suspension types ?

bluechair84

I think the i-drive and freedrive work much better on shorter travel bikes, where you are the kind of rider who sits through stutter bumps and your body weight on the saddle 'activates' the rear end. When you stand, it stiffens up allowing you access to a much more direct power transfer to the rear wheel.
But I'd love to see how it translates in a 9" rig :shock:

I'm only referring to the Intense 5.5VPP as that's where my experience lies.

Anonymous

Yeah, Josh, I agree with everything apart from the "channel the forces to somewhere that inst going to effect the feel of the bike, or waste energy in the shock" thing.
The chain forces WILL affect the wheel one way or another, and it will either extend the suspension, or it will compress the suspension. Even keeping the chain length constant doesn't work because not only will there still be tendency for the suspension to react anyway, but there are also the drive forces of the rear wheel pushing forwards against the ground, effectively "trying" to reduce the length of the bike.

The Kona brake arm thing is, frankly a load of twaddle.

Basically there's two reasons for the brakes to affect the suspension, and I believe that one of them vastly outweigh the effects of the other, to the degree that it can be ignored.
I firmly believe that the fundamental reason for brake reaction is the rear wheel extending rearwards to extend the wheelbase of the bike, and that the action is strong enough to overcome any geometric forces.

joshtp

OK... so braking forces are hard to deal with.... although the ABP Trek use is good.... But pedalling forces..... Stuff like the DW link are very effective! And the I-Drive system is awesome! Although, as we disused, it does have its negatives.

supersonic

'Plushness', as I understand it, is how smooth the suspension feels when it is moving, rather than how it reacts. This is down to the quality of the bearings and shock. Though smaller leverage ratios can offset some issues with shocks.

VPP - as Yeehaa says, is totally to do with where the VPP is, and how it moves (if it moves). Horst link is in essence a VPP. But here's the rub. If the VPP of a system is in the same place as the pivot in a single pivot bike, then they will behave EXACTLY the same under acceleration and pedalling.

joshtp

supersonic wrote:

'Plushness', as I understand it, is how smooth the suspension feels when it is moving, rather than how it reacts.

Quite.... Plushness and suppleness are different things. Supple is the ease with wich the fork or bike absorbs small hits and bumps... a very supple bike gives a very smooth ride over small stuff and feels "floaty" a plush bike is a very smooth one, one that has a very smooth, seamless, effortless stroke. My mates Scott ransom isn't particularly supple, but it is phenomenally plush... He also has a White 46, and that's just everything... Awesome

bluechair84

Is there such a thing as a bike with an adjustable pivot location (to the user), so that we could choose to have a constant chain length (i suppose this would only be realistic in a particular gear) rather than adjustable leverage ratio on the shock like the older Marins.

I'm wondering if it would be possible to choose between improved pedelling efficiency or plushness. I guess it's all done in the shock now by choosing a level of pedal platform.

poppit

How about a SC Blur LT Carbon with a 160 fork? VPP suspension.

joshtp

bluechair84 wrote:

Is there such a thing as a bike with an adjustable pivot location (to the user), so that we could choose to have a constant chain length (i suppose this would only be realistic in a particular gear) rather than adjustable leverage ratio on the shock like the older Marins.

I'm wondering if it would be possible to choose between improved pedelling efficiency or plushness. I guess it's all done in the shock now by choosing a level of pedal platform.

nice idea... would be a total mission to put into reality though. However... lots of bikes have different shock mount holes for diff travel settings... so maybe different linkage pivot holes for different feel?!?!

supersonic

bluechair84 wrote:

Is there such a thing as a bike with an adjustable pivot location (to the user), so that we could choose to have a constant chain length (i suppose this would only be realistic in a particular gear) rather than adjustable leverage ratio on the shock like the older Marins.

I'm wondering if it would be possible to choose between improved pedelling efficiency or plushness. I guess it's all done in the shock now by choosing a level of pedal platform.

Is an interesting idea, and one we might see in the future. In essence this is what DWs axle path tries to achieve - as it moves through the travel, the amount of anti squat lessens. Also MArin Quad.

Anonymous

Also SC's VPP

supersonic

It's a funny bugger SCs, I'll get some pics up of the path and anti squat curves.

Anonymous

joshtp wrote:

OK... so braking forces are hard to deal with.... although the ABP Trek use is good.... But pedalling forces..... Stuff like the DW link are very effective! And the I-Drive system is awesome! Although, as we disused, it does have its negatives.

The trouble with calculating something like braking force is that all your fields of reference move simultaneously.
As the bike pitches forwards under deceleration, the rear wheel loses some traction with the ground, reducing it's dragging effect, AND of course, the amount of braking power available.
On top of that, the rider's weight transfer comes into the mix, as does the geometry of the frame, since the front fork will also react, and compress.
On top of this, the rear wheel will move in the travel to keep in contact with the floor.
Every one of these affects also affects everything else, making it incredibly hard to come up with a mathematical simulation that will take everything into account. It is well beyond my scope (and free time ).
Whilst I do not believe that it is beyond the scope of someone like Dave Weagle, John Whyte or Ian Alexander, you have to bear in mind that they are trying to actively market their own solutions, so will not mention everything, or will push their method as the best solution.

Anonymous

supersonic wrote:

It's a funny bugger SCs, I'll get some pics up of the path and anti squat curves.

You mean the almost s-shape wheel path?
The quad-link system has a similar, yet more pronounced path.

Anyway, all modern suspension systems have advanced to a state where they all perform admirably, and it is down to the rider to pick a favourite.
There are no real stinkers out there any more (cough, with the notable exception of Kona's shullbit "Magic Link" )
(I kid, partially, of course )

bluechair84

supersonic wrote:

If the VPP of a system is in the same place as the pivot in a single pivot bike, then they will behave EXACTLY the same under acceleration and pedalling.

Any idea where the pivot location on a Mojo is? If it's the same as a 5 then it seems awefully expensive... Though they don't make a carbon Orange.

supersonic

I can find out. Small differences can be quite marked, and of course, depends if it moves.

Some anti squat curves:

joshtp

yeehaamcgee wrote:

(cough, with the notable exception of Kona's shullbit "Magic Link" )
(I kid, partially, of course )

It's not that bad! It has its drawbacks... and isnt all they crack it up to be... but its still very clever, and very innovative... Good on them for trying I say... After all Kona aren't really known for their FS innovation.... They do good Ht's and DJ/slopestyle bikes... but for trail bikes and DH they struggle.

supersonic

Mojo HD:

Anonymous

Give a close up of the Mojo's axle path, Sonic.

supersonic

bluechair84

Also - how do you know where the pivot location is on the diagram? Is it the right hand tiips of those amassed wheel path lines? The line tips that are pretty close to the pivot location of a 5?

Anonymous

Hmm, very mundane really :?
It's looks at first glance like a single pivot path, but slightly exaggerated.

supersonic

The anti squat curve shows more clearly though what is happening - pretty linear regression from 100% to 0%

The Orange 5 is very different from the Mojo! The red curve above the crank shows the pivot position migration.

delcol

wow this has got way to technical for me,,,,

ok a nomad would be to simlar to my demo 7 (ie another 7 inch travel bike) granted it will pedal alot better than the demo, but i set my mind on a 160 mm bike.....

i would have to check but i'm sure the blur lt is only 140mm rear wheel travel, which in my opinion is not enough travel for what i want,, i think the head angle is not slack enough, (but would have to check on that)

to my original question, i was just wondering how the 3 different bike i listed would differ (to ride) based on the their design,,

as someone mentioned about the orange 5 and commoncrack meta both are single pivot but one is linkagge driven,, so again would the app (linkage driven single pivot) be better than my hecklers single pivot..

delcol

ooops i just checked the nomad is an 160mm i thought it was 180mm :oops: :oops:

may be there's another possability...

supersonic

The Nomad may not pedal better - have to test really!

Linkage driven single pivots allow the designer to tune shock rate and leverage ratios. May feel better, or to some worse! Is all about feel to you.