2011 RSV4-R Sachs fork internals comparison

[amauri]

When I first read that the 2011 R model would be equipped with a Sachs fork instead of the Showa, I started looking for an opportunity to look inside the new fork.

I finally got a chance to take one apart and compare the internals with the Showa and Ohlins FG616.

My first impression was very positive, Sachs uses very high quality parts in this fork. Nice precision billet aluminum parts compared to less expensive and heavier steel parts on the Showa.

I see that the Sachs also has an extra valve, sort of an anti-dive to help slow down the travel at the very end of stoke. It is independent of the compression and rebound valves and starts to take effect at 35mm from the bottom of fork travel.

Going a little deeper, I see that the pistons are 30mm.
Both compression and rebound pistons are the same, only the shim stack and chk plate are made up of different thickness shims (as expected).

Sachs uses 7mm ID shims, compared to Showa's 6mm and Ohlins 8mm.
That makes it a bit more difficult to source the shims locally, time to start searching for a source of 7mm shims.

There is also a top out spring, I was surprised that it is a very high rate spring.

I believe that the Sachs fork has a lot of potential.

IMO, for those who know suspension and are willing to spend time tuning and testing it from the inside out, this fork can be made to work every bit as good for a lot less money than installing a racing cartridge kit.

This fork requires a spring compressor tool to disassemble, there is quite a bit of preload on the spring.

[V4Victory]

What diameter is the damper Rod in the Sachs? 15mm

[PSolk]

As someone who decided to save the money on a custom Ohlins setup for his Mana and go with the bolt on RSV4-R Sachs setup instead I am very excited by this... My Mana is actually having the RSV4-R forks and Brembo monoblocks done now

I am hoping the Pro-motion guys can dial it in at NJMP October 15th-16th...

Thanks as always for the great info Amauri!

[amauri]

What diameter is the damper Rod in the Sachs? 15mm

13mm damper rod

[Ed / AF1 Racing]

cool pics and info....thanks

did the ohlins cartridge removal tool also work on the Sachs carts? pretty sure we didnt get one in the v4 special tools kit.

[V4Victory]

13mm damper rod

Ah ok, larger than an ohlins 25 then which is 12mm iirc

[amauri]

did the ohlins cartridge removal tool also work on the Sachs carts?

Yes, the same tool to remove the FG616 cartridge fits the Sachs.
Ohlins p/n 4702-04

[potere]

Amauri, have you ridden on these carts yet? They may have potential but they are so prone to diving too fast and they don't do well at absorbing bumps, very harsh on the compression. I don't think I ever felt the anti-top outs being reached. I never really tried seeing if the individual clicks on rebound and compression were as good as the ohlins on my V2 factory before replacing them with the ohlins carts and the TTX on the rear.

what do you see that kept Sachs from going all the way to making this a better fork?

[amauri]

I do remember your less than favorable experience with the 2011 R suspension.
But on the other hand, there have also been very positive comments from others with the same bike.

Not taking sides either way, my intent in posting this info is to give others a look inside the new forks.
I also understand that all riders have very different suspension performance requirements.

I don't own a V4 and have not had a chance to spend any quality time ridding one with the Sachs fork.

Hopefully, the info I've posted will help those who want to experiment with the Sachs.

[V4Victory]

what do you see that kept Sachs from going all the way to making this a better fork?

I'd hazard a guess at cost

[MishMashRSV4]

I do remember your less than favorable experience with the 2011 R suspension.
But on the other hand, there have also been very positive comments from others with the same bike.

Not taking sides either way, my intent in posting this info is to give others a look inside the new forks.
I also understand that all riders have very different suspension performance requirements.

I don't own a V4 and have not had a chance to spend any quality time ridding one with the Sachs fork.

Hopefully, the info I've posted will help those who want to experiment with the Sachs.

Amauri - My 2010 R is making quite a racket in the valvetrain...uncomfortably now. The "common" noise was acceptable..but seems to be getting noisier. Anyhow, i'd be happy to leave it with you beyond the time you need to check my valvetrain for an extended amount of time (Maybe a month or two) to put some miles on one and see what you like / dislike, as well as mechanically fiddle as you like.

[fastmike]

Amauri - My 2010 R is making quite a racket in the valvetrain...uncomfortably now. The "common" noise was acceptable..but seems to be getting noisier. Anyhow, i'd be happy to leave it with you beyond the time you need to check my valvetrain for an extended amount of time (Maybe a month or two) to put some miles on one and see what you like / dislike, as well as mechanically fiddle as you like.

That's a very generous offer Miles. Initially I thought you were off topic, patience was never my strong suit.

So, with time and patience the fork can be made to function reasonably well w/o the big outlay of a cartridge kit. That sounds promising.

Thanks Amauri. Good luck getting the bike back Miles!

[amauri]

I never intended to start a "this fork is better than that fork" discussion.
I just wanted to show how the new fork differes from the old.

So, with time and patience the fork can be made to function reasonably well w/o the big outlay of a cartridge kit. That sounds promising.

IMO, that statement is true about most any late model Super Sport m/c fork.

[amauri]

Miles,

I'm very flattered in knowing that you think so highly of me and would trust me with your bike.
I would take you up on it, but I'm afraid I can't afford buy you a new one if I accidentally damaged yours.

[zvez]

Exc info amauri
Chris