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Have you tried dropping a spring rate then adding compression back in?
All other things the same (ex. same shock) a higher starting leverage offers less compression support; lower starting leverage more compression support. Without changing the shock tune you will notice this leverage offset far more than you will notice the progression difference. On the Kavenz its a BIG offset (~0.3 between the links) with no crossover point like many flip chips. IMO the 3.25 starting leverage is about as high as you would want to go but the progression amount is pretty proportional and the curve looks reasonable.
Somewhere in the 3-3.15 range is roughly what I would consider ideal for modern shocks with standard tunes. Anything over 3.3 generally gets into the too-soft too-progressive region and anything under ~2.9 gets into the area where people start wanting to move from medium to light tunes.
At 73kgs you will have no issue with the softer link unless your shock tune is particularly soft. You will need to increase spring rate 50-75lbs/in to have the same level of spring support.
Interesting point, as Kavenz recommended a lighter tune with the older link. I've had my DHX2 tuned accordingly by Fluid Focus. I wonder if I should consider re-retuning it if I do go with the high leverage link.
All that said, I've been gelling really well with the bike my last few rides and don't know if the juice will be worth the squeeze.
Ive been playing this game a bit, leverage / spring / retune. and also using fluid focus. It's getting to be expensive, I'm considering trying Vorsprung shock where they give us the ability to change shim stack preload which widens our usable area for tunes. New tunes do help, but i've been trying all possible adjustment combinations and using data before sending for a retune, then I can give them some information, like; here are my shaft speeds and my clickers are at X, X, ect. you could do the same, say you try a link and then say this is too stiff and your wide open on clicks or this is too soft now and I'm fully closed. But I've also been in many cases where leverage and spring didn't require new tune, hahah so it;s hard to say for sure.
Commencal Muc Off trying new rear end.
Estimated kinematics from @Downamics on IG
More conversions from seatstay to chainstay axle positions. Possible AR change from what they learned on brake arm or just the feel of linkage single pivot feel?
Changing to a linkage driven single pivot similar to Kona from a Horst setup dramatically increases anti-rise at start of travel and it drops more over full travel. Comparatively, the changes Commencal has made barely change anything. I would hazard to guess that Commencal is more after changes in compliance than kinematics.
Brining this back from a while ago....
Is anti squat then the ratio of moments about the instantaneous center of the rear swing arm? I.e.sum of the moment from the wheel and chain tension divided by moment caused by accelerating the center of mass?
My guess is that they've fettled with the link to cater to Loris' riding style and size. Amaury seems to still be on the normal link, which by my estimations has a lower initial AR with a higher initial leverage rate. The new link seems to have a lower leverage rate, a bit like how Kavenz and some other brands offer different rockers for heavier or lighter riders?
Precisely. Theoretically at 100% anti-squat the sum of the moments about the IC is zero so the suspension neither squats nor rises. In reality, I think you want a little more than that to counter center of mass bobbing up and down. That's a hard one to quantify though. You could argue that for a bike that's geared towards fire road climbs where you're seated most or all of the time you could do minimal anti-squat and see no bob.
Thanks, that makes perfect sense. The diagrams with all the lines over the front wheel you see in other articles don't really articulate what is happening!
The lines don't easily relate to the physical reasoning behind anti-squat but they are fully consistent (can be derived from the force balance with a bit of trigonometry), and a really useful design tool. It's much easier to visualise the effect of moving pivot points on the graphical interpretation.
Remember that all the graphical line diagrams become invalid when there's a moving idler, and if the idler has a different IC to the wheel then the ratio of moment's about the wheel IC is also not correct. Then, it's best to revert to basics; solve the linkage for forces at the shock and define the anti-squat using those terms so that the shock force is zero when the anti-squat is 100%.
Hello! I have a question on how it would change de feel of the shock when using a more progressive linkage , Does it rebound faster?
I have a sc v10.8 and when changing from the middle to the low position on the lower link I feel that the bike is more progressive. I dont have any numbers or info that confirms what im writing but what its supossed to be a geometry adjuster feels more like a dinamic adjustement, the bike feels like it starts softer riding lower in the travel.
In theory, what damping adjustments would you need when using a more progressive linkage regarding compression and rebound.?
AFAIK the lower linkage flip chip on all Santa Cruz model also changes the leverage ratio curve. Rocky Ride4 also affect leverage ratio curve.
I would start with sag cause you might need a stiffer spring (assuming you are on the stock DHX2 or Vivid Coil) or slightly add more air pressure.
Anything moving around linkage pivots will affect the leverage ratio. The question is to what degree though.
@CascadeComponents seated fireroad climbs are where antisquat should shine the most (resisting the CoG weight transfer) as the rider is most fixed relative to the suspension while standing up there's a lot more movement overall and it's harder to cover all the situations.
Years ago pedal bob was handled with climb switches (LSC closed off) then we moved to antisquat when the industry got more informed. Now with all the pedal feedback issues it might be a case of either going back or throwing yet more technology at the problem (pivot heights and idler and smart lockouts).
You might be able to notice the affects of anti-squat more when seated, but standing and pedaling is where most people need more of it. Pedaling technique could be debated, but most move up and down quite a bit when pedaling while standing. That load adds to the squat that would be experienced from accelerations forces alone.
Agreed, but outside DH bikes, are there any other bikes where it makes sense to optimize AS for out of saddle pedalling?
I haven't looked at the V10 in depth enough to compare the flip chip settings, but with most Santa Cruz frames the flip chip makes the bike ever so slightly more progressive in the low setting. Usually it's a small enough amount where I'd say most people wouldn't really notice it. But again, haven't looked at the V10 flip chips.
As far as adjustments for a leverage curve that starts higher and ends lower, getting the right spring rate for sag is the best spot to start. Beyond that, adding a little compression damping is often times useful. Rebound would more depend on the spring you run. If you run a stiffer spring then slowing rebound a little is good, but if you don't run a stiffer spring you wouldn't need to slow it.
Another thing that happens when making a bike slacker is the amount of fork pressure required to handle vertical impacts decreases. I don't think Santa Cruz flip chips are dramatic enough for this to be noticeable, but sometimes if the fork becomes stiffer it can make the rear feel softer than before.
I would depend on the trails. There are plenty of more XC oriented places around here where climbing out of the saddle is frequent.
Sorry if I'm now spamming this, but anyone reading this thread should be interested to know Tony Foales book MOTORCYCLE HANDLING AND CHASSIS DESIGN: the art and science is back in print after 20 years, and in that time I don't think I've found a better reference book on the topic!
Get it now so you don't need to wait decades like I have to buy a copy! I've got a physical copy of the original 80's book but the second edition added a TON of excellent information that is still highly relevant
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Can any kinematicians give me some advice?
I’m running a 32t with o-chain on my arrival (which varies from 140mm to 170mm).
I’m going to pop a new derailleur and shifter on, and wondering if moving to a 30 x 9-45 is a good idea to reduce mass in the wheel and get some ground clearance.
Will the o-chain be sufficient to offset the downsides on 30 v 32t or are there factors I’m missing?
Thank you!
Edit: I’ve just realised that the o-chain may not accept a 30t… but still, value informed perspectives.
this is just from the 170mm model in the linkage web library - so assuming its accurate enough - but dropping both the front ring and cassette would make a negligible change in pedal kickback (like half a degree in the hardest gears, zero difference in the easiest). If you only changed the front ring to 30t and left the cassette, there would be a couple more degrees PK in the easy gears which the o-chain should be able to account for.
So in theory, if you were able to change both - no difference to PK but the easiest gear would be harder (if that matters)
And if you did just do the chainring, the o-chain should offset it enough too.
I'm not sure there would be much noticeable change in ground clearance or unsprung mass, the biggest difference would be gearing IMO
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