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Sandwich

Pig my fish!
Staff member
May 23, 2002
21,031
5,920
borcester rhymes
Frame Size S M L
A Wheel Base 117.4cm*
46.2" 117.4cm*
46.2" 117.4cm*
46.2"
B Chain Stay 46.9cm
18.5" 46.9cm
18.5" 46.9cm
18.5"
C BB Height 36.8cm
14.5" 36.8cm
14.5" 36.8cm
14.5"
D Head Angle 65° 65° 65°
E Top Tube 61.7cm
24.3"
F Seat Angle 68° 68° 68°
G Size 51.7cm
20.35" 51.7cm
20.35" 51.7cm
20.35"
H Stand Over 80.0cm
31.5" 80.0cm
31.5" 80.0cm
31.5"

18.5" chainstays that will probably grow >2". Dear God, why?
 

norbar

KESSLER PROBLEM. Just cause
Jun 7, 2007
11,346
1,587
Warsaw :/
Frame Size S M L
A Wheel Base 117.4cm*
46.2" 117.4cm*
46.2" 117.4cm*
46.2"
B Chain Stay 46.9cm
18.5" 46.9cm
18.5" 46.9cm
18.5"
C BB Height 36.8cm
14.5" 36.8cm
14.5" 36.8cm
14.5"
D Head Angle 65° 65° 65°
E Top Tube 61.7cm
24.3"
F Seat Angle 68° 68° 68°
G Size 51.7cm
20.35" 51.7cm
20.35" 51.7cm
20.35"
H Stand Over 80.0cm
31.5" 80.0cm
31.5" 80.0cm
31.5"

18.5" chainstays that will probably grow >2". Dear God, why?


Not to mention an idler below the main pivot point. WHY? It's like an exibition of bad bike design.
 

UiUiUiUi

Turbo Monkey
Feb 2, 2003
1,378
0
Berlin, Germany
Not to mention an idler below the main pivot point. WHY? It's like an exibition of bad bike design.
the idler is the one and only idea on that contraption that might actually be worth something.
yes there will be pedal feedback, but with this kind of construction you can influence that feedback.
might be worth a shot.

anything else on that bike is just wrong...
 
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norbar

KESSLER PROBLEM. Just cause
Jun 7, 2007
11,346
1,587
Warsaw :/
honestly i think the idler is the one and only idea on that that might actually be worth something.
yes there will be pedal feedback, but with this kind of construction you can influence that feedback.
might be worth a shot.

anything else on that bike is just wrong...
Looking at it again yeah maybe but still there are better options out there.
 

Pslide

Turbo Monkey
It would look kinda cool if you ditched the saddle and integrated some padding into the gray seat tower...

Can someone explain to me why everyone thinks having more weight down by your feet is better than having it in between your knees? Or is it just that kool-aid tastes so sweet?
 

Sandwich

Pig my fish!
Staff member
May 23, 2002
21,031
5,920
borcester rhymes
The thing with the idler...in its current guise, wouldn't it actually contribute to suspension squat? I mean, it looks like torque would pull the idler down...which is going to push the swingarm up, right? Maybe the leverage is so that it doesn't have much of an effect, but it certainly looks like bad news.

As for low COG, I agree and disagree. I don't think too many people are concerned over wobbling a bike back and forth between their knees, but I can't see any reason not to centralize weight and packaging. It seemed to provide a great feeling on my brooklyn, but there was plenty of weight to go around there.
 

Huck Banzai

Turbo Monkey
May 8, 2005
2,523
23
Transitory
Another soul damaging vehicle brought to you by the Sandwich.

Next bike post should involve multiple shocks or discs, or generally extraneous parts (more so than 13 pivots)
 

iRider

Turbo Monkey
Apr 5, 2008
5,648
3,089
They probably looked at the other companies that made bikes more complicated than they need to be and had great success with it.
Specialized -> moar chainstays
Knolly -> moar links
Evil -> moar leverage ratios
Scott -> moar bigger linkages
GT, Lapierre -> moar floatingBBlinkdogbone

So, why not moar higher pivot point and moar moving idler? :D ;)
 

troy

Turbo Monkey
Dec 3, 2008
1,006
739
Not to mention an idler below the main pivot point. WHY? It's like an exibition of bad bike design.
1st : due to very high pivot location this frame has a lot of anti-squat built in.
2nd : idler is moving towards the rear axle (it ain't fixed) , so you probably won't feel any pedal feedback.
3rd: cs lenght on that thing is ridiculous
 
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norbar

KESSLER PROBLEM. Just cause
Jun 7, 2007
11,346
1,587
Warsaw :/


16 pistons, carbon rotors, alloy hats, on a fork with dual external reservoirs? This is like an m4 with tactical-testicles.
That was only a showroom bike. The carbon rotors had more flex than a piece of paper.

@Pslide it is better but by such a small fraction it is not noticeable.
 

CrabJoe StretchPants

Reincarnated Crab Walking Head Spinning Bruce Dick
Nov 30, 2003
14,163
2,484
Groton, MA
It would look kinda cool if you ditched the saddle and integrated some padding into the gray seat tower...

Can someone explain to me why everyone thinks having more weight down by your feet is better than having it in between your knees? Or is it just that kool-aid tastes so sweet?
Lower COG = better stability. It's not Koolaid, it's physics.
 

Pslide

Turbo Monkey
Lower COG = better stability. It's not Koolaid, it's physics.
Oh Physics, that's what it's called! Cheers!

True, lower COG does equal better stability. But your physics will have also taught you that a low COG requires higher lean angles and will initiate a corner slower than a high COG. True story.

I'm not saying high COG is better. But I don't say that low COG is necessarily better either. It comes down to rider preference in how he likes his bike to feel. I ride a low COG bike (Legend) and I don't think the COG is giving me any advantage over say a GT Fury with a high COG. And I doubt there are any GT Fury riders that say their bike is unstable or "damn, I wish my COG was lower."
 

troy

Turbo Monkey
Dec 3, 2008
1,006
739
Moving shock from seattower to bb area, changes frame cog around 2" down. Arguing about that is simply stupid, you are not even taking into consideration rider mass...
 

CrabJoe StretchPants

Reincarnated Crab Walking Head Spinning Bruce Dick
Nov 30, 2003
14,163
2,484
Groton, MA
Oh Physics, that's what it's called! Cheers!

True, lower COG does equal better stability. But your physics will have also taught you that a low COG requires higher lean angles and will initiate a corner slower than a high COG. True story.

I'm not saying high COG is better. But I don't say that low COG is necessarily better either. It comes down to rider preference in how he likes his bike to feel. I ride a low COG bike (Legend) and I don't think the COG is giving me any advantage over say a GT Fury with a high COG. And I doubt there are any GT Fury riders that say their bike is unstable or "damn, I wish my COG was lower."
 

CrabJoe StretchPants

Reincarnated Crab Walking Head Spinning Bruce Dick
Nov 30, 2003
14,163
2,484
Groton, MA
Moving shock from seattower to bb area, changes frame cog around 2" down. Arguing about that is simply stupid, you are not even taking into consideration rider mass...
You have to remember these bikes are being made for riders that will say a crankarm 5mm too short or a handlebar .25" too wide will make or break a podium finish.


Reason and logic can't be applied to racers and their gear selection.
 

CrabJoe StretchPants

Reincarnated Crab Walking Head Spinning Bruce Dick
Nov 30, 2003
14,163
2,484
Groton, MA
And on a side note, the COG of the bike itself is indeed important, mainly how a bike handles in the air. Let me strap a 10lb weight to your BB shell and have you hit a 20' double, then strap the 10lb weight to the seatpost and have you hit the double again. Tell me which is more stable and flies straight. Obviously that's an exaggeration of the effects the shock has on the COG, but the principle is the same. And like I said in my last post, racers are a (overly) picky bunch sometimes.
 
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troy

Turbo Monkey
Dec 3, 2008
1,006
739
Yeah, like every1 here and 99% of customers are racers :) and why not strap 100lb weight to my bb shell? Cmon man... i'm not saying that it has no influence. It has some, but very very small imho.
 

CrabJoe StretchPants

Reincarnated Crab Walking Head Spinning Bruce Dick
Nov 30, 2003
14,163
2,484
Groton, MA
Yeah, like every1 here and 99% of customers are racers :)
Right, because all consumers buy all their possessions based on their absolute bare needs and personal requirements. :rolleyes: Next time I see a guy driving a Porsche, I should assume he's a racecar driver, right?

and why not strap 100lb weight to my bb shell? Cmon man... i'm not saying that it has no influence. It has some, but very very small imho.
Yea......that's exactly what I just said...
 
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norbar

KESSLER PROBLEM. Just cause
Jun 7, 2007
11,346
1,587
Warsaw :/
You have to remember these bikes are being made for riders that will say a crankarm 5mm too short or a handlebar .25" too wide will make or break a podium finish.


Reason and logic can't be applied to racers and their gear selection.
You missed his point. 2'' in terms of bike CoG is nothing compared to real changes in rider + bike cog. You could probably gain more with a 5mm longer stem that lowers your chest a bit.


As for bike handling in the air - yes it matters but again - you would need a big difference to feel it. I'm with Troy on that.
 

CrabJoe StretchPants

Reincarnated Crab Walking Head Spinning Bruce Dick
Nov 30, 2003
14,163
2,484
Groton, MA
You missed his point. 2'' in terms of bike CoG is nothing compared to real changes in rider + bike cog. You could probably gain more with a 5mm longer stem that lowers your chest a bit.


As for bike handling in the air - yes it matters but again - you would need a big difference to feel it. I'm with Troy on that.

I was never talking COG in terms of bike + rider. Hell, at 240lbs, nothing I put on my bike/take off my bike matters to me in terms of COG and how it feels on the ground.

I DO notice how my bike handles in the air with slight weight redistribution, however. I think most people on here would agree.
 

Pslide

Turbo Monkey
Rather than explain the physics behind this, which I'm not sure I can do, I'll give you a real life test. Take a fast corner, hit it Sam hill style, standing proud with high COG. You'll find the bike turns in quickly. Now hit it again, but tucked Steve peat style. Not only will the bike not turn in as easily, but you'll need to give the bike more lean angle. No particular style is quicker, that's governed by other factors. But you don't see too many motocross riders trying to lower their COG in corners do you?

PS - this has been known, although not necessarily well understood, in motorcycle dynamics for a while now. Although most of the study centers around road racing, where things are a bit different and low COG does help.
 

CrabJoe StretchPants

Reincarnated Crab Walking Head Spinning Bruce Dick
Nov 30, 2003
14,163
2,484
Groton, MA
Rather than explain the physics behind this, which I'm not sure I can do, I'll give you a real life test. Take a fast corner, hit it Sam hill style, standing proud with high COG. You'll find the bike turns in quickly. Now hit it again, but tucked Steve peat style. Not only will the bike not turn in as easily, but you'll need to give the bike more lean angle. No particular style is quicker, that's governed by other factors. But you don't see too many motocross riders trying to lower their COG in corners do you?

PS - this has been known, although not necessarily well understood, in motorcycle dynamics for a while now. Although most of the study centers around road racing, where things are a bit different and low COG does help.
You're forgetting one critical element.......traction. Ever notice how Sam Hill tends to drift more than other guys? That higher COG is causing him to lose a bit more traction.

And the moto analogy is pretty much useless as they have motors. Need a bit more speed through that corner? Twist that throttle. COG, traction and speed are a lot more closely related and dependent on one another in gravity-governed situations (downhill racing).

Read this (ironically done by students from the college I went to):

http://simplerobotics.org/Center_of_Gravity.htm
 
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