You had your damper cylinder upside down. The compression adjustment is on the top. That is why that giant air bubble was mixing with the oil. That actually hurts damping performance. If the cylinder was the right way up, the air would have been above the compression piston, and the air would not mix with the oil.
Yeah look at 12.08 aswell whare he's saying the volume tokens go! Half way down under the seal 😂 geez this video's most confusing ever needs to be remade
Apart from the damper being upside down like everyone else pointed out, it's worth mentioning that the bottomless tokens are installed ABOVE the upper seal, not below. Like in the damper stanchion, the chamber above is connected to the main spring chamber by channels. That's why the tokens are only limiting the air volume without changing the actual travel of the fork.
Grrrreat tutorial! Finally someone who took the job really seriously and got us, forknerds from oblivious bumping over trees to scientifically supported cruising through the woods :D Love the dummies!
Really good explanation. It has been difficult for me to find that kind of video. And really clear even for a spanish talker like me. Now I can clearly understand how does the fork work.
Pretty straight forward analogy for explaining bike suspension from rider's perspective and good job for the demonstration of suspension parts! However, there are some points need corrections or better explanation to not misleading non-suspension enthusiast viewers. 6:16 That is the upper part where the compression or lock-out knob located (at your hand reach when you ride). 10:29 I think you wanted to refer to the dimple on the wall of air-spring cylinder tube which has main job is to balance the pressure between positive and negative chamber. Some forks will need a bit of cycling the fork to equalise the pressure, but some new forks nowadays may not need to. Some claim that having dimple at zero travel can affect small bump sensitivity... 11:03 The polymer spacer (Topout bumper) in the negative spring chamber is supposed to work as cushion when fork fully extended. (I'm not sure if this scenario is called 'off the top'?...please correct me if I'm wrong) For bottom-out cushioning, some forks has polymer spacer in lower leg to take the hit from stanchion, some cheap coil spring forks has polymer rod in the positive spring chamber to do that task.
This was so amazing for me to watch and learn from! I had no idea that each of the front forks do different things! Engineering is so awesome! I live in india, i am 44 years old, im new to current MTB tech although ive been oggling all these youtube videos for years now. I used to cycle more than i walked during my schooling days. My bicycle was called the StreetCat RockNRoll ❤😂 The coolest bike available in the 90s in india 😅 Cool dad i have! I still havent ridden a 27.5. I stopped a stranger and rode his 29er recently, felt like i was riding a horse, so awkward!! 😂 I'm traveling to thailand and excitedly waiting to ride a cycle trail and hopefully pick up a frame and suspension and cranks to build a cycle cheaper than they sell in india. I ride agressive street, like climbing down stairs and wheelieing and well not stoppies anymore cuz im freakin 80kgs now (still very fit though). I guess my reason for rambling is im hoping to find hints and suggestions for minimum requirements for my dream cycle build. Okay, sorry for rambling! Thank u for this excellent video!
As some folks has said, you explain the rebound side upside down, the compresion knob is the upper one, and the rebound knob is lower one, near the drops
Springs that are made with a uniform thickness rod will have a linear characteristic. This tweaked to give a spring a progression characteristic changing the pitch of the coil wind and by heat treatment. The true progressive spring will be made by using a tapered rod, one where the rod is slightly thicker over the length of the rod coiled to make the spring too changing the pitch of the spring coil to a smaller pitch at the end where the ticker material is coiled will vary the spring compression progression depending where the pitch changes. If the pitch starts halfway through the spring and the pitch progressively decreases over the remaining length. The the spring will have a linear characteristic for the first half of the compression but will require greater force the more it is compresses beyond the halfway point.
The best explanation i0ve found. Thanx :D I guess the rear suspension's are the same... Air & coil. it would be great to have thos models with transparent cases to view the inside of the forks and the rear shocks :D
What mechanism allows the rebound to compress easily/oil to flow through easily going one direction, but then hard for the oil to flow through going the other direction?
It looks like the video in comment. But, it's easier in rebound rod of that fork. There is a shim with spring, when it's going rebound, it is closed and minimum flow is used. As the rebound rod is getting into compression move, that kind of valve opens, max flow is used, rebound rod won't affect the compression move, as another part of fork is for compression use
Hi, thank you for this well done and very informative video. I'm struggling with a strange problem with my hydraulic (manitou) fork. Lock out function suddenly stopped working, I disassembled it and I found that the plunger have some existing-through-holes in it (that cant be closed by the handle bar command), besides the locking valve that should do the trick. I don't understand how it could ever lock the fork while some holes are always open. Any clue about the principle of whole thing? Thanx
Can you make a video on Cannondale DL50 Headshok by any chance? such as 'How it's constructed, how the shock works and how to service it on a regular basis' and etc. Thanks!
great explanation tools using a clear damper tube, but holding it so that air mixes with the fluid while you're demostrating it is wrong and confusing. It ideally should not aerate and you are forcing the air through the valve with the oil giving an incorrect picture of whats happening. People will google this and get told that mixing oil and air is really bad in a damper and avoid RST and other dampers that operate like this (New Marzocchi Bomber B2 Rail damper) from this demonstration.
He has the damper upside down in the demonstration and explanation. The rebound knob should be at the bottom of the fork, and the black compression knob should be at the top.
If it comes up slow then the rebound damping is closed. If it rebounds fast but doesn’t return to ride height then it’s likely just air pressure. If neither work your stanchion could be binding in the lower, in which case it needs to be rebuilt. Hope that helps
That damper oil would not bubble like that your pretty much boiling it justbhop you have air pressure valves your gonna need em lol thats upside-down thin lower shaft goies downwards into the lowers blue end to bottom would normally be red but will be blue on this demonstration damper
Try using a script for your videos. In that way, what you wanna say is prepared in advance, reviewed, corrected and in the actual video is only the important stuff. As a result you have a straight well structured video, which does not confuse the audience. This is just an advice. Cheers! :)
Excellent props!! Poor prep. I'd like to cast a 2nd vote for @Dimitri... script suggestion. You don't have to actually read from the script, but at least plan out what you want to say. There was 5 minutes of incredibly helpful info in this video, but it was hard to sit thru the 8 minutes of stumbling around and trying to decide what to say while the camera was rolling. I appreciate the video. Thank you for making it.
Wow, what a wonderful explanation. What is the difference between a really expensive shock vs an inexpensive one ($900 Rock Shox vs an AliExpress $150 one). Does the rider need to be on the extreme end of the riding spectrum to notice (and care about) the difference. By way of example, I play a lot of tennis. I change strings once every 2 to 3 months. Roger Federer changes every 7 games. Very casual players buy a racquet and NEVER change the strings. Each class of player is happy and doesn’t notice any difference. How about forks? Can I buy an inexpensive fork, ride frequently, and never notice a difficiency because I am riding mostly xc stuff and never getting close to the limits???
@@robertwasden2691 My original post was 1 yr ago. And you nailed it. 6 months ago I upgraded to a nice rockshox front and rear suspension - transformed the bike. I do have Chinese CF wheels on several bikes and so far no issues at all. I am not a bike park guy and most of my riding is XC and trail riding. They are light and seem well suited for my application.
@@jeromep4148 glad to hear it Jerome...it's all about fun and as long as you are enjoying it that's all that matters! It's great to have some trick bits on your bike but making savings on parts is all good where you can and where it's appropriate. Hopefully many more miles and many more smiles out on the trails!
How does the lockout work when there is an valve in the rod? It would still go through the piston valve right? I dont know how it locks when there is on the top side just an orifice closing
You have slow compression (regulated by the knob, as a needle), and shimmed piston as high compression. As he close the channel by a needle, more oil wants to go by high speed way. It gets harder to push oil bypass
Nice explanation. Few thoughts: 10:07 you said, that for moving from one postion to other you need same force. That's not true, you probably meant same force difference. The linear behaviour of coil can be described as F= k*x , where F is force in newtons, k is stiffnes of the coil in Newton/meters and x is a travelled distance in meters. Whereas force needed for compressing air spring is derived from gas law (for this purpose let's assume ideal behaviour and adiabatic compression - really fast compression): F = p*S*[L/(L-x)]ᵏᵃᵖᵖᵃ, where F is force in newtons, p is initial pressure in air chamber in pascals, S is area of a piston in air chamber in squared meters, L is a travel of a fork, x is a travelled distance in meters and kappa (in exponent) is a heat capacity ratio - for air it equals 1.4. The progressivity of air springs is a result of power dependence. Theoretically, if you use different gas (such as CO₂) you can change the characteristics of the fork (it would be more shallow, linear-like).
In my RochShox Silver TK the rebound is located at the bottom of the upper leg and I am inclined to believe the 2 forks in the video and the compression/damper model (with the transparent chamber) have the damper at the bottom too. I also thought it was the opposite, but maybe it's because he held the model upside down. However, I guess what you say hold true of the inverted suspension forks: www.google.com/search?q=inverted+suspension+forks&rlz=1C1AVFC_enRO812RO812&hl=en&sxsrf=ALeKk01cNxwxXItL3P-BR9JDPf6YW2IKVA:1590328026192&source=lnms&tbm=isch&sa=X&ved=2ahUKEwjE1M7I0czpAhWyzoUKHWrBBJsQ_AUoAXoECA0QAw&biw=1280&bih=891
Is it possible to make a jumping bike like those cars ? I mean since they involved rechargeable batteries in the bike world :-) btw thank you for the video !!!
Hi Sickbiker, I got a problem with my RST Aerial hydraulic compression lockout. It can be locked out, but cannot be locked out perfectly. When it is locked, the suspension is still travelling for about 30 mm. Could you tell me what happened actually to my fork? and what shall I do? Thank you in advance 🙂
Yes, most forks have the spring assembly on one side, and the damper on the other side. The spring side (air or mechanical) has different components than the damper. The damper relies on fluid and shims to slow the movement of the fork (preventing pogo movement). The spring provides support for the bike and rider, but does not rely on fluid. Instead, springs are metal (like on cars and most motorcycles) or air. The air (like in the video) has a dynamic (moving) seal that separates two volumes of the air spring.
7.36 that is Not rebound that is 3 pos compression you are doing it backwards think of it! Go try bolt that into a lower bet you can't because its upside down
Hi , I've recently bought extra oxy replacement existing older ones. I want to evacuate the air and recharge or refill with nitrogen as it has many beneficial effects. Do you know if this is something I should do myself or if I could take it to the shop I'm having any difficulty finding one near me in Concord, NH does that does that work. Unless there was someone you can recommend.
Hey I know this is an old video but do you know if you could stick a rebound cartridge like from a suntour XCR into a suntour XCM that only has rebound?
after watching this video and discovering the inside of the left fork leg(the air chamber one) i don't understand how and why we still have as much fork travel as we had before and after adding tokens/spacers...it doesn't make sense to me because when you add 2 tokens like at 11:44 the thing he pushes from below should have less distance to travel until hitting tokens than without tokens, it doesn't make sense to me..
It makes the fork stiffer because it mounts in two places. Also it makes more space for the internals, which for example makes the air spring more linear
