Can aftermarket shocks be upgraded?

[mashman]

hi all, like the title says... I've got a Sachs shock and I was wondering if anyone knew if it could be "Ohlinsified". Maybe to the point where you have a piggyback reservoir and clicker (instead of the non clicky screw) on the gas cannister...

Any thoughts much appreciated.

Cheers

[James Deuce]

Ask Robert Taylor. He's the NZ Ohlins man, is a site member, and has cast many opinions about Sachs shocks and how they can be improved, generally by replacing them with something else, but I'm not quite sure that's what you're after.

Just PM him. He's totally approachable and will give you some really good ideas.

[CookMySock]

Go here and see if you can find some shim stack pistons to go in it ;

http://www.racetech.com/evalving/menu/searchstreet.asp


DB

[mashman]

Ask Robert Taylor. He's the NZ Ohlins man, is a site member, and has cast many opinions about Sachs shocks and how they can be improved, generally by replacing them with something else, but I'm not quite sure that's what you're after.

Just PM him. He's totally approachable and will give you some really good ideas.

Cheers, I have replaced it with an Ohlins shock and had both the forks and shock sprung and valved for my weight, fark what a difference and now have a brand new sachs shock lying around the garage, no point having 2 :-). The previous Sachs served me well and I was just wondering i it could be re-valved etc... I understand the build quality isn't as good as the Ohlins, but was curious, might be worth noting as a selling point... I'm in no great rush to find out, I'll not bother the busy Robert and Team just now, but if he chimes, all good.

Thanks for the link DB but the don't have my model in there and trying to find spec info on the sachs shock is nigh on impossible.

[Pussy]

I'm confident that the Sachs is able to be revalved, Mashman.

[Robert Taylor]

hi all, like the title says... I've got a Sachs shock and I was wondering if anyone knew if it could be "Ohlinsified". Maybe to the point where you have a piggyback reservoir and clicker (instead of the non clicky screw) on the gas cannister...

Any thoughts much appreciated.

Cheers

In all honesty the very cost of doing what you propose would be prohibitive and very time consuming. Adding a reservoir with a compression adjuster creates a whole new can of worms, the damping provided by the compression adjuster mechanism in the reservoir should represent 12 - 13% of the total compression damping force. That is very difficult to achieve with something less well known, get it wrong and there will be pressure balance problems and cavitation at certain stroke velocities i.e the chances of making it horrible are very likely. What I am saying is that you just cannot fit any old reservoir, it would be hit and miss.
A Race Tech search also confirms that there is very little upspec data for the rear shocks in these bikes, no piston suggestions, no valving suggestions, therefore no solid testing groundwork.
Dependent on your personal height and weight we have had very decent results just replacing the spring on those Aprilias with something suitable for the customer. Happily Ohlins springs will fit as there are no Sachs springs available off the shelf. Also, we have had these shocks apart and can certainly effect an improvement with valving, we have Ohlins damping curves we can refer to on our dyno database and can mimic to a certain degree within the design limitations of what you have.
Also, dependent on the exact model variation we have a lot of good perfectly servicable second hand Ohlins parts ( including a number for Aprilia ) that we can build a shock for, at considerably less than a brand new one.

[boomer]

He should have bought a hyosung...!!!

[mashman]

He should have bought a hyosung...!!!

Errrr yeah, and oh how i will regret the day i didn't for the rest of my life...

Thanks Robert, guess i'll just leave it the way it is and sell it on...