what should be the difference between single pivot and 4bar?

Anonymous

finally managed to ride the edison, it is so good it would make your head spin.

now, i was expecting the single pivot to feel completely different to the fsr it has replaced, but it doesnt feel massivly different.

it is a much better bike to ride than the stumpjumper was but i think this is more to do with the fact that i like a slack bike with longer travel than 120mm. its also about 3 lbs heavier than the stumpy was but it is so much nicer to ride even though its a chunk heavier.

the drive feels more direct, if i hammer into the cranks the shock doesnt seem to move too much although i am using the shock in the highest compression setting, it moves all over the place when i reduce the LSC to the lowest setting.

so, what is the point of single pivot compared to 4bar and what should i be able to notice in comparison?

supersonic

There was a gert big thread on this not so long back, worth hunting out.

Also we did a big tech article in WMB that explains it.

But it depends on the pivot points. If you give me the exact models of the bikes you have, I'll look into the details and sum up the theory.

Anonymous

A bit of a generalisation, but a single pivot should suck less power out of your pedalling than an FSR. FSRs require complicated shock setups to be anywhere near equivalent to more modern designs, since they don't use chain growth to counteract pedal induced suspension squatting.
Also, given the ligthweight nature of the stumpy, you would probably notice the stiffer back end of the Bionicon.

*AJ*

Ive had both and much prefer the single pivot design of my patriot over my old GT.

The GT was very plush and very active, it soaked up everything.

The Patriot rides much more like my hardtail, only has 6" of travel for when i need it. It rails berms and jumps a lot better than the GT did as that lost most of the 'feeling'

bluechair84

I learnt recently on a thread here that the differences between multi pivot and single pivot bikes come down to the way the shock is driven, and less to do with the suspension design itself. Thinking about it, it makes sense because the rear wheel's path troughout its travel reeeaaally can't be all that different from bike to bike. And over such a variety of terrain, a slight rearward path compared to a slight forward path would be useful at different stages of your route.

Anonymous

Actually, the advantage of a true VPP system is that the wheel path DOES change through the travel, to behave differently under different conditions.
So you could have a nice rearwards axle path to absorb bumps nicely early on, giving some chain growth, to combat bobbing, then in the mid stroke, the chain length could remain constant, giving less pedal kickback over bigger hits, then in the last stage, you could agian have more chaingrowth to assist in reducing the bottoming out impact, for example.

As far as I know, not a single FSR design achieves anything like that though.

andyrm

I told you it was a beast! Hard to quantify exactly but my edison feels a lot more active than my bird's fuel ex8. Definitely agree about the stiffer rear end, the dropouts alone are huge.

Anonymous

i did notice that about it physically, the rear triangle is a whopper, each of the tubes is a fair bit thicker than even the enduro's back end but i cant really feel it being stiffer.

the ride does feel different in as much as the drive feels more direct, you can look down at the shock and see it barely moving as i thump along yet over rougher stuff it smooths everything out, which is what i want from my full sus.

of course the variable adjust is the absolute best thing about the bike and i can already see the edison replacing the enduro (if it wasnt for the fact i love it so much)

i was concious that i should have thought harder about buying a different style of sus but it turns out that it is really good.

supersonic

Basically the edison should have more antisquat, and feel more direct under power. You may notice in certain gears, and on big hits, the pedals kicking back though.

Anonymous

supersonic wrote:

Basically the edison should have more antisquat, and feel more direct under power. You may notice in certain gears, and on big hits, the pedals kicking back though.

i have definately noticed that the drive feels noticeably more direct, i didnt even know that it felt soggy on the stumpy but in comparison, it did a bit.

by pedal kickback do you mean the pedals will try to rotate backwards?

Anonymous

Sort of, yes. The chain length increases, which tries to ever so slightly rotate the cranks backwards.
But, in reality, what will happen (especially with a hefty rider) is that the front wheel will be driven forwards.
If you are pedalling though, it will feel like a little extra resistance, something like your brake pads dragging slightly - when you hit a decent sized bump.

Anonymous

that was going to be my next question:

if the pedals are going to attempt to rotate backwards, how would it behave due to my enormous mass forcing them downwards, id imagine i would win the fight between kickback and gravity.

if it happens during pedalling will it feel like a jolt through the pedals of more like a bit of extra resistance?

Anonymous

Depends on the bike. Personally I've never felt a jolt, but as you know I'm no lightweight either.
I've only ever felt a slight resistance.

On my old single pivot bike, another thing happend when pedalling over larger hits, and I think it's more to do with the wheel path, rather than chain growth. If you were pedalling, it would feel temporarily as though the rear end was sprung more heavily, or as if the suspension just wasn't at it's most active.
It wasn't a problem, and if you'd only ridden that bike you may well be unaware of it, but seeing as you're coming from an FSR to the Bionicon, you may well notice it.

bluechair84

yeehaamcgee wrote:

Actually, the advantage of a true VPP system is that the wheel path DOES change through the travel,So you could have a nice rearwards axle path to absorb bumps nicely early on, giving some chain growth, then in the mid stroke, the chain length could remain constant

I know that the s curve of the path is designed to work differently at different stages of it's travel to counteract the likely terrain you are on - but I can't imagine the actual path differing greatly.

Supersonic, that Linkage program of yours, could it show the axle path of a single pivot and a VPP with an S-shape curve for comparison? Ideally from two bikes with similar amounts of travel - a 5.5EVP and an Orange 5 would be interesting.

Anonymous

The actual path does differ significantly though, since the virtual pivot point moves. Most don't describe an s curve, but they describe very different curves to a fixed, single pivot.