Behind the Numbers: GT Force Suspension Analysis

Jun 20, 2019
by Dan Roberts  



If you'd like to know more about the Behind the Numbers series, aren't familiar with the terms being used or want to know why we're doing it then check out our Introduction article for all the information.

Up next in the series we take a look behind the numbers of the GT Force.

It was exciting times when GT released the Force and Sensor. Their previous bikes were always a bit wacky, and while some of the theories they used were interesting, they were probably best left as theories. Which is why when they quietly dropped all their prior quirks and adopted a proven layout lots of us sat up and looked a bit harder at their bikes.

Force Analysis Details
Travel Rear: 150mm to 152mm
Travel Front: 160mm
Wheel Size: 27.5
Frame Size: L
COM Height: 1150mm
Chainring Size: 32T
Cassette Cog Sizes: 50T, 24T and 10T


Many bikes of today are converging on a similar Horst link rocker layout, and for good reason. It’s naturally a stiff and light layout, it can generate good suspension curves, and amongst the details there’s room for a water bottle. But the Force could be seen as a good example that simply just changing to this layout is not job done. No matter what layout you go for, you have to work hard to position all the pivots well and get good curves, surrounded by good geometry and packaged in a form that is durable, reliable and up to the task of mountain biking.






Leverage Ratio

The Force has a leverage ratio progression of 12.9% with an average ratio of 2.75 in the low chip, and there's 13.4% progression with an average ratio of 2.77 in the high chip. The bike has a similar shaped curve to the Specialized Stumpjumper EVO, with a progressive to linear curve in low chip and a linear/progressive/linear in high chip.

There’s more progression than the Specialized, which is good, but overall the ratios are a bit on the high side, down to their choice of a 55mm stroke shock. For example, a 60mm stroke shock would have given an average ratio of 2.5, and a 65mm stoke would have further lowered it to 2.3.

Lowering the leverage ratio would bring more balance to the spring/damping equation - right now it might be a touch too much in favor of the spring. And longer stroke shocks are easily available. Perhaps design got priority and they didn’t want to push the rocker link farther up the seat tube, but it looks like there was room to do it and line up the seat stays really nicely with the top tube.

To be a fly on the wall in the development meetings would provide the reasons as to why they chose this.

A touch of over-springing might be needed on this bike to provide some support. Again, it’s dependent on the aggression level of the rider and their desired output from the bike, but it’s not as much of a predicament as the Specialized. If the rider wants to use most of their travel most of the time, and never really hucks to flat, then it should all be okay. But the pilot style riders might be looking to add some psi and a volume spacer or two to help hold the bike up.

More progressively damped shocks are going to help out on these lower progression bikes. There would still need to be a bit of over springing, but the amount of Newtons of damping support that can be added with a progressively damped shock will help support the bike and resist its want to over use travel.






Anti-Squat

The GT is constantly below 100% anti-squat in all settings and gears and even in the least regressive setting, 32/50, it still quite low at sag and only getting worse the more into travel you’re going.

Riding along a smooth climb, with smooth pedaling and this might be okay. But, factor in impacts while climbing and non-smooth pedaling technique on a technical climb, for example, and more of the rider’s energy input into the pedals is going to be wasted rather than being used to push the bike forward.

Again, we have another bike in the enduro category that dips below 0% anti-squat. The industry really isn’t doing much to help Mike Levy’s hate of lockout levers.







Anti-Rise

The anti-rise curve is pretty nice, rising as it goes through the travel. If it was a bit higher up in percentages then this would further reduce any of the vague feeling at the rear wheel that comes from really low anti-rise figures, as well as give a touch more support to the rider.

However, it’s a smooth curve with reasonable numbers and doesn’t drop off the farther into travel you go. That should provide some nice mechanical support when the going gets tough. And given the combo of leverage ratio and anti-squat, you might be spending more of your time at the second half of travel rather than being nicely supported and held up higher in the travel.







Axle Path

The axle path is predominantly forwards in its trajectory. But really only a true high pivot bike is going to show a vast difference here, and then it’s going to have some compromises in other aspects of the suspension.

But, the Force hasn't got the big forwards travel of the Stumpjumper. Among all the bikes analysed so far, the axle path could be the least perceivable characteristic. Someone would have a hard time singling out the axle path differences between the GT, Specialized and Marin on the trail. The combination of leverage ratio, anti-squat anti-rise and geometry are going to have more of a say in the characteristics of this bike, and it’s only when you go to an extreme that the strength of the axle path characteristic flavor is going to be more noticeable

There’s a more pronounced difference between the high and low chip settings, but this also is apparent in the geometry change between the two settings. Due to the long link lengths and the chip being in line with the shock it doesn’t translate into vast differences in suspension characteristics.




Final Thoughts

bigquotesGT took a positive step towards creating a really good bike with their shift in layout on the Force, and with some tweaking of the details they could create something that performs with the best of them. Criticisms of this bike might be easily pushed aside given its current winning form, but it does have a few less-than-favorable characteristics. Hopefully GT stick with this layout and refine it into something to help a certain Belgian go even faster, if that is even possible.






Previous Behind the Numbers Articles:
Marin Mount Vision Suspension Analysis
Stumpjumper EVO Suspension Analysis
Introducing Behind the Numbers - A New Suspension Analysis Series


176 Comments

  • 64 3
 Are you planning to do this analysis with the Yeti SB150? I would like to see how this plays out with the switch infinity link.
  • 29 1
 Is this where requests go? Knolly Fugitive LT and Yeti SB130 please! Oh, also Norco Sight and Range, thanks.
  • 12 1
 Request for starling murmur
  • 15 1
 Santa Cruz Bronson too please!
  • 5 1
 @generationfourth: I second the Starling Murmur. It would be nice to see how a super simple, old technology compares to these increasingly complex designs. By all accounts, the Murmur rides as well as these modern designs, and if it was made from something lighter than steel it would climb as well as them too.
  • 14 1
 Put a Canfield on the table
  • 11 2
 @islandforlife: and while we're at it, Forbidden Druid, Antidote Carbonjack, any single pivot, oh and why not some Evils

I love these articles and want to see this analysis done on as many platforms as possible
  • 6 0
 Yeah, do some short dual-link bikes, VPP and DW links. SC Bronson and Ibis Ripmo would be popular class-leaders here. Maybe even a comparison between them!
  • 7 0
 I'd like to see the Commie Supreme too. See what it's doing right.
  • 2 2
 How about some direct to consumer bikes like the Intense Primer?
  • 3 0
 @om1wan: linkage design blog has all CB models
  • 2 0
 Scott Ransom please
  • 3 2
 @islandforlife: + Jamis portal / hardline (3VO)
  • 7 0
 Transition bike please!
  • 1 0
 Giant reign sx
  • 11 0
 What the heck, just do all the bikes
  • 20 0
 Klein Mantra please.
  • 2 0
 Kona Process 153 27.5. Please!!!
  • 2 0
 @hamncheez: Indeed it does ride well. Oh and it climbs steep like a goat in crampons.
  • 2 0
 would love to see a comparison with the Bold Unplugged Volume 2!
  • 3 0
 Go to linkagedesign.blogspot.com if you like to see some other bikes, there is no sb150 but I found new sb100 2019 there and couple of old yeti models
  • 1 0
 Mondraker please. Maybe an orange too for a snack.
  • 1 0
 @jdsy2154: And 29er Smile - but obviously they're very similar.
  • 1 0
 @islandforlife: norco sight for sure! so many around aswell
  • 4 0
 The Capra 29 was criticised for being too progressive and many owners have put a coil ahock on. It would be interesting to see it analysed.
  • 3 0
 Also please take a look at Banshee Phantom and Prime, quite interested if he numbers prove my experience
  • 41 3
 "The GT is constantly below 100% anti-squat in all settings and gears...and only getting worse the more into travel you’re going."

Or getting better, when considering pedal kickback on deep impacts. @dan-roberts have you ridden flat pedals recently?
  • 40 1
 Yep... reading a bit too much opinion from this review. Some of us much prefer a low anti-squat (not too low) active suspension set-up. Gets great traction on the tech climbs, climb switch for the fire roads and then it slays the downhills.

After riding high vs low anti-squat bikes, I'm a fan of low.

But it is also about what and where you ride. My terrain is typically fire-roads up (climb switch) and/or a bunch of steep technical rocky climbs where traction and an active suspension is necessary. Then it's pretty much all steep rocky, droppy gnar on the way down, the perfect terrain for low anti-squat.
  • 19 3
 Exactly. Low anti squat deep into travel is ideal. What is up with this guy?
  • 5 3
 @jwrendenver: It's a problem if you pedal hard and sprint and your anti-squat is negative. This will have the opposite effect of the usual anti-squat and make your bottom bracket lower. High speed sprint+lower bottom bracket=pedal strike while sprinting.
  • 9 0
 A regressing anti-squat (that gets "worse") is certainly optimal. That's the right shape for those lines on the graph, they should only be placed higher so that the anti-squat only goes below 100% beyond the sag part of the travel.
  • 6 0
 @DavidGuerra: Yes, a good antisquat curve should be quite high in lower gears before sag and should fall off below 100% after that imo. Gives you a good pedal platform while still being quite active for bigger impacts if it's a reasonably steep curve. For higher gears all below 100% as you won't be putting much power down and want the most active suspension when going fast downhill, at least with a bike like this.
  • 14 8
 Maybe there's some other factors that come into pedal preference than pedal kick back/anti-squat.

Yes, ridden flat pedals for the vast majority of my cycling life. I prefer clips at the moment, but again, pedal kick back was never a factor in that choice.

Having ridden a whole bunch of bikes with anti-squat figures ranging from below zero to almost 200%, I can say that the low anti squat bikes were far more energy sapping and inefficient for riding around and had added harshness from needing to lock out the shock to gain some pedalling performance.

And after spending over a year riding a 160mm 29er with around 130% anti-squat at sag, it's clear to me that the on paper benefit of low pedal kickback is far outweighed by having a good chunk of anti-squat combined with a decent leverage ratio and a comfortable and efficient seated position. That combination pedals very well, has no need to be reaching for a lock out switch on or off road and gives no perceivable disadvantage to the riding experience by having x amount more pedal kick back.

Perhaps worse wasn't the best word to use for stong opinioned people. It sparks a more fuelled debate. But, if you've found a preference in bikes with low anti squat then you're one step ahead of many of the public in having a tool to find the best bike for you.
  • 3 1
 @dan-roberts: It would be really helpful in these analyses if you identified a range where 80% of riders may find the suspension behavior preferable, discussed how the bike fits in with that range, and then slam design features that fall outside that. So far it seems like there's 1 ideal suspension geometry and you're comparing each bike to that hypothetical. A bit like reading Paul Aston's bike reviews. These are great!!!
  • 12 1
 @scottzg: If this review came across as more opinionated, I apologise. There was a dissapointment in this bike as I was excited when I saw it, knowing that this layout can give the tools to create a really great bike, not just a hypothetical one, to then see that it wasn't as good as it looked.

The comparisons aren't made to anything hypothetical, but from experince in engineering and riding bikes, linking these graphs to what works or falls short in the real world. And I would stand in that 80% crowd, but know that the suspension characteristics that help me have a better riding experience also benefit the professionals.

Some of the criticisms of this bike are also true of the Specialized, which shows that it's perhaps a use of words rather than the topic underneath that spark debate.
  • 2 1
 I think what we are forgetting is that high anti-squat numbers mean a higher main (or virtual) pivot point, so while chain growth & pedal kickback can decrease suspension sensitivity on small bump stuff and traction to some extent, the more rearward axle path makes the suspension "get out of the way" on medium and larger hits, hanging up the rear tire less. Its much like having a more slack front fork.
  • 7 0
 I have this bike and I ride flat pedals. You can mob into a rock garden like you're being chased by a demon swarm of mosquitos (which usually you are this time of year in my woods) and your feet stay nicely planted on the pedals.

The low speed compression adjustments on the DPx2 more than make up for any pedal bob. The thing climbs quite well, and has lots of traction for technical climbs.
  • 1 0
 @islandforlife: Can you reccomend some bikes 140-160mm with low Anti-Squat? Stumpjumper Evo should be one I suppose, any others?
  • 2 2
 @NickBosshard: yes.. Ive ridden Knollys, dual link, vpp, and.. Below 50-60% antisquat it suck when youneed too sprint on flattish sections, really bad... I rather have pkbck than shitty antisquat.. Although for pure dh no pkbck is super confortable... On the active suspension, a good shock (read Coil..) will give you perfect traction even if you are in the 100-120% antisquat...
  • 8 0
 @dan-roberts: I think that strong-opinioned is an accurate and diplomatic way to describe the pb comment section. Thanks for the thoughtful response and for writing in-depth critical articles. Keep them coming!
  • 1 1
 I mean negative anti squat is definitely problematic.

"Worse" is relative but in terms of JUST anti squat (technically pedal kickback is more than just anti squat IIRC) it probably is. In an ideal world we have 100% antisquat everywhere and no pedal kickback but that's a fairy tale.

The high antisquat in the platter, lower in in harder gears makes sense for enduro, but less so for XC type riding. I ride a lot of techy climbs and am pretty fit, rarely end up in the platter and the anti squat is annoying over tech features have had to adapt riding style around my current bike.
  • 2 2
 @jwrendenver: Sounds like he can't pedal for shit.
  • 4 0
 @ridin26s: Cheers. There's many more coming!
  • 1 0
 @dan-roberts: Love this stuff. Great to see I'm not the only person interested in learning more about this. Gives us something to play with when not riding (due to injury Frown )
  • 3 0
 Having ridden horst-link, VPP and DW-link bikes. I can only speak of one-man's opinion, mine. But the VPP and DW bikes are noticeably more energetic on rides with varying elevation whenever you are pedaling, pumping, etc. I do agree that if you are pedaling up fire roads with the climb switch, then flipping that off and bombing down long descents, then this is less of a concern but I haven't really found a down-side to VPP or DW bikes except they are generally more expensive.
  • 2 0
 @NickBosshard: This analysis doesn't seem to look at how anti-squat changes with rear gearing. I'm guessing that it decreases on the lighter gears. Just a guess. As for where the most anti-squat is necessary along the gearing. I really appreciate a strong anti-squat on the heavier gears, for sprinting. That's where I would be testing a bike's pedalling performance. For the lighter gears you can sit down and maintain a constant cadence, so a slightly weaker anti-squat won't bother you as much. It can also give you more traction on irregular surfaces on climbs, but less of it on smoother ones. For sprinting I don't care about an active rear end. I mean, I do care but it's not a priority. I just want as much of the pedalling force as possible to go to the rear wheel.
  • 3 0
 @DavidGuerra: The graphs do show three different gears, 32/50, 32/24 and 32/10. It really depends on what you want to use your bike for, for a CC bike your preference makes a lot of sence, but on an enduro/longtravel trail bike, I prefer a more active rear end in the bigger gears I use to ride on the descends. Gives you more traction and the pedaling doesn't make a huge difference anyways so I'd rather have the grip. On uphills I like to have a good pedal platform with decent bump absortion for bigger hits for technical climbing (thus a steep, falling antisquat curve), as a lockout basically makes it worse for tech climbs acros the board.
  • 1 0
 @yupstate: Agreed on all points!

Although in my one experience doing an extended demo of a VPP bike (Bronson), I thought the anti-squat was too great - not just pedal feedback, but outright *kickback*, causing me to lose multiple pedal strokes on a technical rocky climb that none of my three DW bikes have ever had an issue with.
  • 24 0
 I miss the graphs for pedal kickback here. Lots of antisquat results in more pedal kickback wich is why I prefer low anti squat bikes like this. You can always use a platform/lockout to stop your suspension from bobbing.
  • 17 0
 agreed.... Enduro bikes are designed to be raced downhills. For the inbetween stages, use the pedal platform.
  • 9 0
 If I could give more thumbs up to this I would. I demod some bike with lots of AS and they had horrid fatiguing kick back. And actually climbed tech stuff badly as chain tension stopped the wheel moving out the way of chunky roots.
  • 10 1
 @jaydawg69: Most people who ride 'enduro bikes' just hack around their local trail centre though...
  • 6 0
 @justanotherusername: TRUTH. And yeah I agree, I care about chunk performance. Firm-up lever is for sustained climbing.
  • 3 2
 We can do pedal kick back graphs, as it's been requested a couple of times, especially in this article. But as you've pointed out, with the vast majority of layouts a bike with low pedal kick back is going to have lower anti-squat figures. And from experince, the apparent advantage of low pedal kick back, and therefore low anti-squat, is insignificant in comparison to a bike with a good amount of anti-squat, a good supportive leverage ratio and a well thought out seated position. You gain pedalling performance, the ability to absorb impacts better than a bike with the shock locked out and, for me, have a better riding experience.
  • 17 2
 @dan-roberts: But... for lots of other people a higher anti-squat design sacrifices a preferred more active suspension everywhere... whether that's climbing tech where traction is a priority or descending really rough steep terrain quickly.

Many of us have ridden bikes with high, medium and low anti-squat and prefer low. Your "preference" to less pedal kick, and less active suspension designs is just that, a preference that not everyone shares. It's why when I demo'd bikes and from my previous bike experience, I settled on the new Knolly Fugitive LT... but again, it is also terrain and riding style dependent.

First, I think these articles are fantastic!! Love them!... But, I think they could be even better if you approached them from a less biased angle where your preferences take precedence. Adjust them to a more journalistic approach with zero bias and just report on the design specifics, what type of bike each design gets you, comparisons and differences to other bikes (which you do already, just remove the why you think one is better than another) and perhaps what type of terrain or style of rider each design suits best.

Of course, some will still just be wacky and you should point that out and let us know... but again inform us on what each bike suspension design will excel at and what it will do poorly and let us make the decision on which suits our own preferences best.
  • 5 1
 @islandforlife: Completely agree with you about the differing preferences.

I think we start to encroach on the deeper topic of what makes a good bike, and the stagering multitude of factors that come into it, let alone how they all interact.

There's certainly no pushing of an agenda here. All the speculations and comparisons are coming from experience. Be that in riding, development or even in testing out theories of, for example, anti-squat.

While I attempt to be as impartial as humanly possible, removing the rest of the information and just leaving a commentary of graphs wouldn't help. There's definite links between certain undesirable characteristics and numbers, which is what I've tried to show in these analyses. If a little more of a dissapointed tone came accross in this article, then I apologise, but it was stated and explained as to why it came about.
  • 2 0
 @dan-roberts: Makes sense, thanks for the reply... and the concerted effort to answer so many pinkbikers comments, haha!
  • 2 0
 @islandforlife: No worries! I like having a good discussion.
  • 3 1
 @dan-roberts: An often heard remark is that high anti-squat equals less active suspension.
However, I think this would only hold when there is an actual chain force, hence when you're pedaling...

On the downhills you're generally coasting, which means you're not applying a chain force, and therefore you're not affecting the suspension. In those cases, actually a clutch rear-mech is probably a bigger hindrance to the rear-suspension's movement due to the chain-growth resulting in having to overcome te clutch force. (I remember an article on pinkbike showing the Bulls DH team bikes, with Wyn Masters at the time, running a non-clutch rear-mech for smoother suspension action)

Sometimes on a hard impact, you can hear you freewheel engage due to the sudden chain-growth, and then you might feel some pedal kickback as for a brief moment your rear-wheel is pulling at the cranks. Otherwise, I think anti-squat is only a thing when you're actually pedaling, so not during most downhill riding. (But indeed it does matter for technical climbs)

Right? Smile
  • 3 0
 @dan-roberts: I think the issue here is that PB has always been (and hopefully will remain Big Grin ) slightly biased in favour of the more gravity fueled end of the mtb spectrum. I think most readers and commenters will be willing to give up a reasonable amount of pedaling prowess in return for relatively small gains down hill or through very rough sections. At least on bikes with as much travel as the GT.
  • 2 0
 Although I also agree with Gillish, in that there must be some rolling speed at which the rear hub rotates faster than the cassette during impacts, and chain induced effects don't come into play any more. I have no idea what this speed threshold would be. It'd be really interesting to explore I think.
  • 3 1
 @gillish: when you are coasting your feet are holding the pedals at a certain orientation, when the rear wheel hits a larger bump and tries to move through it's travel some of the energy goes through the chain and into your feet. How much energy is dependent on the anti-squat. The more anti-squat the more energy going into your feet and the harder it is to keep your feet at the desired orientation while coasting. It's also noticeable when pedaling with a high cadence over rougher terrain, the rear wheel isn't able to track quite as well, usually referred to as less active (skips like a hardtail would).
  • 1 1
 @yzedf: I think you have missed Gillish's point....
  • 2 1
 @gabriel-mission9: that he coasts with his feet off the pedals?
  • 1 1
 No. That pedal kickback must be negated somewhat by the rear wheels forward rotation.
  • 2 1
 @yzedf: To have pedal kickback, your chain must pull on the cranks, and for that to happen your freewheel must engage. During coasting, that normally doesn't happen.

To get pedal kickback during coasting, the chain-growth due to your suspension compressing must be 'faster' than the rotational speed of the wheel (or actually, rotational speed of the cog your chain is on). That basically only happens on sudden hard impacts, and you will hear it as a 'Klunk!' as suddenly your chain tensions and the freewheel engages.

If you want pedal kickback, it's best to lock your rear wheel. In that case chaingrowth due to compression is always faster than the rotational speed of the cog, because the cog is standing still. A good reason not to skid all the time? Wink You can test this: go down a rough piece of trail with the rear wheel locked, and it will Klunk! all the time. That's your freewheel engaging during compressions.
  • 2 1
 @gillish: explain chainless in your model.
  • 3 0
 @yzedf: No chain, no pedalkickback! Smile And thus no klunks when skidding over bumps.
  • 1 0
 @dan-roberts: While you're taking requests, how about a visual representation of the Instant Center migration, and the Center of Curvature migration, as the Canfield brothers have done here: canfield-balance-formula.com/cbf-explained ?

That would help give people a bit of a look behind the curtain, as to what is driving the more abstract charts that we are seeing. Also, a discussion of why IC is not the same as CC would be cool.
  • 2 0
 @gabriel-mission9 and @gillish: I think that is a radically under-discussed topic, and the important variables could explain a good portion of the widely differing opinions on how important a concern pedal kickback is.

If you run a lower engagement hub, and keep the chain in the more middleish part of the cassette (because, remember that the smaller the cog the more rotation you'll get from each mm of chain growth). and ride steep fast descents where you are not pedaling, then I think you'll find that pedal kick is a non issue, on all but the most extreme chain growth frames.

If you have a I9 Hydra hub with 690 points of engagement, and shift to the 10 tooth cog on every descent, regardless you'll be pedaling or not, then you will find that pedal kick may suddenly become something to consider. Even with a lower engagement hub, if your descents are more gradual and require a lot of pedaling even on rough sections, then, again, it can become a problem.

As gillish said, if the conditions do not engage the freehub, then you can have as much "theoretical" pedal kick in the frame design as you want and it won't hamper the suspension or ride experience in the slightest other than the added drag of the derailleur clutch.
  • 2 0
 @yzedf: Don't forget derailleur clutch friction. That also explains the chainless advantage in suspension suppleness, even if, as gillish is saying, the freewheel needs to engage for actual pedal kick to become an issue.
  • 11 5
 @dan-roberts Pretty interesting to see someone doing suspension analysis on a major mtb website but writing about I-drive that it was "probably best left as a theory". Sanction with I-drive still has one of the best performing rear-ends out there. Apart from that, good series.
  • 3 4
 There was definitely no finger pointing at any certain layout. It is interesting, though, when a manufacturer drops one of their technologies for a new bike without much mention.
  • 5 0
 It's so funny, they treat Idrive like GT didn't won a thing with it, but actually did while other praised manufacturers didn't even get close to the podium. But well let's keep the running joke.
  • 2 0
 Same here, I don't get all the I-drive bashing really. I had a Fury 2017 and now a Fury 2019 and I honestly wouldn't mind riding the 2017 if I still had it. Sure there was some trouble with i-drive bushings but that's due to bad engineering, other than that grip was really good, progression too, and no pedal kick-back/chain slap which the 2019 has too much of.
  • 9 3
 I feel your leverage ratio criticism is off base. This ratio is not that extreme in any way, especially with an air shock. This leverage ratio might actually be able to let you use the compression adjusters, instead of having the compression damping almost fully open, as normal on lower motion ratios with most shocks.
  • 4 0
 2.8ish ish puts you at the start of the high compression shock tune according to Rockshox. Though I wouldnt say it is extreme, its is higher than many modern bikes. You shouldnt need to run your compression damping fully open unless you are running the wrong spring, you are super light, you dont like LSC or your shock tune is way off.
  • 4 0
 @justanotherusername: I totally agree, that you "shouldn't" need to, but most shocks, even the really high end ones, seem to have way too much HSC built in. Lower motion ratios(higher shaft speeds) just exaggerate this.
  • 4 1
 i thought the comments on the leverage ratio were weird... you can have a shock tune with a lot of compression damping on a bike like this and the mid-stroke platform becomes really supportive and its a bike that carries speed well and responds to rider inputs quickly... which some riders will really like.... these articles are kind of silly... so much of the story of all these bikes are completely missed in this kind of "analysis"... especially the Marin...
  • 4 0
 There's no mention of extreme for the leverage ratio. It's got more progression than the Specialized, while will help in some part in reducing the amount of spring needed. But it is generally higher up in the figures all through travel, moving the shock slower than a lower leverage ratio bike and generating less damping force as a result.

Which shock/bike combo has you running your compression damping fully open?
  • 1 0
 Is it true that a lower shock shaft speed reduces damping force? Surely a shock can be tuned to generate the desired amount of damping at the shaft speeds the frame design dictates. Within limits.
  • 1 0
 @gabriel-mission9: A slower shock shaft speed as a result of a higher motion ratio, puts more force(leverage) into the shock, so would mandate more damping control needed, but at a slower shaft speed.
  • 1 0
 @dan-roberts: True true, on my "EXTREME" comment... I was just interpreting your emphasis on the motion ratio wrong, sorry.

I'm 200lbs, race at a pretty high level still, and design shocks/tuning so I'm pretty picky, especially regarding spikes in HSC. Aside from a few newer gen shocks/forks(2017+ Lyrik, GRIP2 Fox, 2018+ DHX2/X2), previous to that I think it's pretty common knowledge that most people racing at higher levels, end up with the compression basically fully off, as there was just too much HSC built into the flow/valving design.
  • 1 0
 @eriksaun: I agree on the damping. My bike I'm working on is admittedly on the "extreme" side if motion ratios, with very little progression. I wish it could have more progression. 3.4:1 to 3.1:1.... Was a LOT of work to nail down valving profiles, spring rates, and MCU bottom out bumpers for the end-stroke progression, but works so good once figured out.
  • 1 0
 @thuren: Yeah, thats what I'm saying. A higher leverage ratio would require a harder damping tune, but this is perfectly achievable.
  • 2 0
 Racers tun their compression wide open? Not sure about that one buddy.
Ive always found the x2 grossly lacking in damping support. Basically bottoms out if you sneeze while riding, even running minimal rear sag.
I really dont get mtb riders obsession with eliminating "harshness". If i wanted a ride like i was in a limo id get in a limo. If i want to have a bike whos handling is predictable from one moment to the next, ill wind on some damping.
  • 1 0
 Its really quite rare that i see a float x2 that isnt rammed full of as many volume spacers as possible. Its basically the only way to stop it using all its travel every time you roll over a blade of grass.
  • 5 0
 Please, please look at Guerilla Gravity, I would loove to see how they compare.

It be very informative to readers if you wouldchoose bikes that aren't like the rest; ie "the GT is just like Specialized".

Generate some discussion by going to extremes.
  • 10 0
 We're trying to include a range of different suspension designs - that's why the Marin was featured last week - but we decided to look closer at the GT due Martin Maes' performance on it.
  • 1 1
 @mikekazimer: I totally value this, and at the same time with 4-bar/horst link and split link designs there is SO much variation in performance it is hard to say "oh a horst link performs like this". So say this bike, the stumpjumper, and say a fezzari la sal peak are all horst links but if you track the IC's and such they are quite different.

IIRC with the fezzari (was looking at buying one recently), the IC stays mostly inside the rear triangle, whereas that stumpjumper was like a meter if front of the bike.
  • 2 0
 @dan-roberts Could you do the analysis for the Atherton bike (ex-Robot) in the geometry and wheel configuration that you yourself would spec out?

Your two cents on Cotic Rocket Max and Bird Aeris AM9 would be appreciated as well. Thanks
  • 1 0
 Agree x10. I hear so much about how these GG bikes pedal so well and I would like to learn more about why since they also use a horst link.
  • 1 0
 @jordanaustino and @jpat22: Yeah, it would be cool to have a way to compare different bikes, either within a given design, or across designs. The antisquat figures between a Specialized horst link and a Norco horst link bike are wildly different, so it would be neat to compare them. If you haven't already done so, check out both the linkage design blog and andrextr's youtube channel and page. If they don't have the info you want on PB, you might be able to get it from one of those sources.
  • 3 0
 I'd like to see an analysis on Trek's ABP or DeVinci's Split Pivot. That suspension design has been my favorite so far for long travel bikes as the rear remains active during hard braking. At least that's what it feels like anyway. Second favorite goes to twin-link/VPP/DW-link/SI style suspension. Would love to see all suspension types have in depth analysis.
  • 5 1
 Your "less than favorable" characteristics are what allow you to go from a good bike, to a great bike. You should stop liking good bikes and realize what makes bike like this, great.
  • 3 0
 @dan-roberts maybe to supplement your introduction to the topic, a review of the major types of suspension designs and what they are typically good or bad at, and how designers manipulate them to get the characteristics they want? Thinking Horst-link, single-pivot, split-pivot/ABP, high-pivot, concentric pivot, DW Link/VPP/Maestro (Dave Weagle would slap me for putting those together, but they are similar designs with the difference being in how the links are set up).
  • 3 0
 We could do this, but it would have to make some generalisations that could lead to some missconceptions when looking at individual bikes rather than a group all with the same layout. There can be a lot of variance between two bikes that share the same layout. And when you factor into the mix the geometry and parts specced on the bike then it makes the differences even more profound.
  • 1 0
 @dan-roberts: Cool, totally agree and that makes sense. Speculation about why the designer chose one type over another is just that -- speculation. I just thought it may help lead into what the design goals were. But I guess the real design goals are typically similar. Body styles, riding styles, and local terrain vary so much, there will never be one ring to rule them all. Kind of like jeans maybe.
  • 5 0
 So, an average bike is ruling EWS, no way could an average rider on a brilliant bike do that. Save the suspension upgrades kids, they may be slowing you down.
  • 1 0
 maybe the reviewer is average? ;D
  • 3 0
 “Again, we have another bike in the enduro category that dips below 0% anti-squat.”

No shit? Most non single pivot bikes do this. And when it happens you’re well deep into the travel, a place where you would never be pedaling. This is not a negative at all.
  • 1 0
 You mean you aren't pedaling in full G-out situations when your bars are flexed an inch down, your fork stanchions and steerer have added several degrees to their normal angles, and your bottom spokes are detensioning? Amateur! ;-)
  • 3 0
 Own a 2019 GT Sensor w/ a M|M RockShox Super Deluxe RCT 185x55 ( stock is Deluxe 185x50 ). Phoenix, AZ's technical / rocky singletrack is loving this setup. Ramp up and/or down LSC here & there for uphill and downhill and it's just as chill as can be riding in 100+ degree excessive heat. The stock shock tune M|L Deluxe is superb too. ( Note that I removed all shock tokens and rarely ever go to pedal mode except for extremely steep grades ). Can't praise the experience enough around here. I'll go thru a good 90 - 95% travel riding down the Geranimo's steeps at about 30 - 32% sag. In my experience, the last 5 - 10 percent is ready if need be.... Just going with the flow and chiming in, respectfully.
  • 1 0
 No clearance issues on that shock setup? My friends has a Sensor and may want to try that.
He is looking for a good rear shock to replace his stock one but he may want the one from my force if I upgrade.
  • 1 0
 @Tvaneijk: A little over an inch of seattube clearance with a fully compressed 55mm stroke shock with a 2.4" rear tire.
  • 3 0
 First, enjoying this series. Second, I would definitely prefer more neutral description of the suspension analysis. And for comments about good or bad, please separate that from the initial description and add a sentence to explain why so that the reader can assess how that might relate to their preferences. I would like to read that actually.

For myself, I prioritize all day technical climbing and dh performance. So, for example, I rode a 6" travel vpp bike for a few years and decided that using chain tension to counteract suspension compression really did not work for me: a) traction was noticeably less under power in the rough, and b) I thought that over a long day it drained some of my power on trail chatter and was therefore less efficient. Sprinted over smooth "buff" trail super awesome though, and maybe that's great in California but not so much where I ride.

Also, pedal kickback is not an issue for me. Maybe that's inconsistent, but I mean deeper in the travel - it's like getting a free body weighted pedal stroke through the rough dips. I do care about brake jack on the descents alot, so definitely prefer designs with independent braking characteristics. Not totally sold on progressivity without being able to also adjust the end stroke damping. For example I added some tokens to my Pike and found the increased spring rate at the end overpowered the rebound damping and got too springy. Had to slow down the rebound and then the early stroke was overdamped and rough. That's all just preference.

So there, if I have a rough idea what I like then I can read some balanced analysis and apply it to my situation. I would also be very interested to read about why the author would prefer something else, and learn how certain characteristics work in concert with others based on author's experience with more bikes than I have time/money to ride - maybe they would work for me and I could get hyped to try.
  • 1 0
 I agree completely with your comment on volume tokens. Excessive amounts make getting your rebound set correctly nearly impossible. And yeah toning down the opinions in the article would be a good move. In my opinion....
  • 3 0
 Does Maes run a stock rocker arm on the mixer setup? Saw Rachels bike at NAm EWS this year and hers was stock- martins is all blue... any info?

Asking realistically could we build martins bike with available parts?
  • 12 0
 Yeah its a stock set up
  • 3 0
 @wynmasters: thanks!
  • 3 0
 @Grosey: stop listening to random guys online. I don't think this wynmasters fella is in the know.
  • 2 0
 @Verbl-Kint: didnt even notice. Name looks like a chatbot. Thanks!
  • 2 0
 The more I read about anti-rise and anti-squat the less sure I am about what is or isn't good. I think the bottom line here is, go ride your bike and have fun. I've yet to regret a bicycle purchase on the basis of suspension kinematics alone.
  • 3 0
 The opinions given about anti-rise/anti-squat given in this article seem a little off base to me. Certainly when he mentions "that vague feeling at the rear wheel" low anti rise numbers produce. What vague feeling exactly?
Anti Rise is a strange measurement at the best of times, varying with the height/weight/style of the rider. Your body position during braking has a big effect on anti rise numbers, so analyzing exact percentages in the article seems a bit silly. High anti-rise deep deep in the stroke seems a negative trait to me, while the article makes out the opposite. I agree with some of the opinions in the article, but some seem very strange. Strange enough that I would go as far as saying I think they are wrong.
  • 2 0
 @gabriel-mission9: Yeah, back when people were running floating rear calipers with adjustable torque arms, like the Break Therapy setup, it seemed that there was a wide variation in preference, where some people liked essentially 0% anti rise with the rear suspension being unimpeded by braking, and others liked some serious anti-rise (otherwise known as squat) under braking, to preserve the bike's geometry, even at the expense of suspension suppleness.

Not to mention the fact that the anti-rise figures don't consider any forces coming from front brake application, so in that regard, it doesn't represent a lot of real world scenarios.
  • 4 0
 We, fellow flat-pedals riders, and other made-of-glass-ankles guys, need kickback graphs @dan-roberts. Please.
  • 3 2
 Many more times I've found my ankles screaming from bottom out forces rather than pedal kick back degrees. But we can take your request on board and do pedal kick back graphs for future bikes.
  • 1 0
 @dan-roberts: maybe I'm in the wrong but I found my Kona Entourage (34/16) way more harsh than my Airdrop Edit (32/12 or 13, didn't remember), and I'm pretty sure it was due to other things than chainstay length and single pivot vs. horst link... But, maybe I'm in the wrong, and I'd be pretty happy to hear the clear explanation Big Grin
  • 2 0
 Ankles screaming from bottom out forces? Really? This seems far fetched. You've watched Rampage before right?

High pedal feedback numbers on a long, fast, washboardy dh run will absolutely tire out your legs faster than low pedal feedback numbers. This can be felt daily during weeks spent at bikeparks in the summer.
I also find bottom out on my rear shock daily during big alpine holidays, but never find myself complaining of ankle pain induced by bottom out. Only ever from long periods hitting trail chatter at speed. There is something very off about this article...
  • 1 0
 Suspension leverage ratios, geometry numbers, bike weights for every popular Enduro/All Mountain bike would be a great buyers tool. As has happened in the moto world, all the competitive bikes eventually align spec wise....bitches.
  • 1 0
 Really interesting series. Do bad bikes even exist anymore? What it also highlights is while the rest of us mess around with graphs and discussing the best solutions, the best riders in the world are riding all manner of bikes and riding them well. Are we splitting hairs? It's great to be pushing the sport with this analytical approach, but the perfect bike will never replace a riders intuition.
  • 2 0
 Those graphs/spec point to a bike that has great initial sensitivity, ramps up to prevent bottom out and has low pedal kick back deep into the travel where anti-squat is pointless. Seems perfect for an Enduro bike
  • 1 0
 Does it actually make any sense to discuss negative antisquat in the highest gear when you're 2/3 into your travel on an enduro bike? The negative antisquat won't matter at all when you strike your pedal doing 40 km/hr and find yourself launched into space.
I would think antisquat matters most up to about 40% into the stroke in low gears to give efficient climbing in crud and keeping momentum in mid gear quicker rooty climbs. In high gears, if a company is going to offer antisquat further into the travel they better offer a higher bb and/or short cranks because that kind of pedalling is frightening (high speed, using more than 1/2 the shock stroke). Just some thoughts...
  • 1 0
 are you just plotting pivot points over a picture of the bike, then using linkage? if so, its a flawed method that has been discussed over and over as to why mm's count on bikes like vpp or dw links. DW himself frowned on people just plotting pivot points over a picture. if you aren't using the exact suspension kinematics its nothing more than you basically designing a suspension system that "looks similar" and analyzing that, not the actual bike.
  • 1 0
 Nope, we're measuring the hard points on the actual bike. You can read more about the methodology here: www.pinkbike.com/news/behind-the-numbers-gt-force-suspension-analysis.html#cid2294864.
  • 1 0
 @mikekazimer: even a measuring tape has flaws when it comes to precision but I'll take it over a picture traced plot if a CMM or hight gauge and indicator on a surface table isnt available Wink

glad to hear its someone actually trying to measure them.
  • 3 0
 Check out these excellent suspension analysis and explanations by
andrextr: www.youtube.com/playlist?list=PL4tH8eqoJoZ9N-v5D6bW3iHK6hXB2m38Q
  • 1 0
 Judging by the comments (particularly about anti-squat getting "worse"), it seems we prefer these articles more about the hard data and less about the subjective opinion of the writer.

Certainly, the poetry should be left out of it: "To be a fly on the wall in the development meetings would provide the reasons as to why they chose this."
  • 4 0
 The last generation Force rode really well!
  • 3 0
 It would be interesting to see an analysis of an iDrive bike to know where they were coming from.
  • 1 0
 I would like to see this type of analysis for early full suspension bikes to see how far designs have progressed.
  • 4 0
 I'd like to see the analysis of my legs when riding my hardtail
  • 1 0
 I notice you're trying to include different suspension designs and layouts, well what about the deviate cycles the guide, high pivot Enduro bike designed to eat chunky alpine terrain.
  • 2 0
 Canfield, Rocky Mountain and Pivot are three companies that reinforce the hatred of lockouts. If they can do it, why is everyone else still fiddling about with trick dampers?
  • 2 0
 Funny how the PB LTS review on the Sensor said it was too firm and your conclusion is the antisquat is too low. You guys are wacky as hell.
  • 1 0
 That firmness was due to the higher-than-necessary compression tune, not the amount antisquat. Multiple factors can influence the way a bike feels out on the trail.
  • 1 0
 If we know all this shite then why hasn't anyone made a perfect tail end paired with good geo? Is that hard to make a horst link with 110% antisquat and a 30% linear progressive leverage curve?
  • 3 4
 Horst link isolates braking forces from suspension. Single pivots are effected by braking but handle square edge hits better. Sounds like this bike is a tad more responsive to small frequencies , less platform . I would like to test ride one . Would be a plush monster with a coil in the back.
  • 2 1
 can confirm on the last part...
  • 5 0
 Why do single pivots handle square edge hits better?
  • 2 0
 @ctbiker888: I wanted one of these, with a coil, but the agents here aint bringing them in.
  • 1 1
 @Riyadh: I see you are from South Africa. Check out Pygas. They have a similar look, but have a bit more put into the design. I have a Hyrax with a Coil on the back, and it is awesome.
  • 1 0
 @oxide: Thats quite funnny, you bought a south african bike and I bought an american one!
  • 2 0
 it would be interesting to see also "extreme" frames like Nicolai G16 or even G1.
  • 3 0
 I don't get it
  • 1 0
 I thought I was the only one!
  • 2 0
 Beautiful looking bike non the less.
  • 2 0
 I don't understand any of this Frown
  • 2 1
 Have you read the intro article yet? www.pinkbike.com/news/introducing-behind-the-numbers-a-new-suspension-analysis-series.html. If you still have questions, feel free to post them up - we're hoping this will be an informational and educational series.
  • 3 3
 @mikekazimer: No, thanks bra!
  • 1 0
 Eminent Onset. There is some pretty unique stuff going on with that design!
  • 2 1
 This is way too scientific for me right now. Hold my beer while I go ride my bike.
  • 2 1
 A beautiful bike with proven race wins and great geometry numbers trumps subjective analysis of these numbers and charts.
  • 1 0
 Great series. Great reviews. Keep them coming. How about doing in-depth analysis of forks?
  • 1 0
 Bulgarians have a very wise saying about numbers and one copulating with them. Wink
  • 2 0
 Still Winning ! SO HA ! Love my LTS FORCE !!!
  • 4 3
 yay no idrive. finally i GT i would buy! great to see the numbers.
  • 1 0
 Looks like.... a Force to be reckoned with.... Pimp
  • 1 0
 Would love to see this for a Scott Genius
  • 1 0
 Can this analyzation of the Force be used for the Sensor as well?
  • 6 9
 @dan-roberts

I find it really weird that your talking about progressively dampened shocks, separate mentioning volume spacers (which is progressive shock) and overspringing like its an absolute. Yet you make no mention of high speed compression control or a hydraulic or ifp bottom out, which non-coincidentally are out of industry favor (probably cause of build cost and complexity)
The only kinds of progressive damping we see generally is that caused by the spring ramping up, or a hydraulic or ifp bottom out.

Stronger spring air or coil, with less preload / more initial air pressure, will create more support, is supple compared to damping, and returns energy unlike oil damping, which allows for stronger backside pumping and more traction as there will be more ground pressure. With too strong a spring and or too much damping for the leverage&system will cause chassis instability and harshness. A soft spring with more preload to achieve desired sag, or an air shock with lower initial psi and less air volume; will not return energy to the ground, create tractionor hold the rider from diving (creating chassis instability) if you add a bunch of damping to a undersprung setup to reduce top of stoke wallow harshness is likely. Within those extremes there can be a few different spring rates that will provide different viable setups for different riders and terrain.

I feel like your proclamation homogenizes the perceived range of what's good, and will influence what all these numbskulls think they should be buying and so what the industry will make.

"There’s more progression than the Specialized, which is good" like who are you to say that more progression is good?
Personally i find linear linkage provides a good basis from which to add damping affect, to achieve the desired ride characteristic. it's much harder if not impossible to take a progressive linkage ration and create a bike that behaves linearly.

Pinkbike is apparently a marketing agency with capitalist agenda's, a puppet for the bike companies who pay. theres always a slant : (
  • 4 3
 @getsomesy, I lost you when you went down the capitalist agenda rabbit hole, but I'll respond to some of your more coherent points. More progression than the Specialized is good - the Specialized is very linear, which means that even with an air can full of spacers it's easier to bottom out compared to a bike with a more progressive curve. For a bike that's meant to be ridden very hard, clanging off the bottom of the stoke isn't a desirable characteristic.

It's all a balancing act, and Dan is drawing on his years of riding and engineering experience to shed some light on the kinematics of these bikes. There's not one bike out there that's going to be the best for every rider, but there are certain characteristics that are more desirable than others across the board.
  • 2 0
 What even is this progressively damped shock mentioned in the article? I don't know of a single position sensitive damper in a rear shock on the market. In an article written by someone with years of riding and engineering experience, some of the language used seems a bit...vague. Also the amount of opinion given was a bit much for me. Saying "A" is better then "B" is very subjective, and one thing that became clear quickly is that my opinion of what is better or worse varies wildly from the opinions given in the article.

I'd agree however that the "capitalist agenda" rant was a bit far fetched. Maybe a case of both sides of the argument getting a little distracted by their personal biases.
  • 1 0
 @mikekazimer: I agree that the shock should clang violently off the bottom in most all circumstance.

Still, my contention is that simply making a linkage or air spring very progressive to avoid bottoming is a fools errand, that it is a cost cutting measure by brands of components and bicycles, promoted by the greased media, to sell us cheaper shit with a better margin. progressive cheap simple shocks and linkage did not come from professional enduro or dh riders & mechanics request nor that of the educated mountain biker, rather it was jammed down our throats by the industry.

The brands, media and bike shops financially benefit from advocating and specifying shocks without adjustable bottom out pressure, oil/ifp volume, low and/or high speed compression, or that don/t require making/stocking shock springs and shop employees that are competent to prescribe the correct spring because these shocks are more expensive to make and setup. air shock with rebound, lsc or lockout and volume spacer setup seems simpler to the layman, and are cheap to spec' they're usually inadequate for optimum performance.

For a long time the preference of educated fast riders has been one that minimizes friction, and maximizes control of forces, by the rider using: spring preload, spring rate, high speed compression, low speed compression, piggyback ifp volume and pressure, hydraulic bottom out and bottom out bumper, as well as the predetermined shock rate.

A linear linkage shock rate with additional control provided by a quality shock will allow the rider/mechanic the widest range of tuning possibilities, avoiding initially mushy or harsh ride, midstroke wallow or bottom out; all while allowing speed sensitive, maximally compliant suspension.... which a highly progressive spring just can't match. Even with a linear linkage rate and a well controlled, feature rich shock, a rider who needs or desires more progressive characteristic could outfit their bike with a progressive coil spring or low volume air shock.
  • 2 1
 YT Capra in the future?
  • 2 1
 They tried to get one, but YT had to back-log their order again so it'll be another 6 months.
  • 2 1
 @bikekrieg: and the warrantyWink
  • 1 0
 Looks like a session
  • 2 3
 Great work pinkbike!!! These analysis are top notch @dan-roberts
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