[Rik]

Since we're talking about marketing BS... how does this fare?

http://members.optusnet.com.au/isaksen/vtbs.GIF

Active suspension under braking, no pedal feedback, from a glorified singlepivot? Oh man, I wish I was dumb enough to fall for crap like that, life would be blissful.

 

[thaflyinfatman]

I will seriously try to tape my camera onto my seatstay or something to show you. I dont see why I have to do it with a bighit though, and with a non spv propedal shock? Hmm...I dont have one of those. The reason that it pedals well is because of the SPV....I thought I remembered saying something about that but I guess not. I have had all the air out of it before, and it bobs like crazy. So I guess I wasnt thinking straight when I said the bike pedals well, because its only due to the shock. All that I know is that my demo pedals well and I can get up hills even with it being a 50 pounder. Some of the longer roads and stuff that we have to bike/walk up to get to the trails I cant ride up with the demo due to its weight. I could pedal up the same hill all the way with my bighit comp when I had it, so that is why I thought that they pedalled really well also.

And yea, I apologize for calling you a curb dropper and whatever else I said.... I guess I am not in a good mood all the time. Plus I am quite loyal to specialized - if your loyal to any one company you might know how I feel (getting defensive if somebody says something negative about it). What kind of bikes do you ride anyway?

I'll let the curb dropper thing slide... because everybody knows you can't drop of curbs, you can only HUCK!

I agree that with SPV shocks, FSR bikes generally pedal pretty well. Having owned a couple and ridden heaps of FSR bikes (including a number of Specializeds) without an SPV shock, I have found them to not pedal particularly well - not "badly" mind you, but not as well as say a DHi or such.

I ride an Iron Horse SGS Team (and a .243 hardtail)... and even with an SPV shock it doesn't pedal that well (I keep it at minimum air pressure at all times however). I love the bike, so it's not that I just hate FSR bikes or anything... I just dislike the marketing notion that FSR is perfect. I've also owned a pair of Norco VPS's (both non-spv-equipped) and they bobbed like mofos.

 

[math2014]

Well said thaflyinfatman.

I would like to comment (and maybe ask if i am wrong), that FRS has 4bars, like Kona/Trek/Banshee which are 4bars but lack the horst link. I guess that ALL 4bars should be flexy or have more pivot wear, and not FSR in comparison to other 4bars in particular.

Correct me if i am wrong... but i can see less pivots only on Bullits/ Hecklers and similar designs....

 

[binary visions]

I would like to comment (and maybe ask if i am wrong), that FRS has 4bars, like Kona/Trek/Banshee which are 4bars but lack the horst link. I guess that ALL 4bars should be flexy or have more pivot wear, and not FSR in comparison to other 4bars in particular.

Designs like DW-link and VPP (which are technically 4-bar) with the solid rear end are significantly stiffer.

<warning! Google-engineer alert!>
This is complete e-speculation, but due to the pivot interrupting the solid member between the frame and the rear wheel, couldn't you build a walking beam style frame (like Kona) that's stiffer than a similar Horst link setup? You could certainly make the chainstay stiffer, I just don't know if the benefit would be lost in the flex of pivot on the seatstay (i.e. the total amount of flex in the rear end is the same regardless of which actual piece flexes). Anyone have better credentials to supply a structural analysis?

 

[math2014]

Designs like DW-link and VPP (which are technically 4-bar) with the solid rear end are significantly stiffer.

<warning! Google-engineer alert!>
This is complete e-speculation, but due to the pivot interrupting the solid member between the frame and the rear wheel, couldn't you build a walking beam style frame (like Kona) that's stiffer than a similar Horst link setup? You could certainly make the chainstay stiffer, I just don't know if the benefit would be lost in the flex of pivot on the seatstay (i.e. the total amount of flex in the rear end is the same regardless of which actual piece flexes). Anyone have better credentials to supply a structural analysis?

BV i agree that VPP and DW style designs should be stiffer providing a solid rear triangle, but which is then attached to the main frame again with 4 pivots... so imho there is now flex again (maybe much less) but simply at a different point. So essentially we move the flex point forwards. Similarly walking beam moves the flex point from chain stay to seatstay.

Then again i am no expert, i just pretend to be one on the internet.

 

[OGRipper]

Wow, this is definitely an...entertaining...thread. It seems that many people don't understand that a "four bar" design is actually a defined thing with specific parameters, notwithstanding the fact that the term is used loosely. Here is one explanation:

"A four bar linkage is a system which has a static bar, two link bars, and the "control" bar, aka the bar who's path you are trying to control. That would make the "control" the bar with the dropout attached (the seatstay on a Horst Link), the links would be the chainstays and the rocker arm, and the static would be the main frame. The whole idea of a 4 bar link is to have a static arm (in bikes, that would be the part of the bike you are trying to isolate from bump forces). Also, with 4 bar links, in order for it to function as a complete 4 bar link, all links must remain completely static in length and shape, only bending at the pivots. This would obviously exclude a shock since it changes in length."

I'm not an engineer, but if you apply that definition, vpp and dw designs are four bars: The entire rear triangle is the control bar, the two links are, well, the two links, and the frame remains the static bar.

Where I get lost is in applying the definition to kona style rear ends. At first glance, it seems those rear ends are four bars, they're just not horst links. So calling them "faux bar" might seem kind of clever but it's just wrong if it's supposed to mean it's not really a four bar. But I've heard engineers say the Kona design is not a four bar. If that's true, can anyone explain? Is it because the rocker arm pivot location prevents the frame from acting as the static bar and uses the shock in it's place, which is not static? Or is it because you can't really control the axle path (other than by changing the pivot location where the chainstay attaches to the frame), so there is no control bar?

Any help...?

 

[OGRipper]

bumpity bump

 

[Kornphlake]

konas are 4 bars, you're simply rotating the entire linkage 90 degrees and moving the axle the other end of the link and adjusting the length of linkages to get from a kona to a horst link. Rather you use a rocker link or a push link or a swing link makes no differance it's still a 4 bar with a shock attached to two of the members in one way or another.

 

[Rik]

At first glance, it seems those rear ends are four bars, they're just not horst links. So calling them "faux bar" might seem kind of clever but it's just wrong if it's supposed to mean it's not really a four bar

I know the term "faux bar" isn't the best or most accurate term, but it's a good way to quickly describe a bike, using BS to counter marketing BS. To sit down and explain to people the techy details of FSR vs singlepivot+linkage, and being pedantic about engineering terms, is going to lose their interest. Note that I also called it FSR, only because alot of people these days don't know who the hell Horst Leitner is, and why their bike would want an AMPlifier. I only use these terms when it comes to quick, simple explanations to those that really aren't interested in getting techy.

 

[Jm_]

NOW I FEEL LIKE I'M TAKING CRAZY PILLS










IS MY CAPS LOCK ON?

 

[binary visions]

I know the term "faux bar" isn't the best or most accurate term, but it's a good way to quickly describe a bike, using BS to counter marketing BS.

The problem is that you're not using BS to counter marketing BS. You're propogating the BS and catering to Specialized's widely spread notion that anything less than a Horst link isn't "4 bar".

You don't have to get technical to explain the differences. You don't even have to explain exactly what the difference is. "These two bikes are both considered to be '4 bar', but Specialized's design is a little different so we call it an FSR" or something would do nicely. It'd take longer to explain why you're inventing a new term than to explain the old term.

Don't push incorrect and misleading terms simply to avoid the extra sentence or two. It's not simply that the term "isn't the best", it's actually wrong and implies something that's not true..

 

[OGRipper]

Yeah, what binary said.

Don't insult your customers' intelligence by assuming they won't want to know accurate information. If they use "four bar" or "faux bar", they bring it on themselves.

But if faux bar means a four bar that is not a Horst/fsr, ok then.