Mountain Biking - The advanced mtb thread.

Ok, this thread is dedicated towards the discussion of the advanced side of mountain biking. No beginners discussions allowed in this thread. This thread is for talking about the more tougher aspects of mountain biking.

So we can't ask which bike is better or if I can use a K-mart Mongoose on a real trail?

Seems like it would be a pretty boring thread.

Advanced mountain biking, you go, you ride, no problems. You are in shape, you have technical skills, and your equipment works because you know what works best for you without having to ask for anyone else's input.

I'll stick to the all skill levels threads.

What is meant is by more of an advanced conversation as in no which bike should I buy threads and more talk about the technical aspects behind the technology.

I think that it would also be a good place to discuss epic rides and what not. I think that in this sub-forum the whole idea of mountain biking isn't interpreted the way it is supposed to be. I think that a lot of people who post here have not(and many have, don't get me wrong) participated in "real" mountain biking, on real mountain bike trails.

Ok first question.

I'm looking for a new DH race bike (old one was stolen) what I want to know is the advantages and disadvantages behind, Horst, Lawill, Singlepivot, parallelogram linkage (like stinkys) and VPP. I don't weant to hear stories about bikes you have ridden, I just want to know the pros and cons behind the designs of these linkages.

Cheers, hope this is in the right thread, if not delete it and I'll post a new thread.

Wow...thats some advanced discussion...yummy..might have to get my brain moving for this.

Horst - in theory is supposed to keep the rear wheel moving vertically in a straight line. By doing this you eliminate brake jack and/or brake squat. In reality the wheel still moves in an arc and does one of the better jobs of REDUCING brake jacks/squat. Also helps reduce pedal bob.

Single pivot. All the characteristics mentioned above occur in single pivots. Depending on where the pivots are located. Depending on location you can eliminate one problem but the other is increasd. Floating disc breaks and SPV valved shocks have revitalized single pivots almost completely eliminating the said problems while still offering some of the simplicity of a single pivot.

Lawill...no clue

Faux Bar (stinks) - react like single pivots. Without the horst link to create the vertical movement they still have some of the same problems. Now you see them coming out with spv shocks (pro pedal) and floating brakes (this years stab) which eliminate those problems.

VPP - A complex series of linkages to do, again, what the horst trys to do, and again semi-succeeds. Downfall is cost and complexity (more linkages more things to break) Again, I haven't been tracking vpp in detail at all as I like fsr and personally don't feel the need for anything more complex and expensive. But thats me. http://www.ridemonkey.com/forums/showthread.php?t=19653&highlight=vpp good discussion on vpp by some actual engineers :D


http://www.mtbcomprador.com/pa/english/
http://www.specialized.com/sbc4Bar.jsp?minisite=10080&a=b (good visual comparison but biased towards the horst link for obvious reasons)
http://www.titusti.com/suspension.html

In short...there is still no perfect system and still nothing works for everyone. In fact...it will never happen

Lawills are notorious for bad shifting and tons of brake jacking.

Thanks a lot, what's DW link, is that like the linkage on the demo 9

Thanks a lot, what's DW link, is that like the linkage on the demo 9

No the demo is simply a slightly modified shcok placement of the fsr. Nothing new or exciting there. IT allow for the same compact feel, the fsr suspension with a 26" wheel. Do not mix up the demo with something like a vpp.

DW is an engineer on ridemonkey designing rear ends for ironhorse...damn near a genious and definately a smart person to read posts off of. Anything I know is indirectly related to his posting on ridemonkey. And I only understand 60% of what he posts....

http://www.dw-link.com/technology.html

Thats the DW-link. I am taking it out of the vpp explanation simply because he would get pretty pissed that I lumped him in with vpp. It is the DW....nothing more..nothing less haha

Quick question...

Is there a significant amount of difference between 2 pot or 4 pot or 6 pot? Do you see less fade in power? Is there a different feel to it?

The way I feel about suspension, the stable platform shocks, in my eyes, are somewhat of a band-aid for underveloped/poor platform designs. I like the Horst the most out of all of them since even with out a SPV setup, its not as prone to jack and bob. So many bikes though, if you take away the SPV, you are left with a Walmart Mongoose pogostick bike. All IMHO of course.

You opinion and mine. Single pivot with floating brake and an avalanche for example would feel great...but still be a crappy design overcharging for a simple design with extras.

Mind,

Think about it this way. More pads more power more control. Overall the 4 pot is signifigant over the 2...and the 6 is pretty much a tossup. Some people say they love them and they make a big difference and some don't. In theory it should be signifigant.

i'm a little late for this, but here's a good site that analyses the physics of common suspension designs:

http://www.math.chalmers.se/~olahe/Bike/

speaking of rear suspension designs, have you guys seen the sketches of the new design being developed by yeti? mael, you've probably read the posts on rm.

Don't want to touch the yeti...thats freaking nuts. I am a simplistic multi gear rider. Anything beyond FSR and I consider it overkill for me. But I don't race which is where the vpp and other features seem to matter most.

i'm a little late for this, but here's a good site that analyses the physics of common suspension designs:

http://www.math.chalmers.se/~olahe/Bike/

Thanks forgot about that one. SLightly outdated but a good starting point.

Can someone explain exactly what SPV does and how it works? Thanks :)

It is a type of damping within a shock that (in various ways) reads the bumps you are coming up to. In their most complex forms it understands the difference between pushing on the fork (fake lockout) and bumps pushing upwards. In lesser forms it is controlled compression damping that doesnt respond well to small bumps. Thats why many people complain of poor small bump sensitivity with SPV valving. Essentially a smart compression damping system.

In short SPV is a more advanced and sensitive compression damping system. Personally the 05 SPV evolve system from manitou seemed to have found a sweet spot between small bump sensitivity and pedal bob.

There is a good explanation of manitous version of it

http://www.bikemag.com/gear/spv/

Propedal and various other spv valving works in similar ways. Eliminate pedal bob while maintaining an active suspension.

Again no system is perfect for everyone riding. I don't like specialized version of it...felt like ass. Manitous (non specialized shock) felt good...so far I haven't felt a rear shock SPV valved that I liked. Fork on the other hand...slider + with spv evolve compression. That said...2002 z1 fr has the same feeling without the fancy term, just a very high end compression system (imo).

speaking of rear suspension designs, have you guys seen the sketches of the new design being developed by yeti? mael, you've probably read the posts on rm.

I think I understand it, and it looks sick, I want one.

No one even mentioned the GT I-drive and their overengineered eccentric bottom bracket. Looks cool, but has had some reliability issues.

I have NOT kept up with the new Yeti design, time to check out RM tonight!

L8R

The GT was always a little heavy on the bob for my tastes... design wise, its kind of a complex Trek Y11 style setup, with an eno BB for added complexity and reliability issues.

No one even mentioned the GT I-drive and their overengineered eccentric bottom bracket. Looks cool, but has had some reliability issues.

I have NOT kept up with the new Yeti design, time to check out RM tonight!

L8R

Weird...easy to understand but I see lot of room for breakage.

Didn't mention GT cause...well...I didn't like it haha...also I came into mountain biking shortly after gt got bought. And the idrive isn't exactly popular anymore :)

Since this is the "Advanced Mountain Bike" thread, I just wanted to say, I got my pant leg caught in my chainrings and it made me cry like a lil school girl cause I ripped my plaid-polyester's.

Off topic though, do you think the iDrive would be more effective on a setup like the Santacruz VP Free has(what the hells that called?)? Being that the BB moves eccentrically on the iDrive, would the two designs just counteract againist each other, or do you think you could have a stable platform type "feel"? (while pedaling) Being both designs kinda try to get rid of good'ole Mr. Peddal Bob, together maybe there can be peace. Or maybe I'm crazier then a 3$ bill..?
Any takers?

More effective...no. In the end the i-drive sacrifices too much with fragility and weight. (VPP btw)

Interesting idea...heres the problem $$$$$$$$$$$ and pounds. Combined the bike would break the weight barrier.

More effective...no. In the end the i-drive sacrifices too much with fragility and weight. (VPP btw)

Interesting idea...heres the problem $$$$$$$$$$$ and pounds. Combined the bike would break the weight barrier.
It wouldn't have to be a tank, I mean adding an iDrive BB to somehting else wouldn't be that heavy. Plus some bikes are already in the 40-45pound category. The likley hood of this ever happening isn't great (if it does, I want royalties). But if someone did some riggin up, it would be worth a ride no?

This is what could be the most imaginative rear suspension design ever thought: I bring you the Yeti 303

http://www.go-ride.com/frames/yeti/2005/303_cad1.jpg

http://www.go-ride.com/frames/yeti/2005/303_cad2.jpg

Yes those are rails that the swingarm are connected too.

Yeah we were eluding to it above. I guess, while not liking pure simplicity...I do like things slightly less complex.

It wouldn't have to be a tank, I mean adding an iDrive BB to somehting else wouldn't be that heavy. Plus some bikes are already in the 40-45pound category. The likley hood of this ever happening isn't great (if it does, I want royalties). But if someone did some riggin up, it would be worth a ride no?

The lightweight xc version my friend has is 35ish pounds. Add a vpp set of swingarms and linkages and a burlier i-drive bb...its weight.

If you look at the current trend. DH bikes are trying to go lighter. More and more are coming in under 40 pounds. I also think I-drive (for pedal-bob and other things it fixes) the nicolai and other multi chain bikes do that without sacrificing strength for a similar weight. (nicolai is excessive in weight but there are others.

The I-drive system gave me nightmares.

There is no way i'd get one of those Yetis. There are 2 sayings, "Keep it simple" and "The more complicated it is, the more chance there is of it screwing up" apply to this frame greatly. And anyway, why would you want a bike that you dont get how it works?

Yeah the new yeti dh bike is a bit perplexing, same with giant's maestro line.

What does Giants Maestro lne look like, how's the linkage work.

Really, when you look at the Yeti suspension, it's not too complicated, just could easily be damaged. Especially if you got something like sand on one of the rails and the cart runs accross it. However they'll robably put some kind of guard on it to stop that.

The Maestro linkage works like vpp does from what I hear.

The yeti 303 would not make a good east coast(USA) bike, western US yes, but here in the east things might break on it easily.

Stickied this for now, don't want it to fall off the first page.

VPP - A complex series of linkages to do, again, what the horst trys to do, and again semi-succeeds. Downfall is cost and complexity(more linkages more things to break) Again, I haven't been tracking vpp in detail at all as I like fsr and personally don't feel the need for anything more complex and expensive. But thats me. http://www.ridemonkey.com/forums/showthread.php?t=19653&highlight=vpp good discussion on vpp by some actual engineers :D


Dont vpp and dw-link bikes have 4 links/pivots, the same as fsr bikes but in different locations?

Vpp and dw-link are different than fsr. FSR has the horst link. VPP is it's own thing, dw-link is it's own thing as well.

ya but they have the same number of linkages/pivots, no?

Dont they go like this
vvp or dw
link behind the bb connected to rear triangle connected to last link thats connected to shock. ( dont know what this one would be called. maybe rocker arm?)
fsr
chain stay connected to seat stay connected to again, link thats connected to shock.

So thats 3 links/4 pivots for all 3 types. Thats all i was trying to state.

So far this is not an advanced mtb thread.....It is a monkey motion thread.




not that there is any thing wrong with that.

I don't believe they do.

http://www.santacruzbicycles.com/graphics/bikes/v11_large.jpg
http://www.specialized.com/OA_MEDIA/2005/bikes/05BigHitFSR_l.jpg

Just posting these to see differences. I think the v11 has quite a few more joints and points. Not saying that is bad, I just believe fsr is good enough.

Same same number of points. Just in difference degrees. I thought there was an extra one to allow for the odd rear pivot movement. Oops...

So far this is not an advanced mtb thread.....It is a monkey motion thread.




not that there is any thing wrong with that.

Huh...

I don't believe they do.

http://www.santacruzbicycles.com/graphics/bikes/v11_large.jpg
http://www.specialized.com/OA_MEDIA/2005/bikes/05BigHitFSR_l.jpg

Just posting these to see differences. I think the v11 has quite a few more joints and points. Not saying that is bad, I just believe fsr is good enough.

The Santacruz has a 5th joint in it right? I've never seen one closeup or cycled through the suspensions travel, but if you look closely at the picture, it looks like the shocks mount (swing arm side) floats on the black bracket for the first few degrees of movement. Or is the black bracket fixed onto the lower (red) chainstays?

It looks like the shock it connected to the first link behind the bb instead of the last one like the blur

The v10 and the dw links are not 4 bar.

http://bikemag.com/news/interbike/giant092404/

The low down on Giant's Maestro. Our rep claims its better than anything ever in the history of the world, but thats his job to think that and make us think that, so I'm a little skeptical. Especially considering Giant's full suspension lineups have been nothing short of awful to date. I will reserve judgement until I get our demo in and can abus... errr... test it. :D

http://bikemag.com/news/interbike/giant_reign1.jpg

Not all their Dual suspensions are awful... What about their DH team and comp.