that's my new shock sorted for the Rune.
For when a decent air shock just isn't heavy enough for you, have a coil shock that behaves like one but it's 11 times more enduro!
mleh, i've had no end of trouble with airshocks and did want the DB Coil iL, but they don't do my size and the Kitsuma is too much i think, so this fits the bill for trail riding with enough in the bag for smashing it through silly stuff.
You'd have to be very brave to be an early adopter on this thing. Or just really enjoy having your bike out of action while you wait for warranty and servicing.
Given I ride with Sui most weeks, I can confirm that the extra grams of the shock really will be a low percentage addition to his whip.
And I'll look forward to having our ride cut short due to a blown shock....again!
have a spare, so all good there -plus my bikes always out of action, or at least in varying states of build quality.
Is the spare also out of action?
Do we ride together?
Ex Stratos Helix owner, just here for the LOLs.
All the downsides of a coil (weight, finding the right spring) with all the downsides of air (stiction, mostly)
The only good thing about mine was that it went some way to combat the stupid falling rate on all my old Marins.
as part of the pink bike article i've discoverd Sprindex https://sprindex.com/ for that oh so in-between spring rate. No idea how it works, but anything for some more weight (is't that the in vogue thing now)..
What I don't get about the Sprindex.. is that in effect it's making the spring shorter, isn't it? So unless the spring is already designed for a longer stroke than the shock... you'll get coil bind before full travel, won't you? Someone crack open the maths/physics...
I am probably being dumb - but isn’t the benefit of coils that they give better improved small bump sensitivity - not worse. Air shocks are far, far better than they were since they introduced negative springs - remember the old Fox Alps air shock, huge stiction.
kelvin
Full Member
What I don’t get about the Sprindex.. is that in effect it’s making the spring shorter, isn’t it? So unless the spring is already designed for a longer stroke than the shock… you’ll get coil bind before full travel, won’t you? Someone crack open the maths/physics…
I often ran a spring with longer stroke than the shock anyway. I assume sprindex are taking that into account and their (for example) 3” spring is actually bigger than a normal equivalent
What I don’t get about the Sprindex.. is that in effect it’s making the spring shorter, isn’t it? So unless the spring is already designed for a longer stroke than the shock… you’ll get coil bind before full travel, won’t you? Someone crack open the maths/physics…
That should be easy to manage from their point of view - simply spec the coil stroke based on its shortest length so a 65mm coil would have eg 67-90mm of stroke.
I assume it works by having a rapidly rising rate in the final few turns of the coil and isolating those as you wind it so the rate of the spring hours down.
What I really don't get is how progressive springs are supposed to work unless the material reacts differently at differing points in its compression. It's not like you can wind a 250 into a 350 spring and get a changing rate, you just get a 300 spring.
Yay they’ve discovered a Stratos Helix from 20 years ago
That was my thought too - except I could not remember the model name. Thank you.
That should be easy to manage from their point of view
Good point!
actually bigger than a normal equivalent
Makes complete sense.
Okay, I'm onside with the idea now.
That was my thought too – except I could not remember the model name. Thank you.
I went on quite the retro-shock journey before remembering it was Stratos!
I'd be tempted for my Escarpe, but TBH I'd probably be more tempted by a plain coil shock. But then I'd also be tempted to look into coil-ifying my Z2's.
i don’t think they’ve messed with the small bump element as the air part is between 0-30 psi only and only really kicks in towards the end of the stroke.
Does it significantly differ from how any other piggyback shock with adjustable pressure/volume acted then?
I loved my mazocchi rc3 TI's and rc3 anniversary.
Could sprung with an air top up.
44 rc3 ti is still on my niece's bike, anniversary got stolen on a bike, 55 rc3 ti got sold when I left 26" wheels.
I wonder if the will do the same for a fork.
i don’t think they’ve messed with the small bump element as the air part is between 0-30 psi only and only really kicks in towards the end of the stroke.
The pressure isn't really the issue with small bump on an air shock, sure it'll need tighter seals to deal with the higher pressure and that effects stiction but any seal will give that.
The ramp on that is also going to be massive. end stroke on a coil shock is under a huge amount of pressure already, for 30psi wouldn't result in a perceptible difference unless it's undergoing a huge amount of ramp, so you're still going to be dealing with many 00s of psi at the end of the stroke so still need very tight seals.
I guess the air portion is active the whole time, the reason for the low pressure being it's not until very late in the stroke that there's a noticeable impact on the spring rate but, that means the seal stiction needs to be overcome at the outset of the travel.
The other option is its completely isolated from the coil until the last ??Mm of the stroke, at which point the stiction won't be noticeable, but that needs a tiny air chamber to allow it to ramp from 30-noticeable before bottom out which will mean getting the pressure consistent and accurate is incredibly difficult.
It's a bold move trying to make a coil shock that behaves more like an air shock but I don't really see the point.
I loved my mazocchi rc3 TI’s and rc3 anniversary.
I had the Z1 anniversary forks and thought the opposite. The damping was amazing (this was before the 66 so single crown forks were lacking somewhat) but by the time I'd added enough air to get the spring rate right they were really too harsh.
I'm sure they would have been better in this sort of implementation where you change the coil spring to get it about right, then add a fairly consistent ammount of air to tune progression.
66's were da bomb (do you see what i did there)..
I had (have) some of the originals, really high axel to crown loved em on the gspot. i bet they are shockingly bad compared to modern internals.
Anyway, the nice man at Banshee is double checking that it will fit the shock cage and im still wiating to find out when they will be available in the UK.
I can see what they’re trying to achieve - I found the Kitsuma coil shock on the standard linkage on my Transition Sentinel blew through the travel and harshly bottomed out unless you ran a coil spring that was too stiff everywhere else (running 20% sag ish).
If they’ve managed to pull it off without robbing the small bump performance of the coil but avoiding harsh bottom outs for bikes that don’t have enough ramp up in their kinematics then it could work well for a number of bikes.
The other option is coil shocks with an hbo. The Pinkbike review suggests that this CC shock works better for them than a rockshox super deluxe with an hbo. <br /><br />
That said - I imagine this is going to be more expensive to service / need servicing more often due to the air aspect of the shock…..so I’d be more tempted to go super deluxe or maybe ext I think.
edit - I fixed my issue with a cascade link for the Sentinel and now it’s fantastic
What's wrong with a coil shock and big squishy bottom bumper?
"What I really don’t get is how progressive springs are supposed to work unless the material reacts differently at differing points in its compression. It’s not like you can wind a 250 into a 350 spring and get a changing rate, you just get a 300 spring."
The pitch on a progressive spring is not even throughout the spring like normal a linear rate compression spring, the small pitch will compress fully before the larger pitch so the rate will ramp up near the end of the stroke.
@kelvin the sprindex doesn't shorten the spring it reduces the active coils which increases the rate.
I’d be tempted for my Escarpe, but TBH I’d probably be more tempted by a plain coil shock.
I'd take some expert advice on that. A friend of mine has been considering this but was advised not to by just about everyone he spoke to, including Vitus. Leverage curve keeps dropping deep in the travel.
I'm a bit non-plussed with the amount of noise for this new shock. Its essentially just a pneumatic instead of hydraulic bottom out. The main difference is that it can be progressive and start earlier in the travel which is going to suit some people's preferences. Push do the same with the ACS3 coil kit for forks.
I suppose its just the standard to shout loudly about the newest and greatest to garner interest/sales.
Odd question about spring rates and making progressive springs, but could you in theory (or practice) stack a lighter spring on top of a stiffer one so that it’s very soft initially for small bumps but then later in the stroke it’s firmer? Just wondered if it would work. Maybe used in conjunction with though spring bearings that were popular several years ago to reduce coil binding (are they still a thing?)
And don’t Manitou something like this in the 00s?
I theory, yes.
Odd question about spring rates and making progressive springs, but could you in theory (or practice) stack a lighter spring on top of a stiffer one so that it’s very soft initially for small bumps but then later in the stroke it’s firmer?
This is what we used to do with twinshock MX bikes back in the 70's.
We also used to fit Schrader valves to the top of coil forks to add air so they ramped up towards the end of the stroke.
Nothing is new.
See also Skunkworks lever driven shocks.
https://motocrossactionmag.com/forgotten-motocross-tech-skunkworks-gp-geometric-progressive-suspension/
Also I miss my Marz 55 RC3 Ti forks (I rode a bike with a pair last week and was still impressed with them). They were great. I’m still a fan of open bath coil forks, they might have their drawbacks, but for low maintenance and reliability they’re great (apart from BOS ones, the performance was great but the reliability and back up wasn’t there). <br /><br />I still have som DJ1s that are about 15 years old still on original seals and oil (I should service them at some point) that still work fine. Lots of oil = happy forks
The pitch on a progressive spring is not even throughout the spring like normal a linear rate compression spring, the small pitch will compress fully before the larger pitch so the rate will ramp up near the end of the stroke
but could you in theory (or practice) stack a lighter spring on top of a stiffer one so that it’s very soft initially for small bumps but then later in the stroke it’s firmer?
Pretty sure that's not how coil springs work. (it's a long while since I did this but the physics shouldn't have changed assuming I'm remembering it correctly)
All that happens is you distribute the force evenly across both springs, eg. A 100 and 200 inlb spring, both with > 1"free travel and of equal length.
The 100 inlb spring compresses 1 inch under a 100lb of force, the 200 1/2 an inch.
If you stack them and apply 100lb of force that doesn't compress the 100lb on by 1" but not the 200lb one.
It compresses them both by 50lb of force as its evenly distributed along the whole assembly so 3/4" in total (0.5*1+0.5*0.5)
Pretty sure the above is correct, where I get a bit fuzzy is: If the 100lb spring is eg twice the length of the 200lb spring.
Iirc the compression becomes roughly 0.823" (0.66*1+0.33*0.5)
