Few people understand the dangers of high pressure hydraulics. It’s typically inexperienced heavy machine mechanics - think big Caterpillar or farm equipment. Theres a small tear in a line and their hand or arm pass by a super pressurized stream and it “cuts” them. That “cut” actually just injected them with filthy hydraulic fluid. These “cuts” are small, don’t bleed much and are not super painful, but Immediate emergency medical intervention is required or they often die.
Thank you for the video! From what I understand, it seems that a disgressive damping setup would be better for my situation. I plan to use my car primarily for street driving, with occasional track days. Given the heavy traffic and the numerous potholes in my area, I need a suspension that can handle both conditions. I hope you can read this comment-could you please offer some advice? Thank you again!
That is the opposite of what is true. I can see no use for digressive damping at all. There is no difference in setup for street or track. Soft springs and linear damping with maximum compression and minimum rebound and the least damping that you can do is good for every situation in a vehicle that relies on mechanical grip.
Nowhere on the internet you can find videos about the development of the (motocross) Ohlins shock absorbers over the last 30 years. Yet THAT would be a particularly interesting topic that would lead to an understanding of the many iterations in constant development. If you compare two shock absorbers in principle (Kawasaki KX500 / 1988 and Kawasaki KXF450 / 2024 - as an example) - what fundamental differences cause the massive progress? Are there big differences in the lever systems? What do the shock absorber pistons look like in direct comparison? How do the control mechanisms work? How do the filling quantities or the oil used differ? How have the shim stacks changed - and why? THAT would be really interesting to hear from an expert!
I am not an expert, just a tech. I am a car racer. I don't know much about motocross almost never do any newer motocross shocks. My mentor, the late Bruce Burness, was on the forefront of this technology in the 70's at the beginning of Ohlins. He was DeCoster's guy for the last two championships and did shocks for motocross champions through the 70's. I am not sure that the shock and forks do the same job with the newer bikes in that so things might be different now with longer travels and a lot of air time. Another problem is that the real guys in the big teams, as in all racing, aren't really giving out the information on what they are doing so a lot of the stuff on the internet comes from "experts" who don't know what they don't know. I wish I could be more help to you but I don't want to be one of those guys with white boards telling people stuff I really don't know about. I am kind of out of stuff I know about.
@@theohlinsguy4649 Thank you for your quick reply! You mentioned that you don't consider yourself an expert. I don't agree with that - and I would like to thank you very much for your videos on RU-vid - which provide a lot of important understanding of vehicle suspension. My question in relation to the further development of shock absorbers on motocross motorcycles (but not only there) and a comparison between the mid-80s and today has to do with the fact that even back then the basic development of the lever systems, the length of the spring travel and the chassis geometry itself were very similar (about 95% of the 2024 status) compared to today - but the shock absorbers / front forks certainly weren't. This certainly also applies to the elements for road racing motorcycles in the Superbike and MotoGP competitions. During the 80’s I was involved in the development of chassis- and suspension-systems for teams in the Motocross World Championship (Kawasaki / Yamaha) - so I'm naturally interested in how the problems from back then were solved. This means fundamental changes, not individual adjustments. BR
@@move-it-777 Dampers are there to stop oscillation. The smoother the tire patch is to the ground the more grip. When you start using them for other things it is a slippery slope. My beliefs are: Linear damping with the most compression and the least rebound (usually both are the same value) and the least amount of total damping possible. Rebound is the enemy of grip. In cars, if aero is more important than grip, you might want to use the damper to keep the aero in optimal position rather than worrying about grip. With motocross I don't know what factors are more important. If it is mechanical grip I think these rules still apply. If you have un-linear linkages this probably would be hard to do. Just my opinion
My understanding is digressive is good for long suspension travel offroad, and specifically for MTB or MX- where you prefer more stability in low speed use, but can soak up square edge "high speed" stuff better. Yes? I agree for road use, it likely doesn't make much sense.
Hi Jay. Unfortunately I don't work on Ohlins motocross shocks or forks. I almost never get them to service and I would need more tools and knowledge. Thanks for asking....
Thank you for the information. This is the first place ive found great knowledge via video on this subject. ive Ive gotten all the knowledge i know about revalving through the racetech book and buying gold valve kits to play with and try and figure out. It seems like good suspension techs keep all this way too close to the chest, treating it like black magic. So i really appreciate you letting people who want to learn, do so without taking an apprenticeship at a shop.
I think "suspension techs" keep it close to the chest because they really don't know what they are doing. They have to make it mystical and complicated to dazzle you with their brilliance. It is not rocket science. It is hard to figure out what you are doing without a dyno but just keep at it and you will figure it out.
Hi. I have a 2002 Ram 2500 Diesel. You might laugh but my recommendation (and what I use) are the blue Monroe shocks from your local parts dealer. $20 to $30 each. I would stay away from any fancy upgrades as I find they are usually really severe. The Monroes last a long time and are cheap to replace.
For a front wheel for a typical passenger car, With shock directly attached to the hub for a car and the hub rotates around the shock as car steers, wouldn't that always be 1:1 ratio?
HI. No. It would depend on factors like where the shock attaches on top and where on the hub. It is actually hard to get a 1 to 1 ratio without some sort of a rocker or crank system. Some BMW cars get more than a 1 to 1 by mounting the rear shock in back of the axle. I personally don't like a 1 to 1 as it is very easy to overdamp and hard to find soft enough springs. A lot of people have all kinds of reasons to do a 1 to 1 but I don't believe any of them. The only good thing about it is you don't have to do any calculations for wheel rate.
Hello how are you ? I need help with a rear shock absorber on a 2014 KLR650, I am in the middle of Venezuela and no one makes repairs on these parts in this country. Could you help me repair it? Greetings
Hello how are you ? I need help with a rear shock absorber on a 2014 KLR650, I am in the middle of Venezuela and no one makes repairs on these parts in this country. Could you help me repair it? Greetings
Hello how are you ? I need help with a rear shock absorber on a 2014 KLR650, I am in the middle of Venezuela and no one makes repairs on these parts in this country. Could you help me repair it? Greetings
Hello how are you ? I need help with a rear shock absorber on a 2014 KLR650, I am in the middle of Venezuela and no one makes repairs on these parts in this country. Could you help me repair it? Greetings
Hello how are you ? I need help with a rear shock absorber on a 2014 KLR650, I am in the middle of Venezuela and no one makes repairs on these parts in this country. Could you help me repair it? Greetings
Hello how are you ? I need help with a rear shock absorber on a 2014 KLR650, I am in the middle of Venezuela and no one makes repairs on these parts in this country. Could you help me repair it? Greetings
Dear Doug, first and foremost thank you very much for your excellent videos, I'm extremely grateful for all this knowledge you're sharing with us for free, I wish you live forever in excellent health. Your videos helped me to fully understand how my suspension works and gave me hope that I'll be able to retune mine for the fraction of the cost of the aftermarket alternatives. I've one question regarding Ohlins m/c shocks: Can you replace the piggyback reservoir with a shorter one? I've an HO0841 that I wish to fit in a '94 VFR750F(after any rework that might be needed), but it seems like that the swingarm is going to hit the reservoir.
Thanks! A smaller reservoir wouldn't really effect anything. The same amount of oil would be in it but just less nitrogen which wouldn't really effect much. I am assuming it is a 44mm ID reservoir. The shortest one is 80mm long.
Thanks a million for your prompt response. I love your gentlemanly manners combined with your halfway British English. It's a real pleasure to listen to your easy-to-grasp explanations. Unluckily the values you represent are quickly disappearing these days.
When I look up that number it shows a conventional fork, meaning the big part is down. I have never done any of these. I looked to see if I could find a manual for them but none were available. I wish I could help more. Try Ohlins USA 838 692-4525 and see if they have any info.
Hi Doug, your video popped up out of nowhere. I'm in Irvine so very close to you. I just got a set of Ohlin R&T for my 2021 BMW M2 Competition. If and when I need servicing done (or revalving), I'll be giving you a call.
@@theohlinsguy4649 very interesting to me. My Penske 8300s are linear, but my Koni Doubles are definitely digressive. but they I read some F4 or F3 cars a have basically extremely digressive curves
Great video, as usual, thank you! I'm just starting out, so could you please elaborate on why you don't want the adjusters too much closed? (said around at 40:00) Edit: I fount an answer under your 'Inside the Ohlins TTX 40' video: "(...)You have to be careful on any single tube shock with a reservoir compression adjuster. If you start closing down the rebound or compression independent of one another the shock gets out of balance and bad things happen. (...)" So this can be a problem, if they are not-so-well valved and/or pressure balance is not checked?
HI Ben. Pressure balancing is time consuming and difficult exercise that is rarely if ever done. If a single tube shock is done correctly it is as good as any shock. One of the advantages of Ohlins TTX technology is that you don't have to worry about pressure balancing or cavitation. It is actually adjustable in a wide range. I wrote a thing on shock adjustability that applies to single tube shocks that I will try to attach. file:///Users/douglasbrenner/Desktop/SHOCK%20ADJUSTABILITY.pdf
Thank you a lot, Douglas! I am just starting to understand suspensions and your videos helped a lot. I come from the motorcycle world, but rather from the convenient, than the competitive side. My questions are, however, rather general. How can you say looking at a graph, that this shock with this setting will work for the intended purpose? What are you aiming for, when revalving? What could be the difference between road use and track-oriented use? Or you mainly try to correct anomalies? I would really like to see another video from you, they are of such a good quality.
Hi Ben. Actually some great questions. As for intended purpose, I only have some experience with vehicles that need mechanical grip. When you get into cars with high downforce made from the underside of the vehicle at some point downforce is more important than mechanical grip. At that point the shock is used for keeping the aero in place. I see many "experts" talk about using shocks in mechanical grip cars to keep the "platform" in a certain position. This is not the job of the shock. When this is done you are giving up grip. There are other ways to do this. There is really no difference between motorcycle and auto damping. Also there is no difference between street and track. Grip is grip. Soft is fast. Shocks put out resistance to motion relative to shaft speed so on the track you just get more damping because the shocks/forks are moving faster. Proper compression damping bleeds off extra energy that would have been stored in the spring so you don't need a heavy spring. Enough compression damping is essential and most shocks I see don't have enough. All I want to know is what is the motion ratio so I know what the tire thinks the damping/spring rate is. I only use linear damping. Most vehicles like very similar damping at the wheel. The great question is correcting anomalies. If you are valving for anomalies like hitting a big bump etc. then you are compromising the other 99% of your grip for 1%. Anomalies are just that and I ignore them in my valving.
Hi. I don't really use any software. I just kind of know what I want to see and mess with it until I get it where I like it. I just have lots of experience but still need to mess with it to get what I want. I have a dyno to see what I have done. I have lots of data stored on my dyno so I kind of know what I have done before to get what I want and I have a starting point. There is no software that tells you what is better or worse that I know of and if you can find one it will be bogus. There is software for Ohlins TTX40s that you can also use with some success on TTX36. Look up Ohlins Valve Referencing Program (VRP). There are a bunch of different shim stacks in the program and last time I looked two valve choices. (linear and digressive) It can get you in the ballpark of where you want to be. I never use two way adjusters (low and high speed) so if you are using single adjustment you can just put the High Speed at about 38 and it usually is close to correct when manipulating the low speed adjustment. Remember that this software just tells you what the damping might look like but not what is better or worse.
Hi Brook. I do some but not all. I don't do motocross shocks. what shocks do you have? The part# is on the top. should be 2 letters and 4 numbers. Send to my email. brennershocks@gmail.com
Good evening, are you still rebuilding ohlins currently? Our Volvo automotive community needs a dedicated rebuilder in the US for Ohlins road and track shocks/struts. On the search, thank you!
Hi The needle can't come up the shaft because there is a counterbore inside the shaft. No oil goes up the shaft because of the o-ring on needle. The needle is held in from coming out the bottom by the shaft jet. The need is held against the rebound shaft by the nitrogen pressure in the canister pressurizing the shock oil
@@theohlinsguy4649 Okey thanks alot for the answear! i Need a new shaft to my KYB Shocks so i have to look if its build the same way! this is the only video ive seen someone replaceing it
very controversial opinion. Not many share it, but kudos for having the fortitude to express it! When you used the corner entry to mid-corner example I don't understand how shock velocity goes from high to low when its all compression and rebound from driver input, which is generally quite smooth.
Thanks for the reply. The video explains it the best I can. Who are the "not many" who don't share it? The video title says why I don't do it. Do what you want.
HI Glenn. Thanks for asking but I am not really doing videos at the moment. I took a look at the FL 969 parts list but couldn't find a service manual. The other problem would be that I would have to have one to do a video and since it is so new I probably won't be getting any soon unless someone bends one up. Pretty interesting piece though. I see where you nitrogen fill it but I can't tell if it is an emulsion fork or if there is a separator piston somewhere.
Hi, I have the ttx36 McPherson with a small reservoir on the front and ttx36 ilx in the rear, the small reservoir is usefull ? I had Intrax before and the reservoir was a lot bigger . Is my suspension solid piston design? Is from an BMW M4 Gt4 race car .
Hi. Is that a TTX46 in the front? If so the reservoir serves a much different purpose. The through shaft does not displace any oil so no mechanism for dealing with displaced oil is necessary. All the small reservoir is for is to allow for oil expanded by heat to go. The separator piston in the canister does not move when the shaft moves. In any TTX there is also no need for high pressure in the canister. They are usually set at between 6 and 8 bar because there is no danger of cavitation with that technology. Usually the TTXs have a solid piston. There are pistons available with blow off and high frequency configurations but I rarely see this in the applications I use.
Thanks Ramone. I am in Ventura county. I just service Ohlins shocks and forks and don't take them off of the bikes or cars. Most of my work gets shipped to me but if you are close you can bring them here
I’m loving the videos and binge watching everything! Motorcycles are my hobby and passion and suspension has always been something I’ve been fascinated by. Being in it for so long, how did you end up in this field? Are there seminars and apprenticeships that one would be able to get into to learn more?
Hi Jason. As everything I have done in my life I have no idea how it happened. I just was lucky enough to have Bruce Burness has a friend and being around racing in the 60s in Southern California. It was interesting to me as it is to you. I fear that seminars are mostly just people telling you things they actually don't know about. Just remember it is not rocket science and you can learn by doing it and making mistakes along the way.
@@theohlinsguy4649 I have a spare shock for my 750 that I took apart specifically to learn on. Seeing the actual parts in my hand, in conjunction with having the knowledge from books and watching videos has helped to some point. Now I just need certain pieces of equipment, but I don’t know if you’ll see enough hobbyist buying that just for a hobby lol.
@@jasonsarmiento3029 Perfect. Some tools can be made and some things can be done without tools but it takes a lot longer to do it. Ohlins tools are at times a bit expensive but there are other sources for tools that are less expensive. Check around on the internet.
