well well well. I had a bit of time on my hands and i was quite curious about the whole topic. first of all: my intuition proved to be right in that you cannot simply compare the leverage ratios you showed up there, because they all need different damper stroke lengths to achieve the same wheeltravel. So this has to be taken into account, which in turn means we cannot simply start at 3 and end at 2 to get the same progression percentage. That means while making sure the leverage ratio results in the same overall damper travel for full wheel travel we also have to make sure progression percentage stays the same. Let's take option B as benchmark and create leverage ratio curves of the same characteristic as shown above for options A and B, respectively. For sake of simplicity lets just look at quadratic functions for these. With the required restrictions (same overall damper travel at full wheel travel and same progression percentage) we get the following functions the different leverage ratios to be able to make a true apples to apples comparison: iA = (15/16) * (-(z/zmax)^2 +3); iB = -(z/zmax) + 3; iC = (15/14) * ((z/zmax)^2 - 2*(z/zmax) +3); Where z is the variable for wheeltravel and zmax is the maximum wheel travel. With a maximum wheel travel zmax of 170 mm we get 68.93 mm of required damper travel for all three of these leverage ratios. Now with the leverage ratios established we can turn them into functions for wheelrate with the general relation: wheelrate = springrate / (leverageRatio^2) As you did in the video we also have to compensate for same amount of sag. Lets assume 30% of sag so 51 mm out of 170 mm. With option B as Benchmark and a coil spring with a stiffness of 78.8 N/mm (450 lbs/in) we get a force of 496.15 N in the contact patch of the rear tire by integrating our wheelrate function over wheel travel and then inserting the 51 mm wheel travel at sag. To compensate for the different wheelrate due to different motion ratios we then have to use different springs in option A and B to achieve the same sag. This comes out to 75.4 N/mm for option A and 82.5 N/mm for option B. To determine progression as you do in comparison to a constant leverage ratio we have to calculate the corresponding springrate too: iLin = 2.5; wrLin = cLin / iLin^2; FwLin = int(wrLin(s), s=0..z) resulting in a springrate of only 60.8 N/mm and a maximum force at the rear wheel of 1653.8 N at maximum wheel travel. In comparison we get the following forces and progressivities (calculated with your method) for the options: A: 2139.5 N --> 29.4% progression B: 2232.7 N --> 35.0% progression C: 2347.7 N --> 42.0% progression this means the message of this video is false and quite the opposite is true! If you have a frame with a leverage ratio profile similar to option A and you somehow change the kinematics to achieve a profile similar to option C while keeping overall leverage ratio progression percentage the same, as well as damper max travel and wheel max travel and if you adjust spring stiffness to achieve the same sag as before you will make this bike more progressive in the sense that you will need a higher spring rate and thus a higher bottom out force. thanks for this little engineering challenge :D greetings from germany. ########################################################################## TLDR: in an apples to apples comparison option C is more progressive than option A, contrary to what the video suggests.

I dont geht why forceVStravel graph of option C is en par or even lower than A or B, when it should be greater in the beginning of travel.

Excellent explanations and advise!

Mhh very interesting explination!

I agree😊

One of very few people who has real scientific knowledge is back agai👍. Thanks for all your work men. Greets from Austria

Well, suspension design is a collection of progressivity, wheel path, anti-rise and anti-squat. Comparing just one is useless, especially when it is the one that is the most adjustable within each design type. Though, they all do have limits (for example, nothing can match the linkage curve of DELTA). So this was uninformative.

How to know which Flip Chip Bolt is compatible with my bike cube Stereo 120 HPA Race model 2016?

Please make a video with sag % front vs rear values for comparisson and types of terrain and steep of the track

Excellent, thank you

Good but the end is way overly simplistic. While an air shock SPRING is progressive, damping isn’t. So combining air with a regressive shock curve does not make a linear setup. The spring may become linear, but damping is still digressive. Motocross has proven that you want damping and spring force to be the same, get progressive curve from frame kinematics. Or combine a progressive spring with a well made progressive shock (very hard to do).

Perfectly explained

Really learn new things from you. Building a mid drive ebike Transition TR500 200mm front and rear! Have ebike TR250 180mm that is Awesome

Video skips from your fuck up. Still making shit videos i see

Just great. :)

Interested to know where you’re at in 2024?

you say that faster riding does no imply faster rebound , but why not though ? in my mind i feel the bumps comes faster therefore if my rebound is too slow to keep up, my suspension will pack up . interested to hear from you or other more knowledgeable people :)

booty break in between the numbers talk

Eu estou com um problema na minha suspensão da roda de trás, é uma manitou metel coil das velhas..., mas quando eu deixo cair a roda sem nenhum peso faz bué barulho. Eu sei porque é que faz esse barulho, ela comprime um pouco o ar do piggyback (nenhum óleo passa para o outro lado das válvulas) e faz o top out muito rápido, e isso leva ao barulho. Como nenhum do óleo passa para o outro lado da válvula (porque não ouve compreensão quase nenhuma) não há o efeito do rebound. O que é que eu devo fazer? Aumentar a pressão do piggyback? Ou será de ter a mola com muita pré carga? Eu já vi uns vídeos teus super interessantes em que falavas disso.

Espetáculo de vídeo e trilhos.

O mal de andar aí, é que um gajo fica mal habituado, e tem de largar dinheiro em pneus, mais cedo do que esperava. 😅

Credibility is in question. When a spring is compressed, it is not under tension. This mistake was made enough times in this video to indicate that it was a misunderstanding of the terms, not just a verbal mistake.

Great to see an upload from you! 😀 What about continuing your great work? Everybody loves you❣

Isto foi no domingo passado? Se sim, não reparei que eras tu.

Very helpful!

This finally made rebound make sense to me! Great video and explanation

Think I watched 8 or more videos before this. Thank you, this is the best clearer explanation by far 👍

excellent! big thanks!¨

as a professional photographer for 21 years , this by far is the best video on rebound damping adjustment

9:30 When you've changed the volume of positive chamber, at the same time sag have schanged. Honestly you cant keep both the same as they were, sag and bottoming out force. If you deicde to get benefits from increased negative chember you have to be aware of those two things, you are going to get deeper into the sag or have higher bottoming out force. Anyway very cool excel and video, I would love to see charts with super deluxe with and without megneg

Great video! How came anti-rise=brake-squat? Does this mean that in a system where brake produces the suspensión to extend (pro-dive) it can also be named anti-squat? Thanks a lot!

It’s not really free if you need to use a $300 camera to acquire footage.

@andrextr There're a mistakes in some of the formulas in excel file. You forgot to take into account the atmospheric pressure - columns AF and AH. This changes pretty much every resulting number from simulator.

thanks i appreciate you making this video !

Welcome back! Motocross bikes have 300mm of travel, and they are basically heavier ebikes.

Great video. Thanks

Why would I test the suspension without the rider (weight)? This isn't to disagree with anything, but I'm confused as to the practicality of the test shown. I'm asking because I've had a devil of a time setting up my rear coil so as not to get bounced off the pedals on tech sections. The CS rep, (Cane Creek-you guys are awesome!) got me to recheck my sag. Increasing hsc and reducing hsr helped, but there are still times when it's a one foot on, one foot off affair.

It would be huge help if the shock makers put out some design stats for the highest and lowest weight riders. What they had in mind for the shock. Oscillations should be involved in the psi's as well as the damping no?

do you have a website with all your bike analyses?

The legend is back

I love your videos! I learned so much from you over the years! Thank you for sharing all of this!

About the 1 meter drop to flat since it takes a different amount of energy for the two bikes they can't both be pushed to flat from the same drop since the potential energy is the same but the energy to the bottom out is different. This is true even though the bottom-out force is the same. The bike with longer travel won't use all of it's travel. For a drop where the 180mm bike uses 155mm travel the 150mm will use 141mm when set to the same sag %. This results in a peak force 10% higher on the 150mm bike so this is the true reason why the longer travel feels more soft. Otherwise, great video always love learning more about bike suspension dynamics. :)

Welcome Back! It is awesome to see you back! I'm glad you've been riding so much !

hes back! WELCOME

This makes totally sense. I have extended travel om my Nicolai G1 to 190mm and it rides much better with a lot mor comfort. Also have a Kenevo Expert that I have gone from 62.55 stroke to 65mm stroke shock, and as you same with same sag short vs long, it is travel in reserve. I have also looked into the market for ebikes with long travel and concluded like you. The only long travel option like 200/200 is the Pole. I am now running my Specialized with 203 Fox 40 in front and gets approx 190mm rear travel. Extra Travel does not weigh more but is so much better comfortable to ride.

Do my tired eyes deceive me? A new video from Andrextr??

what is your opinion on the weight of ebikes, once you get used to it? Is it worth going for 20kg bike vs a 24kg bike?

Welcome back!!! Same as you, e bike was really a game changer for doing more trails. Love the funny part at the beginning 😂

I liked the video after the first 4 seconds 👍 And totally agree with the idea. Why I bought a Kenevo. And of course bike companies know this, but how could they sell more bikes, if not by slowly "progressing" to something which is obvious? Haven't they done the same with the geo?

Great to see another video from you! Fan of your bike analysis from the past. My only worry about getting a big travel E-Bike is that it will ruin me for my analog bikes.