[Closed] dw link bikes with dual chainring set ups

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.

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

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.

He means the angle of the chainline in relation to gravity you monkey.

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)

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).

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.

The MBA stuff was quite involved but I can't find the links now. It was discussed on here last year as well.

You got two things (claimed) used to prevent bob, assisted by chain growth and rider/bike kinematics.

Gearing has a direct impact on chain growth, hence anti-bob or squat.

On the subject of marketing and whatnot, kinematic reasons are typically BS. All that has really been manipulated is chain growth.

When designing for the kinematics, it all hinges on the riders COG, of which is virtually impossible to determine, it's always changing, people are different heights, ride in different positions, ride in the saddle, ride out of the saddle, it's purely chance whether the designer has the correct COG location for 1 in 100.

Science in the bike industry 😆

I also agree that gear choice means diddly squat in the grand scheme of things in comparison to pedalling technique.

As for the wind down forks altering kinematics, it will, due to changing the IC and COG locations and altering their interactions. Dependant on frame design/rider, it may be beneficial, it maybe detrimental.

I.e. 32/32 places more torque on the cassette and so suspension than 22/22.

No, think about it backwards if it's easier, there's a constant power and speed at the rear wheel regardless of gear choice, therefore a constant energy/time, and as energy is force * distance) a constant force at the tyre, so a constant torque on the wheel, therefore a constant torque at the cassette.

So 33-33 is the same as 22-22 just with 50% more tension on a 33% smaller lever.

Then if you think of it as a parralelogram with the BB and hub providing the reaction forces via the chainstay in compression the whole caboodle stops making sense (well in my mind anyway)

So what is dave weagle talking about, and why does my giant squat in the granny when spinning gently up tarmac inclines since I went 1x9 when it barely moved at all when I had a front granny?

Because you don't have a granny in a 1x9

I dunno, I'd guess becasue in a 1x10 you have to mash the pedals at a lower cadence rather than spin?

I think that he has a point if you assume the rider is always in the 32t at the back and just shifts the front gear, which changes the angle the chain pulls at, but if your strong enough to push whatever gear your in at a reasnoble cadence then I reckon it shouldn't make any difference.

Bessides, I went 1x10 to gain ground clearance and reliability not the ability to pedal uphill.

Dave is on about paper maths and physics not real life maths and physics.

Your giant squats when running middle big more than small big because the chain is in a different place which has an effect on how and where the floating pivot acts. It's ALSO because you're more likely to be moving your CoG about as you put more force through the pedals.

So what is dave weagle talking about, and why does my giant squat in the granny when spinning gently up tarmac inclines since I went 1x9 when it barely moved at all when I had a front granny?

I don't understand what you are saying. You seem to contradict yourself. Pedaling up tarmac in the granny it squats. Then you say you went 1x9 but it doesn't squat in front granny gear. Makes no sense at all.

He's using the term granny for the lowest gear at the back unlike the rest of us who use it as a term for the lowest gear at the front

So what is dave weagle talking about, and why does my giant squat in the granny when spinning gently up tarmac inclines since I went 1x9 when it barely moved at all when I had a front granny?

Maestro is not his design, it just impinges on his design, so you can't blame him for your Giant's performance.

shirly its all to do with the poition of the main pivot (theoretical or actual) relative to teh chainring.

if you are in the granny and its lower than the main pivot you get anti squat

if its above (bigger chain ring than designed for)you get the opposite.

therefore if you climb with a bigger chainring it feels more porridgy.

then again you could set your shock up to deal with this/eat less/have a dump/ one less beer the night before which may affect the ride more.

Thank you for your enlightening and not-vitriolic-at-all reply Turnerguy.

The net result seeming to be: 1x drivetrains ruin the anti-squat capabilities of suspension design, so go 2x.

Thank you for your enlightening and not-vitriolic-at-all reply Turnerguy.

that's ok - not sure I can anything vitriolic in it - you can't cast aspersions on Dave Weagle's comments based on someone else's design, that is all I am saying.

If you'd read his comments it might be cleared. His claim is that any suspension design whatsoever suffers, my trance just happens to be one that is similar to dw link.

I rode a Trance X in a back-to-back comparison with a 5-spot, both climbing a steep flat road and some normal terrain.

Although I thought the suspension didn't work as well I didn't notice it having trouble climbing, unlike the single-pivot designs I also tried.

Plus the number of 5-spots and trances with single rings plus a bash must be significant now and I have never seen a comment about a 5-spot squating or bobbing, and only ever some about bob on the maestro system.

Maybe your setup is suboptimal somewhere. Can you find another Trance to compare?

I'm sure there are a lot of other factors that may have affected how my trance was pedalling. I was merely using my trance as anecdote, as the suspension setup did not change when I went 1x9, only the gearing.