ddog Posted June 17, 2016 Share Posted June 17, 2016 As the description notes, I'm having a major issue with my matris cartridge kit. I received the kit from Matt a while back and finally had the chance to pull my forks and bring them into the shop. After re-installing the forks I realized they were bottoming out in bumps and hard braking. After maxing out the pre-load and compression dampening I was still able to easily bottom out the forks with hard braking, and it even happened when I hit a small bump in the road at high speed. This seems like an issue with the spring rate, but @pattonme took my weight information when he ordered the kit so this seems unlikely. I'm also using the fork oil he recommended (5w). The guys at the shop I took it to said they put less oil into the the forks than stock because the new cartridges displaced more fluid. I'm planning on replacing the oil with a higher weight tomorrow and inspect the spring to determine if it's actually the correct rating. Any other ideas? Link to comment Share on other sites More sharing options...
YZEtc Posted June 17, 2016 Share Posted June 17, 2016 My guess is a too-low oil level. This effectively leaves you with a softer overall spring rate due to less air spring effect since there's less uncompressible oil and more compressible air in the fork. Link to comment Share on other sites More sharing options...
ddog Posted June 17, 2016 Author Share Posted June 17, 2016 My guess is a too-low oil level. This effectively leaves you with a softer overall spring rate due to less air spring effect since there's less uncompressible oil and more compressible air in the fork. Assuming the shop filled the oil level to the stock level, what level should I fill to? Is there a known different level I'm supposed to fill it to? Link to comment Share on other sites More sharing options...
bmwpowere36m3 Posted June 17, 2016 Share Posted June 17, 2016 Metal on metal? Wrap a zip-tie around the fork tube to confirm. The oil level is measured down from the top of the fork tube, with the fork collapsed (chrome stanchion pushed in) and the spring removed. The cartridge has no bearing on oil level... granted the fork might take less oil (volume), but the height of the oil in the fork should be the same. I believe the stock fork calls for something like 150-160 mm (down from top). Before you dissemble the forks, have the shop check your static and race sag. That'll give you an indication if the spring rate is correct (and preload set properly). 15-20 mm static and 30-40 of race in in the ballpark. Link to comment Share on other sites More sharing options...
ddog Posted June 17, 2016 Author Share Posted June 17, 2016 Metal on metal? Wrap a zip-tie around the fork tube to confirm. The oil level is measured down from the top of the fork tube, with the fork collapsed (chrome stanchion pushed in) and the spring removed. The cartridge has no bearing on oil level... granted the fork might take less oil (volume), but the height of the oil in the fork should be the same. I believe the stock fork calls for something like 150-160 mm (down from top). Before you dissemble the forks, have the shop check your static and race sag. That'll give you an indication if the spring rate is correct (and preload set properly). 15-20 mm static and 30-40 of race in in the ballpark. It's definitely metal on metal. Initially the pre-load adjusters were all the way out and bottoming out made a loud CLACK noise. It's not very feasible for me to bring the forks into the shop because they're an hour away, so it would be preferable to do at home. Plus with the suspension in this condition I can't ride out there. I may have mispoke when I said the lack of oil was due to a larger cartridge. The guy said something was displacing more fluid, not necessarily the cartridge. I'll try to check the sag myself. Link to comment Share on other sites More sharing options...
bmwpowere36m3 Posted June 17, 2016 Share Posted June 17, 2016 Spring rate is likely not the issue, but it's worthwhile checking with a helper. Also verify you're adjusting the compression correctly (i.e., not making it softer). Basically you'll need to pull the forks off the bike and inspect. After removing the top cap/adjuster and spring, I'd check if the cartridge rod has resistance when you pull up and down on it (do it slowly or fluid will shoot out the top). It should provide resistance in its full range of travel. Next, push down chrome tube all the way down and with the fork upright measure down to the oil level. Beyond that, you need someone with some experience to determine if something else is at fault (missing shims/stack, incorrectly assembled, etc...). Link to comment Share on other sites More sharing options...
ddog Posted June 17, 2016 Author Share Posted June 17, 2016 Awesome I will try that and report back! And as long as the plus side increases the dampening then I'm doing it properly. Link to comment Share on other sites More sharing options...
Premium Member wickedtwister Posted June 17, 2016 Premium Member Share Posted June 17, 2016 Oil level is too low I had a similar issue over sharp bumps could hear a almost springy noise. Pulled apart and oil level was over 20mm low. Filled it to proper level and no issues since. Link to comment Share on other sites More sharing options...
ddog Posted June 17, 2016 Author Share Posted June 17, 2016 UPDATE: The shop got back to me and said they are very sure it isn't low, and that the oil height was ¼" from the top. That sounds way too high. Thoughts @bmwpowere36m3 @wickedtwister @yzetc ? I guess the plan is the same, only I'm more puzzled. Link to comment Share on other sites More sharing options...
Premium Member wickedtwister Posted June 17, 2016 Premium Member Share Posted June 17, 2016 1/4in from top is not how matris recommends you set it. They say to set with stanchion tube down, spring out, and "pumping rod" down it should be 120mm from top. So a 1/4in in any configuration is wrong. I would pull it apart and measure according to how matris recommends if you do that and it is good call @pattonme for advice. Link to comment Share on other sites More sharing options...
ddog Posted June 17, 2016 Author Share Posted June 17, 2016 1/4in from top is not how matris recommends you set it. They say to set with stanchion tube down, spring out, and "pumping rod" down it should be 120mm from top. So a 1/4in in any configuration is wrong. I would pull it apart and measure according to how matris recommends if you do that and it is good call @pattonme for advice. Thanks, I was unaware of the oil level matris recommends. I don't have any instructions for the kit. Link to comment Share on other sites More sharing options...
Premium Member wickedtwister Posted June 17, 2016 Premium Member Share Posted June 17, 2016 When I get home i can scan a copy of mine. I'm traveling for a work until monday. Link to comment Share on other sites More sharing options...
ddog Posted June 17, 2016 Author Share Posted June 17, 2016 Would it be problematic to mix the maxima oil with another fork oil of similar properties? Yamaha kyb 01 5w has nearly identical properties, but is mineral based not petroleum based. I only ask because I don't want to have to drive an hour to pick up maxima oil. Link to comment Share on other sites More sharing options...
Premium Member wickedtwister Posted June 17, 2016 Premium Member Share Posted June 17, 2016 Not sure who carries it but I'm sure you could have it shipped to your house. I would keep the same oil type but I don't know for sure. Link to comment Share on other sites More sharing options...
ddog Posted June 17, 2016 Author Share Posted June 17, 2016 So get ready to have your mind blown... Wait for it..... They didn't put any oil in the compression fork. http://imgur.com/ulk5zPw Link to comment Share on other sites More sharing options...
etorty Posted June 17, 2016 Share Posted June 17, 2016 Isn't possible to mix different fork oils from different brands. All the oils have additives (of different kind). If you try to mix different additives, they will produce foam and the hydraulic properties will be null. You can mix only some kind of fork oils. I.E.: Silkolene Pro RSF SAE 10W with 15W, or 10W with 5W RedLine (you can also check in their web site this info) Light+Medium, or Light+ExtraLight, and etc. www.MT-Series.it Yamaha Official MT-Series Club Link to comment Share on other sites More sharing options...
etorty Posted June 17, 2016 Share Posted June 17, 2016 add: the recommended level for the Matris F15K is 130 mm with the Motorex Sae 5W www.MT-Series.it Yamaha Official MT-Series Club Link to comment Share on other sites More sharing options...
Premium Member phicurious86 Posted June 17, 2016 Premium Member Share Posted June 17, 2016 So get ready to have your mind blown... Wait for it..... They didn't put any oil in the compression fork. http://imgur.com/ulk5zPw Wow... sounds like a certain shop is going to be getting an unhappy call. Link to comment Share on other sites More sharing options...
etorty Posted June 17, 2016 Share Posted June 17, 2016 @ddog: NO oil in the compression fork? Aaaaaarg!!!!! www.MT-Series.it Yamaha Official MT-Series Club Link to comment Share on other sites More sharing options...
etorty Posted June 18, 2016 Share Posted June 18, 2016 I'm actually in trouble with my F15K. long story short: With Motorex 5W and spring K=9 the forks was really strong to compress. Oil level -130 mm, from the top of the stanchion, no spring, stanchion all the way down, the same for the damping rod. On the road: with good road and good asphalt the bike was nice to ride. But on the sharps bumps and with bad asphalt, was a nightmare. Even with all the registers open. With Motorex 2,5W and spring K=9 the forks was really better. Oil level -140 mm. These registers was good for me: C = 15, R = 12. My weight with all the apparel is about 68 kg. For many reasons, at this moment I have springs with K=8,5 and Motorex 5W The forks are not so strong to compress, compared to the first scenario. But, on the road, the behavior is the same: the only way to ride is with all the registers open. My thought is to use the Motorex 2,5W again. I hope I can do the change really soon. www.MT-Series.it Yamaha Official MT-Series Club Link to comment Share on other sites More sharing options...
Premium Member norcal616 Posted June 18, 2016 Premium Member Share Posted June 18, 2016 I have a different set up but had a bit of trouble tuning the suspension because the forks didn't like to be sticking 5mm above the top clamp...as soon as I put the bottom of the fork cap near flush with the top clamp, the suspension got 200% better... 2015 fz-07- Hordpower Edition...2015 fj-09- 120whp- Graves Exhaust w/Woolich Race Kit- tuned by 2WDW Link to comment Share on other sites More sharing options...
ddog Posted June 18, 2016 Author Share Posted June 18, 2016 So get ready to have your mind blown... Wait for it..... They didn't put any oil in the compression fork. http://imgur.com/ulk5zPw Wow... sounds like a certain shop is going to be getting an unhappy call. Oh they got a call alright. I'm getting a refund and they are going to fix the forks. Link to comment Share on other sites More sharing options...
YZEtc Posted June 18, 2016 Share Posted June 18, 2016 Wow, that's an oops-and-a-half. Link to comment Share on other sites More sharing options...
Premium Member wickedtwister Posted June 18, 2016 Premium Member Share Posted June 18, 2016 Pattonme said that the compression leg of the fork had a severe problem with oil flow. I have his modified matris forks and (with proper oil level) they are awesome. I took speed bumps at 15-20 and front feels great. As soon as back hit I knew it. Anyways glad you found the problem and I would Rip the shop a new one. When you add oil make sure you cycle the rod on the inside to get rid of air. Put your finger over the top and you should feel the same resistance thru the whole travel. Link to comment Share on other sites More sharing options...
ddog Posted June 18, 2016 Author Share Posted June 18, 2016 Should I worry about possible damage to the seals from bottoming out? Since I was running entirely on springs it hit pretty hard, but I don't know if the seals are susceptible to damage from bottoming out. Should I have them replace the brand new seals? Link to comment Share on other sites More sharing options...
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