Quantcast

"Aaron Gwin chainless world cup winning run, the mystery explained "

jaydub69

Chimp
Dec 8, 2006
4
1
NV
just gonna help you out here with a sincere response-- the wheel going up and down in travel is stretching the chain out, since there is a non-concentric pivot between crank and wheel. There is room for the chain to grow in the derailleur pulleys, but the crank or wheel has to rotate to accommodate that, which takes energy. Net result is that the bike does move through travel differently without a chain. Try it.
When coasting (freewheel is clicking), the chain does not affect the suspension. Words from an actual bicycle engineer but RM armchair engineers know all.
 
Last edited:

Flo33

Turbo Monkey
Mar 3, 2015
1,058
352
Styria
When coasting (freewheel is clicking), the chain does not affect the suspension. Words from an actual bicycle engineer but RM armchair engineers know all.
And as soon as the chain stay length is increasing due to travel being used what's happening with the chain? Right, there will be tension causing the freewheel to engage with hub stopping the clicker-di-cluck coasting and affect the sus, moar or less, depending on the amount of lengthening.
 

Flo33

Turbo Monkey
Mar 3, 2015
1,058
352
Styria
and yet, no one genuinely fast really gives a fuck!
Tell this SH or AG right after their initial switch to the big S...

It's a myth that the fast guns don't care about their stuff and how it works and that they are fast either way.
 
When coasting (freewheel is clicking), the chain does not affect the suspension. Words from an actual bicycle engineer but RM armchair engineers know all.
My armchair is pretty comfy-- it supports my arms to browse ridemonkey anyway. What about when not coasting, like a locked up rear brake?

I get that there's trivial binding if wheel rpm is faster than cassette rpm when the suspension compresses.. However if something like hitting a rock causes the suspension to compress quickly enough relative to bike speed:

1. You wouldn't know if hub pawls are engaged for a fraction of a second
2. The suspension will resist having to either push the bike forward, spin the tire against the ground, or pick the rider up by the crank
3. There's "pedal kickback" that you can feel on high pivot bikes, so I'm going to skip the force diagram and rely on anecdotal evidence

If you can show with math that there are no instances in a downhill race where the suspension could be bound by the chain I'll be curious to see. Someone should probably already have it around in a notebook of actual bicycle engineering
 
Last edited:

slimshady

¡Mira, una ardilla!
Dec 20, 2007
2,561
660
La Plata, Argentina
My armchair is pretty comfy-- it supports my arms to browse ridemonkey anyway. What about when not coasting, like a locked up rear brake?

I get that there's trivial binding if wheel rpm is faster than cassette rpm when the suspension compresses.. However if something like hitting a rock causes the suspension to compress quickly enough relative to bike speed:

1. You wouldn't know if hub pawls are engaged for a fraction of a second
2. The suspension will resist having to either push the bike forward, spin the tire against the ground, or pick the rider up by the crank
3. There's "pedal kickback" that you can feel on high pivot bikes, so I'm going to skip the force diagram and rely on anecdotal evidence

If you can show with math that there are no instances in a downhill race where the suspension could be bound by the chain I'll be curious to see. Someone should probably already have it around in a notebook of actual bicycle engineering
Antonio Osuna has a good analisis of the pedal kickback/square bump interaction here: http://linkagedesign.blogspot.com/2015/07/angulo-de-ataque-wm.html

TL/DR: Rock Jeebus is a helluva rider.
 

kidwoo

Celebrating No-Pants Day
Aug 25, 2003
22,013
1,694
In my pants
you guys realize that when you are coasting, the chain has no affect on your suspension. It only has affect if your pedaling. Science!

Yeah I was due for a new sig. This is easily as funny as anything else I've ever used.
 

HAB

Chelsea from Seattle
Apr 28, 2007
10,493
848
Seattle
When coasting (freewheel is clicking), the chain does not affect the suspension. Words from an actual bicycle engineer but RM armchair engineers know all.
Who does this engineer work for?

You know, so I can not buy one of their bikes. ever.
 

Mo(n)arch

Turbo Monkey
Dec 27, 2010
4,164
1,087
Italy/south Tyrol
Tell this SH or AG right after their initial switch to the big S...

It's a myth that the fast guns don't care about their stuff and how it works and that they are fast either way.
Well, Sam was actually fast when he got on Specialized. He won the overall that year. After that he smashed his shoulder into earth a few times but managed inbetween to win the world champs in MSA.
 

rbx

Monkey
Well, Sam was actually fast when he got on Specialized. He won the overall that year. After that he smashed his shoulder into earth a few times but managed inbetween to win the world champs in MSA.
I hope im not highjacking this thread..
I find it interesting that a guy can win on a bike that has virtually no anti-squat (even has pro-squat).
But at the time that low anti-squat/low pedal-feedback feature lets Gwinn get in some pedal strokes in the rough sections so gaining some time..
So suspension design is not just getting 100% anti-squat.(what seems to be driving the suspension designer right now)
 

slimshady

¡Mira, una ardilla!
Dec 20, 2007
2,561
660
La Plata, Argentina
I hope im not highjacking this thread..
I find it interesting that a guy can win on a bike that has virtually no anti-squat (even has pro-squat).
But at the time that low anti-squat/low pedal-feedback feature lets Gwinn get in some pedal strokes in the rough sections so gaining some time..
So suspension design is not just getting 100% anti-squat.(what seems to be driving the suspension designer right now)
I'm finding much more babble about square bump absorption these days than anti-squat arguments. At least in press releases and infomercial sites such as Pinkbike.
 

Flo33

Turbo Monkey
Mar 3, 2015
1,058
352
Styria
I hope im not highjacking this thread..
I find it interesting that a guy can win on a bike that has virtually no anti-squat (even has pro-squat).
But at the time that low anti-squat/low pedal-feedback feature lets Gwinn get in some pedal strokes in the rough sections so gaining some time..
So suspension design is not just getting 100% anti-squat.(what seems to be driving the suspension designer right now)
Therefore I'm really curious how that Pole Rinne Ylä behaves, would love to ride one in a direct comparison to one of the anti squat wonders.