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Gimme dat!!
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I am curious as to some of your thoughts about your rides.

I am looking to get an AM with 6 and 6 (or so). I am debating the difference between frame setups, weight, and climbing efficiency. I am looking to try and keep it reasonably light and cost effective (my wife and kids have to approve the purchase) but I would like it to climb well.

I have looked into a single pivot design versus some of the more complex offerings out there. I am curious to know whether the SPs of today perform as well as more complex linkage. I ride a HT but have heard that shocks have improved to the point of overcoming some of the efficiency issues with a SP design.

I am thinking about a new Bullit at this time but don't want to get something that I will want to change out in 2 months.

Any thoughts?

What bike do you recommend?
 

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Freeriding Feline
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A Heckler. Might be slightly short of the 6 that you want though.
The Bullit is a great bike too though. I'm curious to see its comeback.
 

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Menny said:
I have looked into a single pivot design versus some of the more complex offerings out there. I am curious to know whether the SPs of today perform as well as more complex linkage. I ride a HT but have heard that shocks have improved to the point of overcoming some of the efficiency issues with a SP design.
Yeah, single pivots are just fine eg Yeti 575, Cannondale Prophet, SC Heckler, all TNT Turners, all Ventanas, etc, etc. There are differences compared to some of the more complex linkages, but it's by no means true to say that more complex = better.

I would have thought the Bullit would end up too heavy for pedalling uphill. From what you're saying I'd be looking at a build close to 30 lbs. Yeti 575 would be a good reference point.
 

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All three FS bikes I've owned have been single pivot (Heckler, Bullit, Superlight). Coming from a hardtail, I never noticed any of the "single pivot" downsides, and the parking lot rides I had done on linkage bikes really never showed me their benefit. However, I have recently ridden a Knolly Delirium on technical trails and believe there IS a difference that a chainstay pivot linkage bike offers.

A single pivot design's suspension will stiffen slightly when braking on steep descents. On one freeride trail that I took the Delirium on, it felt like I had more travel at 6.3" than my Bullit has at 7.5". It was also easier to modulate braking and keep from skidding the rear tire because the suspension would absorb bumps more then the Bullit's.

However, that being said, there isn't anything that I can't ride on a single pivot that I would consider riding on a linkage bike. You might have a little more control at 7/10s and above, but single pivots are still very capable bikes (and usally much cheaper).

The other "downside" of single pivot bikes is how they climb. Apparently, if you believe the marketing hype, they aren't as active as a linkage bike. I would say that is mostly hype. These days, with a good platform shock, single pivots climb extremely well, and feel active without feeling TOO active and bobing.

I haven't done a good test ride on a VPP type bike so I can't comment on their style, although I'm sure that others will. After riding single pivots for the last 8 years, I've decided to try a different style (Knolly's Four X 4 linkage) on my next bike, but I would never tell anyone to not buy a single pivot. It all comes down to buying the most bike for your budget. If the budget has room for something more expensive without causing pain, get it. Otherwise, I don't think you will be disappointed in any way with the Bullit.
 

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uktrailmonster said:
kristian - how do you know it was the "linkage" on the Knolly that made it feel better?
It's an educated guess. It felt like it had more travel for sure, and since I have been conditioned by years of Specialized/Ellsworth/(pre TNT) Turner marketing that linkage bikes are more active in the rear when braking, I am crediting the feel to the linkage. Part of the improved braking feel could have been due to the Maguras vs my Hayes, but again, I feel the linkage played a roll here too. Just my experience and my $.02 though, I'm not in any way saying that single pivot bikes are bad.
 

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Oh yeah, the infamous rear locking that single pivots are ALL supposed to suffer under braking. Never happened to me yet on my Ventana and it seems the TNT Turners brake just the same as the Horst Link versions.

It could just as easily have been the shock and/or shock setup that made the Knolly feel better.
 

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uktrailmonster said:
Oh yeah, the infamous rear locking that single pivots are ALL supposed to suffer under braking. Never happened to me yet on my Ventana and it seems the TNT Turners brake just the same as the Horst Link versions.
You're just not riding steep enough trails.:D

uktrailmonster said:
It could just as easily have been the shock and/or shock setup that made the Knolly feel better.
I am not an engineer or confident enought to say that isn't contributing to the case. However, if it was a shock setup issue, and I was getting more travel on steep descents, shouldn't I have been flirting with bottoming the suspension out? I know that I never bottomed the Delirium out. I also know that Noel is heavier than I am by 10+ pounds and he wasn't bottoming the bike out either.

Also, if you search for reviews of single pivot bike users who have installed floating brake adapters, you will read similar opinions that the bike feels more active under heavy braking--especially on steep trails.

We could get into a 50 post long debate on this but apparently it doesn't look like you are ever going to buy into the stiffening (I never said locking) argument. I feel there is a difference. The difference isn't as noticable on normal trails, but it was clear to me on a steep, rocky chute. Is the difference worth $1000? That depends on the rider, the rider's budget, (and probably the rider's wife :)).
 

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OK, just my opinion here but I have to say I absolutely believe that SP bikes are wholly and completely inferior to MOST of the other suspension designs that are out there.

I've put many miles on a Flux and NRS and have ridden a Prophet and not a single one of them comes close to either the four bar design (like those employed on my Specialized and Titus bikes) or the FCC design of the Chumba.

SP bikes simply do not address the directional movement of the rear wheel over rough terrain nor do they adequately address pedal induced feedback.

While shock design has come a long way and somewhat makes up for the inherent design flaws of the SP platform remember that these same shocks are going on those bikes with superior suspension designs so, whatever benefits SP bikes enjoy as a result of this technology other bikes enjoy those same benefits.

SP designs are more active (i.e. more pedal bob), more suseptable to brake-jack and not as plush downhill; in essence, the only advantage they maintain over other designs is one of simplicity and even that is highly questionable when you explore some of the linkages SP bike manufacturers use.
 

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I'm bored at work today...

CranxOC said:
I've put many miles on a Flux and NRS and have ridden a Prophet and not a single one of them comes close to either the four bar design (like those employed on my Specialized and Titus bikes) or the FCC design of the Chumba.
Isn't an NRS considered a four bar? It has four "bars" and the pivot is on the chainstay.

CranxOC said:
SP bikes simply do not address the directional movement of the rear wheel over rough terrain nor do they adequately address pedal induced feedback.
I've been reading about "pedal induced feedback" long before buying my first Heckler and keeps coming up in these threads. I can honestly say that I have never noticed it. Maybe I am oblivious to it and my bikes really do have some sort of feed back, but if that's the case, it has never had a negative impact on my ability to ride up or down just about anything on the mountain. This might be an issue if the original poster was moving from a 4 bar to an SP, but since they are coming from a hardtail, it's a non-issue.

CranxOC said:
While shock design has come a long way and somewhat makes up for the inherent design flaws of the SP platform remember that these same shocks are going on those bikes with superior suspension designs so, whatever benefits SP bikes enjoy as a result of this technology other bikes enjoy those same benefits.
When I test rode an Ellsworth Moment, the rep turned off the ProPedal (platform) on the shock because the frame didn't need it. Running too much platform on a neutrally pedaling bike will actually make it ride WORSE (worse defined as less active on small bumps).

CranxOC said:
SP designs are more active (i.e. more pedal bob), more suseptable to brake-jack and not as plush downhill; in essence, the only advantage they maintain over other designs is one of simplicity and even that is highly questionable when you explore some of the linkages SP bike manufacturers use.
Single pivot bikes are not suseptable to brake jack. Brake jack is defined as the bike jacking up in the rear under braking (picture a stink bug). That is not a trait of any single pivot I've ridden and is a misused term to reference to suspension stiffening. SPs are extremely plush on the downhill, provided you are not on the brakes. If you are on the rear brake, the suspension will stiffen slightly. The only time I have ever felt like this was a detriment was on the pirate trails of Vail which are crazy steep. However, I do totally agree with you that a four bar is better in this regard because the suspension remains fully active under braking.

Regarding bob, my Bullit with a Romic on it has zero pedal bob when sprinting out of the saddle, yet it's still very plush. SPs without platform shocks do tend to have a little more bob than a properly executed four bar design.
 

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kristian said:
You're just not riding steep enough trails.:D

I am not an engineer or confident enought to say that isn't contributing to the case. However, if it was a shock setup issue, and I was getting more travel on steep descents, shouldn't I have been flirting with bottoming the suspension out? I know that I never bottomed the Delirium out. I also know that Noel is heavier than I am by 10+ pounds and he wasn't bottoming the bike out either.

Also, if you search for reviews of single pivot bike users who have installed floating brake adapters, you will read similar opinions that the bike feels more active under heavy braking--especially on steep trails.

We could get into a 50 post long debate on this but apparently it doesn't look like you are ever going to buy into the stiffening (I never said locking) argument. I feel there is a difference. The difference isn't as noticable on normal trails, but it was clear to me on a steep, rocky chute. Is the difference worth $1000? That depends on the rider, the rider's budget, (and probably the rider's wife :)).
Ok I'm not going to start an argument here. I am a professional suspension engineer BTW, although that doesn't mean I know everything there is to know about bikes. There's no reason why you would expect to bottom out your rear suspension on a steep downhill when most of the weight is on the front, particularly under braking. The amount of travel you get over bumps is determined by the spring rate and the wheel-shock leverage ratio and how that changes over the suspension stroke eg linear, rising rate, falling rate. It has nothing to do with whether or not it's a single pivot design. Sure, when you apply the rear brake, the braking forces are reacted through the rear linkages which can lead to a jacking or compressive force, depending on the linkage geometry. Again this does not ONLY apply to single pivot designs as some people seem to think. It's not necessarily a bad thing either in moderation. It's no different in principal to anti-dive or anti-squat on a car suspension. Some DH racers prefer minimal brake induced forces (hence the use of floating caliper brakes), some prefer to have a degree of compressive force under braking to counteract the extension from load transfer. Steve Peat always did just fine on a single pivot Orange with a non-floating caliper, so it shouldn't slow the likes or you or me down at all.
 

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CranxOC said:
OK, just my opinion here but I have to say I absolutely believe that SP bikes are wholly and completely inferior to MOST of the other suspension designs that are out there.

I've put many miles on a Flux and NRS and have ridden a Prophet and not a single one of them comes close to either the four bar design (like those employed on my Specialized and Titus bikes) or the FCC design of the Chumba.

SP bikes simply do not address the directional movement of the rear wheel over rough terrain nor do they adequately address pedal induced feedback.

While shock design has come a long way and somewhat makes up for the inherent design flaws of the SP platform remember that these same shocks are going on those bikes with superior suspension designs so, whatever benefits SP bikes enjoy as a result of this technology other bikes enjoy those same benefits.

SP designs are more active (i.e. more pedal bob), more suseptable to brake-jack and not as plush downhill; in essence, the only advantage they maintain over other designs is one of simplicity and even that is highly questionable when you explore some of the linkages SP bike manufacturers use.
Well, both the Flux and NRS are 4-bar designs for a start. Sorry, you sound like a marketing man's wet dream.
 

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kristian said:
Isn't an NRS considered a four bar? It has four "bars" and the pivot is on the chainstay.

I've been reading about "pedal induced feedback" long before buying my first Heckler and keeps coming up in these threads. I can honestly say that I have never noticed it. Maybe I am oblivious to it and my bikes really do have some sort of feed back, but if that's the case, it has never had a negative impact on my ability to ride up or down just about anything on the mountain. This might be an issue if the original poster was moving from a 4 bar to an SP, but since they are coming from a hardtail, it's a non-issue.

When I test rode an Ellsworth Moment, the rep turned off the ProPedal (platform) on the shock because the frame didn't need it. Running too much platform on a neutrally pedaling bike will actually make it ride WORSE (worse defined as less active on small bumps).

Single pivot bikes are not suseptable to brake jack. Brake jack is defined as the bike jacking up in the rear under braking (picture a stink bug). That is not a trait of any single pivot I've ridden and is a misused term to reference to suspension stiffening. SPs are extremely plush on the downhill, provided you are not on the brakes. If you are on the rear brake, the suspension will stiffen slightly. The only time I have ever felt like this was a detriment was on the pirate trails of Vail which are crazy steep. However, I do totally agree with you that a four bar is better in this regard because the suspension remains fully active under braking.

Regarding bob, my Bullit with a Romic on it has zero pedal bob when sprinting out of the saddle, yet it's still very plush. SPs without platform shocks do tend to have a little more bob than a properly executed four bar design.
In order:

#1: No, while it has a linkage on the chainstay it is absolutely not a Horst link (it sits waaaay to far forward for that distinction) therefore it is not considered a true "four bar" design. Designs like this are commonly known as "faux bars" meaning they're somewhat like a four bar but...well...not.

#2: That's likely because you don't really have anything with which to compare the Heckler. Spend a solid amount of time on another suspension design and I can virtually guarantee you'll notice it. Some SP designs (like the Trek Fuel) do have very little pedal bob as a result of where they place the shock but they also handle very poorly on the descents. With the SP you simply can't have both.

#3: That's a matter of preference. I change my ProPedal setting on my RP3 all the time depending upon the terrain. For anyone to say you should or shouldn't use the platform settings on a particular shock is somewhat ignorant IMO.

#4: I know what brake jack is and, I'm not sure where you're getting your information but SP's are highly suseptable to brake jack. This is due to the fact that the chainstay can't sink into the dirt under braking conditions like a Horst link bike can.

#5: That's highly unusual. Your bike - by its very nature - should experience a decent amount of pedal induced feedback as the result of hammering out of the saddle. Maybe it has something to do with the stiffness of the shock but, for the most part, any long travel bike (SP, four bar or otherwise) should have movement when standing.
 

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uktrailmonster said:
Well, both the Flux and NRS are 4-bar designs for a start. Sorry, you sound like a marketing man's wet dream.
Would you care to rephrase that? The NRS absolutely is not a true four bar design given the placement of the linkage and the Flux doesn't even come close with the linkage sitting on the seatstay instead of the chainstay (a pretty worthless place to have a linkage).

Why the jerk attitude BTW?
 

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Ride on
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CranxOC said:
In order:

#1: No, while it has a linkage on the chainstay it is absolutely not a Horst link (it sits waaaay to far forward for that distinction) therefore it is not considered a true "four bar" design. Designs like this are commonly known as "faux bars" meaning they're somewhat like a four bar but...well...not.

#2: That's likely because you don't really have anything with which to compare the Heckler. Spend a solid amount of time on another suspension design and I can virtually guarantee you'll notice it. Some SP designs (like the Trek Fuel) do have very little pedal bob as a result of where they place the shock but they also handle very poorly on the descents. With the SP you simply can't have both.

#3: That's a matter of preference. I change my ProPedal setting on my RP3 all the time depending upon the terrain. For anyone to say you should or shouldn't use the platform settings on a particular shock is somewhat ignorant IMO.

#4: I know what brake jack is and, I'm not sure where you're getting your information but SP's are highly suseptable to brake jack. This is due to the fact that the chainstay can't sink into the dirt under braking conditions like a Horst link bike can.

#5: That's highly unusual. Your bike - by its very nature - should experience a decent amount of pedal induced feedback as the result of hammering out of the saddle. Maybe it has something to do with the stiffness of the shock but, for the most part, any long travel bike (SP, four bar or otherwise) should have movement when standing.
The NRS most definitely has a Horst Link, due to the pivot placed below and in front of the rear axle between the rear wheel and the main pivot on the frame. The NRS is also a four bar design due to the fact that the wheel is separated from the frame by two parallel links, just like all other Horst Link designs. The Flux used to have a Horst Link and only recently switched over to a faux-bar configuration.

Sometimes folks tend to get a bit religious about their suspension preferences, especially the Horst Link. It is easy to get real data confused with marketing hype generated by the bike companies. When you make broad, sweeping generalizations about brake jack and pedal feedback then you sound like you have bought into the marketing stuff. When you question the experience of other riders then you will get hostile responses. Make sure to check your facts and keep your mind open.
 

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it's always dangerous for the manufacturer to get involved in these conversations...

... but, since I've been posting on MTBR for close to 10 years, wtf... :)

Anyway, let's clear up some common misconceptions first:

Suspension designs: If the rear wheel is located on a swing arm with one pivot between it and the front triangle, then it is considered to be a single pivot design. All other designs are linkage designs. Typically, all linkage designs are inherently four bar designs becaue 3 bars make a triangle (and those don't move - hence why they make for good roofing trusses and bridges) and 5 bars are under-constrained, meaning that you have one link too many and things flap around in the breeze.

So, any linkage bike uses a four bar linkage. In fact, if you want to get really technical, a four bar linkage bike actually has "Two" four bar linkages

- one that includes the front triangle, the chain stay, the seat stay and the rocker link
- the second one includes the frame, the rocker link and the shock. Because a shock can change it's length, it is the equivalent to "two linkages" which can open and close like scissors.

Anyway, bike manufactures all have their fancy linkages (our frames have two plus the shock linkage for three (!) four bar linkages! :) and call them different names. Sometimes they advertise the merrits of their designs, sometimes they exagerate the abilities of the designs, and some times they flat out lie. Ah marketing is a brilliant thing!

Anyway, it can get really confusing. Technically, bikes like Kona's which use the so called "Faux Bar" design have four bar linkages, but only as far as the shock is concerned. The rear wheel is on a swing arm so in terms of pedalling, pedal feed back and brake interactions, the design is considered a single pivot. However, the shock is actuated by a linkage which can be tuned to achieve a desired suspension feel.

Additionally, bikes like VPP, DW link, Maestro, NRS, are all technically four bar linkages. It's just that the chain stay and rocker link have shrunk down to a few inches in length and the seat stay has grown into a massive rear subassembly.

Typically manufacturers advertise a few things about their suspension

- Neutral braking
- Zero pedal Bob
- Zero pedal feed back
- super plush, bottomless suspension
- vertical wheel path
- etc....

How much of this is true and more importantly what will it do for you. Even more important, how much can you benefit from this?

The simple truth is this: There are three main things that are considered when designing bicycle suspension:
- pedal induced suspension movement (i.e. bob)
- suspension induced pedal movement (i.e. pedal kick back or feed back)
- Braking interactions (i.e. suspension extension, suspension neutrality, suspension compression).

However, there are many, mant other characteristics that can become very important factors and can even superceed the original three key suspension items. Cost is a major one, so is weight. Then other characteristics can start popping up: wheel path, tire clearance, chain stay length, lateral rigidity, suspension quantity of travel, shock location, etc...

A good suspension design will achive a nice balance for the frame's intended application (and hence trade offs) with all suspension design characteristics. Want a DH bike? Well, tire clearance is important, lateral rigidity is important, amount of travel is important, good standover height is important, serviceability is important, the list goes on.

In terms of pedalling performance, three things mainly cause the suspension to "bob":
1. tension on the chain when the chain is not perpendicular to the wheel path
2. the squat of the rear end and the rise of the front end (like stepping on the gas in a car) due to the force of acceleration being at the rear tire's contact point on the ground, but the Center of Gravity (CoG) of the bike / rider combination being much higher up.
3. any change in the CoG location (i.e. due to the rider not being able to pedal in a 100% perfect circular shape).

Some designs just ensure that the chain is as perpendicular as possible to the wheel path. However, the wheel path is controlled by the suspension - the rear wheel can only travel along a line that is generated by the suspension linkages / swing arm.
The chain, on the other hand, can change it's location (and hence angle relative to the rear wheel path) by simply switching gears. Big chain ring at front and small cog at back have a very different chain line than the granny gear up front and the granny cog in the rear cassette. It's up to the designers to figure how much (if any) they want to compensate for the effects of numbers 2 & 3 (if at all) in our list above.

By keeping the wheel path fairly cicular around the BB axis, you keep the chain length from changing too much. If the chain length doesn't change much in length, you won't notice much - if any - pedal feedback.

The flip side is that some designs use a CHANGE in chain length to help over come the tendence of the rear suspension to squat when accelerating. These designs aim to help prohibit the rear wheel from squating under accerlation by trying to "pull" the wheel to a different location (typically the sag point). They do this by changing the chain length so that tension on the chain pulls the wheel into the position of shortest chain length.

What no one wants to tell you is that ANYTIME you use the chain length (tension) to move the suspension, you are going to have pedal feed back. How much does this bother you and is it perceptived? That is a different answer. To some it's a big deal (myself included), while others don't notice anything... OK - it's late, and time for me to go to bed!
 

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CranxOC said:
Would you care to rephrase that? The NRS absolutely is not a true four bar design given the placement of the linkage and the Flux doesn't even come close with the linkage sitting on the seatstay instead of the chainstay (a pretty worthless place to have a linkage).

Why the jerk attitude BTW?
I apologise for the attitude. But you are talking like someone who's just swallowed all the marketing hype. I'm guessing you don't have an engineering background, so I guess your gross generalisations are a result of reading loads of techno waffle on the manufacturers websites and magazines. Read Noel's post above, he designs bikes and talks a lot of common sense from what I've read.

As I always try to state in these conversations, there are good and bad designs using all the different generic linkage types and there is no clear winner. Engineering always involves compromise and you have to consider the entire bike design as a whole, not just judge entirely by the name of its linkage!

So the Flux you rode was the new TNT version with as you say "a worthless seatstay linkage". Well it's only worthless in the sense that it doesn't affect the wheel path. If you pop over to the Turner board, you'll read that virtually all the riders think it performs as well as the old Horst Link version. There are some who even think it's slightly better due to improved rear stiffness i.e one less pivot between the back wheel and main frame.
 

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knollybikes.com said:
Anyway, it can get really confusing. Technically, bikes like Kona's which use the so called "Faux Bar" design have four bar linkages, but only as far as the shock is concerned. The rear wheel is on a swing arm so in terms of pedalling, pedal feed back and brake interactions, the design is considered a single pivot. However, the shock is actuated by a linkage which can be tuned to achieve a desired suspension feel.

Additionally, bikes like VPP, DW link, Maestro, NRS, are all technically four bar linkages. It's just that the chain stay and rocker link have shrunk down to a few inches in length and the seat stay has grown into a massive rear subassembly.
That's a nicely balanced quote from someone who clearly understands basic engineering. I suspect the term "Faux Bar" was invented by manufacturers marketing their "True 4-bar" designs to make them sound inherently superior.
 

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uktrailmonster said:
Steve Peat always did just fine on a single pivot Orange with a non-floating caliper, so it shouldn't slow the likes or you or me down at all.
Doesn't mean a thing. Steve Peat would still win on a 20" girls pixie bike from Walmart (with or without the pink tassels on). The main thing is that the bike you throw your leg over makes you smile when you ride it.
 
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