Matris rear shock hydraulic preload position

I had a Matris shock installed on the Norge - the 46KDIS.  Rebound and Hydraulic Preload, no Compression adjustment.  Have a question about the orientation of the hydraulic preload unit and whether I need the one facing the other way or if it can be rotated (and how)?

Even though I ordered the Norge M46KDIS, after install, the shock place said it was not the right shock for the bike but they made it fit with liberal use of a Dremel on the splashguard.
It arrived looking like this below.  The valve on top is the nitrogen fill valve.  The tube and collar is the hydraulic preload.
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On the back of the preload 'tube' is an allen bolt.  
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Apologies for the orientation.  That is the rear tire in the top left.  They cut a channel for the Nitrogen valve and the preload adjuster on the throttle side but the preload is still a little hard to get to and I want to be able to adjust when 1up or 2up.
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Another view looking toward the front of the bike.
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I get the impression the shock should be installed 180 degrees so the nitrogen valve faces forwards, but in this setup, it does not allow access to the preload adjuster - you can only see the allen bolt on the back.

It seems like on their website, the preload unit for the Norge has an alternate preload adjuster which has the adjuster and the allen bolt reversed. Norge M46KDIS

Do I need to get that alternate preload adjuster or can I rotate the shock the 180 degrees and the preload adjuster 270 degrees.  How do I do this?

Can I get a spring compressor (spring is 777 lb/inch or 136.2N/mm), then rotate the preload once the spring is isolated?  Do I need to loosen/remove that allen bolt?  When I loosened it, shock oil came out so unsure if it is a locking mechanism or just the refill port?

The hydraulic unit can be rotated around the shock body. Remove and replace for 180*, and brute force for the 270* option.

From memory that unit is located on the body by use of a ring (circlip) in the threaded grooves. It can be located in any groove you desire to pre-load the spring on assembly, and then you have the option of further pre-load via the hydraulic unit. I have rotated the unit by hand, but with a 10kg spring.

You could put the hydraulic unit in a vice (please use soft jaws and a rag), and poke screw drives thru each eye and rotate. NO NO NO!, not your eyes dummy, the shock eyes.  

You lost hydraulic oil from the pre-load unit, not the shock. Mine used to leak from that fill port. Cost me $50 for a tiny tube of Wurth hydraulic oil sealant, had to get Scotty to fix it. The longer allen head bolt is your pre-load adjuster. 10 clicks per millimeter of pre-load. Very hard on the hand with a standard 'L' shaped allen key, a 'T' bar is much easier.

Appreciate that. Took me a lot longer to get it out than to get it back in today. I ordered a lighter rate spring so when that arrives will switch it out and rotate the preload. A few weeks wait from Italy I expect.

Back from holiday to some GRiSO Ferlinghetti.
My Matris with 135nm spring gave me 19mm sag and after emails to Matris they recommend 40-45mm sag. So thinking that the rising rate is 3:1 and each 360 turn off preload is 1mm I have backed off 4 turns which I think is 4 MM and now have 42mm sag! Matris also recommend 14-16 clicks off on compression and 20 clicks off rebound which I have done.
Front forks now with 9.5 springs with k-tech valves and running 5 rings showing on preload (flush with 6th ring at yoke) 2.25 turns out on compression and 24 out on rebound. I have 34mm bike sag (seems a lot) and 14mm rider sag so 48mm overall.
I am 103kgs. Will ride it and update later.

Watching with interest to see how you go.

Seems far better. Still 'firm' over small but sudden bumps so I will back off more compression. May go one more turn less rear preload too. But overall big improvement on the shock as delivered. Also now 400 miles on the Matris and thinking that maybe it benefits from 'running in'. Will update when I've tried 18 clicks off on compression and one more turn off preload.

Am running approx 10mm preload. Difficult to measure but my calliper squeezed in at an angle comes to about 10mm and looks like 10 threads showing above the lock ring. Have gone back 2 more on comp and rebound so now at 18 clicks out compression damping and 22clicks out rebound damping. Still firm' but not uncomfortable.

Hey Brendan, I think/assume you stuck on 135nm ? ......I'm planning to switch my Matris spring to 115nm tomorrow - also good excuse to ride down to Frome & back as I've put the SACHs unit back on for now......once I've refitted it (I've got it down to about 30 minutes to swap rear shock and only requires dropping off the wheel, undoing dog-bone linkage, & the top bolt); will let you know how it feels with softer spring.....

For the moment I have stuck with the 135Nm. I don't think its perfect but having backed off the preload so now approx 10mm wound on, and backed off the comp and rebound damping to approx 20 clicks off (haven't got my note with me recording what it actually is at the moment) its better but I have reservations. My plan is to see a suspension specialist (maybe PDQ in Taplow) and get a pro set up and see if that does the trick. If not then I have left it open with Bike Torque who have offered to swap the Spring. All rather disappointing in so far as whilst there is no doubt that the shock is beautifully engineered, it was sold to me on the basis that it was completely 'bespoke' built to my riding weight and riding style/use and when I called up to order the fellah at Bike Torque declared that I would not need to have a pro set up as the shock came pre-set to my exact requirements and was a 'fit and forget' item! Let me know how you get on with the 115Nm although I think you are a tad lighter than my svelte 105kgs!

Great weather plus 400 miles round trip on some great roads and some clagged up motorways with tramlines between lanes that make it hard to steer straight (some are like minature valleys) and of course ....New Spring fitted FOC by Adam at Bike Torque Racing - great service and genuinely good bloke. It's a lot slimmer than the original (I bought the original just in case I'd made a mistake changing to 115 nm); hopefully fit it this weekend and report back....I promised Bike Torque Racing to tell them experience also just in case anyone else asks

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Did Adam 'set it up' on preload, and damping so its ready to fit? Interested to hear your report once fitted and road tested.

No, he just changed the spring and left all the settings - I guess he hasn't got any guidance how to set up a 115 nm shock. I am just planning to fit-test-adjust-test-adjust-test-adjust-test-adjust........Just fitting it now !

First impressions after just 30 minutes on roads nr my house is that finally it feels like there is a spring in the suspension !. At relatively low speeds in urban areas (40-50mph max; honest officer) it is much better on major bumps/speed humps/manhole covers etc; smooth, stopped rabbit hopping over everything... currently everything is 14 clicks out on compression damping; 20 clicks out on rebound; no extra rear height (I don't like the way the front end gets all twitchy Vz strong arming it around); and preload is whatever it is but currently giving roughly 17mm static SAG (haven't even measured rider SAG as was keen to ride it).

Big test is whether it will top out too quick on high speed rural stuff as above 70 mph on fast urban bends I can even get the OEM & the 135 nm Matris rear working a bit more like they are suspension units... lets see....oh and I'm still 77 kg dressed.

After tear-arsing around I'm absolutely loving the Matris with 115nm spring; it feels like a different bike with no bucking around and even going flat out (WOT up to red line then upshifting) acceleration up the by-pass and curves/roundabouts it is far more stable than 135nm or the OEM....it just feels like the suspension is now working & the rear wheel is now staying on the ground (I couldn't even get close to this with 135nm and preload backed off). I also suspect I could go even lower rate and still not top out the travel but 115nm works. I'll measure full sag properly at some point but having too much fun just riding it...

Big thanks to Bike Torque Racing for replacing with the lighter spring; they are good outfit to deal with & not their fault that Matris only recommends one rate........I may be an outlier (in many ways ); but Matris should probably re-think the one-size-does-all as I suspect they have spec'd it too high on spring rate for normal mortals.

Hey Paul, I am glad you are getting your shock sorted and its not just there as an expensive bauble :-)

Changing mine for a Stelvio has made such a difference i no longer think about the rear suspension at all now!!!

When we hook up next it would be good to do a bike swap and see. I think i will still like the ground clearance of the Stelvio, oh and the price

Hey Keith; I could still crank the height up an extra 1 inch (bishop & actress joke hiding in there somewhere)...but I couldn't get the price down (another bishop & actress joke in there as well)

So Paul are you keeping with the original ride height? or are you giving it a rise :-)

Hi Paul. I'll assume that it's not a typo that you're 77kgs riding weight. How and why you ended up with a 135nm spring is beyond me. Anyway, I'm really interested and pleased in that you're enjoying the 115nm spring. That said, from the plethora of suspension threads I've read on here, I was under the impression that a spring of that weight was more for blokes of at least 90-100kgs.

I'm about 85kgs riding weight, and my Wilbers rear shock came with a 95nm spring. Mathematically, something is amiss here. Granted, the Wilbers and the Matris will have their own particular valving setup etc, but the spring rates should surely be in the same ballpark for two blokes who are within 10kgs of each other?

Not sure if any of the more expert among us have any views here?

Hi Brent, you are right and I read lots of threads where the springs are softer than Matris (even the stock is softer); but the Matris currently comes as 135 nm standard for all riders irrespective of weight or riding styles & apparently Matris say that they have 'dun the maths' and spec'd out the appropriate spring for the bike and that different riders & different riding just requires adjusting the settings.....

I could have gone softer but it was a one-off 'favour' that they agreed to change the spring for free from their recommendation (which remains that one spring fits all) & my mind just niggled about going too far the other way plus what would happen with a pillion & luggage (taxi for my daughter).

Would be good to hear if anyone knows whether spring rate is directly related to weight irrespective of shock brand/type. The only good advice I found was that "you know spring is too high rate if you have to back the pre-load so much that static SAG goes too high"...and "The spring that has a very stiff rate will feel harsh, like it's hitting a barrier or very stiff spot"......with both boxes ticked on that basis I went lighter and 135 down to 115 felt like a significant jump down.

At least I feel I'm closer to the optimum today....& now I have seen how easy it is to change the spring I'd be happy switching lighter again if I feel it could improve..

Yes they are related. However there are many other things that need to be considered.

If the spring is too hard then you can reach a stage where the shock will no longer compress with the load of the bike and rider even when there is suspension movement left. The sping has exceeded the leverage ratio available in the suspension design. The opposite of this with a soft spring which can become coil bound, although this is unlikely on a GRiSO with such short suspension movement.

Putting a  spring onto the shock and not being able to set any sag usually points to it being too soft as you have to wind up the preload to compensate for the load and when you take the load (rider) out of the equation the spring will simply extend and use up any static sag. This is the problem with the standard spring.

You then get different shock compression and rebound ratio's that can confuse you into thinking that the spring is too hard or too soft. But that is not directly spring related.

There is an ideal spring weigth for the bike. It is one where it will hold the bike with the correct amount of static sag and be able to be adjusted to compensate for a rider and pillion and luggage without hitting the bump stop.

Bike manufactuers help here by giving their suspension a non linear leverage cycle movement which will allow for a softer spring to be used. Most people make the mistake that when you change the leverage value by a muliple of 2 that you will need to put a spring that is twice as stiff.  But actuall applying twice the force to a given spring makes it move twice as far, you can see then that you are able to use softer springs but can change the leverage ratio to make them appear stonger as the stroke and leverage changes.

Ok, that's enough!! If you want to understand it a bit more try clicking HERE

In the pursuit of knowledge (for the common good of the forum ); I've just ordered an 83 NM spring to test......changing shock is so easy; spring so cheap; changing spring looks a breeze (with the Matris machine it did anyway); life to short to 'not know what could have been'....only downside so far is my wife is wondering if my home office has become a suspension shop.

In Houston all next week so will post progress & results in a couple weeks; shortly followed by adverts for unwanted springs !

Looking forward to your report Paul. I think that an 83Nm spring will be too soft and require too much preload to get the ride height correct, but I’m interested in how it’s goes. The factory spring is a 95Nm apparently, just as a reference point.

I haven't fitted the (yellow - ) 83 nm spring yet but some feedback on the 115nm and some interesting findings.....

SAG and preloads (front is stock but with upgraded compression adjuster; rear is 115nm Matris) for me at 77kg and targeting 35mm rider SAG I get...

FRONT 3.5 rings out preload STATIC 20 mm RIDER 33 mm
REAR 10mm preload STATIC 15 mm RIDER 35 mm


With 'out the box and std' rebound and compression settings it was still quite harsh around local roads & up to around 70mph on fast rural roads.....so I went for major change in settings way outside std...
.. set it up with ALL TURNED OUT COMPRESSION settings front and back; 3 Turns Rebound on front forks and 25 clicks out on Matris Rebound (which goes out to 36 or more clicks !). Front feels it could go a bit firmer on rebound but the back feels perfect.

Long and short is I'm amazed I finally found comfortable settings for casual riding (I always know I can dial in firm for sports mode); and that taking compression settings out completely just woke up the suspension with no obvious downsides I could find. Nothing is bottoming or topping out in normal riding with these settings. Suggests Matris is spec'd up for racetrack in std settings so anything else is way back off that.

If I fit 84nm spring I guess I'll just go closer to standard 14 mm preload to deliver less static SAG for same Rider SAG.

Paul, that is the solution for the standard shock as well, it comes out of the box with far too much compression damping dialed in, as it needs to make up for a soft spring.

Glad you are getting closer to a good ride!

I didn't manage to improve the Sach by taking out all the compression damping so hadn't thought Matris would respond so well...hey ho

BTW....knob-head council gritters out in force happily spreading tonnes of salt & grit at the first sniff of frost despite it's completely dry (gives them lots of overtime I'm thinking).....