Matris fork cartridges - tuning/setup experiences?

Hi all. This is a bit long-winded, but please bear with me.

18 or so months ago I had a Wilbers rear shock fitted to my GRiSO. I followed this up some months later with a Matris fork cartridge kit. Both jobs were done by a well-regarded Melbourne-based suspension shop. Rider weight data etc was taken at the time of ordering the components.

Now, to be clear, the bike is considerably better than it was as stock. However, I still feel that it’s a fair way off where it should be for compliance and balance. Good tarmac and smooth, sweeping bends are fine (no wallowing), but when I head into the hills and encounter the usual ripples and bumps typical of secondary roads, its tough work. The bike still bangs over bumps. You can feel it shuffling and jolting around, like you feel every one of its 240 odd kilos in weight. I still get plenty of kidney-shaking experiences, and it’s a tiring experience. My mates on a Honda CB400 and a Ducati Monster 1200 are quite relaxed riding the same roads and complain nothing of the bumps. Not being the best or most confident rider in the world, the bike’s behaviour just gets into my head a bit, and the pleasure of riding fades away.

I need to start somewhere, so let’s look at the Matris up front. When I got this done, I thought “gee, it’s pretty firm”, but I thought it may loosen up a bit over time. It hasn’t. I don’t know what pre-load they dial into this, but when I sit on the bike, the front forks will barely move, maybe a mm or so, That’s it. If I roll the bike backwards and grab the front brake, the bike barely moves upwards on the forks, like it’s almost topped-out just in its static position. I’m guessing that I’m using less than half the total fork travel even over rough roads (will have to check using the cable tie on the fork method though). So, before you ask, I’ve done far less riding recently than I’ve wanted to, and thus haven’t yet started messing around with the various compression & rebound clickers etc. Obviously, I need to experiment, but I’m not really sure where to start. If anything, it feels like the preload is too high, and perhaps the compression damping is too stiff.

The Wilbers on the rear is better, but it can still bang around a bit, like it needs less high-speed compression damping. However, with the supplied 95nm (9.6kg) spring, I’m worried about bashing the bump stop to death if I back the compression off. For the record, I’m 75kgs walking out of the shower, so add riding gear and let’s call it 83-85kgs (say, 185 pounds).

So, should I start at the front, and wind-off some pre-load and/or compression damping, going a few clicks at a time? Also, when talking about how many “clicks”, is this from hardest setting back out (anti-clockwise), or the opposite?

Advice/thoughts appreciated. Many thanks.

Brent.

I feel the Matris fork spring rates are much higher than what's actually stamped on them. I lied and said I was 85kg wringing wet, but the springs are still too stiff. I think they are racetrack oriented, so don't work spectacularly on our goat tracks. I wound the pre-load right off, and then added 5 clicks. The compression damping is wound out by a number of clicks that I don't remember. I just kept going out until it felt right. Only the worst bumps rattle my teeth now. Michael called it 'cushy' when he rode it.

I run 5W oil in mine.

Brand of 5W oil is important as all the different brands vary slightly. Penrite Mark?

I use Penrite in my Sport front forks - 5W - and get the amount right (380 ml = plush; 390 ml = firm but still working well; 400 ml = race track performance) for a ride "I" like. I do have different fork as well, so this has absolutely no bearing on what you are doing Brent. I always fill to 380 ml, as I like the ride whether loaded (off to a rally) or not. Some food for thought.

Oz1200Guzzi wrote:

Brand of 5W oil is important as all the different brands vary slightly. Penrite mark?

Correctly correctington.

Thanks gents. Yes, the invoice for the forks did stipulate 5W oil, so I can only assume that is what went in. As for Penrite, I don't know.

As you had it set up by a suspension shop, can you not go back to them & explain what you're experiencing?

Nobleswood wrote:

As you had it set up by a suspension shop, can you not go back to them & explain what you're experiencing?

I can and I should, but given that they're only open on weekdays, and I don't get any rostered days off work, taking a few hours out of a workday can be awkward. Also, I'm trying to educate myself a bit about such matters, rather than taking the bike back to a shop every time an issue pops up.

Hi Brent, starting with the rear shock. Does it feel like the seat boots you up the bum coming off a bump? Lifting your butt out of the saddle. Race oriented set up has the rebound on the soft or light end of the spectrum, to keep rear high for sharper steering etc. I always have to add 2 more clicks of rebound after shop has had it, just to get a smoother ride.

Remember, firmer rebound is clockwise direction of the knob on the bottom of the shock, while you are laying on your back under the bike, looking up!

With the front, just wind a heap of preload off (you can always wind it back in later).
If it comes back at you too quick off a bump, jarring your wrists, add several clicks of rebound.

Compression damping adjusters operate mainly on the "Low speed" damping circuit. Usually set on the firm side as the main objective is to control squat, in a turn. "High speed" compression damping (if you don't have a 2nd adjuster) is normally a set and forget internal shim set. You can alter this by going to a lighter weight oil.

My Hypermotard had 50mm Marzocchi forks with sealed cartridges, "High speed" comp damping was so hard it would tank slap at 60kph on small bumps.
The cheap fix as an experiment was 2.5w oil. That transformed the bike so dramatically and set the bar so high, I've spent a fortune on my Guzzi to get some sort of comparison in ride quality.

Ghezzi, thanks for your advice. Yes, the rear of the bike can certainly give me a kick up the bum on a decent bump. My arse has left the seat on more a few occasions. I may have to tweak the rebound setting a bit and see how that goes. The Wilber’s has both slow and high speed adjusters.

In terms of the fronts, consensus appears to be confirming what I suspected, that the Matris forks are likely a bit hard in terms of preload and possibly compression. I can sort of see the picture forming now, where I have the front forks overly tight, with almost zero sag, with the Wilber’s at the back that has a softish spring and potentially too much high speed compression and a tad too little rebound. End result is the front of the bike not balanced with the rear, hence I feel like I’m sometimes fighting the thing over bumpy roads, especially in the bends.

Excellent Brent, again high end suspension is normally the salve of the race brigade, where speeds are high, with 60 degree lean angles, 200HP and their race tracks are smooth.

We ride at half the speed, half the lean, with half the horsepower and on goat tracks.

Your "Hi speed" compression will need to be right at the soft end, like only 3 or 4 clicks in from fully out.
The "Lo speed" compression will be somewhere in the middle of the range.

It took me about six months to get my head around all this, and then finally I got it sorted.

The front end may need to be redone with softer springs, and less "Hi speed" compression, but play with the full extent of your adjusters, there is nothing to lose.

I think you need to back everything off and try to set the static and rider sag.
The ability to get the correct sag will also tell you something about whether the springs are too hard.
I have standard forks but rebuilt by K-Tech here in the UK with 9.5kg springs and I find them excellent, travel in normal use just about 1" from bottoming out, and if used in a particularly 'spirited' manner closer to 0.25" from bottoming out - but that is in track day mode. I'll try attach a photo where you might be able to zoom in and see the tell tale on the fork.
I started with 9kgs springs which i found a tad soft and although they didn't bottom out. I went back and K-Tech changed for 9.5kgs which felt compliant but planted with plenty of feedback on what was going on at the tyre.
I expect the damping set up in Matris is too firm, and springs rate too stiff. I am 100kgs without gear. I guess at 75kgs you might go down 8/8.5kgs on the fork springs and might need to alter the damping - even the valving to get more compliance.[You must be registered and logged in to see this image.]

BBB888 wrote:

I think you need to back everything off and try to set the static and rider sag.
The ability to get the correct sag will also tell you something about whether the springs are too hard.
I have standard forks but rebuilt by K-Tech here in the UK with 9.5kg springs and I find them excellent, travel in normal use just about 1" from bottoming out, and if used in a particularly 'spirited' manner closer to 0.25" from bottoming out - but that is in track day mode. I'll try attach a photo where you might be able to zoom in and see the tell tale on the fork.
I started with 9kgs springs which i found a tad soft and although they didn't bottom out. I went back and K-Tech changed for 9.5kgs which felt compliant but planted with plenty of feedback on what was going on at the tyre.
I expect the damping set up in Matris is too firm, and springs rate too stiff. I am 100kgs without gear. I guess at 75kgs you might go down 8/8.5kgs on the fork springs and might need to alter the damping - even the valving to get more compliance.[You must be registered and logged in to see this image.]

Agreed. You need to set sag, then damping and rebound to your needs. I'm on the stock suspension and have no issues. But I'm not hard to please. Can't speak to the new bits, but if you spent the $$ the shop should work with you to dial it in.

mmm- recently went to Wilburs rear shock to give new life for my almost GRiSO - Breva 1100 with matched Wilburs front springs and revalve by a "Melbourne suspension specialist" , worst ride I have ever had , front and rear bottomed out continuously . was meant to be set up as per supplied weights etc . Forks went back to them for round two attempt.not yet re fitted and tried , but they didnt change the spring . rear Wilburs shock is a poor performer , bottoms out and yet skittish on rough corrugations . tried various damping settings to no avail. the rear was previously std Sachs apart from Marios supplied heavier "10 k" spring. it coped ok , but likely it will go back on, as will std front - even standard sloppy Guzzi front didnt actually bottom out on every bump in our Aussie roads !! Seems Wilbur maybe made for bmwobble u's on cruisy autobahns only
interested in more feedback on the brand for use here in aust.

Dave

The problem is not the product, its the set up.
Did somebody get lbs confused with Kg regarding your weight?

If you live in Adelaide, go visit Walter Presig from YSS suspension, he will set it up with you on the bike.

And remember, out of the box set up will never be spot on, you need to play with it.

I have Wilbers on my Stelvio and it sure is better than stock. With swapping bike I have used the stock one for a day ride, and difference is the small bumps that kill your back are filtered out with the Wilbers, and not with stock shock. I do have the expensive 641 Wilbers with high and low speed damping. Setup at suspension shop and that is fine for me. Your stories hear as wrong setup/ spring rate.

Hi, thanks for the feedback. I really did expect the Wilburs to be far superior than stock. I provided them with all weights , riding style etc , Wilburs have " custom" built the shock and supplied the matched fork springs. I was told the rear shock was pre set to suit the specs provided . To me - it seems the set up they gave me was designed for smooth German autobahns , not typical rough Aussie "bitumen" . Mind you I could almost bottom out the front end ( within 1 cm of max travel) - sitting in my driveway and just pushing down on the handlebars with brake on. That aint right. Trying to work it out with the mob who ordered them from Wilburs for me. Hopefully a Happy New Year will eventuate. Not planning much riding at present - considering half our country is ablaze , my issues need to be kept in perspective !

OK, about to start playing with the settings for the Matris forks. Going to start with preload. The ‘standard’ setting out of the box was 9 “clicks” to achieve a fully out position. That’s pretty much per the recommended 10 clicks setting as displayed on the product card that came with the fork kit. The forks would barely move at all when I jumped on or off the bike at this setting. So, I’ve wound out all the preload, then just tightened it again by a single click. Already I can see some static sag evident that wasn’t there previously. The bike seems to now settle into the forks more, if that makes any sense.

Will take it for a ride this weekend to see how it feels.

However, this leads me to the question of if there’s any danger in simply using no preload at all i.e. just using a single click of preload just to take up any slack? Do I risk bottoming out the fork travel by doing this?

If you bottom out, then yes add some preload. I consider preload as ride height until you bottom or top out.

OK, first test ride today. Matris fork preload wound out (only 1 click in from full out). Compression damping wound out a further 2 clicks to 12 out (10 is stock). Immediate difference in compliance. Still a few sharper bumps coming though, so adjusted comp out a further single click (now 13 out in total). Marginal improvement but worthwhile. No floatiness evident.

Did the cable tie thing on the forks, and I’m now using a lot more of the fork travel than previously. The tie was pushed down to within about 32mm of the fork base. Now, what I don’t know is if this means I still have circa 30mm of fork travel left, or if the fork is technically bottomed out earlier than this? Adding another click or two of preload to be on the safe side wouldn’t bother me, given I have none dialled in at present.

In terms of the rear, took two clicks of high speed damping off the Wilber’s rear which also immediately helped. Low speed damping feels fine.

Overall, I’m sure that further fine-tuning can be done, but it’s already a much more pleasant machine to ride. Don’t know why it took me so long to do this!

Brent.

Respect to all as suspension can be a dark art . Ive had my learning curve.
Sometimes it is the product. I even contacted Wilburs to see if they could check the build spec.
Mistake . never ask a German company if maybe they made a mistake .....
at least they responded to my email - well the first one .......not the second

Aust Wilburs dealer actually offered to "rebuild it" to make it better but seeing as it was custom built by Wilburs for me in the first place , it seemed to be a wild goose chase. The Wilburs design compared to Sachs has more length in the body and less actual travel in the rod part. So the spring has to do more over less travel. Spring was about "13 kg" and linear compared to my existing 10 kg King spring. So the Wilburs was hard over small bumps - but ran out of travel and bottomed out a lot when touring Dealer agreed to take back the Wilburs rear shock for refund .
Front forks went back for 3rd go and revalving . The Wilburs fork springs are as soft as std Guzzi .. despite being advertised as " will not bottom out " . Yet to ride it with V3 forks as I am staying the fuck home Old SAchs rear unit about to go off to Hoeys for a rebuild in the hope they can polish a turd LOL
Hope all are keeping safe and getting lots of quality shed time.
Dave