- I'm Dan Roberts.
We're here in the forest below (indistinct) Switzerland.
and this is the Fox 38 versus the RockShox 7.
(rock music)
Bigger is better is the mantra
that you hear a lot these days.
Size might be important to some people,
maybe it's what you do with it that counts.
Looking back to the inception
of the EWS some seven years ago,
bigger is definitely better in that regard.
Wheel size has grown, frame robustness is up,
and travel has increased to tickle the undercarriage
of free ride and down hill bikes.
Many consumers now forgoing that quiver of bikes
for one bike to do it all.
Speed is up too with racers and your average Joes alike,
going faster than ever before
and doing it all on this single bike
that's designed to go up the hills
as well as hurtle back down them.
So then, we're all around bigger
and this year FOX and RockShox applied that mantra
and gave us two new fork offerings.
Both of these sit at the top of the travel tree
for single forks for their respective brands
with only the FOX 40 and the RockShox Boxer
having more travel.
Both Rinda and Joey are racing
and heavy hitting riding and with their long travel steps
there have had to have been some changes compare to the
Lyric and 36 to help them cope with these intentions.
Both have stanchion diameters up at 38 milometers
and in the case of the FOX 38,
have travel options of 180 mm travel.
In the case of the RockShox Zeb,
have options of 190 mm travel.
For that lonely single crown, is a hell of a lot.
With so many similarities in terms of dimensions,
intentions and release timing,
it was only fitting that we put them head to head
to see how each one performs
and if one stuck it's larger diameter head
in front of the other.
(rock music)
The 38 is available in 150mm to 180mm travel options
in both 27.5 and 29 wheel sizes.
The 27.5, there's a 37 or a 44 mm offset.
For the 29 there's a 44 or a 51 mm offset.
It comes in price options
from $949 USD all the way up to $1199 USD.
Our 29" factory 170mm fork with an uncut steerer
weighed 2358 grams.
FOX's naming is pretty easy to follow.
With the 38 referring to the diameter of the stanchions
and this being their most noticeable change to the new fork.
Slightly more hidden away though
is an oval butted steerer tube
designed to place more material
at the front and back of the tube
to help boost the stiffness under hard riding.
There's a return of the floating axle,
something that the 40 always had and older 36s too.
With either the QR axle or the Balt anchor bolt,
the hub is clamped against the brake side lower leg
leaving the other leg free to float on the axle
for the spacer to find it's perfect alignment.
The idea being that a fork's friction shouldn't be
at the mercy of hub tolerances
and allowing the fork legs to be correctly aligned
gives them the path or least resistance when in use.
FOX also incorporated bleed valves
on the back of the lower legs to purge
any built up air either through big changes in elevation
or air ingress through riding.
They also double up as two of the mount points
for the FOX mud guard.
The lowers also have molded in channels
to give the lower leg oil a chance to recirculate
up to the firm rings sitting just under the wiper seals
and lubricate the seals and bushings.
With the onset of larger head tubes
either through design choices
or the 1.8 inch lower head set standard,
FOX offset the arch forward
to ensure it would clear the frame at full travel
no matter the bike it's fitted to.
The 38 uses a 180mm post mount for the brakes
with options that go all the way up to 230 mm rotors
by using adapters.
Fork dimensions are easily available
through the FOX tech help page on their website.
But compare to the same travel 36 from 2021,
you're looking at 3mm longer axle to crown
and compare to the 2020 36, it's seven milometers longer.
The air spring of the 38 is a bit different
to the rest of FOX's single crown forks.
With it using an inner tube inside the fork stanchions
which then uses a smaller diameter piston
than the 38 milometer diameter leg would suggest.
This changes the compression and expansion ratios
while also increasing the air volume
that the lower legs take up.
Reducing their ramp up effect
in the fork's overall performance.
The air spring is tuneable with snap in volume spaces.
With the maximum number varying on the travel of the fork.
With shorter travel versions recommending more spacers
to help the air spring ramp with the reduced travel.
Max fork pressure is up at 140 psi.
The 38 uses FOX's latest damper unit called Grip2.
It offers high and low speed adjustment
for both the compression and rebound.
It also uses the newly designed adjusters
to change the high speed compression and rebound
dubbed VVC or variable valve control.
They use small propeller shaped plates
that when turned via the adjuster adjust the fulcrum
or pivot point changing the mechanical leverage
and effectively stiffening up the entire shim stack
or valve behind it.
Some system uses seven clicks of adjustment
to match FOX's new generation shocks
that also use the same system of VVC.
Those three dampen adjustments use a needle
and orifice style arrangement
to meter the oil flow through the valve
and control the low speed compression and rebound.
The 38's damper is somewhat open bath
circulating damping fluid through the damper
and into the lowers meaning that the two systems
use the same oil for lubrication and damping.
This negates any problems with the sealed damper
possibly ingesting the bath oil,
becoming plump and affecting the fork performance.
It also means that the lowers on the damper side
are lubricated by a lot more oil.
The name Zeb comes from the explorer Zebulon Pike
who's famous around the Colorado Springs area
that RockShox has their headquarters.
But it too has 38mm diameter stanchions.
Zeb is available from 150 to 190mm travel
in the same wheels sizes.
It has a 38 and 44mm offset for the 27.5 version
and a 44 and 51 offset for the 29 inch.
It costs between $699 USD and $999 USD.
Our 29" Ultimate 180mm travel with an uncut steerer
came in at 2274 grams.
That's 184 grams lighter than our FOX 38.
RockShox uses a torque end cap fitment for the hubs.
While the hub width remains the same at 110mm wide,
the end cap surface contact is upped considerably
to help with overall fork stiffness.
All though you do need to use the end caps
to get this benefit.
Without and you have to wiggle the hub around a bit
to line it up to get the axle in.
The Zeb uses a simple bolt on axle with no floating system.
All though every set of RockShox forks I've had
you need to splay the leg apart ever so slightly
to get the hub to slide in.
Leaving me wondering if this is their method
of mitigating a narrow hub width tolerance.
The Zeb also offsets the arch to clear the large head tubes
and uses a 200mm post mount for the brake.
Even though the Zeb can go as low as 150mm travel,
it's a bit more fitting to see the minimum rotor sizes,
200mm, given the fork's stout intentions.
Max rotor size is up at 220mm
and there's also a bolt on fender available for the Zeb.
Compare to the same travel Lyric from 2021,
the Zeb has a 5mm longer axle to crown
and compare to a 2020 Lyric, 4mm longer.
The Zeb uses a similar air spring design
to the other RockShox forks dubbed DebonAir.
But again the system found in the Zeb is unique to it
due to the piston diameter for the increased stanchion
and the different negative volume defining part
to adjust the positive to negative chamber ration.
The air spring is also tuneable with spacers
but on the Zeb they screw in
with the aid of an 8mm hex tool.
There's even a dual positioned air spring version available
allowing a quick change in fork travel on the fly.
Max pressure for the Zeb is up at 148 PSI.
The Zeb uses the Charger 2.1 sealed damper cartridge
with adjustments for low speed rebound
and high and low speed compression.
Low speed adjustments use the same needle and orifice
metering system with the high speed compression adjuster
preloading the compression shim stack
with four clicks of adjustment.
RockShox say they worked to bring the new Charger 2.1
damper adjustment window more aligned
with what was needed in the real world.
Allowing people to potentially
use the extremes of the clicks rather than have an extreme
that would never be used by the public and racers alike.
(pop music)
The 38 requires a few extra set up steps
coming from the floating axle.
But once done it's set for that hub width
when using the QR axle.
The kabolt uses the pinch bolt
each time you have to take the wheel in and out
and forgoes the tube spacer that you would use
with the QR axle.
Recommended settings are printed on the side of the fork
outputting air pressure and rebound clicks
for various rider weight ranges.
At 75 kilos all kidded up, it suggested 93 PSI
with six clicks of low speed rebound and five of high speed.
All clicks being measured from fully closed
with the first click you encounter coming back
being counted as one.
The fork came with one volume spacer installed.
RockShox also prints the recommended pressures
on the side of the fork.
But their side markings printed on the stanchions
make initial set up a doddle.
They also have the online Trailhead setup tool
either on the website or via the app.
Inputting the fork's serial number on the back of the crown
gives you access to fork information documents,
set up guides based on your weight
and type of bike, plus all applicable service
and upgrade kids for that fork.
The fork stick is suggest 62 PSI while the Trailhead app
suggested a slightly softer 59 PSI setup
with nine clicks of rebound from fully closed.
The fork came with zero fork spacers installed.
(pop music)
I've been out testing both forks for the past six months
in terrain ranging from
the demanding steeps of (indistinct) Switzerland
to the fast root filled forests of Russia and Italy
with everything in between being thrown the fork's way.
Out of the box the 38 took a few more times
around the houses to get to a happy window.
With it needing much more pressure than recommended,
about 105 PSI, some 12 PSI higher
than the suggested settings.
That up in pressure also needed a change
to the rebound damping clicks
to keep the biggest ring in check.
Whereas the Zeb ended up the closest
to that recommended settings
with me finding that happy window pretty quickly
from those recommended settings.
Both forks exhibit fantastic sensitivity
and have maintained that through out a whole summer
and autumn season of riding.
All though I might be in trouble
for not servicing them earlier.
The Zeb feels like butter over the small hits and chatter
and that left me removing it
from my list of things to think about as I rode.
The 38 matches this, but there's a touch more information
coming through to your hands.
Not in a bad way, and definitely not harshness,
just a nat's whisk of more feeling than the Zeb.
When those hits get bigger and the going gets rougher,
is where the forks become more separated in feel.
The 38 gives the impression of riding lower in it's travel
almost like you're missing a stem spacer
from under your stem.
Whereas the Zeb keeps a higher ride height.
On the flip side though, in these rough sections of trail
is where the 38 then offers more composure than the Zeb
with it being efficient in it's uses of travel
with the repeated bigger impacts.
The Zeb gives the feeling of more movement
through the travel which then needs a bit more body language
from your arms to keep up with it.
I tried more pressure in the 38, up at 110
and up at 115 PSI to try and help it ride higher,
but was met with an increase in overall harshness
even when reducing the amount of compression
to account for the bigger spring.
I also tried more compression with the same spring rate,
but again, the harshness increased
and I found myself coming back again.
Eventually setting it three tokens,
five clicks of high speed rebound,
eight of low speed rebound,
three of high speed compression
and 10 of low speed compression.
With the Zeb I tried more tokens in the fork
as an experiment but came back to the stock setting of zero
finding it to be the best balance of travel usage
without hitting a wall of progression in the air spring.
I eventually settled at 70 PSI in the air spring
which calmed the fork's movement through it's travel
without bringing too much overall harshness
into the equation.
I settled at nine clicks of rebound,
nine of low speed compression,
and two of high speed compression on the Zeb
giving me usable options in damping either way
depending on the terrain or how hard I wanted to ride.
When in that happy window,
I could ride hard and happy with the fork
but just had to have the knowledge of more arm movement
in the really rough sections of trail
to help with the fork's character.
For anyone with a boxer, they might know this feeling
all though with the Zeb, that character trait
is far less pronounced.
In the steep trails
which are in abundance around this part of the Alps,
both forks ride well and neither dives drastically
while in the steeps or while grabbing a bunch of brakes
from thinking you're 10 men and letting off them
for a bit too long.
That is though,
with the 38 needing a higher bar height than the Zeb.
But once the bar height is good,
then the fork does offer good support
even though it might be riding lower in its travel.
I can appreciate some people
will run the 38 with 180mm rotors
but given the intentions it's a little fiddly
to have to use adapters on the brake mount.
The Zeb is just a bolt on and go.
Another small point is that our FOX 38 ended up having more
than the stated seven clicks of adjustment, up at nine.
We've taken apart some of their rear shocks
using the same VVC design.
It could actually be a dead click
when you go from turning one direction to the opposite.
FOX suggests that you service the 38 every 125 hours
or yearly or if you live in extreme conditions
or give it extreme use,
then you should service it a bit sooner.
There's a four digit code on the back of the fork
which in combination with the FOX website
will bring up all service specification and part data.
For the 38, it needs 40mm of lower leg fluid
in the damper leg and 20mm in the air lower leg.
It's a familiar scenario for working on the 38
for lower leg services, air spring swaps,
for changing travel or for servicing
and they're no more difficult
or any different than normal 36.
RockShox suggests a lower leg service every 50 hours
and every 200 hours a damper and spring service.
Searching on the website
with the serial number on the back of the crown
brings up all service and specification data
along with recommended upgrading service parts.
In both lower legs the Zeb needs 20mm of oil.
The RockShox Zeb is the same
as all other RockShox forks to service.
For the lower legs air spring changes
are familiar and simple.
Picking a victor between the two forks is no easy task
with each fork having lovable traits
in their character that I cherish.
While neither fork is perfect,
the ride arounds for each of them is neither problematic
nor a hindrance.
I've been switching backwards and forwards
between which one I prefer, usually with that aligning
with which one is partly to the front of the bike
that I'm riding.
Both the 38 and the Zeb are excellent offerings
for this long travel, aggressive single crown fork.
But bringing in the factors of price, weight,
and set up along side performance, it's the RockShox Zeb
that sticks it's nose slightly ahead of the 38.
It's a cheaper and lighter package than the 38.
With setup it got me to a happy place in those settings
far faster and with much more ease than the 38
and that, for me, counts for a lot.
Those recommended settings that RockShox give you
being far closer to the final settings that I had
when testing had finished.
The performance of the 38 is top notch
and it's composure on trail while remaining supple
is a tiny bit ahead of the Zeb.
But that's not enough with all things considered
and it did take more tinkering
to find that happy window of setup compare to the Zeb.
Something that people with less understanding of suspension
and tuning might take longer to find
or may not even find at all.
Especially with the 38 settings at the end of testing
being so far away from the initial settings
that FOX suggested.
There will always be diehard fans of FOX and RockShox alike
and if you like a fork that is supple
and feels like it's working away underneath you,
then the Zeb would be right up your street.
On the other hand, if you like your forks
to have a bit more of a stuck to the ground feeling
and have more tinkering options,
then the 38 might be what you're after.
But after many months testing in many different terrains
and conditions and with the editorial gun to my head,
it's with the RockShox Zeb that I find the winner.
Like this match up?
Don't agree with the verdict?
Perhaps just wanna skip all the information
and go straight to voicing your opinion?
Then let us know what you think in the comments.
(rock music)