did you mean to write the worst? horrible audio with pops from breathng into the mic, to no structure. Its all over the place and repeating the same thing over

Portuguese accent

Thanks 👍

Sorry for the very late response (I've been quite away from youtube), yes, kickback is more relevant at lower speeds (like climbing). At faster speeds it becomes more irrelevant as you said. Antonio Osuna from linkage design blog has some working models & animations about that, you might want to check it up. Bye :)

+Bence Kormos Linkage X3 from bikechecker.com bye

It's the Linkage X3 from bikechecker. Bye :)

+Samuel Hall You can see my recent video of Giant Glory analysis, you have the full method on the anti-rise. Basically it's the line that comes from the rear contact patch that passes either on IC (anti-rise) or in the chain-swingarm point (anti-squat). If that line passes at CoG height (~1.1m) on top of front wheel, then it's 100%. CoG stands for the center of gravity. This is the graphical method to calculate this things, either on MTB or in Motorcycles, and it's the method that Linkage uses. The a2 on the older linkage version is the anti-rise, while a1 the anti-squat. Now you have that in separated tabs. Bye

The yellow zone is based on the graphical method of anti-squat (I didn't invented the method). But basically a 100% AS is when the AS line has the center of gravity (CoG) heigth above the front axle. Since the typical CoG heigth for a bike + rider is similar to the wheelbase (~ 1150mm), then this AS 100% line has an angle of nearly 45º (yellow zone)... There are a lot of articles about wheel size discussion, and I dont have much more to say, specially because the advantages and disadvantages are hard to quantify making it a quite subjective topic and because I still ride 26 eheh :))

I have a couple of videos about Giant Reign and Trance analysis. The Niner, Maestro, or SC VPP have the same type of system, the difference is how and where the pivots are placed, and that creates different characteristics. For instance, the Maestro and VPP are optimized for anti-squats around ~100% (good on pedaling) on a singlering setup (30/32T) while Niner have lower anti-squats (around 50-80% depending on the models), this is because of the Instant Center location in part due to the lower placement of the lower link (which is bellow the BB). On the other hand, Niner and Maestro are slightly progressives, while Nomad 3 is very progressive... Those are some of the main differences. Regarding the wheel size, the frame needs to be redesigned to accommodate bigger wheels (clearance issues). Usually the kinematics are well preserved between different wheel size's frame models. Bye

The Liteville 301 mk13 160mm has good anti-squats (120% on average for singlering setup) and very low anti-rise (10%). So the bike pedals well and it's very neutral to braking forces. The progressivity is 30%. Orbea rallon also has good pedaling efficiency but it's a linear frame (only 5% progressivity). The anti-rise of rallon is around 70%. Bye

Great Andre, Thank you!

thank you.

This not proves that the both forces are equal! The rear moves only when you overcome the friction forces and the gravity in case you are on an ascent, but this does not mean that you exert this amount of force to the pedal. For example, if you grab the brake then stand on the pedal, you exert all your weight, yet you still won't move. That's because the brake diverts the force you applied to elsewhere. The suspension will also compress, because the swingarm will divert some of your force not into the chain but into the suspension. Think about vectors. The vectorial sum of the forces are zero, but that does not necessarily mean that there is only two opposing vectors in the system.

The suspension has the tendency to compress under acceleration due to the inertia (weight transfer). Since the swingwarm and chainline are not fully horizontal, the driving force and the chain pulling force can counteract, or enhance, the suspension squat. The article bellow has a nice and intuitive explanation (in the present video I only talked about chain pulling forces to simplify, because they are the major forces involved in traditional FS mountain-bikes, but on high-pivot bikes, or motorbikes, the swingarm angle is steeper and thus the driving force have a major contribution to the the overall anti-squat) www.sportrider.com/more-fun-geometry#page-3

+Rafael Defavari obrigado Rafael. Amanhã vejo o fórum. Valeu :)

+On Board With Ziggy Yes, I can try to redo them... I've been more busy these days but I will try... But I remeber that am V4 is pretty normal, an has an anti-squat and anti-rise around 100/90%, respectively, and a normal progressivity for an enduro bike (around 20-30%, if I remember correctely).. Bye

I want to make a video exactly about that, but I still didn't make it (no much free time lately). Anti-squat is a result of two factors: 1) Chain pulling and 2) Swingarm angle (also called as driving force or free/natural or frame anti-squat). In this video I only talked about chain pulling since it's the most relevant force for most traditional bikes. As I explained, the anti-squat of these systems depend on the chain growth, and this amount of growth is proportional to anti-squat % and inevitably to pedal kickback amount. On most high pivot bikes (or motorbikes) you can achieve good anti-squats with minimal chain pulling since the 2nd point starts to be more relevant. So what is this 2nd point (swingarm angle anti-squat, also known as frame or free anti-squat)? It's easy to understand. Imagine a side view of an high-pivot bike (with a steep swingarm). When you accelerate the wheel spins and the wheel axle moves forward. This forces the swingarm to rotate counter clockwise around the main pivot (extending the suspension). That's the "free" anti-squat. It's just a result of how steep the swingarm line is. On a bike with an horizontal swingarm this free anti-squat will be very low and the bike would depend mostly on chain pulling to achieve good pedaling efficiency. On high pivot bikes or in motorbikes you can change the chainline (with idlers) in order to decrease a lot the chain growth and pedal kickback and still having good anti-squat (from this "free" anti-squat factor). Not sure if I answered the question. Probably not. lol

Thank you very much Andrextr. I think I understand you (despite my poor English). My doubt maybe is related to the necessity to do a diagram or graphic of forces and moments in the case of the idler-pulley on any link of the suspension. I think the current version uses a secret method by I-Track Suspension. Look at the Linkage X3 Anti-squat graphics in the case of a system with idler on swingarm, you can see the I-Track mark behind. As you say in the note of your video, on the I-track web they also say talking about the "normal" graphical method: (www.i-tracksuspension.com/suspensiontheory2.html#graphical) "There are a number of suspension designs where this graphical method does not apply. These include: - Unified Rear Triangle (Trek, Klein) - Independent Drivetrain (GT i-Drive, Mongoose, Lapierre) - Swingarm Mounted Idler (Corsair, Balfa, Empire, Commencal) - i-Track Suspension The engineers at i-track suspension have a strong understanding of vehicle dynamics, and have been able to devise new graphical methods, to enable the % Anti-Squat to be accurately quantified for all of these suspension systems. These methods are currently kept as a ‘trade secret’. " It´s a shame this method isn't shared (despite I think I understand their reasons), but above all, it's a shame it is hidden on the Linkage program. It's bad for us, the users of the program (that we paid for it...). Best regards

Yes, when you place the idler on swingarm (unsprung mass) then the chain force on the idler is also transmitted to the swingarm so it would affect the final result (thus, you need to use that new patented method). If you place the idler on the main frame then it uses the normal method because the forces at the idler won't affect the suspension.

Hi, I don't understand which method is used to calculate the ICas point for an Horstlink system on linkage software. Does anyone know how it's built?

+tuyen chi nguyen it's the interception point between chain line and swingarm line, being the swingarm arm the line between rear axle and IC

I made a video to talk about the software. Video name: "Linkage X3" simulation software (MTB suspension Ep.16)

+Клековкин Женя Yes, it's good ideia to use the same CG heigth and same frame size to make direct comparisons.

And what's better: to use the same CG height for all bikes or to use CG height like a stack height? Thanks)

Thank you my friend! Im still alive but dont have much time for videos now... cheers 👍

@@andrextr we miss you for sure!

Yes, anti squat in only relevant on first half of travel (near SAG), where you spend most of time pedalling. VPP system has very good antisquat on first half of travel and then they decrease sharply on second half of travel for instance

@@andrextr also, does the degree that the bike is on effect anti-squat values? For example pedalling at 30% sag at a 0 degree incline versus pedalling at 30% sag on a 20 degree incline

+miguel lopez Yes, anti-squats change between gears. That's why singlerings are an advantage for engineers (they can design the bike to work well with one chainring). Brake jack/squat is not affected by the gears. This video is only about anti-squat (how suspension behaves under acceleration, and not under braking). On downhill you should go with small cogs (like 11T), because that decreases a lot the amount of pedal feedback (kickback). Bye

+andrextr nice.. in a world dominated by marginal gains everything helps..

Yes true. I was planning an update on this video to include the driving force, some years ago, but never did it, and now I don't have much time for this :D

Glad to hear you're busy! I've checked out a few more of your videos and your explanations are very very good, thank you!

Do you have a method of calculating driving force antisquat? Some method of quantifying it in order to calculate overall antisquat when combined with chain tension antrisquat? I for one would be very interested!

Liteville's bikes usually are very progressive. The 601 is no exception (progressivity around 50-60%). The anti-squats are good on small chainrings (around 100% in 22-26T), but they can drop to like 50-60% in a 30-32T... Brake performance is good (which is quite common in horst-link type of bikes). Bye

No, it's similar to Zerode example in the video (not sure if you saw it). In DH V4 the main pivot (IC) is also very high, so despite the chainline, since the IC is also very high it won't have a negative anti-squat (not sure about real DH V4 anti-squat values, since the idler and the main pivot are not concentric and I cannot see the main pivot position on the pictures because it's occluded). Moreover, the idler is located on the swingarm (unsprung mass) and not on the main frame, therefore it requires a further step and different method to calculate the anti-squat (it's an exceptional case, listed on the video description where this classical method is not fully valid). Bye

Ok great! Thank you!

Sim, o antisquat diminui com a altura do centro gravidade e aumenta com a distância entre eixos. Como riders mais altos também usam bikes de tamanho maior (com maior distância entre eixos) acaba por compensar e minimizar o efeito da altura do rider. O peso não tem influência neste caso.

In most bike designs, the distance between bottom-bracket and rear wheel hub increases during suspension compression. This causes the chain to "grow" which pulls the pedals backwards (pedal kick-back). In normal bike designs, the anti-squat is somehow dependent on this chain-stretch effect. Basically (and to simplify), when you apply force on the pedals, the tension created on the chain counteracts the chain-stretch and prevents the suspension to compress under acceleration. Therefore, with the correct amount of anti-squat (and chain-grow) the suspension stays relatively quiet under pedaling, saving energy for the rider. This is particularly important in XC / Enduro bikes where you spend most the time pedaling.

Still don't get it =(

+Jesse Chen It was an exaggeration just to demonstrate the chain pulling effect otherwise I couldn't lift the wheel because my bike has low antisquat.

Jesse Chen you are right the pedal never goes backwards because is the inverse pulling! The experiment need to be tested in the order way!

Hello my friend! Since making a video takes several hours I am offering now an online service to analyse bikes if it interests you: www.andrextr.com

It's a great question. First I should have said "some" people instead of "many". Indeed, most bike manufacturers aim for a 100-120% anti-squat, while a few have higher anti-squats (up to 170% in some cases). The guy from the I-track suspension believes it is good to have higher than 100% AS (and it makes some sense for me). However other experts believe that the anti-squat force does not match with the frequency of vertical body movement. Therefore it would be pointless to have 150% for instance. I don't have any real data to confirm one of the hypothesis. The values on the table were merely a rule of thumb to help people to understand the numbers. I don't have data to confirm if 130% indeed causes pedal bob from excessive suspension extension, however, it's easy to imagine that a 200% or more, can cause this. In my recent video (AM V4 vs Kona 153) I changed the value to >>140% (much higher than 140%), to be on a more safe side. What I can ensure is that a lower than 100% is not enough to keep the suspension fully quiet under pedaling & acceleration (the lower the value the worst it will be). Bye :)

+andrextr thank you for the reply and for sharing your awesome work!

Tung Trinh Its the same rational. if both lines are fully parallel we assume that they would cross at the infinite, and as a result the antisquat line would also be a parallel and have the same angle as the other two lines.

+Martti Heino You need to prolong these lines until they cross somewhere in the space. This cross can happen at long distances if the lines are quite parallel (and it can happen at the left or right of the bike). If they are truly and fully parallel the cross happens in infinity, therefore the antisquat line will cross at rear tire contact point and it will be also parallel to chain line or pivot axle line. I will talk more about antisquat in a future video. Bye

Thanks for the prompt answer and can't wait to see the follow-up video on the anti-squat! I understand the virtual ansti-squat point being long distance from the lines. I was wondering of the effects of this on the behavior of a pivot system like the DMR Bolt. To my understanding this A-S point would be greatly variable depending on the gear you would have on the cassette, therefore determening the angle of chainline and pivot-axle-line being positive or negative. This would then slightly pull or compress the shock, if I understood you right. What I still wonder is the actual effect of a certain pedaling force when translated into the shock. This is because of the very low angle of pull that the chain would make on the single-pivot swingarm type design like the DMR Bolt. To me it feels like that force would be extremely low, since the vector component that is in 90 degrees to the pivot-axle-line can be the only force that translates into the shock. In any case I love your videos! Awesome work Andre.

+Martti Heino In DMR Bolt the antisquat will change a lot across different rear cogs and also they are quite low, or even negative on smaller cogs. The advantage of this is the minimal chain growth. When it's negative it means that the chain tension is actually compressing the shock amplifying even more the pedal bob. When the linkage is well designed the antisquat is similar across all rear cogs (see my recent video of DMR Sled). In the follow up video I will talk about another force involved in antisquat which was not mentioned here. It's the driving force. On high pivot bikes the swing arm has a steep angle and during the acceleration the suspension has the tendency to extend (the wheel is moving forward during acelleration so the steeper the swingarm the more this acelleration rotates the swingarm at main pivot, extending the suspension). So, on high pivot bikes you don't need much chain pulling to get 100% antisquat. So, you can design a system with minimal chaingrowth (with an idler pulley) and still get good pedaling efficiency. On normal bikes (non high pivot), the antisquat effect comes mostly from chain pulling (the disadvantage is the increased pedal kickback and chaingrowth). Bye

Hi. The Spicy has OK anti-squats (around 80%, which are not great, but it's ok). Anti-rise around 65% which is also OK. The biggest problem in my opinion is the leverage ratio. It has an overall progressive ratio, but the last 20mm are extremely regressive (can't understand why they did it like that)... So, the total progressivity is ok (around 20%), but the last 20mm are almost useless and won't provide a good bottom-out resistance. Without that regressive part, the bike would have a better bottom-out resistance with an overall progressivity of around 30-35%. Bye

Thx Andre

No, it means that all your leg force is transferred to spinning the rear wheel. No energy is wasted on suspension movement. But I understood your doubt :) ultimately what matters is suspension movement. Suspension is a energy “sponge”, it soaks energy from bumps and from you. The role of Suspension is to absorb energy and dissipate it (absorb energy from bumps when it compresses and dissipate it by heat during the rebound due to hydraulic friction). When suspension moves by your pedaling or body motion it is stealing energy from you. This is why longer travel bikes feel more heavy and sluggish on pedaling and short travel bikes feel more reactive and nimble. Its mostly due to the amount of suspension movement. No movement = no energy wasted.

@@andrextr thanks for the explanation!

Lester Ma the anti-squat is an intrinsic characteristic of the suspension linkage design and it is related with pedaling efficiency independently of shock adjustment. In some shocks you can adjust compression damping and make it firmer or even locked, which also increases pedaling efficacy.

Norco's are quite good. The Range has a quite high anti-squat (average AS around 140%, for a 32T chainring), and a very good anti-rise (around 50%). It also has a nice progressivity (30%). Good enduro bike overall. Bye

+andrextr thanks so much

+Dante Vergil What? :D Don't believe it. Probably you are in the more than 100% zone, but not in the 500% :) Which bike do you have?

+andrextr Kona Stinky Six 2010 maybe i've measured wrong so correct me

Kona stinky have a anti-squat close to 0% on average. In higher rear cogs (eg:28T) can be positive (+40%), and in smaller cogs is negative. Check it here this pic (the pic was done in fully extended suspension, however it's more correct to do it at SAG): ep1.pinkbike.org/p5pb13512247/p5pb13512247.jpg

+andrextr So is that a bad thing?

It means that it has low efficiency during pedaling. But since Stinky is not a trail bike, I guess it's not very important... The advantage is that is also has a low pedal kickback... Specialized Demo 15 also has a similar anti-squat :) Bye

+Vid Lipovšek lol

+David l as I said, I change the chain line to exagerate the effect. My bike has low antisquat with original chainline, its very hard to lift the suspension on normal chainline.

:D Nice to see your effort, but the swingarm line (green) is not correct. The swingarm line conects the rear axle with the IC (instant center). And in that bike the IC is close to the BB (the bike is a horst-link, see my Ep.10 about IC). Given that in that bike the rear axle is so close to the chainstay pivot, you can even simplify and do the swingarm line between rear axle and the main pivot (near BB). Bye :)

dude i understand only 5 or 10 % of your english - pls make Anti-squat picture for frame what i brougth in : i9.pixs.ru/storage/2/5/2/ASjpg_6325211_22425252.jpg and u dont answer the high AS zone its good or bad and why ?

My english is not that bad :D Here you have the pic: oi66.tinypic.com/wcmjjb.jpg Your bike don't have 500% AS. And yes, too much anti-squat is not good (it should be around 100% to be good). As I said, in your case, you can simplify and do the green line connecting the rear axle with the main pivot. You can even simplify more and assume your bike as a swingarm 4-bar (look at this video in the AS part: kzfaq.info/get/bejne/kNOao6ZhqM2nhqc.html).Basically when the main pivot is right on top of the chainring you get around 100% anti-squat. I can't see exactly the position of the main pivot in that photo, but I would say that on the smaller chainrings you get around 100%, while on the larger chainring you get lower values like 50% or less. Bye

my english bad not yours)) you say : " while on the larger chainring you get lower values like 50% or less... " it means the half of my power when i pedaling go to nowhere ? and if its yes can you recommend XC full suspension frame with good values of your knowledge of suspension ?

No, it means that you only reduce pedal bob by 50%, during an horizontal acceleration. It doesn't mean that you lose 50% of your total energy. The energy that you lose corresponds to the energy required to compress the shock during each "bob". The more it bobs the more you lose. When you have 3x chainrings (like the bike on the picture you sent me), you can't get 100% AS for all of the 3x chainrings. It's a compromise. There are many XC / Trail bikes with ~100% AS, specially with a singlering transmission setup. For instance, Cannondale Scapel with a 32T setup (the main pivot is on top of the chainring). But there are many many other examples. Bye

Ahah :) actually I just saw the wheelie scene at 0,25x on KZfaq and in fact you don’t see the rear suspension compressing during the launch, despite the front wheels lift the ground. So it looks like it had some decent amount of antisquat in rear suspension linkage. PS: i don’t understand nothing about drag racing not sure how much antisquat they run

Dalhe Zéi

+AntonCor I was already expecting your positive feedback :D lol - In the car example, the front suspension is extended in the drawing and in the real picture. So, not sure what do you mean with that... (?) - Vertical aceleration frequency is a good point, but as I said in that part, "there are many people that THINK". I was just sharing a view (with the reference bellow). The only error is SOME people instead of Many. So you might want to discuss that with the author i-track. Bye

And what about URT... You can have Anti-squat without the chain tension extending the suspension.

+AntonCor The URT (Unified Rear Triangle) is a pretty hated an obsolete system in each the BB is directly attached on the rear triangle, instead of the main frame. So, as you know better than me, the classical method presented here does not applies in these type of bikes where the BB moves (fortunately they are a minority on MTB market). In URT the BB is on the rear triangle and your weight is part of the unsprung mass. So, although this video was about "normal BB bikes", I guess the URT migth have a very low pedaling efficiency. Bye

+andrextr GT is still using a variation of the URT design and Lapierre had a couple of models just a few years ago, it's not as popular as it was in the 90's but it's still used and you can design it to have very high Anti-squat. Then you have 6-Bars systems (Felt Equilink...) that need a different method, and systems with floating idlers (Commencal V4...), that need another method. There are too many exceptions and you are trying to make it too simple...

+AntonCor yes that was the point, to make it as simple as possible in order to everybody to understand the basics :) Bye

That's because it was an exaggeration as explained elsewhere (in order to demonstrate the effect). My bike has a low anti-squats, and with the normal chain configuration it is very hard to lift the rear wheel with my bare hands. By changing the chainline as I did, the anti-squat becomes Huge, and therefore, it's pretty damn easy to lift the wheel and demonstrate the anti-squat effect. Bye

I see now at 6:20 you're explaining your strategy; still, I find it a bit too confusing. Language may be a part of this, but a simpler explanation is that when the chain line pulls above the lower pivot point, it is tending to 'lift' the rear wheel, unloading the traction. If shifting to the granny, or smallest chain ring, the chain line dips lower, then running below the lower suspension pivot, pedaling then has the opposite effect ie levering the rear downward, imparting more traction. This is also a fundamental design aspect of the earlier Wiegle frames, unfortunately either abandoned or forgotten with the new "improved" single chain ring bikes that see minimal changes when only rear shifting occurs. It may be that better designs which somehow neutralize pedaling and chain forces over the range of gearing have overall good traction, but it could be argued the ability to alter the squat/anti-squat simply by shifting to a small front ring is a very useful trick now abandoned for 1x gimmicks and marketing.