why such low pressures in the Zeb's?

Dave_B

E*POWAH Elite World Champion
Aug 29, 2020
1,467
1,593
Newquay
lots of posts on here about users running lower pressure than what the trailhead app suggests. I'm the same. 95Kg rider, 2 tokens, 65psi pressure and very rarely if ever get full travel. (Trailhead suggests 92psi)

why are such low pressures needed in the Zeb's? (I have the latest buttercup version)
 

Planemo

E*POWAH Elite
Mar 12, 2021
605
706
Essex UK
I believe it's because they have a large internal volume compared to some other 38's. My Domains are the same.

If you never hit full travel why are you using tokens? I don't run any. I think zero is actually recommended by RS too, partly because of the issue you describe. Tokens do reduce the volume so you would think this would help but in doing so the ramp-up becomes so high you never get to use full travel. Put simply, the volume designed into the system is too big for the available travel (especially on 190mm) and adding spacers is a crutch to reduce the volume but then brings other problems such as excessive ramp. I suggest removing the tokens, adding a little pressure and just see how you go. I really like my domains (with SKF seals) but I'm not a big jumper so I don't need tokens but I do use up most of my travel at the correct sag so They are about right. Super plush and work well throughout the travel. TBH I'm not sure what pressure I am actually using as I'm not that bothered but I remember it being pretty low, somewhere around 70 I think.
 

RustyIron

E*POWAH Elite World Champion
Subscriber
Jun 5, 2021
1,831
2,850
La Habra, California
lots of posts on here about users running lower pressure than what the trailhead app suggests.

Avoid falling into the trap of trying to follow the advice of everyone who posts on the interwebs.

With that said, I'll offer some advice. Set up your fork with the pressure that gives you the sag you're shooting for. That's what your o-ring is for.

The volume spacers are to keep you from bottoming out. If you're not bottoming your suspension, you might want to get ride of some spacers. They make your ride harsher.

Something to think about: Lowering your pressure to move deeper into the travel will result in a harsher ride. You might not want to do that.
 

Dave_B

E*POWAH Elite World Champion
Aug 29, 2020
1,467
1,593
Newquay
Yeah thanks, I know it’s all a setup compromise. Sag is good at my pressure. May remove a token and then re-assess.
 

THA

Member
Sep 16, 2023
76
90
Finland
In case of Zeb, especially with 180-190 mm stroke, the lower leg pressure ramp is, as I can think off, the main issue. Something around 40-45 psi is significant bottoming pressure - playing the main role in lower pressure rates at least. Adding volume spacers, if I understand this correctly, increases the the + chamber pressure You need, to get the same sag - due to equal rise in - chamber pressure, but giving more mid stroke support.
I felt 2 was way better than 0, but I got only max. 130 mm stroke with 32 psi - so personally I gave up with air. But for an average/normal weight rider I would suggest to try to add volume spacers, increase the pressure and try Secus - that might be just what You need.
 

Shjay

Well-known member
Apr 30, 2019
835
491
Kent
I would say removed one & increase pressure. Also what travel are you running. I found my modified Yari was horrible at 170 with one token but good at 160 with no tokens! Now running a DSD runt in there with Novy Splug damper = epic 😂
 

irie

E*POWAH Elite World Champion
Subscriber
May 2, 2022
2,577
2,632
Chichester, W.Sussex, UK
lots of posts on here about users running lower pressure than what the trailhead app suggests. I'm the same. 95Kg rider, 2 tokens, 65psi pressure and very rarely if ever get full travel. (Trailhead suggests 92psi)

why are such low pressures needed in the Zeb's? (I have the latest buttercup version)
For your weight Trailhead suggests 92psi only if E-MTB is selected whereas if MTB is selected 82psi is suggested.

There have been multiple posts on here which you must be aware of stating that MTB should be selected.

I am 80kg ready to ride with 160mm Zeb A2 forks (no tokens) and 68psi is suggested. I prefer 65psi.

What is the issue?
 
Last edited:

Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,554
5,043
Weymouth
The same applies to Fox 38s and it may just be that both forks are designed for enduro and the pro riders are probably running those forks with a lot more air pressure and compression. They ride fast and hard enough for the fork to be working in mid stroke but most of us would find those settings too harsh. My EMTB tuned Fox 38 is very different to my non EMTB tuned Fox 38 despite both being Factory/Elite versions. The EMTB tuned fork works well with Fox recommended compression/rebound settings ( or close) but with reduced air pressure. The non EMTB forks work best with much more opne compression and rebound settings and lower air pressure than Fox recommend. No doubt the situation is very similar with RS.
 

Plummet

Flash Git
Mar 16, 2023
1,152
1,634
New Zealand
Add tokens and remove air because they progressively ramp up more.
If you remove a token you will need to add pressure in.

I'm running the following at me 76kg in my birthday suit.
Voima 25kg ebike
190m zeb 2 tokens 55psi
Rocky slayer mtb 14kg
170mm zeb, 1 token 60psi

Side note. I never run with the manufactures suggesting they are always impossibly harsh and over pressured and over damped. I always wind out the settings from factory and run less pressure. No matter who the manufacturer is.
 

ebikerider

Active member
Oct 1, 2019
706
484
Australia
From my experience most standard forks don't have enough damping so talk of them being over damped is not what I've felt. The harshness from adding extra on the dials is more due to the design of the damper and the lack of ability to flow oil without spiking transferring too much feedback to the rider. I've had dampers modified to remove this harshness and generally I'll up the pressure after this as the fork has started to function correctly (or close to).

Another reason for guys running lower pressures than recommended is to do with tight bushings. Zeb's are commonly tight. Rockshox put longer bushings in these and with their usual inability to hold tolerance in production forks they have ended up with a heap of forks with tight bushings. Get the bushings sorted and the damper modded and the Zeb isn't a bad fork.

Then put on a Secus and it helps with the progressiveness. As usual...just add $$ :)
 

Plummet

Flash Git
Mar 16, 2023
1,152
1,634
New Zealand
From my experience most standard forks don't have enough damping so talk of them being over damped is not what I've felt. The harshness from adding extra on the dials is more due to the design of the damper and the lack of ability to flow oil without spiking transferring too much feedback to the rider. I've had dampers modified to remove this harshness and generally I'll up the pressure after this as the fork has started to function correctly (or close to).

Another reason for guys running lower pressures than recommended is to do with tight bushings. Zeb's are commonly tight. Rockshox put longer bushings in these and with their usual inability to hold tolerance in production forks they have ended up with a heap of forks with tight bushings. Get the bushings sorted and the damper modded and the Zeb isn't a bad fork.

Then put on a Secus and it helps with the progressiveness. As usual...just add $$ :)
my experience is opposite to yours. Custom tuned forks/shocks excluded i pretty much wind most dampening out on all my suspension to get them faster and less harsh.... therefore they are over damped.
 

ebikerider

Active member
Oct 1, 2019
706
484
Australia
my experience is opposite to yours. Custom tuned forks/shocks excluded i pretty much wind most dampening out on all my suspension to get them faster and less harsh.... therefore they are over damped.
Generally when I hear that I feel it is misunderstood. IME when riders feel that their forks are overdamped it is likely because the damper is spiking and/or it is bushing bind. This is not too much damping, it is ineffective damping. Opening everything up is one method people use to try and avoid the spiking and then end up relying on air pressure and/or tokens for support. Bushing bind is a huge problem on a Zeb from my experience too (I'm referring to this fork as you have one).

Good chassis.
Friction reduction.
Useable range of effective damping.
Correct spring rate/air pressure.
Suitable progression.

Of those 5 things, the new Zeb for example delivers on the first one. The rest need to be sought.
 

Plummet

Flash Git
Mar 16, 2023
1,152
1,634
New Zealand
Generally when I hear that I feel it is misunderstood. IME when riders feel that their forks are overdamped it is likely because the damper is spiking and/or it is bushing bind. This is not too much damping, it is ineffective damping. Opening everything up is one method people use to try and avoid the spiking and then end up relying on air pressure and/or tokens for support. Bushing bind is a huge problem on a Zeb from my experience too (I'm referring to this fork as you have one).

Good chassis.
Friction reduction.
Useable range of effective damping.
Correct spring rate/air pressure.
Suitable progression.

Of those 5 things, the new Zeb for example delivers on the first one. The rest need to be sought.
Doesn't feel like busing binding to me. Air pressure and tokens is what you should use to set up support. That is the primary spring rate.

Any way. I'm happy with my Zebs. I have them working how i want. No binding or spiking with a good amount of progressiveness and dampening to get 80% travel for 90% of my riding then using the last 20% with Bigger hits.
 

Robstyle

Active member
Nov 17, 2021
116
135
New Zealand
It's just Zeb things @Dave_B
I found exactly the same with my one. The new air spring is quite progressive in nature.
I found it quite fussy to setup to be fair!

Mines sitting on my shelf as my backup fork when others get serviced lol so I can't remember exact settings, but I ran no tokens, definitely on the low end of pressure and quite a bit of LSC.
 

Dave_B

E*POWAH Elite World Champion
Aug 29, 2020
1,467
1,593
Newquay
There have been multiple posts on here which you must be aware of stating that MTB should be selected.

I am 80kg ready to ride with 160mm Zeb A2 forks (no tokens) and 68psi is suggested. I prefer 65psi.

What is the issue?

the issue I have is getting full travel, no matter what combination of pressure and tokens I use.
I am going to try no tokens and 60 psi with a fast rebound and HSC and LSC in the middle. then adjust from there.
 

irie

E*POWAH Elite World Champion
Subscriber
May 2, 2022
2,577
2,632
Chichester, W.Sussex, UK
You shouldn't get hung up on trying to achieve full travel, just depends on the terrain and how you ride. Most important is the fork working nicely on your typical terrain. Most of the time I don’t use full travel and when I do that's mostly when I drop into something unexpectedly, or in bike parks (typically in summer).
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,991
9,388
Lincolnshire, UK
You shouldn't get hung up on trying to achieve full travel, just depends on the terrain and how you ride. Most important is the fork working nicely on your typical terrain. Most of the time I don’t use full travel and when I do that's mostly when I drop into something unexpectedly, or in bike parks (typically in summer).
Yep, I try to keep that last 10% for the unexpected. It must work because I have never bottomed out the suspension.
 

irie

E*POWAH Elite World Champion
Subscriber
May 2, 2022
2,577
2,632
Chichester, W.Sussex, UK
I set my suspension up to bottom out 9n my biggest reasonable hit. If it doesn't then you might as well have a lesser travel fork.
Longer travel over rough terrain can also make for a more comfortable ride. What you may want from a fork is not necessarily exactly the same as what others may want from a fork ...
 

rzr

Active member
Sep 26, 2022
384
242
bcn
Zeb Ultimate 2021 170mm. I weight 74kg (+gear) and on mellow trails 67psi, in bikes parks 70-74psi
no tokens, sometimes a few clicks of HSC/LSC.

if you don't use travel ,that's ok. and if you don't feel excesive diving or geo upset on steep trails that's ok too.
however new Zeb (with buttercups) has more compression damping than previous (this is what I understood from reviews)
 

THA

Member
Sep 16, 2023
76
90
Finland
Generally when I hear that I feel it is misunderstood. IME when riders feel that their forks are overdamped it is likely because the damper is spiking and/or it is bushing bind. This is not too much damping, it is ineffective damping. Opening everything up is one method people use to try and avoid the spiking and then end up relying on air pressure and/or tokens for support. Bushing bind is a huge problem on a Zeb from my experience too (I'm referring to this fork as you have one).

Good chassis.
Friction reduction.
Useable range of effective damping.
Correct spring rate/air pressure.
Suitable progression.

Of those 5 things, the new Zeb for example delivers on the first one. The rest need to be sought.
Totally agree with You, ridiculously underdamped fork + progression / mainly due to lower leg pressure ramp-up.
It's only so little One can do with air spring pressure when lower leg dominates - depending on riders weight/pressure, but having huge effect over all. Underdamped on trail riding and sudden rise / spikes on high speed hits. But as You said, good chassis - so I'll continue to work with this to make it perfect ;)
 

Zed.

Active member
Apr 26, 2023
167
224
Deepest Bandit country (Wales)
running lower pressure

set sag & try for comfort, suggested pressures are just a starting point (y)

Longer travel over rough terrain can also make for a more comfortable ride.


^^This (y)


not 'Zeb' related but...


I'm running a 37mm Manitou Mezzer on my 'keep-fit' Nukeproof Mega @ 180mm (+10mm over spec.) and it's really comfortable even over rockgardens & drops😎 it's running ~63psi in the main pos/neg chambers and they don't have tokens as such (it doesnt get to full travel so far🤠)

I've just bought another Mezzer to replace the Rockshox35 on my Treck Rail5 and am hoping for similar results🤞

Rich.
 

Dax

E*POWAH Elite World Champion
May 25, 2018
1,724
2,109
FoD
I set my suspension up to bottom out 9n my biggest reasonable hit. If it doesn't then you might as well have a lesser travel fork.

It’s nice to keep a little something in reserve, so bottoming it is a rare occurrence. I can only think of one occurrence when I’ve bottomed out my forks recently, no desire to repeat it.
 

ebikerider

Active member
Oct 1, 2019
706
484
Australia
I set my suspension up to bottom out 9n my biggest reasonable hit. If it doesn't then you might as well have a lesser travel fork.
Hopefully others don’t take this as a good way to set up their fork. It leaves nothing in the tank for an over shoot on a jump, a general fuck up or even riding progression.

I have a 140 fork that I rarely bottom so with your thinking I may as well be on a rigid fork as I set my forks up leaving a little in reserve at any travel.
 

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