www.DaveMossTuning.com We all know there's oil in them there forks. So... how much and why? Answer me that, Mr. Dave Moss. G'ahead, try. www.DaveMossTuning.com
One of the facts that makes this channel (Dave) so popular and liked is that I've never heard him saying what must be done and certain numbers need to be followed. He gives you the knowledge not the "copy paste" method and is up to you how much are you going to learn and apply in real life.
Exactly - I hope to inspire riders to go make one change and start their journey on making them find settings to their bike rides the way they want it to.
@@nolydpot8967 The App was discontinued several years ago as there were no users so all the content was removed and placed into Total Access on the DMT website. I may bring that app back in the near future based on levels of interest for basic set up, rebound and compression fine tuning and tyre wear.
@@CatalystReactionSBW okay then Dave thanks very much i really appreciate it was looking everywhere just wanted to get the correct yss PD valves for my 1990 Suzuki dr 800 sr42 model, don't know the inner diameter of the fork tubes it's the 41mm conventional damping forks
Love the vids Dave, keep 'em coming! And this one pertains to what I was experiencing just last week at the track, where our local tuner suggested I run slightly less oil in the forks. Now you just explained why. Thanks!
Daniel Crowder Yep, gotcha! I understand why. I'm experimenting with everything now. I even poured and measured different oil level heights in the fork, then poured the oil back out and measured, just to collect data and see what heights gave me what volumes.
Thanks for the advice in this video. I've just done a fork oil change on my 2003 Yamaha R6. What you say rings true to what I was feeling with this bike. They were 'overfilled' by 100ml in each leg. The bike wouldn't hold its line properly, was very nervous, turn in was slow and over bumps it was kicking back. The height was 70mm, Yamaha spec is 106mm. I've now set it back to original specification and it's like riding a different bike for the better. Holds it's line, turn in is spot on, loads more feel. I can't wait to get this on track now and have a bit more of a play with the settings.
I just changed my fork oil myself for the first time thanks for your videos. I just got this bike recently and it has been so stiff despite I turn down the compression and preload. I just poured out the old fork oil and it is about 120ml more than the manual recommended. That might explain why it was so stiff. Can't wait to go for a ride tomorrow
Excellent work and thank you for using the videos to assist you with this task. Set compression in the middle of the total range and make sure you put preload at minimum when you go for an exploratory ride at 50-60% ability to assess fork travel and braking stability. Take the preload and compression tools with you :)
Ahhh Thanks.. Finally, i got an answer..Thanks Dave. you re my hero. (my last two weeks has been spent on internet, on some garages and finally asking Honda service, but every folks answer made me much more confusing..) i got an expert point of view with your video. Thanks al ot again. By the way, i get DMtunnig app for ios.)
Great video! I recently changed my Honda CRF Showa fork oil with Yamaha S1 zero weight and made huge improvement to small bump chop.Just purchased RMZ with SSF air Tach forks, and they are harsh through mid stroke. Do you recommend lowering fork oil hight or swap to lighter oil to start? Thanks!
This and other videos are very helpful. Retired certified master auto tech in Thailand. 2019 Tracer 900 GT. 11 lbs Givi engine guard. I'm 183lbs. Performance upgrades. Run in A mode wot most of the time... Stock suspension was a major disappointment. Installed Ohlins ya-357 shock. Huge improvement but at 15,000km had front rebound at one click... To soft, floundering. Stock oil is 5w. Did dump and run with Repsol 10w. Oil removed measured 50ml short of what service manual said. Refilled to exactly what manual said knowing has some residential still in shock. Did setup per previous videos... Just did my favorite twisty road test ride. Wow, it finally performs the way a bike should. The bridge jumps that could only do in 2nd gear before was able to easily do 3rd gear. Big air and lands flat, smooth and stable. Trailbreaking then power on at 8,000 rpm snapping a power wheeie in 2nd gear... Most aggressive ride ever. Thanks Dave
I think you just answered my question of is it possible to just add oil to the top of my forks on my Gsxr 750 without removing them. Great video and info!!! Thanks Dave!!!
Thanks for the videos Dave. I replaced the oil on my Aprilia Shiver and went with a slightly thicker and slightly more oil. The Marzocchi forks that came on mine (Aprilia used Showa and Sachs as well) are non adjustable and had a bunch of dive under braking. I figured that this was my best course of action as no one makes a spring or cartridge kit for the OEM Marzocchi, although they do for the Sachs and Showa options. It helped a bit for sure but I can't help but dream about how it would be with a nice set of suspenders... Just another reason to consider a bike upgrade, based on one of your past videos it seems you may be a fan of spending the extra for the Multistrada with the Ohlins instead of the electronically adjustable Skyhook?
Electronics define your experience and I want to be mechanical and use my good judgement verses a software answer. All the bikes I've tuned have returned to manual suspension for the sheer simplicity of quick adjustments and visceral results. So.... can you get a surrogate set of fork with better cartridges in them?
Mr.dave im using 2t oil for my fork but the problem is the bounce of my front shock is toohard,the amount of oil that i put is 60ml base on my motorcycle manual.what oil can you recommend to me to use for my fork stabilizer?im weighing 68to 70kg.Do you think what viscosity is neded for my fork oil? Thanks
Hi Dave just come across your channel whilst researching how to raise the height of my front forks, I have a 2014 Suzuki vzr1800 which I have triked and so weighs more than standard I measured the forks and had a gap of 75mm between the outer sleeve and the bottom bracket. I was going to put heavier oil in but found it easier to add 30ml in each as I didn’t want to remove fork this gave me 80mm gap. I was wondering if this is a safe amount and whether I may be able to go a further say 15ml to gain some more height ?
I removed the top of the upside down fork and poured more oil in with a syringe lol because everytime you wheelie and drop down because you are scared to crash a lot of fork oil is on caliper. Doing this a lot of times would obviously drop the oil level far beyond factory recommendations. I mean, I think they'v engineered it to drop oil out from an overload so adding more oil is a good thing. You have to jack up the bike on the exhaust after to put the top back on because it's hard to lift it back w/ the other handlebar.
Thanks for being proactive. You can only add so much oil as you can create hydraulic lock so please be careful. If you start losing fork travel you have too much oil in the forks.
Yes, thanks for the awesome vids. Just going to add a few more mL to the left shock than the right as the left seems to be leaking more than the right at times. I like the soft feel but I've put the bike to stock using this guide as messing with sag and everything requires the bike to have everything working as new (maintenance). Old setups if you create sag, depending on how hard you push it stays up or down say 5mm rather than returning to the same spot with new oil. I think a lot of people who mess with their settings think they know what they are doing don't so running on the street can be very dangerous. You can only truly know your setup is good with a lot of special equipment like race engineers. Things could feel good at certain levels but to truly test if things work or not can be dangerous and can lead to unpredictable behaviors that create irreversible unwanted results. The suspension is rock hard in the winter compared to the summer when hitting certain bumps. How do you soften up the compression during the winter? What dials do you change? www.sportrider.com/suggested-sport-bike-motorcycle-suspension-settings
Anthony Abelardo Dude, if you're fork seals are leaking then you need to replace the seals, not just keeping adding oil to the forks. That is very dangerous, as the oil, as you stated, leaking on the calipers is also going to soak the pads and the rotors. There goes your brakes. And no, manufacturers do not design forks to automatically leak oil when they are overfilled with oil.
Hi Dave, not sure this is the right place to ask you: how do I remove an oil lock piece from a conventional showa 45 mm fork ? I’ve been trying hitting more or less gently from the open side but there is no way the o-ring is letting the bad animal moving at all and is too far deep to grab it with a kind of pliers. Should I warm up with flame or putting inside the oil lock a precise rod diameter and try cocking around? Thanks from Italy!
Awww man awesome vid Dave i'm so glad i watched this, i have been freaking out about putting the wrong amount of fluid in my forks! I watched another of your videos on changing fork oil, and when you put new oil back in it, you said there would be heaps of air in the cartridge so you pumped it about 10-15 times, do you only do that once or do you take the top off and check your level to see if it dropped at all, and then do it again?
I should also add that i am a bit confused with something you said in a comment that, to do an oil change on the fork, the fork it does not have to come apart, but then you said in another comment that to check the oil level the spring has to come out.....wouldn't you have to check the level after doing an oil change?
@@spinna6996 Thanks for the kind words and I appreciate you leveraging the content. There are 2 ways. One is a "dump and run" of oil out, the volume recorded and oil back in to the same volume. Two is to take the cap, spacer and spring out, change the oil and set the level EXACTLY where you want it to be.
I totally fucked up. Well i got around to doing the forks with my buddy. And we used what the shop book said 495cc’s of fork oil. When I jousted them after the new oil I couldnt get bottom out. That should have been the sign to stop what we were doing. Compression change didnt really effect how the bike went through the stroke. Anyway thanks dave for the help, i knew i should have opened up your vid while we were doing it but we were rushing and had oily hands! Will do some more research and end up taking oil out
Perfect,,, just perfect!! Such a short and simple informative videos, THANK YOU. Just one thing mixed my mind, 1:42 , how you can not change oil volume while changing its height in the fork? If we add more oil to increase the height, we increase ("play with") volume as well, don't we?
Oil volume can be used as a reference but oil height is more precise so you actually choose the volume YOU want. Yes, volume and height are both the same if you know what volume you needed to get the height you wanted.
@@CatalystReactionSBW appreciated ! for a regular street bike, do you recommend to play with height by +/- 5mm or 10 or 15mm ?? Can you give any tip about it..? Thank U
I have a question. I have a 15 crf250r and my seal got something in it and I lost a good bit of oil. I cleaned the seal and it stopped leaking but how do I add oil and know how much to add?
You add oil by unscrewing the fork cap which will give you a gap to put oil back into the fork. There's no way to know how much you lost so if you are okay with an educated guess, a little bit of oil is literally 10cc. If oil coated the forks and the brakes, 15-30cc might be approriate. With taking the forks apart, you don't know what you lost in precise terms. Hope this helps!
Dave. I bought a 2008 Yamaha royal star venture used a couple years ago. My owners manual suggests that the fork oil need never be replaced. The words they use are, not necessary. these are air assisted forks. That means I am putting air in that has moisture in it. I cannot see that moisture ever escaping unless I have a bad fork seals that will also allow oil to escape… I feel that Yamaha was not 100% correct in suggesting that the fork oil need never be replaced, simply because of the moisture in the air introduced to the forks that will cause corrosion of the fork springs, and their corrosion, no matter how tiny the particles will not do the insides of the forks much good. I have owned dozens and dozens of motorcycles over the decades, trials, bikes, trail, bikes, motocross, road racing, sport, bikes, touring bikes, commuter bikes, I have always done my own work. I have never drained fork oil out of any of my forks that looked as fresh as new. It always looked cooked/ dark/ sometimes black
Very interesting. Did you check for witness marks on the fork caps to see if there are any recent tool marks.? When the oil was fully drained, were there any black strands of metal visible when you go down the base of the fork? When the fork was allowed to drain over night, did you see any sludge or metal paste? As per your perception based on experience, there should be some contamination from the fork spring scraping on both up and down strokes.
Your example in the video at 1:20, "If you were running 150 before then bump it up to 100" are you talking millimeters? A 50 mm difference seems huge. I raised mine from 130 to 120 and thought I'd done something ;) Can it really be changed 50mm? Thanks for your videos. I've been riding 55 years, and you are helping to demystify suspension for me.
Yes correct - millimeters. It all depends what you start with and what the maximum oil height is. That tell you what you can do BUT, you have to take the cap, spacer and spring out to see what you have first!
My follow-up question concerns a BMW S1000R. Problem: as I find Soft and Normal suspension settings lacking compression (Hard is a no for much of the roads I ride), I needed to add quite a bit of preload to prevent bottoming. Would slightly raising the oil level help me and allow me to decrease preload, thus I could enjoy a plusher ride due to less kinetic energy stored in the springs? If yes, how many mm's would you suggest trying? Thx!
Changing the oil may help. I believe stock is 100mm? You can do this a little easier by adding 25cc in each leg which is a lot less work. If that makes no difference you have to go to a much stronger spring as your weight and ability require that change.
Yes, adding oil to the forks would help in that regard with the air spring effect. You would work in 20cc increments and must bottom out (just). A loss of travel might mean hydrolock and that will reintroduce harshness back into the forks.
If I understand it correctly, adding preload (e.g. via a longer preload bus) makes the suspension softer because the oil level will be lower (under load) than without the added preload. The bike sits higher, so the oil level is lower. Right? So to keep the suspension feel similar with added preload, extra oil should be added. Yes?
Great train of thought in regards to oil level and air gap. Where we need it most is under the compression/braking stroke and note that extension is controlled by rebound. Adding preload may extend the forks creating less air gap (based on internal engineering) and yes with the forks extended , oil level in your thinking is lower due to extension. BUT adding oil does not work as you may hydrolock the forks. So, based on that explanation, please watch this video: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-EiZY0lcqeR8.html
Hi Dave Moss respect to you and your years in this game. I have a question about when loading a dirt bike onto a trailer. 1) When you use straps to hold down to bike side to side strapping on the the handle bars people are telling my I need to use a wooden block or I will blow the fork seals. (these are an open chamber upside down fork KTM) I don't agree. Here is my logic. Once the bike is strapped down compressing the forks or really your compressing the springs only not the oil ... after you bleed down the air using the fork bleeders you cannot blow the seals as there is no pressure. Before you answer lets say during the traveling the bike does not oscillate up or down I believe that no pressure will build up in this case therefore no pressure on the seals. What do you think ? Thanks mate
Agreed when traveling if the forks do not move, you won't build pressure. Stick a Go Pro on the back window and watch the suspension move. Period bleeding during a drive can help relieve air pressure. I tie down my CRF450X at about 25% of travel to avoid pressure build up.
Dave On 2018 R1 feel like would benefit the front forks working further down in the stroke then now working more at the upper part of stroke in the corners while leaned over ... sounds like lower oil level may help this as you said about mid stroke of travel.. is this correct ?
I replaced my fork oil because the forks were underdamped even though the rebound was wound in the whole way. I replaced the oil with factory spec 5W oil and found it's still doing the same thing. I'm considering next time going to a 7.5W do you think this is a good idea? I ride a K8 GSXR600 with standard springs.
Thanks for getting your fork oil changed! Fork oil viscosity is not like engine oil that is standardized all over the world. So, if the 5w was too thin, jump to 10w right away and you should be in the middle of the damping range. If you do use thicker oil you might not need the same amount so be careful with that.
I bought a used bike from the dealer a year ago, and I just now decided to adjust the suspension. I noticed my rebound damping adjustment on the left side has 7.5 turn limit, while the damper on the right has a 2.25 turn limit. I am baffled. I know this bike does not have compression damping adjustment, only rebound. Explains weird wavy wear pattern on the front tire, only 9k total miles, original tire. Unless I am wrong? Looking for some answers.
I guess am lucky, I have a 2019 and have drain screws on the bottom of my forks, just put back in the same amount, just hope the factory fill it with the Wright amount in the beginning. Lol.
If you are going to do only one of the two, figure out what is most urgent. If you cannot control rebound, oil viscosity. If you keep bottoming out oil height. If you bottom out and can't control rebound, take a minute to figure out what oil weight to change to and how much more than stock volume you will try.
Hi Dave, i would like to know...how can i know the right oil level on the fork if i don t have the service manual of that bike? Thanks so much for your videos, awesome!! Best regards from Italy
Forums will generally have that information in the technical section including volume and viscosity. You can ask the service department of the local/regional dealership that represents the brand or email corporate for help. You can go by oil height instead. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-_k_JvZ4Idfc.html
Remove cap, spacer and spring. Collapse the forks to their minimum length. Add oil. Bleed the cartridge/damping rod correctly. Then measure from the top of the tube to the oil surface and make it 108mm.
Dave do you have video "Fork Service for Yamaha R1 04-06"? I would like to do fork service.. I think my bike have still original oil (previous owner ?? never replace) I have seen your Yamaha R6 fork service.guide but the R1 2006 fork are different.. Thanks and greetings from Slovenia
Dave..this would be great..if you have the opportunity please do. On www.r1-forum.com/ forum is quite a lot of interest for YAMAHA R1 04-06 fork service guide. Thanks
Love your tutorials Sir! Quick ? Upgrading the forks on my 2017' SV 650 with Cogent Dynamics DDC' along with 10W fork oil. What would be a good starting point for air gap. Mostly twisty riding and a track day now and then. Still using stock springs/ weight with gear 195 lbs and will install CD preload adjusters. Thanks in advance!
Dave Moss Tuning Dave, I’m getting ready to change the factory 8 weight fork oil to Motul 15 weight oil in my 2018 Suzuki SV650 per your recommendation. You recommended a 130mm air gap. My local dealer provided copies of the maintenance procedure they use. It specifies an 84mm gap. This is measured without the spring and fully compressed. This is a massive difference and I would greatly appreciate your comments before I start work. Best Regards.
@@ronniefranks4351 If you use thicker oil it moves slower so the thin oil needs more volume for the air spring effect to assist in bottoming. It also allows you to feel the new oil and get plushness. If you do get close to bottom, you can add 40cc to each leg to bring the oil level up. Given you local roads, climate and your speeds, 15w may be good for Winter and Spring but 20w might be better for summer. Test, test some more and define what you need :)
Dave Moss Tuning Thank you, sir. You’re responsive, very helpful, and a valuable asset to motorcycling (and all us knuckleheads who don’t know better.)
What will happen? Rider weight: 89kg Pillion weight: 76kg Fork oil used: Heavier oil than recommended. Fork oil quantity: Quite less than recommended. Will the ride be plush-comforting coz of lesser oil? Or Will the ride be stiff-coz of heavy oil?,
Just interested i have matris f15kit instaled on yamaha f76 fuly adjustable,but no even with half turn preload and fiew clicks of rebound and one of compresion ride still feals harsh, is it because there is to much oil in forks? Thanks Dave
Take a look at your fork travel using a zip tie and mark fork bottom out. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-eds3dn1LBkw.html Once you have that information you can see if this is oil or spring related.
Thanks for replay , but i have tried with zip tie and even after agresive ride doest come near to bottom out, some 40 mm from triple clamp, if i put preload gets stiff, if i add compresion bit jumpy but comfortable on lower speed with aceleration handlebar start to woble, same with rebound, so whay i think there is a problem with oil because i tried everything else, components are year old with matris rear shock, absorber, new tyres, road attack 3. So drive is possible only on very lo rebound, and even less compression, half turn preload,shame have seen faster bikes with more copliant forks then mine.sorry for my english.
@@tomislavkljakovic2676 If you have marked bottom out correctly and 40mm is from the bottom out mark to the zip tie, oil or spring may be the culprit. Unscrewing the fork caps would be the first test to measure installed preload. Then oil level second.
literally done this as the weekend there. 490ml came out each fork and I put 500ml back in. don't have a clue what weight was in the bike before but I went with 7.5w.
It is just one of those things you can do with the forks off the bike. You can also do it this way: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-eds3dn1LBkw.html
Dave Moss Tuning thanks Dave appreciated! Will give that link a watch. rewatched the video and know exactly what you mean now. possibly service again in the winter and I'll do this.
also look up the OEm recommended oil and then look up what you used via a fork oil viscosity chart (use Google). Look at the viscosity index number to compare them. That is also very useful information to have in acquiring a deeper understanding of fork oil and how to best use it.
Hi Dave .. Honda says fork needs a 167mm air gap , its small 125 cc bike ( cbf 125) . I set the air gap to stock but when braking the front end dives a lot . Front end feels smooth over bumps etc but I dont like that it dives so much under braking. Would it be ok to decrease air gap to 157mm ? Any chance this can ruin the fork seals ( just replaced them ) ? I also mixed fork oil from the same brand ...10w (70%) with 15w(30%) to get better results but its not where i want it yet. By the way i searched for stiffer springs but there is nothing available here, only stock springs. I am 75 kg .. Thank you!
It should not cause wheel vibration. Old thick oil is cause suspension action to be harsh until the oil becomes less viscous. That is felt through the handlebars as fork oil takes a lot longer to warm up than shock oil (no engine heat assistance).
Hi Dave I have a 92 harley fxr. It calls for 9.2 oz of type E fork oil. I have had it done at 10,000 mile intervals. My mechanic I talked to said he needs to take forks of of bike,clean out and reassemble. Is that really necessary?? The fork seals don't leak...never have. He charges$100.00 for fork seals and fluid and $300.00 labor. That seems like alot!!! It does not seem like much to just raise the bike off the ground,drain oil in forks take caps off and replace with correct amount of oil. What am I missing?
If you have a drain bolt at the base of each fork, that allows you to drain the oil out. Taking the forks apart and doing a strip clean is essential work as so much metal builds up in the bottom of the fork. I will do that every 20-30k depending on use. You can price seals on line, that is not a problem and the labor seems to be consistent with dealer prices.
I am gonna change my fork oil soon...maybe with Maxima/motorex brand. I like the way you are explaining things.. but How do I measure things like "heavy" or "aggressive" I am 80-82 kgs and ride everyday (commuting) at usually between 80-120 kph.. Only sometimes I speed up to 130 and rarely to 140+ .. Am I a heavy/aggressive or a light/relaxed rider? How am I going to get the best of both world from combination between oil viscosity and oil level? What approximate combination are the right for me & my riding characteristic to begin with? My bike is Kawa er6n 2012. factory spec for fork oil: KAYABA KHL34-G10 (I believe its 10w) & When changing oil: approx. 405 mL (13.7 US oz.). After disassembly and completely dry: 479 ±4 mL (16.2 ±0.14 US oz). Thanks Dave!
Thanks for the kind words. You ride at average speeds of 100-140kph. Aggressive would be over 150kph all the time. The fork springs in your bike are very strong and the shock is softer. If you have over 12,000kms on the rear shock, the rear will be much softer than the front, so you should have the preload adjuster 3 notches from the strongest/maximum setting. Use Maxima 10w. Replace by the volume you remove from the fork or by setting the oil level at 130mm.
Thanks for the reply.. Currently, bike reached 24k+ kms. What do you mean by "...should have the preload adjuster 3 notches from the strongest/maximum setting"? Should I set the shock preload stronger/weaker? I forgot to mention that I've replaced my rear shock with Ohlins KA-1100-16 (specific for ER6n) at 20k kms. Ok. Maxima 10w then :) Can I assume that Volume I remove from the fork is the same/close as the spec in the manual? (completely dry: 479 ±4 mL)? Thanks again, Dave...
With the Ohlins shock check that you have 10-12mm of static sag with a cold shock, and then see how much travel you use. You should access 70-80% of the chrome tube and be 8-12mm from the rubber bump stop
More oil is for air spring effect to aid with much slower bottoming out. There is a video on that. Thicker oil is generally slower movement to keep rebound under control.
hey dave👍 I just rebuildt my 41 mm shawa forks on my 06 flstci and put type E fluid in em. I considerd them dry but didnt remove the springs. I put in 13.9 oz as oposed to 3.4 oz on the wet side. Do yo think that will be ok or 1/2 oz to much?
See how much travel you use. As long as you vigorously pumped the cartridge to make sure it was empty you should be fine. If you lose travel, then you have too much oil.
When you brake, one fork will collapse fatser than the other so the bike might steer in the direction of the leaking fork. For maximum braking/panic stop, the bike might steer to the leaking side profoundly.
I recently changed the seals (stripped the whole fork down and cleaned it out with an air line) on my fzr400 the specified oil capacity is 433cm³ so I put in 433 ml . The level from the top of the inner tube to the oil is specified at 106mm from top to oil (with no spring and inner tube compressed), with 433ml it was not close to 106mm so I add more oil till it was at 106mm from the top, am I correct in doing that?/ best course of action? . Thanks
I call the honda dealer for spec. on oil level for my forks on a 2008 h0nda cbr 1000rr THEY said 17.5 oz I fill with 16.5 oz any advice much appreciation
1. Did you strip clean the fork and take it all apart? If so, there is no issue being 1oz less. 2. Did you "dump and run" and make sure the volume you extracted was 16oz or more? If not and you find you are not getting the same travel, you may have too much oil in the fork.
If you are stating travel available and want to know how to measure fork bottom out, use this video: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-8om9opU5Q5w.html
hi dave...i have honda nc 750x 2014 and in manual says 101mm air gap when spring and spacer out ...some users drive with 140mm!is 39 mm too much?i drive mostly 90-130km/h so i am not a agressive i guess and i want comfortable as it can be on front tire and our bad roads....Should i put same amount of oil when changing or just try 140mm?is tap good when pushing fork down or must i add oil or remove it (i have problem understanding language?thnx you are the best
It is always easy to add oil, so start at 140mm and see how that feels when riding for both braking and corner entry. If you feel the forks dive too fast, add, 20cc of oil to each leg. Ride again and see what change that makes.
The recommended volume in the service manual is fine unless you are over 90kg. Then you would need thicker oil to the same volume. 440cc is the volume IF the fork is completely disassembled.
+Dave Moss Tuning . hi Dave just a quick one? I have to soft suspension on my ktm 2018 so I popped more oil in to stiffen the suspension, this help but for steep down hills the suspension was still to soft, so I have put some bigger springs in,this is much better and the suspension feels good apart from i am only using around 65% of the chrome leg and the front sits a little high. if I take the oil out that I added will it lower the shock slightly or do you think I need to shorten the spring because of to much preload. any advice would be appreciated thank you.
Hello I have a 2014 honda crf 125f and I'm trying to remove the Alan bolt on the bottom of fork and is not coming off? Any recommendations to get it off? Thank you
If the fork base is held in a vice and the allen will not move, turn the fork upside down and put some diesel fuel into the opening. Give it a couple of days. Try not to use air tools as you can snap the head off. Apply some heat via hair dryer or propane torch and get it nice and warm, then us a long breaker bar and sustained force. That should make it pop free.
@@CatalystReactionSBW the fork is still on the bike tryed heating it already and put some gb weld bolt loosener on it wont budge. Should I just take fork off ?
Found online for the 600R: Amount for change - 273cc Amount for rebuild - 317 - 325cc Type - SAE 10W20 Front Fork Air Pressure Standard - 8.5psi Front Fork Air Pressure Usable Range - 7.1 - 10psi Front Fork Air Pressure Maximum - 36psi
@@CatalystReactionSBW ok. Thank you for responding. Thanks a lot for your videos too. They're helpful. I've been struggling with the forks since i bought the bike. I don't have the money to take it in anywhere, so i appreciate all of the info i can get.
First thing to do is a simple oil change to the right viscosity and volume, and that does not require the forks to be disassembled at all. Have you done that?
@@CatalystReactionSBW yes. First i tried changing the oil level because the oil looked clean. Then i changed the bushings, seals, and oil. I then tried lowering the oil volume to the lowest amount my manual says is ok. I didn't have the right size hex bit to take out the cartridge, so i ordered it. My bike is an 02 yz250. I can't get the forks to compress the way they should. When i get on the bike and jump up and down they don't compress. They do a little when i hold the brake and push forward, but only about a couple inches. They're also sticky. They don't move smoothly. Today I'm going to try what you suggested in one of your videos about using a little grease to help with striction problems. I didn't try to get them to fully compress while they were off the bike. I've also messed with the adjusters and made sure they're not binding. The axle was a bit messed up. So i filed down the spots that were causing it to grab the forks so it could move smoothly. I jump up and down on it and push it forward while holding the brakes before tightening the pinch bolts.
@@CatalystReactionSBW one thing i forgot to mention is that the springs aren't marked, but according to my manual the standard size springs are the only ones with no markings saying the size. The standard size is for 140-170 pounds. I'm at about 165 pounds. So these springs shouldn't be too stiff for me.
Thank you for your comment. The spring rate cannot change as it is a fixed piece of metal designed and engineered to maintain its rate for years of service in the forks or shocks. What can change is the air spring effect via different oil levels with compressed air. Hence off road bikes having fork bleed valves to be used daily.
Isn't the oil level in the fork is proportional to oil volume in it. So higher level means higher oil volume. So how does Dave separate the two in this video...
Oil level and volume depend on displacement based on fork internals present when setting oil height eg: 440cc might = 130mm oil height in a 43mm fork vs a 45mm fork (inner diameter). I always belled the fork very carefully to remove air and then set oil level. Higher oil levels = more compressed air to assist with bottoming out.
Hi Dave hi everyone on RU-vid I own a 2020 Yamaha tenere 700 I’ve covered around 2500k miles on the bike from new Today I was driving slowly on a bumpy road and I noticed a sound coming from the front end of the bike. I stopped and held the front break on and rocked the bike and I can hear & feel a spring or something similar inside the right upper fork leg jumping about or popping sound & I don’t feel and such popping in the left fork, It becomes more apparent over bumpy ground. Would anyone be able to share some information on what this might be thanks jon
@@CatalystReactionSBW thanks Dave. Am I right in saying that a preload spacer/washer might need to go in the forks. From what I can see in other Yamaha forums this seems to solve this problem. Thanks jon
You can do that of course! But, if that was the wrong volume (used bike purchase) would it be better to get the volume right, then go for the simple process after that?
