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There is a recent thread somewhere on this forum where a guy with a new Levo SL broke a DHX2 shock shaft. Damaged his frame. Fox sent him a new shock but Spesh won't do anything for his frame as the shock is not approved for use on the frame.
The Fox is not approved for 'yoke' style suspension linkages. Apparently it's not flex or alignment but has to do with leverage ratios but I don't know that for certain.

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The durability issues with Fox coils is due to flex causing misalignment between the two shock ends. Leverage ratios don't play into it. You can run a DHX2 on a bike with more extreme (DH bike) or less extreme leverage ratios with no issues. Because the upper end of the shock is rigidly mounted, any flex out of plane will cause significant bending loads. Also if the yoke isn't perfectly in line with the shock it puts the shock in bending. A shorter yoke isn't less prone to being out of line with the shock, but it won't apply as large of a bending moment. This loading actually affects all shocks to some extent. Air shocks are more rigid so they aren't prone to snapping, but they do go through bushings faster than on other frames.

Now a bit on what makes some coils fine to run and some not. Stiffness of a solid circular cross section is proportional to its radius to the fourth power so a larger diameter shock shaft makes a huge difference. If you compare a 9 mm shaft to a 12 mm shaft (assuming same material) the 12 mm shaft is 316% stiffer. Having a hollow shaft does decrease stiffness a little, but it's often still stiffer than a smaller solid shaft. The modulus of elasticity plays into it as well, so a steel shaft will fair better than an aluminum shaft. Fox's shock shafts are steel, but they are the smallest out there so they don't handle the bending well. That said, because they are steel they will generally bend before catastrophic failure. I have no issues with running a DHX2 on frames with a long yoke, but I do periodically inspect it for signs of bending. This can include blowing out the piston seal by the way. So if your DHX2 is leaking there's a chance it's also bent. I would run the DHX2 over a Super Deluxe coil for this reason actually. Because the Super Deluxe has an aluminum shaft, it will show no signs before breaking and will fail catastrophically.
 

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The durability issues with Fox coils is due to flex causing misalignment between the two shock ends. Leverage ratios don't play into it. You can run a DHX2 on a bike with more extreme (DH bike) or less extreme leverage ratios with no issues. Because the upper end of the shock is rigidly mounted, any flex out of plane will cause significant bending loads. Also if the yoke isn't perfectly in line with the shock it puts the shock in bending. A shorter yoke isn't less prone to being out of line with the shock, but it won't apply as large of a bending moment. This loading actually affects all shocks to some extent. Air shocks are more rigid so they aren't prone to snapping, but they do go through bushings faster than on other frames.

Now a bit on what makes some coils fine to run and some not. Stiffness of a solid circular cross section is proportional to its radius to the fourth power so a larger diameter shock shaft makes a huge difference. If you compare a 9 mm shaft to a 12 mm shaft (assuming same material) the 12 mm shaft is 316% stiffer. Having a hollow shaft does decrease stiffness a little, but it's often still stiffer than a smaller solid shaft. The modulus of elasticity plays into it as well, so a steel shaft will fair better than an aluminum shaft. Fox's shock shafts are steel, but they are the smallest out there so they don't handle the bending well. That said, because they are steel they will generally bend before catastrophic failure. I have no issues with running a DHX2 on frames with a long yoke, but I do periodically inspect it for signs of bending. This can include blowing out the piston seal by the way. So if your DHX2 is leaking there's a chance it's also bent. I would run the DHX2 over a Super Deluxe coil for this reason actually. Because the Super Deluxe has an aluminum shaft, it will show no signs before breaking and will fail catastrophically.
That's great info, thank you.

What's the solution? Can't a shock manufacturer create a bit more narrow mounting point and have some kind hemispherical bearing (not sure that's even a thing) to allow the shock to move a few degrees this way and that and not be locked in place to remove the bending stress on the shock?

Do you consider this a 'problem' with Spesh bikes? I mean, is it bad design, nature of a flexy bike, poor tolerances or what?
 

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The durability issues with Fox coils is due to flex causing misalignment between the two shock ends. Leverage ratios don't play into it. You can run a DHX2 on a bike with more extreme (DH bike) or less extreme leverage ratios with no issues. Because the upper end of the shock is rigidly mounted, any flex out of plane will cause significant bending loads. Also if the yoke isn't perfectly in line with the shock it puts the shock in bending. A shorter yoke isn't less prone to being out of line with the shock, but it won't apply as large of a bending moment. This loading actually affects all shocks to some extent. Air shocks are more rigid so they aren't prone to snapping, but they do go through bushings faster than on other frames.

Now a bit on what makes some coils fine to run and some not. Stiffness of a solid circular cross section is proportional to its radius to the fourth power so a larger diameter shock shaft makes a huge difference. If you compare a 9 mm shaft to a 12 mm shaft (assuming same material) the 12 mm shaft is 316% stiffer. Having a hollow shaft does decrease stiffness a little, but it's often still stiffer than a smaller solid shaft. The modulus of elasticity plays into it as well, so a steel shaft will fair better than an aluminum shaft. Fox's shock shafts are steel, but they are the smallest out there so they don't handle the bending well. That said, because they are steel they will generally bend before catastrophic failure. I have no issues with running a DHX2 on frames with a long yoke, but I do periodically inspect it for signs of bending. This can include blowing out the piston seal by the way. So if your DHX2 is leaking there's a chance it's also bent. I would run the DHX2 over a Super Deluxe coil for this reason actually. Because the Super Deluxe has an aluminum shaft, it will show no signs before breaking and will fail catastrophically.
Thanks for the insights Cascade Components. For those of us looking to get a coil which do you think can survive this bike the best? I know the Storia and DVO Jade have 14mm shafts but I think they're aluminum. I'm still trying to decide if I'm going with a coil or a Super Deluxe Ultimate MegNeg. Several of my buddies have been running the Super Deluxe air shocks for a while now with no issues. Until I decide I'll patiently await the arrival of my new link.
 

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That's great info, thank you.

What's the solution? Can't a shock manufacturer create a bit more narrow mounting point and have some kind hemispherical bearing (not sure that's even a thing) to allow the shock to move a few degrees this way and that and not be locked in place to remove the bending stress on the shock?

Do you consider this a 'problem' with Spesh bikes? I mean, is it bad design, nature of a flexy bike, poor tolerances or what?
Beefier shock shafts and more bushing overlap inside the shock would go a long ways. Spherical bearings can alleviate a lot of stress as well. Technically you need one on both ends of the shock to truly solve it, but just one end still helps for sure.

I don't think I'd call it a problem necessarily. More just a consideration. If it were intended to be a bike that was more DH oriented like the Enduro I'd consider it a problem, but it's enough on the trail side of things.

Thanks for the insights Cascade Components. For those of us looking to get a coil which do you think can survive this bike the best? I know the Storia and DVO Jade have 14mm shafts but I think they're aluminum. I'm still trying to decide if I'm going with a coil or a Super Deluxe Ultimate MegNeg. Several of my buddies have been running the Super Deluxe air shocks for a while now with no issues. Until I decide I'll patiently await the arrival of my new link.
Of all the shocks out there, the one that looks the best in terms of long term durability is the Push HD shock. Obviously that is quite expensive though. I've heard of DVO telling people they don't recommend running their coil on the Stumpjumper. EXT doesn't seem concerned about it, but haven't seen enough of their shocks on the SJ to really know about long term durability for sure. I wouldn't have concerns about any air shock so a good solution for those looking for a coil like feel that's less expensive than a Push and not prone to wear would be a large volume air shock. Since the shock stroke is only 55 mm the ramp up is pretty linear on anything large volume.
 

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Cascade, what do you consider the ideal progression for a coil shock application? For an air shock application?
Or is this all just up to personal preference, the specific application and terrain? If so, please elaborate.
From what I've seen all the Cascade links do sort of the same thing, up progression. Am I wrong, or is your position that more progression = more better in all scenarios?
Thanks.

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Great forum, lots of information. Love reading it all. I have S3 comp coming, hopefully before April. Upgraded the fork to a performance elite grip 2, carbon bar and new stem, XT shifter, hunt trail wide wheels, and putting my old saint brakes on it. Should cut some weight and up the functionality.
Wondering if anyone has been riding or tried the high/slack setting? Was thinking low/neutral would be best but the high/slack looks interesting. On paper it has the steepest STA, longest reach, second longest wheelbase and second slackest HTA at 63.5. I ride in Fernie BC, so steep technical climbs and fast, steep downhills. Some flows berms too. Not much flat riding. I was surprised to see the slack settings have the steepest STA. Would it climb best like this or are the geo numbers deceiving?
 

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I run my Evo in the high BB & slack hta setting and it's good like this. It climbs and descends the best in the setting imo.
My only complaint really is I wish the BB was a bit higher still. Well and the S4 CS longer (I'm on an S5), a bit more LR progression, and a steeper effective sta. Built in dropper would be helpful as well.
The improvement in sta was noticable and helpful btw.

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Great forum, lots of information. Love reading it all. I have S3 comp coming, hopefully before April. Upgraded the fork to a performance elite grip 2, carbon bar and new stem, XT shifter, hunt trail wide wheels, and putting my old saint brakes on it. Should cut some weight and up the functionality.
Wondering if anyone has been riding or tried the high/slack setting? Was thinking low/neutral would be best but the high/slack looks interesting. On paper it has the steepest STA, longest reach, second longest wheelbase and second slackest HTA at 63.5. I ride in Fernie BC, so steep technical climbs and fast, steep downhills. Some flows berms too. Not much flat riding. I was surprised to see the slack settings have the steepest STA. Would it climb best like this or are the geo numbers deceiving?
The SLX's are basically Saint's with a better lever and updated bleed plumbing?

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I run my Evo in the high BB & slack hta setting and it's good like this. It climbs and descends the best in the setting imo.
My only complaint really is I wish the BB was a bit higher still. Well and the S4 CS longer (I'm on an S5), a bit more LR progression, and a steeper effective sta. Built in dropper would be helpful as well.
The improvement in sta was noticable and helpful btw.

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Mullet link with 29" wheel solves two of your problems ;)
 

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Well maybe I’ll keep the slx brakes. I’ll have both sets and one will be going on my old bike. Rocky instinct 140mm
 

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Mullet link with 29" wheel solves two of your problems ;)
I'd certainly test the mullet link with a 29er if it didn't cost me progression. But dropping down to 15% progression or whatever combined with a coil seems ill advised.
Besides, I'm just letting you buy everything and planning on buying your old test parts. ;)
Really just don't want to go down the path of throwing the whole kitchen sink of parts and gear at the bike when it already works so well.

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Someone over the pinkbike evo thread states that:
“I also confirmed w a specialized experience center. DHX2 is not compatible w the yoke and specialized will NOT frame warranty if that shock is used. They said it was the shock and not the yoke, and specialized is working on a fix.”
I wonder what fix they are working on...
 

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Great forum, lots of information. Love reading it all. I have S3 comp coming, hopefully before April. Upgraded the fork to a performance elite grip 2, carbon bar and new stem, XT shifter, hunt trail wide wheels, and putting my old saint brakes on it. Should cut some weight and up the functionality.
Wondering if anyone has been riding or tried the high/slack setting? Was thinking low/neutral would be best but the high/slack looks interesting. On paper it has the steepest STA, longest reach, second longest wheelbase and second slackest HTA at 63.5. I ride in Fernie BC, so steep technical climbs and fast, steep downhills. Some flows berms too. Not much flat riding. I was surprised to see the slack settings have the steepest STA. Would it climb best like this or are the geo numbers deceiving?
Why would that surprise you? Slackening the HTA will rotate the rest of the bike forward/down a hair. It climbs fine like that.
I'd certainly test the mullet link with a 29er if it didn't cost me progression. But dropping down to 15% progression or whatever combined with a coil seems ill advised.
Besides, I'm just letting you buy everything and planning on buying your old test parts. ;)
Really just don't want to go down the path of throwing the whole kitchen sink of parts and gear at the bike when it already works so well.

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I’m headed to st George/Sedona/Tucson on Tuesday. I’ll have the ext with me to try out this setup on 🤞🏻
 

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NBD!!! Picked up my Comp today :)

Are complete builds supposed to come with a seat post shim or is it just the frames (I didn’t get one)? If I move to a longer oneup post later in the year I might go narrower diameter. Not a big deal, just curious.
 

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Discussion Starter · #1,277 ·
The SLX's are basically Saint's with a better lever and updated bleed plumbing?

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SLX is the four piston XTR/XT design with some lower cost changes. Saints are a completely different package with forged calipers, etc that have been around for years. Zee's are the lower cost version of the Saints. BTW Saints are my favorite trail bike brakes by far.
 

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Discussion Starter · #1,278 ·
NBD!!! Picked up my Comp today :)

Are complete builds supposed to come with a seat post shim or is it just the frames (I didn’t get one)? If I move to a longer oneup post later in the year I might go narrower diameter. Not a big deal, just curious.
The standard bikes come with a 34.9 post. Just the SWorks comes with a shim for the AXS dropper. The stock post on the Comp is fantastic though.
 

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The standard bikes come with a 34.9 post. Just the SWorks comes with a shim for the AXS dropper. The stock post on the Comp is fantastic though.
That’s what I figured but just wanted to be sure, thanks. It seems to operate pretty smooth from messing around with it last night. I’m not changing anything this season, just run what I brung and feel it out. maybe do a few changes next winter and a longer drop is on the list, assuming it will fit

It’s going to be a loooooooong wait til the snow melts around here. I have the stumpy sitting in front of my road trainer for extra motivation to put some miles on to prep for the season :)
 

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SLX is the four piston XTR/XT design with some lower cost changes. Saints are a completely different package with forged calipers, etc that have been around for years. Zee's are the lower cost version of the Saints. BTW Saints are my favorite trail bike brakes by far.
I've been on saints for the last three seasons, they're great brakes.

Best I can tell from past reading, at least the XT calipers are also machined from a forged block. The SLX's are definitely a bit different though. The caliper is about 3mm wider than my Saint caliper and that mainly seems to be for the pads retracting further from the rotor. There's also the aforementioned difference in the bleed ports which the first gen XT 4 piston do not share.

I've not ridden the SLX's and can't find any direct comparison to Saint's. Have you ridden the SLX'S?

If the Saints are indeed that much more powerful I'd like to switch the calipers over before selling my other bike. I won't have the benefit of having ridden the SLX's first to compare though which doesn't make for an informed decision.

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