Viewing 12 posts - 41 through 52 (of 52 total)
  • 1x and suspension kinematics
  • Doh1Nut
    Full Member

    all ratios were same 1:1 either 32:32 or 22:22 ( didnt do 22:32)
    Power input also the same so you would be going up the hill at same speed in all.
    I thought that chain tension would probably be quite high – I just wanted to quantify it.
    and see how variable it was

    milko9000
    Free Member

    When I switched to single-ring on my SB-66, I ditched the shifter, mech, chainguide and bashguard. And I think it was about the same time that I got the shock a Push tune as well so maybe that’s part of it. Anyway, if I lost any suspension performance I definitely didn’t notice it, whereas the decreased weight and faffery was clear as a bell, haven’t looked back since. The numbers thing is interesting to me in the abstract but in practice, not so much.

    jemima
    Free Member

    Fair enough Doh1Nut 🙂
    And then we have to note that your chain tensions are revolution averaged and will vary between zero and likely double that figure twice per revolution.

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    Doh1Nut
    Full Member

    Oval rings ❓ 😀

    kimbers
    Full Member

    hmmm i went from 2×10 to 1×10 with a 40t expander on my process 153, which is sort of single pivoty

    my completely unscientific take on it is that it felt better on techy climbs with but had to pedal smoother on smooth climbs

    i used to flip the lockout on, on the long smooth ones, but find now that I dont need to at all, so i must have adapted

    edit: actually i also swapped shocks and the avalanche tuned dhx pedals and tracks the terrain much better han the monarch it came with, i have no idea how that effects the kinematics tho!

    robinlaidlaw
    Free Member

    Now, if you look at the line along which that force is acting (which is different for the 32 and 22 chainrings) and where that line is in relation to the pivot, you can see that those two options will have a very different effect on the suspension.

    I stand to be proved wrong on this, but I thought it was more a case of the angle between the line of the chain as viewed side on and a line through the wheel axle and the pivot than whether the chain actually passed in line with the pivot. In other words, for the Orange 5 situation the chain leaves the sprockets above the hub and the chain line and the axle/pivot line converge towards the front of the bike. This tends to try and extend the suspension by an amount which creates about the right amount of anti-squat for flat surfaces.
    Putting it into the small ring drops the chain at the front and increases the angle between the chain line and the axle/pivot line, increasing the anti-squat for climbing.
    So, your argument is that running a single ring removes the ability to increase the angle of the chainline in this way for climbing. Which would be true except for one thing, we are mostly running larger sprockets on the back to compensate for the larger rings, which has the exact same effect on the chainline, increasing the angle, just from the other end by lifting the back, not by dropping the front.
    Edit: The change may be slightly less than it used to be though, 24t granny with 32 middle used to be normal, an 8t difference, now we are usually going from a previously 36t largest sprocket to a 42t, only a 6t difference. Of course if you used to run an 11-34 cassette, it’s the same.

    dangeourbrain
    Free Member

    Genuinely interesting thread thank you, sorry I’ve nothing constructive to add really – though I’ll throw in a non constrictive post then enjoy doing the reading up to figure out where all this comes from.

    jameso – Member 

    7 or 8 years later, I wonder how this statement sits with DW, SRAM and most FS brands –

    I imagine in the same way as it sits with most of the non technical comments in this thread. Most riders don’t seem to care.

    They sell bikes and fashion sells better than science. (my personal opinion is 1x is largely fashion driven, the explanations I’ve had largely boiling down to its lighter and it leaves room for my (heavy) dropper remote though I like my granny ring too much to not be bias any how)

    As much as the aforementioned might think that square chain rings are ridiculous they would still spec them if they were fashionable and allowed them to show a paper weight saving over round ones, because those are what most people buy, not something which actually works [a little] better, largely as most of us (me included) aren’t capable enough to notice the difference any how, and unlike when suspension first appeared is now quite refined so doesn’t need every helping hand it can get to work better.

    AlexSimon
    Full Member

    7 or 8 years later, I wonder how this statement sits with DW, SRAM and most FS brands –

    On twitter, DW takes every opportunity to say how backward he thinks having a front mech is!

    roverpig
    Full Member

    Which would be true except for one thing, we are mostly running larger sprockets on the back to compensate for the larger rings, which has the exact same effect on the chainline

    Sort of true. You are right that the rear sprocket also affects things and has been largely ignored on this thread so far. But looking at tables of anti-squat percentages it would appear that the front chainring is much more significant than the rear sprocket. Also shifting between rear sprockets seems to work in the opposite way to what I would have expected, with smaller sprockets giving larger anti-squat. So, on your 1x setup, as you climb and shift into a larger sprocket you are reducing anti-squat just when you want to be increasing it. I’m still trying to get my head round this though and am happy to be corrected.

    Northwind
    Full Member

    AlexSimon – Member

    On twitter, DW takes every opportunity to say how backward he thinks having a front mech is!

    Lets be honest, absolutely everything that DW says publically is an advert.

    roverpig
    Full Member

    Lets be honest, absolutely everything that DW says publically is an advert.

    He’s hardly alone there to be fair. We seem to get fed a lot of marketing BS with our mountain bikes. Most of it sounds plausible but often contradicts the equally plausible stuff we were told before. I guess I’m just trying to work out whether this year’s BS is any more relevant than last year’s BS.

    maxtorque
    Full Member

    It’s the same with the old classic of “rearward axle path”. Work out how much the rear wheel would actually have to move backwards to even slightly reduce the impact, and you’d have to stop and pick it up afterwards!

Viewing 12 posts - 41 through 52 (of 52 total)

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