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Discussion Starter · #1 ·
Trying to find a split pivot bike to demo in my area (Denver) and am coming up empty handed. As far as I know, it's really just the Atlas and the forthcoming but not yet available Spearfish. What else is out there that I could try? I like the concept of it, but want to see how it rides before I buy one.

Thanks
 

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There's also the BH Lynx 4.8 29, which I find even more interesting in terms of geometry than the Atlas.
However I don't know about availability.

And then there are all the Trek offerings, which are not "Split Pivot", but basically the same thing.
 

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Discussion Starter · #5 ·
^^Har Har.

That Lynx is sexy, but a bit more bike than I'm after. Looking for an xc bike, already have a longer legged trail bike. Plus the local dealer only has hardtails...bummer.

Good call on trying the Trek. Might just have to try out a supah-fly.
 

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Trying to find a split pivot bike to demo in my area (Denver) and am coming up empty handed. As far as I know, it's really just the Atlas and the forthcoming but not yet available Spearfish. What else is out there that I could try? I like the concept of it, but want to see how it rides before I buy one.

Thanks
Keep looking man. Definitely don't buy before you try. I learned that the hard way.
 

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its been said - but you can try a trek abp to get the feel of the design until your specific targets become available... while they likely wont provide the exact feel - it will be oh so close. There arent any treks that have the geo of the new spearfish - primarily the uber short chainstays and slacker head combo - so keep that in mind as the spear should be an uber fun, nimble bike
 

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Discussion Starter · #10 ·
^ agreed. It's the combo of the suspension and geo that has the interest peaked.

Trek dealers are a plenty, so I should be on a demo within a few weeks.
 

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its been said - but you can try a trek abp to get the feel of the design until your specific targets become available... while they likely wont provide the exact feel - it will be oh so close. There arent any treks that have the geo of the new spearfish - primarily the uber short chainstays and slacker head combo - so keep that in mind as the spear should be an uber fun, nimble bike
Since when is 17.2 an uber short chainstay?
 

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Discussion Starter · #12 ·
Maybe not 'uber' short, but in the fs xc 29er world those 2 are about as short as I can currently find. Pretty keen on the 69* head angle on the salsa as well.
 

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Is the split pivot nothing more than a floating brake stay? In other words, other than subduing brake jack (loading the suspension under braking) is it not transparent? Im not trying to be the dick here, I 'm just unsure.
 

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Rohloff
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Is the split pivot nothing more than a floating brake stay? In other words, other than subduing brake jack (loading the suspension under braking) is it not transparent? Im not trying to be the dick here, I 'm just unsure.
I don't know that its' a "floating brake stay" but I do know ABP/Split Pivot is suppose to allow the suspension to be more active while braking. FWIW, I had the pre-ABP Hifi/Superfly and have ridden a lot of other bikes. I cant' say I've noticed any benefit to the ABP/Split Pivot system while braking.
 

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Trail Ninja
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It's intended to offer a similar result, in theory, as the floating brake design (not to be confused with a car's floating disc brake). On a single pivot design, there's just the one pivot and link (swingarm or wheel link) controlling the movement of the rear axle. On a majority of those single pivot designs, the disc brake caliper is anchored to that link/main swingarm and, in theory, the forces that go through it under braking can affect the suspension significantly. You can't normally put the brake on the seatstay if it pivots, since it won't follow the movement of the axle, which the rotor also follows. A floating brake caliper design you see on some bikes, like the older Konas, anchors the caliper on another link, and to a link that follows the axle, with the braking forces being transmitted to the link that doesn't move as much, as opposed to the main swingarm that does move a lot. On the ABP and Split Pivot, the brake is moved away from the main swingarm, and since the concentric pivot means that other arm/link moves with the axle, the caliper follows the axle and rotor as it compresses.

Brake jack is considered to be the stiffening of the rear suspension under braking, causing the suspension to extend. This effect was dramatized by MBA, particularly Richard Cunningham. A lot of brake jack is unwanted, since when you hit the brakes, your weight shifts forward and up, in a similar direction as brake jack, which ends up wanting to throw you over the bars. In reality, most single pivot bikes don't have brake jack. They have what's considered brake squat, or brake anti-rise. Having a decent amount of this is desired, as it can balance out that forward weight shift when you slow down. In other words, brake jack is a myth. I'm not declaring myself to be an expert at this, but I at least know that those who dramatize brake jack don't really have much of a clue. There's a lot of happy people on single pivots these days and it's not because DW made it cool with Split Pivot...

P.S. Beware that the "chainstay" isn't always the main swingarm. For example, the Devinci Wilson has a high pivot and its main swingarm is what some may consider the seatstay. In this case, the brake is put on the chainstay to get the floating brake effect.





There are analysts that try and analyze various bike's suspension characteristics, if you want to see things in greater depth (ex. linkagedesign.blogspot.com). For example, SC Bronson vs Yeti 575 (27.5):



In this, it shows that the Yeti has brake squat forces that balance out the forward weight shift when braking by close to 100% (on level ground), throughout its range of travel. The Bronson, however, has less brake squat and is more susceptible to forward weight shifting the deeper it is in its range of travel. One can interpret from that that to compensate, the rider on the Bronson would probably be more behind the saddle and lower to counter that force, while the Yeti rider would more comfortable in a balanced and neutral low attack position in comparison. Doesn't show that either suffer from some major flaw that makes them unrideable; but it may teach you more about your bike and how to ride it optimally, by knowing more about it. I've browsed quite a bit of that site and I can't say I have seen a design that was really questionable besides the Zerode, honestly, but I can't really say it's bad, just unusual.

TL;DR: brake jack is a myth, floating brakes aren't needed, and I don't know enough to really say if its more than theorized mumbo jumbo or not, but I suspect that it really doesn't offer as big of a benefit to a rider as they hope that you would believe. I can say that it at least offers them, as designers, more control over the suspension to get a balance, or better compromise, of all the characteristics that they want a bit easier.
 

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It's intended to offer a similar result, in theory, as the floating brake design (not to be confused with a car's floating disc brakeOn a single pivot design, there's just the one pivot and link (swingarm or wheel link) controlling the movement of the rear axle. On a majority of those single pivot designs, the disc brake caliper is anchored to that link/main swingarm and, in theory, the forces that go through it under braking can affect the suspension significantly. You can't normally put the brake on the seatstay if it pivots, since it won't follow the movement of the axle, which the rotor also follows. A floating brake caliper design you see on some bikes, like the older Konas, anchors the caliper on another link, and to a link that follows the axle, with the braking forces being transmitted to the link that doesn't move as much, as opposed to the main swingarm that does move a lot. On the ABP and Split Pivot, the brake is moved away from the main swingarm, and since the concentric pivot means that other ar

A lot of brake jack is unwanted, since when you hit the brakes, your weight shifts forward and up, in a similar direction as brake jack, which ends up wanting to throw you over the bars. In reality, most single pivot bikes don't have brake jack. They have what's considered brake squat, or brake anti-rise. Having a decent amount of this is desired, as it can balance out that forward weight shift when you slow down. In other words, brake jack is a myth. I'm not declaring myself to be an expert at this, but I at least know that those who dramatize brake jack don't really have much of a clue. There's a lot of happy people on single pivots these days and it's not because DW made it cool with Split Pivot...

P.S. Beware that the "chainstay" isn't always the main swingarm. For example, the Devinci Wilson has a high pivot and its main swingarm is what some may consider the seatstay. In this case, the brake is put on the chainstay to get the floating brake effect.






In this, it shows that the Yeti has brake squat

throughout its range of travel. The Bronson, however, has less brake squat and is more susceptible to forward weight shifting the deeper it is in its range of travel. One can interpret from that that to compensate, the rider on the Bronson would probably be more behind the saddle and lower to counter that force, while the Yeti rider would more comfortable in a balanced and neutral low attack position in comparison. Doesn't show that either suffer from some major flaw that makes them unrideable; but it may teach you more about your bike and how to ride it optimally, by knowing more about it. I've browsed quite a bit of that site and I can't say I have seen a design that was really questionable besides the Zerode, honestly, but I can't really say it's bad, just unusual.

TL;DR: brake jack is a myth, floating brakes aren't needed, and I don't know enough to really say if its more than theorized mumbo jumbo or not, but I suspect that it really doesn't offer as big of a benefit to a rider as they hope that you would believe. I can say that it at least offers them, as designers, more control over the suspension to get a balance, or better compromise, of all the characteristics that they want a bit easier.
A Bicycle does NOT have measurable weight transfer. The mass of the rider is 600% of the vehicle. If the rider just straightens his/her arms, the cg shift via geometry is essentially nullified.
Geometry induced rear wheel hop is a whole nother deal, and just happens to be the opposite arc of brake induced lift.
This would be where the most scrutiny should be in choosing a split link scheme.


IMHO.YMMV. nmfr

Sent from my XT907 using Tapatalk 2
 

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As far as single pivot brake jack/squat, etc. I've got a yeti SP and have owned numerous Horst links, VPP, etc. the only downside to a single pivot is the suspension stiffening under hard braking (call it what you want) which kinda sucks on rough downhills but you get used to it and can overcome it if you have any skills. Even my gen 1 Nomad had some of this issue even though it was a mini link. I say that if you need a FS bike to make you a better rider, stick with a HT.

BAck to the OP point, I really like the looks of the new Salsa. But might as well hold off on the demo as that bikes geo is different enough to effect the ride more than the split pivot design. You will be able to see how a SP performs while braking hard in the rough but that's about it. Depending on how Salsa has done with the custom damping on the shock, it may not climb and descend like other split pivot designs. Shock valving has a LOT to do with a single pivots characteristics.
 
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