put it on, see if you like it first.
If the $130 includes supplying & changing the seal & filling with Nitrogen again then that's a pretty good deal I would think (but I'd still give it a go first).

When you take the spring off you'll be able to check:

a. damping & adjustment is working fine (with the spring off)
b. it's not leaking

Does it have both oil and nitrogen damping ?
Will both be required to be replaced in case of malfunction ?

[posplayr]

This is one of the options for the rear shock


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'86 and '87 GSX-Rs have the same type ends on the shock. The spring rate would probably be too light, but adjusting preload should take care of that. Not sure of the length on them from eye to eye though.


Originally posted by Billy Ricks.

http://www.gixxer.com/forums/showthread.php?t=198803&highlight=shocking+condition

none of the GSXR 1st gen shocks are 330mm. 315mm at most

EDIT:

In the case of the SU635 it can be extend by 0.6" ???????

EDIT: Ohlins confirmed that 17mm can be added making the shock 315+17=332mm or 13.07" Apparently stroke is increased as well.

http://www.gixxer.com/forums/showthread.php?t=266658&highlight=ohlins+shock

[Billy Ricks]

Does it have both oil and nitrogen damping ?
Will both be required to be replaced in case of malfunction ?

Yes to both. The shocks usually have somewhere around 150-250 lbs of nitrogen in them.

[GSX750ES junky]

Today I opened the front fork.
The springs were 20mm shorter than service limit. The sonic spring replacement is on its way.
The oil was an extreme version of a rotten eggs soup. No surprises after 26 years I guess...
I also noticed that the oil seals are leaking and this surprised me since the previous owner replaced them 2 years ago.
1. Could it be due to friction with the corrosion on the chromed stanchions (see picture) ?
2. Do I need to replace them ? In case I need to replace them, can I trust these after market ones ?

http://cgi.ebay.com/SUZUKI-GSX750-GSX-750-FRONT-FORK-STANCHIONS-TUBES-/220737708698?pt=UK_Motorcycle_Parts&hash=item3364fe229a

3. The dust seals look OK. Should I replace them if I replace the oil seal ?

[GSX750ES junky]

Which year Ducati monster ?

On the stock I measured 325mm from hole to hole.

This one is 12'' (304mm).

http://cgi.ebay.com/ebaymotors/DUCATI-ST2-Monster-M620-800-900-ST4-Rear-Shock-_W0QQcmdZViewItemQQhashZitem53e0f12553QQitemZ360256185683QQptZMotorcyclesQ5fPartsQ5fAccessories

This one the picture shows 330mm

http://cgi.ebay.com/ebaymotors/Ducati-Monster-900-M900-REAR-MONO-SHOCK-_W0QQcmdZViewItemQQhashZitem2c5a5aca49QQitemZ190494460489QQptZMotorcyclesQ5fPartsQ5fAccessories

Come to think of it...Is it wise to put a 10 years old shock ?
Why not buying a new one ?

Salty Monk,
The other day you told me that you managed to fit the shock on the second link (Ducati Monster 900 year model 2000) onto your GSX750ES.
I bought it for 50$. It seems to be in pretty good condition but since I restore my GSX750ES with no compromises I decided to ask a friend of mine who runs a shop that restores high end shock absorbers to replace the oil, gas and oil seal.
This guy is a real pro but somehow he faced difficulties that he didn't face yet:
In the picture below you can see a red arrow pointing at a golden cap.
I quote what he said:
" I opened the golden cap and at this point (in all previous shock absorbers I dealt with) under the golden cap you push X which enables you to remove Y. Y secures the chrome rod. Unfortunately I'm not able to push X and I do not want to apply to much pressure because there might be a possibility that this shock is designed differently than all the ones I dealt with".

Any idea ?

[salty_monk]

No idea unfortunately... I never opened mine up. Good luck

[GSX750ES junky]

I want to email "Sachs" and ask them to provide a service manual or at least a drawing but I can't find their website. The only Sachs shock absorber I was able to find are for cars and they seem to be part of ZF transmission. company.

http://www.zf.com/brands/content/en/sachs/products_sachs/suspension_sachs/suspension_SACHS.html

[GSX750ES junky]

I talked to our main Ducati dealer and he says that these Sachs shocks from early 2000's cannot be serviced. Well, they can but it is very hard and very expensive. I decided to leave it as is. After all, the eBay seller says it had only 17,000 miles. Considering the way it looks it makes sense.

Salty Monk,
This shock was designed to a 170kg motorcycle. Our beloved GSX750ES weighs 220kg.
Did this shock work fine for you without having to replace the spring to a stiffer one ?
I mean...when you ride solo you apply the same weight as a couple of people would on the original Ducati Monster.

[salty_monk]

I tried it with the Ducati spring. Way too stiff with my 160lb butt... The leverage ratio on the ducati must be way higher.

I swapped the stock spring onto the Duc shock, the shock allows you to run more preload than the stock one & it worked out fine...

[GSX750ES junky]

"I tried it with the Ducati spring Way too stiff ..."

1. When you say Ducati spring you mean the yellow one that came with the spring I bought ? I only got it with a yellow one.
2. What is the stock one ? An additional spring from Sachs (what color) ?
3. If I understand correctly, a spring that came from a "too light bike" would not necessarily be too soft because each bike has its own suspension mechanism with its own leverage ratio...

[salty_monk]

1. Yes the yellow one that came with the Sachs Shock
2. The Stock one from the Suzuki Shock. I just removed it from the shock body, it comes apart easily with compressors.
3. Yes you are correct. The leverage ratio on the Monster must be substantially more than the Suzuki. It started to feel about right with 160lb of nephew on the back...

[GSX750ES junky]

LOL !!!
Thanks :-)

[Big Rich]

I believe he meant he re used the Suzuki spring onto the Ducatti shock.

This thread is a gold mine of info. Thanks guys!

[GSX750ES junky]

I removed the old spring, had it sand blasted and powder coated to have a perfect look.
I still wonder though, if a 25 years old spring doesn't have metal fatigue. Not something that would be visible to the naked eye...
On the other hand the bike wasn't used for 10 years and it's a street bike, not a motocross...