After many years on Fox i've got a bike built up this season with Rockshox suspension. Super deluxe coil shock is sorted but I have the new 180mm Zeb Ultimate with the charger 3 damper and can't get full travel out of the thing.
TL:DR: Doesn't seem to matter what pressure or how many spacers the o-ring is always stopping 25mm from full travel. Is this just the way Zeb performs; hits a wall of pressure at 25mm from full travel or has anyone heard of specific issues with the internals that would cause it?
Detailed version:
- I'm 6.2' / 225lbs in my riding gear which has the RS app suggest 80psi in the fork.
- the 180mm Zeb ultimate with charger 3 damper is a brand new fork; about a month old with ~400km of hard DH/Enduro riding on it including 3x whistler days, shuttles, etc so should be well broken in.
- I've ridden the fork from 83psi down to 73psi dropping 2 psi at a time and have also tried 0,1 & 2 spacers while running laps on the same DH trails to see if I can get full travel.
- I didn't go below 73psi because fork was just way too soft to ride confidently by that point.
- HSC full open & LSC 4 from full open/soft.
- Changes to pressure and/or spacers make very large & noticeable changes to the way the fork rides in the usable 155mm of travel but every run, regardless of what my settings are, the o-ring is always exactly 25mm from full travel! With one exception...
- There's an 8 foot drop to flat that I was sessioning trying to get full travel and I was able to get to 13mm from full travel on this feature. It's brutally hard hit and changing the number of spacers didn't seem to change things in end stroke; 0 or 2 spacers would still only get me to 13mm from full travel. It's a brutal compression so should absolutely be able to bottom the fork on this feature (no problem bottoming here when I was on the Fox 38...was actually the oposite, trying to tune the ramp up so I could hit this feature without bottoming so harsh the fork clacks).
- I've aired down the Zeb completely and cycled it to full travel to make sure there wasn't a mechanical stop or something. The fork also has the bleeder valves on the lowers which i've made sure i'm using to ensure it's not an equalization issue between the positive & negative chambers.
First post and it's a long one but if you've made it this far i'm super curious if this just the way it is with the 180mm Zeb or if someone else out there has come across this and found a specific issue preventing full travel?
Cheers
the 180-190mm zebs are notoriously progressive and given proper ride height may never hit full travel.
You have 2 options here.
Does the fork feel good to you? Cut the O-ring off a go about your life
Or Trutune or Carbon Air inserts, which act in a way of anti volume spacers, making your fork more linear and easier to use full travel.
dunno, my 180mm ZEB on my ebike slaps off bottom if i set it up like that.
I’ve been testing the Zeb 180mm and riding at 76psi on Kenevo SL with 0 volume spacers. I weight 180lb
while testing and Using data acquisition the max travel I’ve been able to reach is 153mm and that was with 33% dynamic sag running 72psi(if I remember correctly)
In my opinion the stock valving was way to stiff and ramps up. Along with the air chamber ramping up its over powering the end stroke. But in the positive side of things the initial stroke and travel feels smooth. So I’m not hating on the ramp up, but personally I’d like something a bit more linear.
I’ve been trying some other settings with a suspension shop in California called Fluid Focus. Should be sweet when things get dialed in!
At 180/190 the new Zeb is very progressive and riders that aren't that sendy will struggle to get near full travel.
I have a 170mm ZEB and that thing has hit bottom a few times, but only when things go pretty wrong. It's also a 2021.
The current Charger 3 version has firmer damping and more preload from the IFP spring. The Debonair+ air spring has a larger negative spring (identical to the Luftkappe) so you'll be running higher pressure that a previous gen ZEB. All will effect the ability to get "full travel".
But are you really concerned that it's not bottoming out?
Does it ride well? Is it harsh?
People often seem over concerned about being able to use all the travel their fork offers. If it rides good and leaves you 10mm+ off of big hits, I'd say that is a win! I hated the days of clacking forks multiple times a ride.
I’m not hung up on “trying to bottom out” and I think the fork is great but you can feel it ramping up from mid to 155mm where I’m stopping my travel. I’ve even forcefully lifted and slammed the front into on coming roller faces to try and max out. I think they did a great job with the initial travel and hold up and forks rigidity. In stock form I think it’s a near perfect for bike park set up but not the best on chunky trails.
I ordered the TruTune last night which sounds like it negates “volume spacers”, and will test that. The goal for me, is a more linear feel.
Have you serviced the lower leg oil? Too much lube oil can add a bunch of casting ramp.
I run zeb 180 at 70 psi, no tokens, 165 lbs and can bottom once in a while.
Also worth doing a lower leg service to remove all the machining swarf left in them.
I've been happy with the Tru tune insert in my 150mm Fox 36.
It reduces ramp up and what ramp up is there is less quick and harsh.
I have never seen this in any brand of fork, have you actually seen this or just heard of it?
A lowers service is still worthwhile, and check that the bushings are sliding freely. Forks don't really "break in" much in the early stages apart from a small amount of seal friction or just distributing grease/oil around the place. Over a year or two they can become smoother but if things like the bushings are too tight, it won't really improve. Also make sure no ones gone in and wiped away too much grease from the air spring because they heard from some insta-suspension-tech that forks have too much grease in them from factory (this hasn't been a problem for MANY years now). I've opened a lot of bone-dry air springs recently because of this that felt terrible.
The main thing though is 25mm left over is totally fine. If the rest of the travel works great then pay no attention to it. Suspension works in ways that are very counter-intuitive so there are lots of reasons it might not reach the end of the travel, even if you set it up quite soft. For example dropping the pressure right down will encourage higher damper speeds so the damper will soak up alot of the energy in the first half of the stroke, meaning there isn't much left to compress it the rest of the way. Then if you make it stiffer its just purely spring force preventing full bottom out. So the 2 settings give the same total travel used, its just for different reasons. Allthough bear in mind that the "stiffer" setting has more travel available so is travelling further before it reaches that end point too.
180mm is a lot of travel so you shouldn't really be needing all of it most of the time. Getting to the end of the stroke doesn't mean its working any better and in most cases is probably less than optimum. I personally expect to see around 10-20% left in "reserve" that may never get used but I do sometimes find that over time I will randomly encounter a place that does it. Just don't let it guide how you set up your fork
Yeah I have tried serviced and tried different valving in the damper.
I did consider the oil height but there wasn’t much in there to be over recommended amount.
What kind of hit can you bottom out on at 70Psi? And you say bottom out because you feel a clank or see the ring at the top?
for what it's worth, I'm riding a 38 @ 180mm no spacers and 115psi, Even if I lawn dart an 8 foot drop to flat I'll still have 5mm left in the tank. If sag is fine, cut the O-ring off, it should be renamed the anxiety ring.
Loud clank and oring on the bottom out graphic.
usually high front end in the air to slapper landing while hard on the brakes. There’s 2 jumps on a super steep trail that consistently do it. That’s probably the only spot I ever bottom the fork.
Just to echo others thoughts, I wouldn't be looking to use full travel on a 180mm fork all that often. I'd want to leave the last little bit for the "oh my God I'm going to die" moments.
As embarrassing as this is to admit, I can often go through an entire summer without bottoming out my fork. Yes, that is a reflection of my age (no more intentional hucks to flat), but it also is a reminder that suspension is there for control first, then comfort.
The idea you should be bottoming 1-2x a ride is silly. On that note, I think I've bottomed my dirt bike suspension (for real) like 2x in my life, and both times it literally saved me from a bad injury. This is what I'd leave that last bit for...
For fun, did you try taking all the air out of the fork and cycle it? That'd tell most of the story right there. If there is too much oil or some weirdness going on in the lowers it'll reveal itself with 0 psi in the fork pushing through the travel...
This is one of the downsides of long travel single crown forks, and it sounds like the Neopos pucks might be the ticket for you to get more travel out of your fork. With these long single crowns, there just isn't any more room in the fork legs for a bigger negative chamber, positive chamber, and lower leg volume, and all of the long travel single crowns have trouble to varying degrees with overly-progressive spring curves. With a dual crown there's a lot more room to increase air spring volumes and slow down the ramp up. For instance, for my last downhill fork I ran 5 volume reducers and for my 180mm 2021 Zeb Ultimate I run 1 and they feel very similar. I'm a 190 pound tall former pro, so I can only imagine these forks are often way too progressive for smaller riders who don't ride that hard.
Like others have said, that isn't always a bad thing, and it's a pretty subjective judgment call. My Zeb never ever gets full travel and I love it. It allows my bike's geometry to stay upright and composed through rough terrain without diving and scaring me. Bottoming my fork on a rough trail is rarely a happy feeling. I can only remember audibly bottoming it once the entire time I've had it, and it was horrifying. It was in a race run at a DH race and I gapped into a really steep set of braking bumps while braking hard. The fork blew through the travel instantly and bottomed out with a loud metal clack. I almost blew off track! That's why I try to set up my shock so it bottoms out every once in a while, but the fork should be stiff.
You've got some good responses here... and I agree with most, if not all of it.
That being said, the zeb is more subject to ramp up from air in the lowers then any fork I've used before, that combined with the relatively massive air spring positive chamber volume, can make using full travel a rare event. I have a 21' ultimate @ 170mm, that I've run stock, with a vorsprung secus and now with a vorsprung smashpot. In stock form, it was definitely very hard to get the last 10mm of travel while running the right sag and no tokens. It would happen, but very rarely and only when i had completely messed up and needed saving. Once I added the secus to it, it was a lot easier to balance the air spring pressure, mid stroke support and being able to use full travel. Obviously, now that it has a smashpot in it, it's a different animal entirely.
One other thing is that mine 22', definitely needed the bushings burnished in order to get rid of some fairly grabby bushings. Mine still isn't perfect, and realistically I would need to not only burnish (clearance) the bushings but also validate the alignment with the uppers to get it to slide any better. For the air spring, I definitely think that air springs built with slickoleum and slick honey feel better than the sram dynamic seal grease.
I have a charger 2.1 in mine, which now has some re-work done to the internals (lighter mid-valve spring) and a firmer shim stack on the base valve. I played around with an HC97 but wasn't able to get along with how that felt so I went down a different road... this doesn't help you as you've got a 22' with the charger 3... but figured I'd add the context for others with a zeb looking to mess with it.
I think burnishing the bushings and the secus made the biggest difference in the fork. After playing with a 38 and the zeb, I see why fox went down the road of doing the reduced volume inner air spring cartridge. I don't think that way of designing the air spring (in the 38) is any better or worse for my usage... however, in my experience, it certainly makes it a bit easier for lighter weight riders to get the air spring dialed.
That being said, 170mm and up is a lot of travel... it really comes into play once things get stupid. It seems a bit weird that you keep ending up with the same amount of remaining travel. I would suggest also having some friends record you on video so you can evaluate your front/rear weight balance. You may also be ever so slightly under sprung in back, which may contributing to the travel used.
My experience where it differs from the previous responses.... Started with a 170mm Select+ with Debonair, Charger 2.1 and 1 token. It was OEM on a Canyon Torque. I'm 195-ish fully kitted.
Sag was 30% at 48 psi, which was much lower than the 70 psi trail head recommended, but that's what I needed for 30% sag.
I was using full travel and it bottomed out occasionally (when arguably it should have), but with the lack of support it felt like it was always sitting in the last 1/3 of the travel. I upped PSI closer to recommended but all that really did was decrease sag and how supple it was. From what I've read this experience seemed common for this fork.
Added a PUSH installed HC-97. No change to PSI and I backed out HSC, LSC and rebound a few clicks from PUSH's recommendations after some testing. Support felt much better throughout travel and having effective LSC and HSC adjustments was welcomed. Use of travel and bottoming out were unchanged from pre HC-97.
Recently upgraded to Debonair+ (with only slight changes to HSC and LSC over the 6 months of having the HC-97) and I began to experience what you are. For me the lack of full travel is due to the air spring, not damper. I could remove the token, though that seems like it would have limited effect based on others experience.
Compared to rear suspension behaviour, the percentage of travel used is more or less equal front and back other than the rare few times I've bottomed the rear casing a jump and the front has 10-20mm left.
I'm no suspension expert so I'm always looking for input or tweeks, but have been riding long enough to understand the feel I'm looking for. Even though I don't get all of the travel the bike feels balanced so I'm running with it.
Be very (very) careful with setting sag to 30% on a fork, especially in a flat parking lot. I've never found running that much sag to result in a controlled or comfortable ride. Here is why...
1) When we are setting sag we are generally doing it in a flat parking lot. This is not where you ride a bike. In general, the bike is pointed downhill when you want your fork to really perform well which puts a significant amount of weight on the front of the bike changing those sag measurements immensely. (33% is probably closer to 45% when riding downhill - resulting in one chaotic crazy ride)
2) The opposite happens to the rear of the bike where 33% sag in the parking lot starts to act like 25% on trail in a downward direction. To add, I believe rear suspension has a slightly different job & interacts with the rider differently than front suspension. Depending on the bike's kinematics, rider preference, where they ride and how they ride the rear suspension can be setup with a much higher amount of variance (25% sag to 40% sag - and all can work)
Up front you are usually going to find yourself really close to 15-20% sag (or even less). The more linear your fork's spring, the less sag you generally run which can often give the rider a heightened sense of control. YMMV.
Super helpful info as I also have a Zeb (non-Buttercup with Charger 2.1) that is quite good in the first third of travel but really hard to get in to that final third.
Have been on the fence about Secus vs HC97 as the damper is fine and your explanation plus what I know about the Secus makes sense for why that is so effective for a Zeb.
I know that there is truth to having travel when you need it and also not being obsessed with how much travel vs quality but if I compare my Zeb to other forks at the same travel I use (Mezzer, 36, RFX M.2) the Zeb uses less travel on the same trails with the same meat wad pedaling (that would be me) so it isn't those items even if there are definitely very legit points in them.
Don't underestimate the coil spring, too. For anyone who's really having trouble getting close to full travel, the Secus is going to increase positive chamber pressure, which isn't going to help you get to bottom out. The Secus does bleed off some of the pressure that builds in the lowers, which will help reduce ramp up near bottom out, but those two features (increased positive chamber pressure combined with lower leg venting) are going to work against each other near full travel to create a result where the fork is a little easier to bottom out, but not in a way that's a total game changer. For riders looking to cycle through full travel significantly more easily, a coil spring kit like the Smashpot is going to be the ticket because it allows a lower actual spring rate near the end of travel.
In response to Jeff's comments about sag, I wholeheartedly agree and I'm glad he brought up the sag discussion. 33% sag is only going to be helpful for absolute beginners who need the maximum magic carpet feeling and who aren't going fast enough or riding steep enough trails to benefit from increased chassis stability. For average "black diamond" riders I agree that 25% sag is good, more aggressive riders and racers should be running closer to 15%, and very aggressive riders will want to run even less. For reference, I typically run 10% sag, because I want to be able to jump into bullshit or jam on the brakes as late as possible into a turn and have the fork stay up in the travel. As a result, I have to put up with a stiff fork everywhere else. Back in the day, Aaron Gwin's fork was famously basically locked out for the same reasons. So I wouldn't recommend running 10% sag, but I also wouldn't recommend running 33%. Sounds like riding a teeter totter.
On a bike meant for more downhill I have always set sag for rear standing on the pedals and for the front getting in a full attack position over the front. I still will aim for 25-30% depending on the bike and have never had an issue with it having to much sag when in full DH situations. I did that with the Zeb on the after after a number of rides I have made a few psi increases because I felt like I was a tad too soft but still within 5 psi of original sag psi.
I only do the sitting sag measurements on a bike that is going to be more XC/trail ridden.
I was hoping to get one or maybe two responses if I was lucky but Vital Mtber's, you guys delivered the goods! Some great responses/discussion here so thanks.
In addition to reading every response above I've also done quite a bit of digging IRL and asked various techs/riders who are at a high level in the sport. Figured I would post a bit of a follow up just in case any other riders come to the forum with similar questions as mine. Short version is basically that this is simply the way the Zeb rides; However, I have added a couple caveats below:
- Some of the top EDR/EWS racers on this fork are actually using a lighter tune than what comes stock. Would think this is maybe something to consider if you're a lighter rider.
- Like many of you above mentioned, everyone tells me it's worth a service with a particular focus on having the bushings checked. Going to do this in a week or so just to be sure. I doubt there's anything wrong with the bushing TBH but i'll certainly report back in a couple weeks if it does end up changing the way the fork rides
Cheers all.
@TEAMROBOT I definitely agree on the smashpot vs secus (and by extension vs luftkappe and A1+ air spring). One thing that was very noticeable to me when I first got my zeb, was how much the fork seemed to sink through the mid stroke and would then ramp up hard at the end. There seemed to be some pre-load on the initial air springs (ala c1 air springs in the pike/lyric) that stopped the fork from sinking into it's travel while sitting static without a rider on it. This meant that it wanted to sit with very little sag, very high in it's travel, but I kept blasting through the mid stroke and then sorta struggling the position of the ramp up at the end. I am not an engineer... so I'm just spit-balling on what I felt here... That being said, it seemed to me that the hammock effect of the air spring, when +/- chambers were equalized, in the middle of the stroke was extremely pronounced. It basically meant to me that there was only one option, run what I would consider oversprung, which made the mid stroke feel much better, but at the expense of a wall of progression that I could only keep in reserve.
The secus seemed to give me the ability to balance bottom out vs dynamic ride height. It seemed the window of positive air chamber pressure was wider, in that I could more easily balance sag (ride height) vs bottom out and actually start playing around with pressures vs volume reducers. That's when it became clear to me that the lower leg air volume was playing such a massive part on this fork, more so then I've experience in the past on any other product before. That being said, I haven't tried a luftkappe or the A1+ air spring to see if the increased negative chamber volume and increased ramp up from the positive chamber reduction... would allow me the same wider setup window with similar amounts of freedom for adjustment. My hunch is that getting that negative volume without dealing with the air in the lowers (as the secus does) would make it very difficult for me to find a setup that would allow me to use the appropriate amount of travel and get the support I want.
I also agree that running anything over 20 - 25% sag in a fork is crazy. You're basically volunteering to run the fork in such a way that you're smashing into the wall of progression from the air spring voluntarily. You're far better off running less sag, keeping the fork higher in it's travel where the spring rate of the air spring is lower and it absorbs small bumps well, while maintaining the geometry of the bike... then you are trying to soften it up and then ramming into progression while also steepening your head tube angle. Beyond that, the comments about rider weight balance downhill vs on flat ground are dead on.
Now, regarding the damping... we have @Dave_Camp in this thread... and I'm guessing he's doing 90% shaking his head no at these responses and 10% indifferent or in slight agreement... at least for riders that can't send as hard as he can. I'm going to trudge on here... and I know that I'm likely firmly into that 90% category with my comments... but I don't really feel like digging into my pile of work just yet... I digress...
I would find it hard to believe that any riders would be running less compression valving then the stock damper provides. The charger 2.1 (and the new grip 2 vvc from fox for that matter) provide little to no compression damping when run wide open. My guess is that this is deliberate, knowing that many riders aren't servicing their fork often enough (most) and some riders are simply very light weight. If I had to hazard a guess... you could end up with a significant amount of your required compression damping made up between air spring seal drag and dust wiper/bushing drag on a fork that has not been serviced (I'd guess as much as 70-80%). The shim stack on the basevalve on the charger 2.1 is very, very soft and I've only parking lot tested a charger 3, but I believe that is even softer.
I am far from a pro, but I ride with a few shredders here in socal, and I've read my fair share of bike checks and I have yet to find anyone running a significant amount of HSC on these forks. This is one of the things that I was heading towards in the suspension design thread that I started. The HSC adjuster (as almost all HSC adjusters out there) puts pre-load on the basevalve shim stack. Not to get further into the weeds, but the Charger 2.1 damper, has an HSC adjuster that can completely remove pre-load from the basevalve when run in fully open, which is not something every product out there does. The way it's valved from the factory, with EXTREMELY light valving on the base valve, allows you to actually play with the HSC adjuster as a consumer, and it does something that's perceivable... I would contend that we as consumers, and the industry overall, would be best served to give up on HSC adjusters for top tier products, and instead offer a blackbox prosumer version of the damper with three off the shelf HSC base valve tunes. IMO, just like with regards to coil sprung suspension products... you're better off with the right spring rate and no-preload then you are with the wrong one and pre-load. I look at basevalve valving the same way, I'd rather have the proper shim stack (with no HSC pre-load), and a parabolic needle LSC (bypass) adjuster then have an HSC adjuster that clickity clacks, but isn't overly usable due to induced harshness in the system.
Again... further in the weeds here... but because of the above, I fail to see how anyone would be running lighter compression valving then the stock c2.1. In my case, going the opposite route and nearly tripling the valving on the base valve in order to be able to run the HSC adjuster completely open, with no pre-load on the shims was an improvement in performance. This allows me to leave the HSC adjuster open, and tune compression to taste using the LSC/bypass adjuster. Otherwise, lighter valving on the base valve would require clamping down on the HSC adjuster... and as mentioned above it works similarly to how pre-load on a coil spring does. It raises the minimum force required to crack the shims open and thus, instead of a gradual gradient into the flow path resistance, you have a more platform feel that starts to creep in. The trade-off for me, is that if I want to re-balance HSC/LSC, I have to fire up restakor and figure out what different recipe of shims will be required to stiffen things up where I want them.... and this is clearly un-sustainable from a consumer perspective.
This is not a design fault of Rockshox by any means... the charger 2.1, is in my opinion one of the better designed dampers out there. It's not subject to tolerance issues in the HSC adjuster like some other dampers (grip 2 vvc). That being the case, most riders (myself included) find that anything more than +1 (from full open) on the HSC adjuster starts to add significant harshness. The harshness that's perceived from a consumer level on these dampers is apparent because we simply aren't riding hard enough to need the kind of support that expert/pro level racers need. Pro's will deal with and welcome what consumers would perceive as harshness as they need absolute control when putting un-imaginable energy into the bike. We as consumers however, are harder to predict and design product for as we tend to be all over the place with body position, weight balance, improper setup and not enough service on the products. Rockshox, can't sell a product that simply has no adjustability because people think that they know better and need a ton of clickers to turn. They need to accommodate as wide of a range of energy put into the product as possible and the charger 2.1 does accomplish that. For the rest of us that ride like muppets... there can be still be some aspect of only being able to get the damping about 90% perfect.
As for bushings... I find that rockshox generally has tighter bushings then fox does (in the current generation). It's the one thing on the chassis side that I think that fox is potentially doing better than rockshox. It's a total double edged sword however from a mfg perspective. I have definitely over clearance bushings on fork lowers and it causes a very slight observable click. I've never over done it to the point where there is a knocking sensation like a loose headset. However, it's obvious to me that the difference between properly sized for maximizing performance and too loose causing clunks and clicks that consumers wouldn't tolerate is for sure in the range of thousandths of an inch. For fork manufacturers, this is a damned if you do, damned if you don't scenario as you'd technically want to run them as loose as you can, but that would potentially significantly reduce service life. Remember that the major mfg's need to make a fork that will work for a Pro/Expert rider that gets the proper work done and also 275lb dude on a trek rail that does fork service once every 350 hours. Very few consumers want to be signed up for potentially replacing the bushings in their fork (or their lower leg assemblies) during their ownership of the product. I would make that trade for 10-15% performance. Again, it would be rad if I could buy a blackbox pro-sumer tuned fork that had this work done from the factory for an additional 200-300 dollars.
TLDR: run 15 - 25% sag in front... use sag as a starting point and gut check reference and not the gospel. Record yourself in slo-mo using any of the current generation phones and camera modules to check your ride height. Poor mans data acquisition. Regarding damping, the stock valving and function on this fork is well good enough for 98% of riders doing 90% of their riding. If you're chasing the dragon on valving, there are some minute gains to be made... IMO no where near as significant as just keeping the fork serviced (lower leg/air spring service every 6-8 weeks), checking the bushing tolerance and dialing in the spring side to your preference via either; stock w/proper setup and slight compromise, secus, a1+ air spring, luftkappe or smashpot.
So run an Ohlins?
Their 3 chamber air allows you to adjust the end stroke ramp. Not getting full travel? Back off the end stroke ramp air pressure. Need more bottom out support? Add air.
They have a three click HCS system that doesn't use spring pre-load on the shim stack (they use an oval shim).
Do you like very firm compression? Have the TTX18 re-shimmed from their documented shim bank. Lighter rider and like less compression? Their shim bank has that covered. With their shim bank you don't need to rely on guessing or some guru's claimed magic, it's documented damping curves from the Ohlins team.
Well said sir. I have 19’ Pike with a C2.1 RC2 damper. The air spring is quite good for stock AFTER burnishing my bushings. The damping on the other hand, when things go consistently rough the spring no longer feels plush due to the harshness coming from the damper. I try to run LSC at least halfway from open but after awhile I almost always start backing it off. HSC is another story, only time I can run any of the clicks and not get pretty bad harshness is on smooth out flow/jump trails.
I will go Rockshox over Fox ANY day of the week but while I was in Angel Fire back around Memorial Day I was able to ride a few bikes that had the newest Zeb with C3 and an older one with C2.1. Both of them became jackhammers when bombing down any trail that was blown out or just gnarly. The fork I mainly run on my Hightower V2 is an EXT ERA V2 and when switching back and forth between those forks and my ERA, it was like night and day as far as being able to maintain the level of comfort/confidence/aggression I started each trail with. My ERA is not without issues unfortunately but in those circumstances it outshined them clear as day. I have no idea as to what might be different between these forks that keeps the ERA more comfortable on long and incredibly rough descents. Would love to hear anyone’s thoughts on why that may be the case. Just an observation guys. Like I said tho, I think Rockshox suspension are pretty awesome. I have a Tractive tuned SD Air on the Hightower and i believe that is THE best shock setup you could possibly have on the previous model Hightower with the horribly limited options for a rear shock
That approach to sag setup makes total logical sense. I've already added PSI to get closer to 20% in the old parking lot scenario, which seemed safer than setting it up going down hill.
And I removed the token to see how far I'll get into the travel. Because if I understand @ebruners point of minimum spring weight/preload to achieve desired sag on a coil fork and applying that to air.... you'd want to start with no tokens and HSC open once sag is set by PSI. Then let the damper do its thing and add HSC through testing until the desired "feel" is achieved. No matter the damper type there has to be a point you stop adding HSC, add a token then start again with HSC open and repeat?
I'd think this is still on topic because HSC and especially the token is going to affect the end of travel performance/using all of the travel. And for the OP and anyone not able to achieve full travel, if you're running no tokens, sag at anything other than 0 and not getting full travel the issue would have to be on the damper side, contradictory to my first response bc he tested HSC wide open and no tokens and still couldn't achieve full travel.
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I muddied the waters talking about pre-load on valving shims vs spring pre-load on coil springs in a thread that is mostly about air spring forks. The two are completely separated. While you're on the right track with regards to setting up the air spring: Set sag with no tokens as a start... compression damping is separate.
To oversimplify... damping is speed sensitive and springs are position sensitive. Meaning, damping doesn't change as something moves through it's travel. Springs on the other hand, respond differently depending on where they are at. An air spring, has a different rate later in it's travel then it does in the beginning where as coil springs have the same rate later in the travel then they do at the beginning.
With air springs, you're basically limited to pressure and positive air volumes in order to get the desired result... unless you want to modify things. Then you can get other ways to tune things on the spring side through modification (enlarge negative volume with vs luftkappe or rs a1+ air spring, add negative volume and a mid valve that controls/bleeds air ramp up with vs secus, or do away with all of that and switch to coil).
The damping comes into play as too little damping and you're fully requiring on the spring to hold you up. Damping and spring rate work in tandem to do their jobs. However, with a lot of modern damper design, it's really the spring that's doing most of the heavy lifting. When you switch to coil, you find that you're adding in a lot more damping then you would with air... that's purely because you're not dealing with the 5-20lbs of force added to the system through seal drag. The simple truth is that for most riders that are in the intermediate to advanced window, 90% of how a fork feels comes down to the right spring rate and the right rebound setting. Once you start really pushing the limits, or are very far outside of the design intent window due to weight or riding style, then you're likely going to need to just run things firm and be strong AF to hold on... or look to make changes to the damper.
To simplify a few things...
1) A more linear spring with less sag often will give a more comfortable ride being the bike has more avaliable travel that requires "less force" to go through its travel. The downside is a really strong, active and aggressive rider may "push through" their travel more than they like - IE, the bike doesn't respond to their input as they'd like.
2) HSC is for supercross and red bull rampage (mostly). Going as light as possible here is likely going to yield the best performance for most riders. We rely on air springs, HBO (in some cases), fork lowers and bottom out bumpers for ramp up when we screw up.
As a chronic over-thinker I’m pretty sure this is a bad thread for me! Just got a Fox 38 for my Spire and am now extremely stressed about number of tokens and HSC lol
I gave up on using sag as a reference on forks after I measured it 4 times in a row and got a different number every time. I suppose you could average a bunch of measurements but I still don't trust that sag is consistent enough to use as an indicator. I start at what the mfg recommends for my weight and then bracket from there. It also seems like the Zeb is really sensitive to air pressure, like a 3 psi difference is very noticeable so it's worth really spending time bracketing air pressure in fairly small increments in my opinion.
My experience with a Charger 2.1 Zeb was that no tokens and a bit more pressure than recommended felt best, lower pressure and more tokens felt harsher which I interpret as the fork hitting the progression wall more often. I don't hit full travel very often but I don't really care.
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