Forum menu
Thought I read somewhere that dw bikes are designed around specific chainring locations. Does this mean manufacturers should specify whether It's designed for a triple or double?
Indeed.
do they ride differently in say a 42-21 to a 32-16?
That's what I'm wondering. Purely an acedemic question as I ride a HL bike.
You think that's not affected by chain growth?
Slightly OT, but I recently built up my mojo and went 2x10 at the same time by fitting 28/38 chainrings to my triple.
I'm pleased I did this as the chain was rubbing on the lower part of the stay when I originally fitted the crank with th 22 granny on. I could have fixed this but I would have needed to shorten the chain excessively.
Not at all. Just that manufacturers didn't make the same claim of optimisation, which if true, should now bite them on the bottom.
shimano claim the 10s sytem is optimised for full suss bikes due to chainring size.
I found that when I went 1x9 on my maestro bike it pedalled a lot worse in the granny, but I could just be imagining it.
(Maestro being a dw link copy)
continuity - Member
I found that when I went 1x9 on my maestro bike it pedalled a lot worse in the granny, but I could just be imagining it.(Maestro being a dw link copy)
Granny? 1x9?
any bike will pedal differently in different gears as (for instance) you put a lot more tension on the chain in the 22T.
Granny is biggest rear ring. 34 front, 34 back.
noob!
that's a double facepalm!
read this for DWs take on it:
http://dw-link.blogspot.co.uk/2008/10/single-chainrings-and-detrimental.html
Shit; that's fascinating.
The one he links to is even better.
http://www.mbr.co.uk/advice/suspending-beliefs/
Guess it's time to go back to 2x/3x!
1x10 (34T) has been a revelation on my DW 5 spot. I've not noticed any adverse effects but I'm not the most sensitive person.
Weagle seems to say that for bikes that incorporate anti squat; i.e. Maestro, Dw-Link, VPP e.t.c, going 1x means you lose all of that anti squat as soon as you point the bike up a hill.
The designs were meant to have a 2x or 3x drivetrain.
Variable front chainlines are ALWAYS going to be a good thing for mountain bikers who ride their bikes on variable terrains. Without them, suspension bikes might still be considered a bad idea, and I would most likely be riding motocross.
Weagle seems to say that for bikes that incorporate anti squat; i.e. Maestro, Dw-Link, VPP e.t.c, going 1x means you lose all of that anti squat as soon as you point the bike up a hill.
The designs were meant to have a 2x or 3x drivetrain.
So they're so sensitive that climbing in the "middle" (single) ring is inefficient, even if you use a bigger sprocket on the back than you might otherwise ?
Nah, I'm out
You might be asking yourself, “What exactly is “anti-squat”? Anti squat is a force that balances the effects of mass transfer on the suspension, giving the best possible bump compliance, while at the same time providing excellent energy efficiency. There are two forces that combine to create anti-squat; chain pull and driving force. Chain pull force is multiplied through your rear cogs and wheel as a lever creating driving force. Because of this leverage, driving force is always the greater than chain pull force, but both are significant. If you hear someone talking about “chain pull force” without mentioning “driving force” in the next sentence, there is a good chance that they have a bridge to sell you somewhere.OK, now for the tie in! The amount of anti-squat that a suspension can develop is based on (among other things) the angle of the ground that the bike is riding on and the angle of the chainline. It just so happens that as a bike is climbing a hill, the amount of anti-squat drops because the direction of gravity in relation to the bike changes. What this means is that if you are pedalling along in your 32-18 on flat ground and have just the right amount of anti-squat, then start to climb a steep hill, say 15 degrees or so, the amount of anti-squat is going to lessen. It just so happens that moving the chainline downward, say like if you selected your 22T ring, increases anti-squat. In an Apollo 13 like turn of events, people actually use their 22T ring when they climb hills as steep as 15 degrees (you basically have to). The two changing anti-squat amounts balance out, leaving the rider with very similar riding characteristics while climbing in the granny and riding on the flat in the middle ring. Amazing, huh? As you may have guessed, the same goes for descending with a larger ring.
Because of this, chainline variability made some very poorly designed suspension bikes that would have otherwise been unrideable at least reasonably useful enough that people eventually tinkered away and arrived at bikes that performed well enough for suspension to become a reality for the masses.
Variable front chainlines are ALWAYS going to be a good thing for mountain bikers who ride their bikes on variable terrains. Without them, suspension bikes might still be considered a bad idea, and I would most likely be riding motocross.
I design for optimization in the middle ring in the flats and light climbs, granny for the big climbs, and big ring for the descents. There is a lot of overlap there.
So
anti-squat ... is based on ... the [b]angle[/b] of the chainline
CBA to measure it but I doubt there's much difference between the angles of 32/36 and 22/25 (broadly equivalent gears)
I'm missing something, aren't I ??
What all that means is that Mr DW's bullshit smells the same as every other bike designers 
If you can get away with 1x10 for where and how you ride then go for it... it really will make SFA difference to how your suspension works... how are a few mm or degree's going to matter on a bike thats being being ridden around by an evolved monkey 🙄
He means the angle of the chainline in relation to gravity you monkey.
Is that affected by something other than the angle of chainline on the bike and the angle of the bike to level groundHe means the angle of the chainline in relation to gravity you monkey.
pass us a banana ?
They're independant but coincide.
If you have a smaller front ring, and switch into it, the levering force produced by the front ring on the rear cog is reduced, therefore creating less squat.
Up a hill, the force of gravity in relation to the suspension reduces the amount that the suspension acts to counter squat.
Luckily, when you go up a hill, you change into a smaller front ring.
Therefore, you don't experience a big loss in anti squat.
Would you like that fairtrade or organic?
Isn't he just saying that It's a fluke that when the ground points down, the chainline angle compensates by going up? Therefore remaining about the same relative to ground?
If you have a smaller front ring, and switch into it, ..... (as compared to the middle ring)
Only if you keep in the same rear cog each time though - isn't that a daft comparison ?
Maybe I've made a pigs ear of it.
Say you're cycling along in 32t front 22t back. You get to a hill, you switch to 22t front, 22t back.
When you shift from the middle (on the flat) to the small, the angle that the chainline attempts to pull the cog at is closer to horizontal than if it were in said middle.
This means that the levering force on the rear cog, and therefore the levering force on the rear suspension acts to create less chain pull force (i.e. less movement in the suspension).
and what if I go to 32/32 instead ?You get to a hill, you switch to 22t front, 22t back.
Nothing. Same angle.
Maybe it has to do with the increased leverage force of a 32 front?
I.e. 32/32 places more torque on the cassette and so suspension than 22/22.
And if you use an Alfine you have no hope 🙁
When you shift from the middle (on the flat) to the [s]small[/s][u]granny[/u], the angle that the chainline attempts to pull the cog at is closer to horizontal than if it were in said middle.
FTFY
I ran an alfine on a floating link (Giant trance / maestro) and noticed nob all difference to the 3x9 setup.
I found that my trance pedalled worse in a 34/34 than it ever did with a double. It would even bob if I was cycling up a road incline whilst seated.
And I noticed this before I read the article. Weird.
It's all irellavent anyway as bad pedaling technique has a far greater effect on pedal bob than any pivot or gearing ratio.
That doesn't make it irrelevant, and I'm pretty sure there were a load of pieces of research out a while back that suggested that the natural instinctive pedalling technique turned out to be biomechanically efficient.
We're talking in a like-for-like situation; e.t.c seated, spinnning.
There was also discussion in one of the American mags a while back about climbing being harder with adjustable forks wound down. Does this also relate to chain vs incline angle?
Actually that would be the opposite; wound down forks levels out the effect gravity has on the suspension and so makes it easier.
Does your system bob - yes
Does your system bob a lot - depends how much you're mashing the pedals
Does your system really make that much difference - insert nano engineer bs
That was the science, practice said different, hence the discussion.
Link to it?
[url= http://www.ridemonkey.com/forums/f19/adjustable-fork-causes-drag-228968/ ]linky[/url]
kinked hydraulic cables 😆
I was expecting something with a bit more weight to it; I'm not sure that has anything to do with it. STA issue, but not to do with suspension kinematics.