# Horst link climbing performance or lack thereof



## snow snakes (Sep 13, 2021)

I picked up a Stumpjumper Alloy last fall, with the idea that it would be a good all-around full-suspension to complement my aggressive hardtail. However, I’ve been having a heck of time getting it to climb the way I want, despite a pretty aggressive st angle and faster rolling wheelset and tires. Admittedly I’ve only done pretty basic fiddling with the shock, but it just seems to dive and wallow any time power is applied to the pedals. Since I got the bike, I’ve tried bikes with different suspension designs, even with more travel, that seem much more supportive on the uphill while still being quite nice on the down. Doing more research, this characteristic seems fairly common of Horst-link bikes and pre 2021 Stumpjumpers in general. Long winded background out of the way: is there any way to get a supportive climbing platform from this bike, or should I start looking for a different frame?


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## TylerVernon (Nov 10, 2019)

Only thing I can think of is to go to a smaller chainring to increase the antisquat.


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## snow snakes (Sep 13, 2021)

TylerVernon said:


> Only thing I can think of is to go to a smaller chainring to increase the antisquat.


Could be worth a shot! I was thinking of a smaller chainring anyway, since I spend a lot of time in that bottom gear wearing down the teeth.


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## epittman (Apr 4, 2021)

The new bikes like the one you have are made to be pedalled with your butt on the seat. As soon as you stand up the rear end will suck up your effort.

Try pedalling with a fair bit of effort on the flat. If you still get a bit of bob then dial in a bit of rebound and compression dampening on your shock. You won't need much.


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## 11053 (Sep 19, 2009)

Newer Horst link bikes climb fine/great.
Start adjusting your suspension= experiment with PSI/Sag.
Try measuring sag as a percentage of shock stroke in mm vs just a percentage.
Meaning if the target is 28-30% sag range, convert that to mm and measure.
When you do that conversion, 1mm will have a significant difference in ride feel.
Also try adjusting rebound and compression as you increase or decrease psi.


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## Ratt (Dec 22, 2003)

11053 said:


> Newer Horst link bikes climb fine/great.
> Start adjusting your suspension= experiment with PSI/Sag.
> Try measuring sag as a percentage of shock stroke in mm vs just a percentage.
> Meaning if the target is 28-30% sag range, convert that to mm and measure.
> ...


^^ what he said^^
Most suspension design have converged to the middle (~100% anti-squat) so they pedal about the same or as close together as they every have (DH, race XC, some enduro are exceptions).

Unfortunately for you this might mean endless hours of shock/fork tuning to get the feel you like. Its all give and take, you may get rid of your pedal wallow by over dampening the shock but the bike will feel rougher on the descents.


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## snow snakes (Sep 13, 2021)

11053 said:


> Newer Horst link bikes climb fine/great.
> Start adjusting your suspension= experiment with PSI/Sag.
> Try measuring sag as a percentage of shock stroke in mm vs just a percentage.
> Meaning if the target is 28-30% sag range, convert that to mm and measure.
> ...


I haven’t tried that yet, will do. Thank you. 


Ratt said:


> ^^ what he said^^
> Most suspension design have converged to the middle (~100% anti-squat) so they pedal about the same or as close together as they every have (DH, race XC, some enduro are exceptions).
> 
> Unfortunately for you this might mean endless hours of shock/fork tuning to get the feel you like. Its all give and take, you may get rid of your pedal wallow by over dampening the shock but the bike will feel rougher on the descents.


Honestly a little rougher on the descent would be okay, I’m coming off a hardtail so ultra-supple isn’t necessarily my style, mostly I guess the traction and big hit support is what I’m after. Still trying to figure it out! Trying to get the interplay right between two pieces of suspension is probably three times as hard as just setting it up on the front end, go figure.


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## Blatant (Apr 13, 2005)

Start by providing facts about your shock setup. What year is your bike? What shock? What’s your riding weight? What pressure is in the shock? What’s your static sag?


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## snow snakes (Sep 13, 2021)

Blatant said:


> Start by providing facts about your shock setup. What year is your bike? What shock? What’s your riding weight? What pressure is in the shock? What’s your static sag?


It’s a 2021 Stumpjumper comp alloy with a Fox Float DPS performance. 210 PSI with 6 clicks of rebound, I’m about 170 pounds. As close as I could get to 30% sag.


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## Blatant (Apr 13, 2005)

Empty the shock. Start airing up from zero, every 20 psi, compress the shock 10 times to equalize. Do this up to 100 psi. Measure sag with all your gear seated in the saddle.

I measure sag with a little ruler by mm. You can generally find mm sag range on the manufacturer site. The bike should climb well with good traction once you get it dialed.


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## LMN (Sep 8, 2007)

Add some air, see if it improves. Start with 10ish increments.


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## PhillipJ (Aug 23, 2013)

Blatant said:


> Empty the shock. Start airing up from zero, every 20 psi, compress the shock 10 times to equalize.


That is some cargo cult bike maintenance.

You just need to be able to compress the shock to the transfer port and sometimes that's hard if you put 200 PSI in the positive without allowing any pressure to get into the negative port so it's a good idea to do it a couple times as you go. You're not making your suspension work better by doing any more than that.


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## Brodybro29 (May 10, 2021)

snow snakes said:


> It’s a 2021 Stumpjumper comp alloy with a Fox Float DPS performance. 210 PSI with 6 clicks of rebound, I’m about 170 pounds. As close as I could get to 30% sag.


Try to close the rebound one click more. I have the carbon stumpy and going one click less than the recommandation really helped the pedaling performance. I have something like 210PSI and 4 clicks of rebound so maybe 5 or 4 could work for you. It is my only bike and shock or fork I can feel such a difference between two successive clicks


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## leejohnh22 (Mar 23, 2020)

Unfortunately the Stumpy you have is one of the worst culprits of prioritizing plushness at the expense of pedaling performance and progressiveness for that matter. 

If you take a look at the anti squat graph (see link below) it already starts at below 100% at sag and dives even further throughout the travel. Then, looking at the leverage curve we can see it is not very progressive either so bottom out support is lacking in general.

What this means is that the best "solution" is to add a bunch of compression to aid in the resistance to pedaling, and a tokens in the rear to help resist bottom out. However, even doing that is simply a bandaid to mask the bigger issue.

On the flip side the stumpy is quite liberal and active with its travel, which deletes a lot of the small/mid chatter which some people do like, so different strokes for different folks.

Link here :Linkage Design


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## snow snakes (Sep 13, 2021)

leejohnh22 said:


> Unfortunately the Stumpy you have is one of the worst culprits of prioritizing plushness at the expense of pedaling performance and progressiveness for that matter.
> 
> If you take a look at the anti squat graph (see link below) it already starts at below 100% at sag and dives even further throughout the travel. Then, looking at the leverage curve we can see it is not very progressive either so bottom out support is lacking in general.
> 
> ...


Yeah, I would be inclined towards a Ripley AF but they’re hard to get their hands on around here.


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## Cary (Dec 29, 2003)

leejohnh22 said:


> Unfortunately the Stumpy you have is one of the worst culprits of prioritizing plushness at the expense of pedaling performance and progressiveness for that matter.
> 
> If you take a look at the anti squat graph (see link below) it already starts at below 100% at sag and dives even further throughout the travel. Then, looking at the leverage curve we can see it is not very progressive either so bottom out support is lacking in general.
> 
> ...


This. It doesn’t matter the design, horst link (which hasn’t been used for years), linkage actuated single pivot, DW Link, or other, when you have low antisquat it will feel mushy pedaling, but be plusher when not. That is a tradeoff in the execution of the design, not the design of the particular suspension itself.


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## snow snakes (Sep 13, 2021)

Cary said:


> This. It doesn’t matter the design, horst link (which hasn’t been used for years), linkage actuated single pivot, DW Link, or other, when you have low antisquat it will feel mushy pedaling, but be plusher when not. That is a tradeoff in the execution of the design, not the design of the particular suspension itself.


Hmmph. Time to find a Ripley then…


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## Cary (Dec 29, 2003)

snow snakes said:


> Hmmph. Time to find a Ripley then…


Or Spur, or phantom, or tallboy, or anything that has higher antisquat at sag, which is most bikes now. The Stumpjumper is a good frame, just not a good match for you.


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## snow snakes (Sep 13, 2021)

Cary said:


> Or Spur, or phantom, or tallboy, or anything that has higher antisquat at sag, which is most bikes now. The Stumpjumper is a good frame, just not a good match for you.


The Ripley AF is definitely my top pick right now, even though the Spur/Phantom/Tallboy are all bikes I’ve considered. The Ibis is the only one I can get my hands on that would be less than a $1-2k jump after selling the stumpy, and it seems to be pretty much a straight upgrade in every regard besides brakes.


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## Mudguard (Apr 14, 2009)

Does the shock have any low speed compression?


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## Sanchofula (Dec 30, 2007)

snow snakes said:


> I picked up a Stumpjumper Alloy last fall, with the idea that it would be a good all-around full-suspension to complement my aggressive hardtail. However, I’ve been having a heck of time getting it to climb the way I want, despite a pretty aggressive st angle and faster rolling wheelset and tires. Admittedly I’ve only done pretty basic fiddling with the shock, but it just seems to dive and wallow any time power is applied to the pedals. Since I got the bike, I’ve tried bikes with different suspension designs, even with more travel, that seem much more supportive on the uphill while still being quite nice on the down. Doing more research, this characteristic seems fairly common of Horst-link bikes and pre 2021 Stumpjumpers in general. Long winded background out of the way: is there any way to get a supportive climbing platform from this bike, or should I start looking for a different frame?


It's your suspension set up, it's not the suspension design.


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## d365 (Jun 13, 2006)

If you had a lot of square edge/chunky riding, you'd probably think the Stumpy shines. That's where bikes with high AS, like the Ripley, can get hung up/have pedal kickback. Everything has a tradeoff somewhere.


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## Sanchofula (Dec 30, 2007)

snow snakes said:


> It’s a 2021 Stumpjumper comp alloy with a Fox Float DPS performance. 210 PSI with 6 clicks of rebound, I’m about 170 pounds. As close as I could get to 30% sag.


The only time I pay attention to sag is when a see a guy with his pants hanging around his butt.

To the OP: Set up the shock up so it performs on par with your fork; assuming you like how your fork performs.

Dougle calls it harmonizing, I think of it as a finding an equilibrium.

Easiest thing to do is set the LSC, HSC, Rebound to a middle setting, add air pressure until it stops "wallowing", then work on fine tuning one damper feature at a time.

All of my bikes are Horst, works great, supportive and poppy.

I wouldn't run a smaller chainring unless you need lower gears for climbing. That bike is optimized for 30-32t. Too much antisquat will produce "suspension rise" which won't help anything.


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## Suns_PSD (Dec 13, 2013)

leejohnh22 said:


> Unfortunately the Stumpy you have is one of the worst culprits of prioritizing plushness at the expense of pedaling performance and progressiveness for that matter.
> 
> If you take a look at the anti squat graph (see link below) it already starts at below 100% at sag and dives even further throughout the travel. Then, looking at the leverage curve we can see it is not very progressive either so bottom out support is lacking in general.
> 
> ...


That's the 2019 and they did in fact pedal like wet mattresses.

The 21+ however pedal much better if they are dialed in. I think it's the flex suspension pivot bikes. They seem to have a springiness that gives better results than the AS alone would indicate. I know my Spur is like this. Doesn't have great AS numbers but it sure pops up and goes on the pedals.

One thing I'd say is that the Spesh bikes wisely have the AS fall way off quite quickly which really allows them to work well, however if your sag is just a little off the pedaling performance can fall off a cliff.

Measuring sag correctly can be quite challenging. I'd recommend the OP add rear air pressure in 5 # increments and in particular really pay attention to pedaling performance.

I had actually gained 9# pretty recently and was pedaling like a dog, but then I added 6 psi to my own SJ Evo rear shock and was back to scorching up the hills again next ride out. It makes a substantial difference.


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## snow snakes (Sep 13, 2021)

Nurse Ben said:


> To the OP: Set up the shock up so it performs on par with your fork; assuming you like how your fork performs.
> 
> Dougle calls it harmonizing, I think of it as a finding an equilibrium.
> 
> ...


It’s a Float DPS performance, so pretty limited adjustability, but I can at least mess with rebound damping and pressure IIRC. 



Suns_PSD said:


> That's the 2019 and they did in fact pedal like wet mattresses.
> 
> The 21+ however pedal much better if they are dialed in. I think it's the flex suspension pivot bikes. They seem to have a springiness that gives better results than the AS alone would indicate. I know my Spur is like this. Doesn't have great AS numbers but it sure pops up and goes on the pedals.
> 
> ...


FWIW it is the alloy 21 frame with no flex stays! Gonna give it another chance once the snow melts off.


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## DMFT (Dec 31, 2003)

-Have you checked with Cascade Components to see if they make a Progressive Linkage for your bike/model???
It's a simple and not too expensive upgrade. Worth looking into for sure...


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## prj71 (Dec 29, 2014)

snow snakes said:


> Admittedly I’ve only done pretty basic fiddling with the shock, but it just seems to dive and wallow any time power is applied to the pedals. Since I got the bike, I’ve tried bikes with different suspension designs, even with more travel, that seem much more supportive on the uphill while still being quite nice on the down. Doing more research, this characteristic seems fairly common of Horst-link bikes and pre 2021 Stumpjumpers in general.


I've seen this exact phenomenon on every horst link Specialized bike that I've been behind on the trail and ones that I have rented for trail riding. It's the nature of that beast. LeeJohn22 described it best and is spot on.



> Long winded background out of the way: is there any way to get a supportive climbing platform from this bike, or should I start looking for a different frame?


Climbs and pedals like a hard tail...Yet able to soak up some of the bigger hits. The Living Link suspension design is the real deal. Not some gimmick.









Mayhem 130


In this era of mind-boggling complexity, we at Spot Brand never forget that the best solutions are often the simplest and most elegant.




spotbikes.com


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## Sanchofula (Dec 30, 2007)

snow snakes said:


> It’s a Float DPS performance, so pretty limited adjustability, but I can at least mess with rebound damping and pressure IIRC.
> 
> FWIW it is the alloy 21 frame with no flex stays! Gonna give it another chance once the snow melts off.


Buy a good used shock off PB, something with a bit more adjustment.


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## Sanchofula (Dec 30, 2007)

prj71 said:


> I've seen this exact phenomenon on every horst link Specialized bike that I've been behind on the trail and ones that I have rented for trail riding. It's the nature of that beast. LeeJohn22 described it best and is spot on.
> 
> 
> 
> ...


It's not the bike, it's the shock and the set up.

It may be true that some bikes with horst link pedal poorly, but that's the shock and tune speaking.

It'd be silly to buy a new bike before trying to make the current one function better.

People often have this same opinion/experience after riding a bike at a demo.


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## Brodybro29 (May 10, 2021)

snow snakes said:


> It’s a Float DPS performance, so pretty limited adjustability, but I can at least mess with rebound damping and pressure IIRC.
> 
> 
> 
> FWIW it is the alloy 21 frame with no flex stays! Gonna give it another chance once the snow melts off.


Trying to dial the rebound and the pressure first is a good start.
I am not 100% sure about the alu version but the carbon came with 2 negative spacers as well.
I forgot that before but you can also try to remove one or both and increase even more the air pressure to have more platform around SAG. I am currently running 1 spacer in mine.


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## PhillipJ (Aug 23, 2013)

DMFT said:


> -Have you checked with Cascade Suspension to see if they make a Progressive Linkage for your bike/model???
> It's a simple and not too expensive upgrade. Worth looking into for sure...


Usually you'd run more sag with more progressive suspension to keep bottom out forces similar. Seems like that would make OPs problem worse.


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## Jayem (Jul 16, 2005)

I look at the AS mid-travel and the curve (or lack thereof), that tells the more accurate story IME. At the sag point all you get is a static “if the suspension never moves” situation, which flies out the window on any real climb trail. You get into a feedback loop IME where you try to get over a bump, pedal real hard, suspension has much less AS at the new position deeper in the travel, you try to pedal harder to maintain momentum, but it penalizes your further by compressing further due to pedal force, ends up feeling very soggy and like it’s using more travel under power uphill for the same sized bump (if you were just cruising on level).

there are HL bikes that climb decent, but there’s little reason to go HL these days given what is possible from a single pivot and you end up with a flexier design due to the pivot in between the rear wheel and main pivot. I ride a HL bike and it climbs decent, nothing to write home about, but much better than older versions. Specialized has kinda been all over the place with some of their AS curves/amounts in the last 5 years.


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## jonyferr (Feb 11, 2021)

TylerVernon said:


> Only thing I can think of is to go to a smaller chainring to increase the antisquat.


For this specific bike, I think you need a higher chain ring to increase the antisquat/pedal efficiency. A smaller chain ring will only make things worse.
The latest stumpjumper models have a higher pivot location/centre of rotation than previous models. It seems pedal efficiency was not the main priority when designing the frame.


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## Suns_PSD (Dec 13, 2013)

jonyferr said:


> For this specific bike, I think you need a higher chain ring to increase the antisquat/pedal efficiency. A smaller chain ring will only make things worse.
> The latest stumpjumper models have a higher pivot location/centre of rotation than previous models. It seems pedal efficiency was not the main priority when designing the frame.


No.

Sent from my SM-G715A using Tapatalk


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## DaddyFatStax (Dec 10, 2018)

Okay I'm reviving this thread. To the OP, I think you must in fact have a 2020, not a 2021 if it doesnt have the flex stays. I too have a 2020 SJ and run it with a coil spring that was given to me, over sprung with at 800lb spring (205lb rider weight). Although fox is known for being terribly inconsistent with their spring tunes and it feels much softer than an actual 800lb spring. My lighter weight friends agree when they hop on.

Somehow this works out pretty good, although I'm coming from years of only riding hard tails so maybe I don't know what good small bump compliance feels like. To me its miles more forgiving than a hardtail but still has good support for pedaling.

That said, has anyone tried the cascade link on this bike? Really wondering if it's all its cracked up to be and would it make the platform tangibly "better"?


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## Ratt (Dec 22, 2003)

DaddyFatStax said:


> Okay I'm reviving this thread. To the OP, I think you must in fact have a 2020, not a 2021 if it doesnt have the flex stays. I too have a 2020 SJ and run it with a coil spring that was given to me, over sprung with at 800lb spring (205lb rider weight). Although fox is known for being terribly inconsistent with their spring tunes and it feels much softer than an actual 800lb spring. My lighter weight friends agree when they hop on.
> 
> Somehow this works out pretty good, although I'm coming from years of only riding hard tails so maybe I don't know what good small bump compliance feels like. To me its miles more forgiving than a hardtail but still has good support for pedaling.
> 
> That said, has anyone tried the cascade link on this bike? Really wondering if it's all its cracked up to be and would it make the platform tangibly "better"?


Stumpjumper have high leverage ratios, bigger coils are normally needed. ya 800 sounds high but i think had a 600lb in an old FSR and I only weighed 160lb back then. 

2 other problems;1) Stumpys aren't very progressive and probably blow through travel easy with a coil. 2) its a yoke bike, yoke bikes aren't too kind to coil shocks and crack them in half.

A cascade link usually adds progression to a bike, which you need but will add softness to the beginning of the travel and ramp up at the end. Some people don't like that suppleness because it adds in brake dive and midstroke wallow. In the end mtn bikes are a sum of compromises.


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## Monty219 (Oct 26, 2020)

Ratt said:


> In the end mtn bikes are a sum of compromises.


That sums it up.

For me, part of the fun is working on skills to compensate for the given bike’s compromise. In the case of full suspension pedal bob, my favorite bicycle cross training is fixed gear riding. Practice pedaling standing up on a fixed gear and keeping your core in a stable position. It has done some good for my pedal stroke over 20+ years.


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## DaddyFatStax (Dec 10, 2018)

Ratt said:


> Stumpjumper have high leverage ratios, bigger coils are normally needed. ya 800 sounds high but i think had a 600lb in an old FSR and I only weighed 160lb back then.
> 
> 2 other problems;1) Stumpys aren't very progressive and probably blow through travel easy with a coil. 2) its a yoke bike, yoke bikes aren't too kind to coil shocks and crack them in half.
> 
> A cascade link usually adds progression to a bike, which you need but will add softness to the beginning of the travel and ramp up at the end. Some people don't like that suppleness because it adds in brake dive and midstroke wallow. In the end mtn bikes are a sum of compromises.


 Thank you for the reply, that actually makes a lot of sense.


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