Horst links

Specialized and...

bluronthetrails said:

Which other bikes besides certain DH bikes like the Intense M1 come with the 4-bar horst link rear suspension? I am trying to eliminate all those bikes that'll cause me trouble (pedal-bob) when I'm climbing etc...In terms of category, I am looking for XC and all-mountain bikes only....

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Specialized
Turner
Titus
Some KHS

That should get you started and all should have something in the category you are considering.

Good luck,

JmZ

and another ...

Add Norco XC FS bikes to your list ("Fireball" and "Team" I believe are the model names). I have a Fireball and like it much more than my previous Fuel 100.

I think that you will find the main function of the Horst Link is to elimnate the moment reaction of the braking forces from the suspension reaction. It is an integrated floating brake system that works quite well at keeping your suspension active under braking loads.

The Horst Link's function on the pedalling forces is much less. The anti-squat function you talk about is really a relationship between the low horst pivot and the higher bottom bracket pivot that the horst link forces. You will notice that companies like Turner still use this but Specialized has greatly decreased this relationship to make their suspension more compliant across the board.

The final factor of an anit-squat system is the relationship of all this to the shock. Early ellsworths used a serious falling rate for their suspension keeping the shock stiff initially and more compliant deeper in travel (an early stable platform concept that only worked with rising rate air shocks), where as the Turners use a slight rising or even linear rate keeping the shock compliant throughout the travel and utilizing the swing arm geometries to keep it stable under climbing. Specialized limited the geometry to better utilize the stable platform (brain) shock that keeps the suspension anti-squat anyway so there is no need to have the geometry do it too, but they kept the horst link to utilize its anti brake squat characteristics.

So bikes that utilize the horst link will have better braking performance and depending on geometry better anitsquat under acceleration tendencies, although this is becoming moot with the advent of stable platform shocks.

Bikes that utilize a four bar non horst link (i.e. kona and trek) suspension will not have the active braking and probably the geometry will be such that they will not have the anti-squat acceleration either, but stable platform technology will take care of that. All the extra linkages are there strictly to mount vbrakes and drive the shock.

Finally on a budget you can get all that with a single pivot frame (they exhibit anti-squat acceleration tendencies depending on the pivot location (see Santa Cruz Heckler) but always exhibit brake jacking), with stable platform shock, and a Brake Therapy floating rear brake. It won't be as good as a well designed 4-bar (i.e. Turner) but it will be as good as the 4-bar non horst links (i.e. KONA) with much less complexity.

So to sum it up:

1. The horst link 4-bars are efficient in braking and climbing but stable platform has rendered the geometry a moot point.

2. Non Horst links are effectively complicated single pivots but can be stiff and perform very well with stable platform shocks.

3. Single pivots and virtual pivot point bikes need a floating brake to perform almost as well as the 4bar horst link suspensions and perform on par with the non-horst link 4bars.

long winded but I hope that help. I heartily recommend a titus for your needs, they offer all versions of good 4-bar Horst link bikes from XC to FR/DH/Extreme

horst et al

bluronthetrails said:

I guess i was using a misnomer then. Anyway, in terms of geometry, any good bikes in the XC/All mountain category with a geometry which has the 'anti-squat' tendency when the chain tightens or in other words, you pedal?

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True horst style suspension designs do not use chain tension to counteract bobbing. They are designed to be as neutral as possible to drivetrain induced forces. This means that differing amounts of chain tension will neither compress nor extend the suspension, leaving the suspension free to respond to the terrain. These bikes will "bob" in response to up and down movements of the rider, but the smoother the pedal stroke the less of that bobbing there will be. Also the use of a platform equipped shock will eliminate almost all of that kind of bobbing.
A true horst style suspension will exhibit excellent bump absorbtion whether under a sprint, coasting or braking: these qualities are the real benefits of the horst design. The secondary benefit is that drivetrain forces do not induce bobbing.
The vpp design uses chain forces to stabilize the rear triangle, in other words the more tension on the chain the less able the suspension is to respond to terrain irregularities. The benefit of this design is very good acceleration while sprinting (as long as there are no bumps to absorb). The drawbacks are very apparent when you climb technical terrain in the granny gear (high chain tension): the suspension is almost locked out by the high tension in the drivetrain. This drawback drives me crazy on my blur as I like to do long rides in the high mountains which include alot of steep singletrack climbing-but for some people they would rather have the crisp acceleration under an all out sprint than active suspension on a steep climb. To each his own.
Be aware that all bikes with a horst link are not really horst style designs as is mentioned in some other posts. If you want the benefits of truly active horst style suspension test ride: titus, turner, specialized. BTW check out titus-ti.com for more good info on different suspesion designs.

rockcrusher said:

I think that you will find the main function of the Horst Link is to elimnate the moment reaction of the braking forces from the suspension reaction. It is an integrated floating brake system that works quite well at keeping your suspension active under braking loads.

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While that was true on horst-link bikes with rim brakes, its not on ones with disc brakes. The spinning wheel, when you apply the brakes, tries to pull the frame member in whatever direction the pads were pointed when they were applied. On rim brakes, pads are pointed downwards, usually in the direction of the BB and 90 degrees perpendicular to the direction the seat strut actually moves as the suspension compresses. Thus brake forces are not working with/against the suspension compression. I own an Amp B-3, classic mac strut and the original concept the horst was applied with, and applying the rear brake definitely leads to the suspension stiffening up and compressing partially.

But with disc mounts, the brake is usually being pulled in a direction close to that which the actual suspension would be moving in, thus compressing the shock partially and leading to crappy riding suspension with the brakes on.

A floating disc mount takes the brake forces and transfers them from the disc mount thru a long rod directly to the main frame. And when the suspension begins to move in response to a bump, the floating mount pivots around the axle, thus keeping the suspension operating independantly of the braking action.

Bikes that utilize a four bar non horst link (i.e. kona and trek) suspension will not have the active braking and probably the geometry will be such that they will not have the anti-squat acceleration either, but stable platform technology will take care of that. All the extra linkages are there strictly to mount vbrakes and drive the shock.

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Actually in such cases, and with single pivots also, as long as the shock isn't in line with the direction the brake forces are trying to pull the caliper in, your suspension will be less affected than if they're in the same direction.