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Which Rear linkages to look at for DH race and park bike?

saber63

Chimp
Sep 14, 2016
3
0
Hello! After spending many years riding like a total dork. (over biked and under skilled) I think my testies finally dropped, and i'd like to give cat 2/3 DH racing a go. And start crushing the gnar on the double blacks.

More seriously. After 15 days in Whistler this year my Driver 8 just Isn't cutting it and the Bronson Trail bike can handle anything with an uphill I care about. I demoed a Session9.9 and a V10.6. They certainly helped provided more confidence in the technical stuff, and just as fun on the flow. As an electrical engineer with a solid mechanical background, I would enjoy discussing the suspension and geometry differences, and their effect, on the current range of 650b DH bikes. Maybe not a bike by bike basis. But general trends in LR and the like.

I'm not a good enough rider to tell when a bike "feels" better if it's just what i'm used to, Or if it really is performing better than the other option. Maybe the other bike actually has more/different potential?

I have spent a fair amount of time looking up the discussions of UDI and others regarding linkage graphs of different bikes. For being the DH section you guys sure do talk about uphill "EndurO" crap a lot ;) I do know this topic of "best suspension" has A LOT of opinion. But i'm mainly looking for the technical performance differences. So I can better try my time demoing or test riding kit. It would also be great to consolidate some of the knowledge on this topic so it's easier to find when searched for.

I also understand that most if not all the modern DH bikes are VERY VERY good. And the rider and setup probably has more effect than suspension design. And it probably doesn't matter which DH bike i go with. But I would atleast like to feel like I am making an educated choice.

-Levi
 

HAB

Chelsea from Seattle
Apr 28, 2007
11,580
2,006
Seattle
Looking at the type of linkage isn't very helpful. Every type of linkage you can imagine has been implemented poorly by somebody at some point, and there are good examples of most. Relatively subtle changes in pivot placement (especially on mini link bikes, e.g. VPP, DW-Link etc) can have quite dramatic impacts on suspension characteristics that you couldn't hope to identify by eyeballing.
 

kazlx

Patches O'Houlihan
Aug 7, 2006
6,985
1,957
Tustin, CA
I also understand that most if not all the modern DH bikes are VERY VERY good. And the rider and setup probably has more effect than suspension design. And it probably doesn't matter which DH bike i go with. But I would atleast like to feel like I am making an educated choice.

-Levi
You said it yourself. Any of the popular proven DH bikes are going to be fine. I ride a Banshee Legend and love it. The key is making sure your setup is sprung and dialed in for you. Other than that, all you can do is see if you can throw a leg over a bike and see how it feels, but even then, settings and everything else will make a bike behave totally different.
 

allsk8sno

Turbo Monkey
Jun 6, 2002
1,153
33
Bellingham, WA
In my limited riding experience, I find vpp to soak bumps beautiful but bit dead feeling, yes shock makes difference, but that is my takeaway on them, they also don't hope well, which I find makes them not as poppy off jumps, though I've only ridden freeride/am vpp.

Faux and single pivots on the other hand seems more playful, but lower pivots are a bit harsh in chatter. They are poppy and bunny hop great...mostly that is again shock setup.

Horst I can't ride....always feel awkward, but no riding on the DH variety, again just am bikes and older bighits (24" rear version)
 

Udi

RM Chief Ornithologist
Mar 14, 2005
4,915
1,200
I think you should be able to glean most information you need from the discussions already on this forum, sounds like you've already done a bit of that. As you and others here have pointed out, most DH bikes are pretty good these days.

A good starting point might be eliminating what will and won't work for you specifically - for example for some, pricing and availability may exclude some options. Depending on your height, you may fall between sizes on a lot of bikes and eliminate more there. At least for me there are a few bikes I quite like, but either can't justify spending on, are hard for me to get, or flat out don't exist in a size that fits me.

Your idea of "consolidating" is unfortunately a little unrealistic because opinions vary and as you've probably seen, heated debate can result - no one wants to dive into that head first (least of all me) for the sake of the kind of generic debate you're suggesting.

I'd start with doing a little groundwork yourself and figuring out which sizing/geometry works best for riders your height, eliminating options that won't fit or flat out can't be purchased, and then testing the remainder. Don't forget that setup has a huge impact - so take time on each test to ensure suspension setup (sag, damping) is matched, along with cockpit (lever positions / rotation), geometry adjustments (bb height, cs length), and other factors like tyre pressures etc. Comparisons are only as objective as you make them.
 

saber63

Chimp
Sep 14, 2016
3
0
Missing link. You've heard it here first.
HAHAHAHA oh man, I spent some downtime reading through those threads. It would have been funnier but it reminded me to much of a few past coworkers....
I think YT comes with the most good times.


So horsey link is the right answer I believe.
Ah, now for average joe dentists types like myself? Or for gwinners only?


Hmmmm I seem to have worded my questions wrong, and missed my intension.


However it would seem UDI and others made a better point... I really need filter stuff out first. Makes sense.
And I understand not wanting to rehash stuff here. But damn it can be hard to find the very useful discussions via search, I have found a few... Just feel like a sticky with some "best of" type links regarding suspension could really help those of us tired of the marketing wank.

I did however find a Spanish blog with a massive number of linkage graphs. Which more or less answers one request (I have no clue if they are correct, but it's a nice place to start)

I feel like maybe i have missed something, or forgotten, Or simply can't find it in a search. If some one could provide a link? But information regarding the general "feel" or "type of ride" that certain curve shapes provide. Along with the shock types? tunes? that worked well with them... I thought i read it while in whistler (had an off day from injury) But can't seem to find it now!

Thanks all!

-Levi
 

Jm_

sled dog's bollocks
Jan 14, 2002
18,855
9,560
AK
HAHAHAHA oh man, I spent some downtime reading through those threads. It would have been funnier but it reminded me to much of a few past coworkers....


Ah, now for average joe dentists types like myself? Or for gwinners only?


Hmmmm I seem to have worded my questions wrong, and missed my intension.


However it would seem UDI and others made a better point... I really need filter stuff out first. Makes sense.
And I understand not wanting to rehash stuff here. But damn it can be hard to find the very useful discussions via search, I have found a few... Just feel like a sticky with some "best of" type links regarding suspension could really help those of us tired of the marketing wank.

I did however find a Spanish blog with a massive number of linkage graphs. Which more or less answers one request (I have no clue if they are correct, but it's a nice place to start)

I feel like maybe i have missed something, or forgotten, Or simply can't find it in a search. If some one could provide a link? But information regarding the general "feel" or "type of ride" that certain curve shapes provide. Along with the shock types? tunes? that worked well with them... I thought i read it while in whistler (had an off day from injury) But can't seem to find it now!

Thanks all!

-Levi
There are some generalities, but the bikes vary so much that it's not worth getting into the weeds. Specialized has significantly falling anti-squat curves, but is slowly improving this on their line. Rocky Mountain also uses a horst link and has managed to make a flat ant-squat curve, which is pretty rare for a horst link. Going downhill, this may not be the biggest issue, and so on, but my point is that even when you think you know what one will do or what you are looking for, the specific bike may be a good or bad example of that general design, just like there are outstanding single pivots and ones like Orange makes, and within a certain company they may be inconsistent (possibly because their entire design philosophy is like shooting blindfolded and sometimes they get lucky). Some companies have good reputations for making good bikes, regardless of the actual suspension, like Transition, others. It is tough, because there are a lot of good bikes these days.
 

Sandwich

Pig my fish!
Staff member
May 23, 2002
21,031
5,921
borcester rhymes
these things tend to gravitate towards the most successful option...:


That being said, my vote is to grab whatever the latest 26" bike you can get from 2014 that fits you and is in good condition. Ride the hell out of it, then worry about what you don't like about it once you get to the top of Cat2/start on cat 1. I can tell you some things I don't like about my bike, but I can also tell you that it's not hampering my ability to ride. It can go as fast as I want it to. Save your money on 27.5 with a 26 bike and spend more on protective gear, great tires, and lift tickets.

Or get a summum.
 

saber63

Chimp
Sep 14, 2016
3
0
Please don't look at my rear linkage, bro.
mmmmmmm too late, bro :brows:

That being said, my vote is to grab whatever the latest 26" bike you can get from 2014...

Or get a summum.
Ha, not a bad plan. Thankfully I'm already set on gear, And I may even do the first race or two the Driver8... we'll see what I come up with this winter.

I've certainly got enough great info, and some pointing in the direction on what I should REALLY do.
And also where to start looking if i want to get into the theory and maths etc... behind it all.

Thanks again everyone
 

Sandwich

Pig my fish!
Staff member
May 23, 2002
21,031
5,921
borcester rhymes
This might be a dumb question, but are there any downhill bikes that have linkages designed for any other riding then racing and bikeparks?
I don't really think so. It used to be that the internets decided that a bike with a more linear shock rate was better for racing, while a more rising rate was better for bike parks and jumping. Lately, kidwoo called me a dentist for thinking that, so it's been decided that you need a rising rate for all riding needs.

The point I was trying to make above was that many modern bikes are all settling on a very similar shock rate, which is somewhat rising from start to finish. Very few bikes do anything VERY linear (orange), or batshit crazy (dw). So, it's honestly hard to go wrong at this point in the game unless you pick up a bike with a shock that doesn't match well (like extreme rising rate and small volume air shock).

Antisquat is a little bit different, but I'm speaking specifically on leverage rate. Opinions on AS especially for DH are totally varied.
 

Westy

the teste
Nov 22, 2002
54,241
20,022
Sleazattle
I don't really think so. It used to be that the internets decided that a bike with a more linear shock rate was better for racing, while a more rising rate was better for bike parks and jumping. Lately, kidwoo called me a dentist for thinking that, so it's been decided that you need a rising rate for all riding needs.

The point I was trying to make above was that many modern bikes are all settling on a very similar shock rate, which is somewhat rising from start to finish. Very few bikes do anything VERY linear (orange), or batshit crazy (dw). So, it's honestly hard to go wrong at this point in the game unless you pick up a bike with a shock that doesn't match well (like extreme rising rate and small volume air shock).

Antisquat is a little bit different, but I'm speaking specifically on leverage rate. Opinions on AS especially for DH are totally varied.

Kidwoo is the voice of the internet?

I didn't vote for him.
 

kickstand

Turbo Monkey
Sep 18, 2009
3,441
392
Fenton, MI
Pick the bike you think looks the prettiest. Seriously, MOST all of the DH bikes out there right now are really good, and unless you're at the faster limits of Cat1, or carrying a Pro card, they will all get the job done quite well.

You'll adapt to it, unless it flat out sucks, then you won't. I've had 4 DH bikes over the last 5 or 6 seasons. (Bighit (not the 24" rear tired thing), TR450, TR500, V-10). They have all felt awesome, until I got on the next bike which was better....the 450 was better than the big hit, the 500 was a more refined better 450, and the v-10 is new fangled 650b and all that jazz, but I wouldn't rate it any "better" than the 500, In fact ever since I switched I've wanted to jump on a 650b TR500 to see how it would feel in comparison, my 500 was set up 26".

I have also ridden a handful of other DH bikes, they all feel "similar" but totally different at first, but as you get more runs on them they all start to feel the same-ish again, even with their differences.
 

Udi

RM Chief Ornithologist
Mar 14, 2005
4,915
1,200
Just to make it clear - I don't think the graphs above actually form an optimal example of anything necessarily, and there's examples of good and less-good bikes even within that small selection.

I don't really think so. It used to be that the internets decided that a bike with a more linear shock rate was better for racing, while a more rising rate was better for bike parks and jumping. Lately, kidwoo called me a dentist for thinking that, so it's been decided that you need a rising rate for all riding needs.
I'm not sure that's a good basis for drawing a conclusion, and before deciding on a supposedly "correct" amount of progression, what's the purpose of any amount of progression?

If it's for the purposes of better bump absorption, there's a point past where returns start to diminish, and then bump absorption actually starts to suffer. As I've detailed in another recent thread, depending on the rest of the design, relying completely (or excessively) on leverage curve alone for bump absorption isn't ideal because stability suffers as a result (dynamic geometrical stability to be more precise - wallowing for laymen's terms) - and in this respect certainly a flatter leverage curve / less percentage total progression is definitely superior as you suggest.

Obviously the shock intended for the frame throws another variable in the mix - but the take home message is that there is no perfect LR curve because net bump absorption performance is a combination of things like LR curve, axle path, and shock spring curve.

Now on the flipside - if you have a dead flat (or close to it) leverage curve (and/or wheel rate curve if we assume a ~linear sprung shock), you rely excessively heavily on axle path for your bump absorption performance, and (assuming you even implement this solution - often manufacturers don't) you get other geometrical instabilities in the form of CoM shifts that you are familiar with, along with F/R normal force variations and thus increased F/R traction variations as a function of elapsed travel.

I don't think I've read the posts you're referring to, but I think you're actually correct with your original line of thinking at least in a generic sense. Without throwing around exact numbers or naming specific bikes, I do think some LR curve progression is always important on the rear specifically (partially to do with breakaway forces, a little to do with jumping), but I also think a great bike designer will use LR progression *sparingly* as part of a package - and certainly - if you can get away with less, then you'll build a more stable and predictable bike that can be ridden faster.

Certainly there are far less "bad" bikes now than ever before, but if I was to name the most common mistake (and a minor one, to be fair) across the spectrum of "pretty good" bikes in current times, it's excessive progression.

This isn't directed at Sandwich - but before someone else asks what the golden combination of x/y/z is:

a) "sometimes science is more art than science, morty"
b) i don't have the golden numbers, but even suggesting them makes people upset
c) searching my posts over the last year will have more numerical answers if desired, but i'd prefer not to open those worm cans all over again
d) i agree with @kickstand pretty strongly in the sense of "just pick one, they're all pretty good" and also that humans adapt very well and very quickly to small deviations from normal or perfect
 
Last edited:

csermonet

Monkey
Mar 5, 2010
942
127
see? i started with, "just go buy a bike and enjoy" and now I've gone and triggered Udi's page-long response button. Sheesh.
I like Udi's page long responses. Even if I have no interest in the topic being discussed, I always find something useful in them. So keep triggering