Fox Announces New FIT4 Fork Damper & Roller Bearing Kit for Shocks

Aug 14, 2019
by Richard Cunningham  
Fox FIT 4 damper Roller bearing shock hardware kit
Fox offers outboard roller bearings to replace the inboard shock bushings.
Fox FIT 4 damper Roller bearing shock hardware kit
The new FIT 4 damper's most visible differences are a smaller, 8mm shaft and new seal head.

A good portion of Fox's success in the high end fork market can be contributed to its FIT damper. Lighter riders and those of us who like supple suspension tunes, however, have complained that Fox's FIT4 dampers are too heavily damped in the initial stroke. Fox has addressed this with a running change that includes a smaller diameter, eight-millimeter shaft, a lighter shim stack, modifications to the rebound circuit and a reconfigured FIT bladder. Reportedly, the new damper assembly also saves 35 grams and Fox assures us that their new tune retains the mid-stroke support that we have come to depend upon.

Fox plans to upgrade all of its non step-cast forks (36, 34 and 32 FIT4 forks) with the new cartridge as a running change and will also offer it, along with the roller bearing shock eyelet kit, as aftermarket options. It's a positive step for Fox and an opportunity for existing FIT4 fork owners to stay current without having to pony up for new ones.

The aftermarket roller bearing kit came on the heels of that announcement and should make a lot of riders happy. Technically, roller bearings are the best option for highly loaded, slowly rotating applications - and they take up very little real estate compared with ball bearings. Sealing slender-profile roller bearings from the elements, however, has been problematic.

Fox seemed to have solved the sealing issue with eyelet inserts that look like tiny headset cups. They house larger diameter bearings with full contact seals. Fox says that no special tools are needed to install the roller bearing kit, but you'll probably need their extractor tools to remove it. The kit retains for $30 and the extractor tools cost $110 USD.
Fox FIT 4 damper Roller bearing shock hardware kit
Roller bearings are housed in machined, press-in cups.



Official Fox Press release:


FIT4 Damper Upgrade & Roller-Bearing Shock Hardware Kit

Fox has implemented an important update to model year 2020 forks equipped with the FIT4 damper, and also introduces a new, low-friction roller bearing shock mounting hardware kit. Read on for more details....
New FIT4 damper
2020 FIT4 Damper Update

On the compression side, all 2020 FIT4-equipped forks now feature an 8mm damper shaft, new bladder construction, and a reconfigured shim stack. The 8mm damper shaft has a smaller cross-sectional area, therefore it pushes less oil through the base valve, allowing for less damping. The updated FIT4 damper provides more sensitivity while also maintaining low-speed compression support during aggressive riding, giving riders the ability to tune their fork to feel playful, aggressive—or both.

The rebound side implements Fox's latest tuning improvements through a wider opening check valve and a reconfigured shim stack. The new FIT4 damper assembly construction is lighter as well, with an average weight savings of 35 grams.

This update is implemented on all 2020 FOX 32, 34, and 36 non-Step Cast fork models featuring FIT4 dampers. Step Cast fork models received this damper makeover in MY19.

In its fourth generation, the patented FIT4 closed cartridge system provides three on-the-fly compression damping positions—Open, Medium, and Firm—to adapt to varying trail conditions. Factory Series forks feature 22 clicks of low-speed compression adjust in the Open mode, allowing riders to fine-tune their exact damping preferences. FIT4 is the damper of choice for riders looking for a lightweight fork with lockout and loads of performance.

Fox FIT 4 damper Roller bearing shock hardware kit
The roller bearing kit (right) can be installed without special tools, but Fox says you'll need their tool kit (left) to remove it correctly.

Roller Bearing Shock Hardware Kit

Also new for 2020 is an 8mm x 30mm roller bearing shock mounting kit (part# 812-06-096-KIT). Deploying outboard-mounted full complement roller bearings—as opposed to standard bushings—allowing the shock to move more freely as the frame cycles through its travel. Roller bearings reduce friction and improve performance to such a degree that, in some cases, more rebound damping and/or low-speed compression damping may be needed in order to compensate for the decrease in friction.

The roller bearing shock mounting kit is compatible all current Fox shock models and it is also compatible with many popular brands such as Santa Cruz, Transition, and many others. A special tool is needed to remove the bearing kit from the shock—Mounting Hardware Bearing Assy Install and Removal (part# 803-01-406). For installation instructions, click HERE.

To verify compatibility of this kit with your bike, please visit your local bike shop or call FOX customer service for additional assistance.

Fox Service West
38 Isidor Court Suite 120
Sparks, NV 89441
800.369.7469
Fox Service East
95 Underwood Rd
Fletcher, NC 28732
800.369.7469






178 Comments

  • + 56
 You have a very small shaft.
  • + 54
 The story of life, sooner or later men get more concerned about adequate fluid flow than the size...
  • + 4
 Not after seeing a Smuggler with an X2 on it.
  • + 7
 @WAKIdesigns: Tell me about it. I'm mid fifties and....wait, I've said too much already!
  • + 7
 Wasn’t the big deal about the big shaft on Fit4 that it displaced more oil?! And now Fox is walking it back? (To distract from creaking CSUs, maybe?)
  • + 7
 Assures us that their new tune retains the mid-stroke support that we have come to depend upon. This is all I got out of this article. Can't stop laughing
  • + 0
 how mush izzit
  • + 5
 What is this, a shaft for Ants!? It has to be at least twice the size.
  • + 0
 @WAKIdesigns: so true...
  • - 2
 No worries buddy, I got the rock shock
  • + 2
 @WAKIdesigns: hank hill has a narrow urethra and was rejected from the armed forces because he couldn't evacuate his fluids fast enough under duress.
  • + 2
 @Apfelsauce: I don't get why they refuse to address this issue...seems like such an easy fix (greater crown/steerer overlap).
  • - 1
 @serathestaii: it is simple, most buyers will look at the weights table. Fox 36E is free of all these issues but it weighs 2200g. That is at least 200 too much for elite endurbro racers
  • + 1
 @WAKIdesigns: That's light! My DVO Onyx SC weighs 2280g lol
  • + 0
 @serathestaii: how’s that fork? Cold you compare it to Fox 36?
  • + 1
 @WAKIdesigns: I only have a couple of rides on it...still tweaking the setup. Stiff chassis, very plush. I haven't ridden a "modern" 36 so I'm not sure how it compares. I think it's kind of crazy that no one's reviewed the Onyx yet.
  • + 1
 @WAKIdesigns: It's supplied with an integrated, bolt-on fender (similar to the one Syncros makes for the 36), which is nice. Zip ties are for holding helmets together—not fenders.
  • + 1
 It's really not about how big the shaft is. Remember the DHX RC4 with the thick shaft?
It came out so gloriously and right away FOX was gone from all stock bikes with CaneCreek DB's replacing them... lol
  • + 0
 @xander8: Man, a shaft inside forks chassis is a different story than a shaft on a shock, especially one that is compressed by a yoke increasing the leverage. Furthermore RS has adressed this issue even further by increasing the bushing offset inside the shock.
  • + 1
 @Apfelsauce: I've gone though 5 csu's under warranty on my 36 which is mad, never had a single issue with my lyrics
  • + 1
 @rupert030203: If I only could fit Grip 2 into a Lyrik chassis... I will be buying the 36 but I will be pissed off if I will get the creaking CSU issue everybody is talking about. I was thinking of getting the 36E with chunkier CSU but it has thicker walls on uppers as well which means only Grip 1 or Fit 4 from 34 can be fitted. Not Grip2. So no.
  • + 1
 @WAKIdesigns: yeah I'm fed up with the 36 creaking so I'm set for a lyrik next but still theres something about fox that rockshox don't quite have
  • + 1
 @rupert030203: to be fair my ‘16 Lyrik has bushing fitment issues. Many people had them on Lyriks and Boxxers.
  • + 2
 @rupert030203: I am also considering DVO Onyx
  • + 38
 No one ever:
.
.

.
Fox: Yeah let's introduce a couple of extra proprietary tools that if NOT used, voids all warranty.
  • + 1
 Is the tool only needed for bearing removal? Should be years before that's necessary...
  • + 12
 @hifiandmtb: If you're riding in the UK or Canada it'll be a matter of months not years before they wear out
  • + 2
 @hifiandmtb: Yeah I wonder how life span compares to their current bushing
  • + 1
 @hifiandmtb: Had to remove the cups to service the air can on a Rocky Mountain, and it was a trash system. Non-existent problem.
  • + 1
 @AD4M: @hifiandmtb I wore out the lower shock bearing and bushing in 3 weeks at Whistler last September, Intense M16 and DHX2 shock. 2 weeks of wet weather just trashed it to the point of needing new bushes and new mounting hardware as it wore the anodizing off the shaft.
  • - 4
flag cheetamike (Aug 14, 2019 at 10:32) (Below Threshold)
 I have yet to wear any shock bushings out in the last 7yrs. I ride all year round. Bearings are smoother , but are truly meant for full 360deg rotations . Your not seeing that in a shock application.
  • + 11
 @cheetamike: by that logic, bearings shouldn’t be needed anywhere on a bike frame except for the BB, and headset if you do barspins
  • + 3
 A hammer and block of wood voids warranties??
  • + 6
 @tacklingdummy: you use a block of wood?
  • + 2
 @hifiandmtb: Yes, only to remove it if you want to transfer the bearings to another bike. The cups simply press into the shock using something like padded vise jaws..
  • - 1
 @kleinblake: that's true. all pivot bearings should be Igus bushings.
  • + 4
 @kleinblake: Yup , not sure what you do for work. But I have spent 30+yrs working as a machinist. Seen lots of roller type bearings fail when a plain bearing would have done the job.
  • + 2
 @bigtim: Yes, of course. I have used block of wood to put in shock bushings, headsets, BB, headset washers, etc. because the tools and they are really pricey to use just once or twice. Wood is good because it soft and is unlikely to damage the part too much. However, I have evolved and bought most of the specific installation tools like a universal BB/headset tool which is great for removing and installing.
  • + 3
 @RichardCunningham: You'll need to remove the bearings to service the air can if they are installed on the stanchion eyelet.
  • + 2
 @tacklingdummy: I believe this is a classic example of the infamous.... wooooosh.
  • + 2
 Haven't companies learnt about putting bearings in things that only have 5 degrees or movement yet?
  • + 1
 @RichardCunningham: The eye let bearings are a ball style no?

Deep groove ball bearing 6900-LLU-MAX-ENDURO - 10x22x6 mm
  • + 3
 Yeah, bushings are generally better for applications like these, small space, high loads, low rotation rate, etc. But bushings wear out and create clearance which creates unwanted noise. Not good.
  • + 30
 Dampers in Fox's forks are not position sensitive, they are just speed sensitive. So there us no such think as "too heavily damped in the initial stroke" or "mid-stroke support" from a damper.

It's about time to stop confusing the customers!
  • - 1
 @Happymtbfr it doesn't have to be position sensitive, you can separate low speed, mid stroke, high speed and end travel stroke by adjusting the shimstack accordingly to produce spesific resistance in specific shaft speeds, although this requires extensive test and adjustments to determine shaft speeds in various conditions, when done right its more than enough to get a good result. Position sensitive dampers tend to change resistance regardless of shaft speed thus giving not refined damping when you reach the limit but with a different shaft speed.
  • + 1
 That explains why i never used much of the travel on my 2016 Fox36, I'm to slow. I was experimenting with lower pressures and tokens to use my travel (don't know why really), but that just messed up everything. Well, bike is sold and now I'm on a Lyrik. Lets just say that for å comfort/slow rider like me that fork seems to be more suiting.
  • + 4
 “Just” speed sensitive is what you want in a good suspension system.
  • + 5
 @erikskon:
Speed sensitive has nothing to do with your riding speed, if that's what you meant.
  • + 1
 @Loki87: I mean not exactly, but they are complementary.
  • + 22
 "A special tool is needed to remove the bearing kit from the shock—" Yes, a 10mm socket, 16mm socket, and hammer. Very special!
  • + 13
 I have a specialized block of wood and specialized hammer. Both precision instruments.
  • + 1
 @tacklingdummy: use a specialized rubber.... Mallet... Prevention is key
  • + 1
 @Lagr1980: I do sometimes. But the rubber mallet doesn't have that force like a hammer at times.
  • + 15
 They're using 6900 LLU MAX Enduro BALL bearings and call them ROLLER bearings......oh, and let's not forget:
"Technically, roller bearings are the best option for highly loaded, slowly rotating applications - and they take up very little real estate compared with ball bearings".
  • + 0
 costs need to stay down somehow
  • + 3
 Welp, balls roll I guess... that being said, it's a minor, yet egregious mistake if you're in the mechanical world.
  • + 1
 Any bearing with a rolling element is a roller bearing so ball bearings are a subset of roller bearings.
Perhaps they are thinking of needle bearings in that last sentence?
  • + 2
 Slowly rotating applications ?? Really so using them in wheels is a waste of time I guess.
  • + 1
 @bogey: Ball bearings use balls, roller bearings use cylindrical rollers. Needle bearings also use cylindrical rollers but with relatively tiny diameters.

A 6900 is definitely not a roller bearing. But probably still a good choice for the application since they're using the MAX version.
  • - 3
 @huntingbears: Any bearing with a rolling element is a roller bearing. This is basic mechanical engineering and in engineering text books.

en.m.wikipedia.org/wiki/Rolling-element_bearing
  • + 5
 @bogey: Any bearing with a rolling element can be called a rolling bearing or a “rolling element bearing”. Yes.

However, only bearings which use rollers can be called “roller bearings”. It’s that whole adjective vs noun thing.
  • + 13
 With all the talk about Grip dampers being amazing entry level and Grip2 being the top of the line must have....I don't understand where the FIT4 damper fits in. If I were on the market for a new bike, it would be that damper I would likely avoid when looking at model spec.
  • + 2
 Agreed. I don't understand why it still exists.
  • + 2
 I agree, I'm still amazed by the damping performance of my Rhythm 34 fork and have friends (with more $$) that are convinced that GRIP2 is the current holy grail of fork dampers. Nobody really thinks about FIT4 anymore!
  • + 1
 It's for those who don't care much about tuning and just want to go ride. It's nice to get the fit4 to perform a little closer to the grip2 if you're a set-and-forget person.
  • + 9
 @Pavel-Repak: I thought that was what GRIP was for!
  • + 1
 @Garethccc: If you want more than a single sweep adjuster - ie lockout and trail on top of compression
  • + 1
 I believe the grip2 is great for racers and really hard charging riders; FIT4 is easier to tune and more supple
  • + 1
 People like climb switches. Grip and grip 2 don't have these. Personally, I'm not interested in them, but it does come up a LOT still.
  • + 1
 @j-t-g: GRIP damper you just turn the knob all the way and its "locked out", GRIP2 is the only one thats not easily locked out.
  • + 5
 I, for one, am a little peeved that the 34 hasn't gotten the GRIP2 option yet.
  • + 0
 @j-t-g: Grip locks crazy firm, it's super easy, just turn the lever all the way clockwise. How can you make a comment like this if you don't know something??
  • + 4
 fit4 damper is lighter. xc oriented folks want it to be lighter. that said grip and grip2 are phenomenal and i dont disagree with you
  • + 0
 Perhaps thats XC oriented damper is why it was always so overdamped at the beginning of the stroke? You'd think XC racers would want the opposite - super supple initial stroke, then a really rapid ramp up in compression. My guess is thats what the new 2020 FIT4 aims to do.
  • + 3
 Grip 2 is only offered on the 36 because it is a twin tube architecture that wouldn't work as well if it was shrunk down to fit in a smaller diameter stanchion. Fit 4 is a good and light option for trail forks, Grip is an affordable, heavier option for trail bikes. If you're looking for a burly, light, twin tube damper fork. Check out the MRP ribbon SL, I recently swapped my fit4 34 for one, saved weight, increased stiffness, and it has a far better feel and adjustability. Plus assembled and tested in the USA.
  • + 2
 @hardcore-hardtail: interesting. Never thought about the limitation of the GRIP2 damper in regards to size. Then again, if the GRIP2 is just a more advanced version of the GRIP technology that exists in the 34, why would it be so hard to adapt it to the smaller bore?
  • + 1
 The fit weighs less, which is obviously important for XC forks and some folks care about it even on the 36 for some reason.
  • + 2
 @hardcore-hardtail:

Grip2 is available in 40's.

But yes Fit4 is lighter. Would you choose a Grip2 34 if it was available? Personally... the MRP is ugly AF and what exactly does assembled and tested in the USA mean? The FOX stuff is all tested in the USA... and assembly here doesn't really mean what it used to. Especially if you're still sourcing all your parts from overseas. The sourced parts are just as important if not more so.

I'd be curious if compared directly if the MRP ribbon SL is really any stiffer than the 34. It's a 35 so in theory it should be. At 120 it's 3.94 lbs. The Factory 34 with Fit4 at 130 is 3.92 pounds... so it's not really lighter... especially if you compare 130 to 130. Believe the Fox is over 1/3rd pound lighter. And that's without a kabolt. And that's with the old Fit4 in it.....

It is cheaper though.
  • + 0
 @hardcore-hardtail: better yet, get a DVO.
  • + 1
 Agree. FIT and RS’s RCT3... silly on a trail bike; silly on most any bike for that matter. Please don’t dumb down top dollar suspension. Keep it on the low end models for rides willing to sacrifice performance for an “easy” product.
  • + 1
 @onemanarmy: Last I checked MRPs suspension products are manufactured in Colorado. Could be wrong.

Suntour, Manitou, and even Fox's own GRIP has proven you don't need to spend a ton of money, or have a gazillion adjustments in order to have a great damper.

The fact that Vorsprung and Push are selling out of their coil conversion kits also shows how much air spring technology is lagging behind damper tech.
  • + 11
 Initial stroke dampening can’t be magically softer in a speed sensitive damper so there is some marketing bs right there.

The aftermarket (ie vorsrprung et all) have taken fox’s stuff and turned decent forks into what they should be for the $$$ for reasonable money.
  • + 7
 Am I the only one stoked about this bearing assembly for shocks? This a HUGE reduction in friction over a conventional DU bushing and will help small bump sensitivity for bikes everywhere (unless they're already trunnion mount). Probably reduce service intervals, too.
  • + 19
 You've never heard of RWC needle bearings?
  • + 2
 @schofell84: to be fair, no.... that seems a more logical solution, but I'd take either over a conventional DU given the choice.
  • + 9
 rwc needle bearing kits have been around for at least ten years now, no special tools needed for install. Make a huge difference in sensitiity.
  • + 2
 My RWC needle bearing setup wore out in about a year, it was smooth at first but I was reinstalling the original bushings sooner than I would've hoped.
  • - 2
 @badbikekarma: not true
  • + 6
 @masonstevens: replacements are $6.95. Well worth it IMO.
  • + 3
 @masonstevens: and RWC has superb customer service. If they don't think you got a good lifespan out of your bearings they'll send you new ones free of charge.
  • + 3
 This has been said a lot this week already. Bushings are still better than ball bearings for oscillation. This design uses balls not needles or rollers and is therefore not a roller bearing. My EXT storia has properly sized hardware in a high end bushing. If I’m not careful with the o rings off of the hardware, the sleeve can fall out. There is that small amount of friction in a good bushing design. Racing bros makes bushing upgrades if you want to reduce friction.
The rwc kit is a proper roller bearing and also works very well, but you have to be sure to use the correct size hardware in it or it can and will wear out prematurely.
  • - 3
 @mountainyj: are you saying that ball bearings ARE NOT roller bearings?!
  • + 1
 @plume: you are right, I forgot they need to be pressed out in with rwc's tool. Or, ive somehow fudged a generic bushing install tool, or maybe it was a vice and sockets, to istall/remove it, its been in my shock so long with no problems or play i dont remember. No special tools needed for regreasing though, and install into an empty eyelet just uses a vice if i remember correctly
  • + 1
 @badbikekarma: Right on. The RWC tool makes a big difference. And, bearings make sense on certain frame designs. I think Rocky Mountain specs their bikes with something similar.
  • + 5
 Had a look at the fox site, isn't a 6900 bearing a single row deep groove ball bearing?
  • + 1
 here was shit
  • + 2
 I wish they rolled out something like the grip2 without the bladder across their whole range. Nothing against FIT but the rubber bladders are terrible for cold weather riding. The bladders make the suspension in subzero temps super stiff and around -10 Celsius (14 F) and bellow the bladder has a tendency to rupture on larger hits. Goes for RockShox charger as well.
  • + 2
 GRIP 1.5 with actual HSC/LSC and a real midvalve stack would be great. Must be accounting rather than engineering, the compression side of GRIP2 doesn't look to complicated to fit in a 34.
  • + 6
 Cool! Can’t wait to take care of 4 more bearings!
  • + 15
 You will only use them on the eyelet that sees the most rotation.
  • + 8
 They will probably only need changing as often as bushings, and make the back end a lot more plush. I noticed a big difference when I went to needle bearings.
  • + 18
 @drjonnywonderboy: Can't see any real benefits from an engineers point of view. The rotational speed is rather small and the bearing stays roughly in the same position most of the time. Add impacts and you have some very good reasons why most companies don't use roller or ball bearings for this application, as you won't get the needed static load-carrying capacity for that size of bearing, leading to idle marks in the bearing (same story for many pedals and even frame bearings, thus many are using cageless bearings with maximum ball number now).

A bushing deals far better with the sudden high loads (if you bottom out a 3" shock w/ 450lb spring you get roughly 3000N of load on each bearing, without counting the peak when hitting the end of travel and damping forces) and if you choose the right fit, it runs very smoothly too. For looser fit, you'll obviously have to change them more often compared to tighter ones, but realistically you buy a pack of 10 for 20€ and you're happy for years to go, changing them is a matter of a few minutes.
  • + 8
 I have a Giant, shock mounts run on bearings already [smug smile]
  • + 4
 @Highclimber: this reply needs to be its own comment
  • + 8
 @Highclimber: Thats why you use RWC's needle bearing kits.
  • + 5
 @ctd07: Yes, trunnion mounted shocks already run on bearings.

I put the RWS kit on two bikes and honestly didn't feel a lick of difference.
  • - 2
 @Highclimber: As JohanG states, many modern shocks are supplied with trunnion mounts with bearings of a similar size used.

I would imagine fox have tested these a little more than a back-of-a-napkin load guesstimate like you have done, no disrespect.
  • + 8
 @Highclimber: And your headset bearings don't see sudden high loads? BB bearings do only rotate? They don't support you on huck to flat drops?

The article mentions full-complement bearings, which are most often cageless. The linked service manual shows ENDURO MAX bearings, which are full-complement.
  • + 2
 @JohanG: mines pre-trunnion, just designed properly
  • + 11
 I know this is an eternal discussion and I understand perfectly how some may feel against it, but I rather take care of more bearings and have the improvement in small bump sensitivity. RWC not only builds needle bearings for the shock mount in every size (huge improvement for my VPP linkage bike) but it also has bearing press and removal kits for both the shock and linkage of your bike that make the change of bearings a breeze (www.enduroforkseals.com). RWC, santa cruz in the new MegaTower, now FOX. Take note IBIS Cycles, some of us still wonder how much better the RIPMO would be. There is just no physical way a bushing will rotate with the same ease of a bearing, however, bushings last more. Just an opinion.
Cue the down votes
  • + 6
 @Highclimber: A tight bushing fit results in loads of stiction and a loose fit means a wobbly back end. I always feel like most of the rear suspension damping on my bikes is coming from bushing friction rather than the from the damper. I get what you're saying about longevity though. Ultimately it's a performance vs. maintenance trade off. Given that there are lots of other bearings that need replacing anyway, I'd go for performance.
  • + 1
 Lower one only, on both of mine anyway. Which doesnt rotate much. Giant really should put a big loop on the top linkage at teh pivot that allows a bearing instead of a bush at the top, as the top mount rotates quite a lot, comparatively.
  • + 1
 @Highclimber: This is how i understood the reasoning behind bushes. loaded bearings really need to be spun, rather than rocked back and forth. could you use two one way bearings, one facing in each direction, on each side (a total of 4 bearings per mount), which would allow for free rotation in the overall system, but prevent each individual element from just idling back and forth....?

patent pending!!!
  • + 4
 @JohanG: sometimes you get very lucky with the tolerances of the bushing, shock eyelet and the hardware rod diameter/length anddd you get a nice smooth stiction free movement...sometimes it's just plain shitty and you can feel it when going with the conversion... Been there..
  • + 3
 @Highclimber: I don't know about the engineers point of view, but on my old Santa Cruz 5010 is was a huge difference, not subtle.

Also, good job reminding us you are an engineer in the first sentence. You can keep your certs.
  • + 1
 @McNinja: I put my weight my the shock and rotated it on the lower IGUS bushing, noting the friction. It moved easily. Then I installed my RWC kit as instructed and did the same test. It also moved nicely, but I couldn't tell a difference. Couldn't tell a difference riding, either. So maybe if your bushings are sized correctly then they are not a big help. But I hear that there is a lot of variation in the machining of these shock eyelets so some people will have sticky actions on their bushings.
  • + 1
 @Lagr1980: dang I should have read further and saved myself some typing. oh well. Agreed.
  • + 0
 @Highclimber: Great explanation, I totally agree...nowadays the use of bushing is increasing also for industrial applications (>10000 cycles/day) and even for light load applications..this is just another marketing invention for bike nerds
  • + 1
 @flowisforpussies: I'm the guy who installs the bushings that are replacing bearings in the field. The ones you engineers say are "better". We save the bearings for a reason.
  • + 0
 @fluider: headsets are tapered roller bearings, and need to support huge moment loads while rotating smoothly. Pretty different use case than a shock bushing/bearing. The rollers give a lot more distribution of load (in terms of Hertzian contact stress) than ball bearings, even full complement. I think the point you're making is probably that this shit is more complicated than people's broad generalizations, and dependent on actual engineering calculations and data on loads in the joints, bearing specs, etc,...which if so, I totally agree.
  • + 1
 @dirt-klaud: I cant name a single headset that uses tapered roller bearings.
  • + 4
 Yeah Ill stick with RWC needle bearing kits, super easy to install, swap out, and occasionally repack with grease
  • + 1
 I got a set from syntace recently, very solid, as well as RWC
  • + 3
 "it pushes less oil through the base valve, allowing for less damping" : I though bigger oil volume was better, why not change piston tuning to get a lighter tune ?
  • + 1
 I think it means that less oil is pushed per shaft movement, so the same damping would equal more movement.
  • + 1
 Yah I’ve always though more oil flow lead to better control. Certainly makes something easier to tune. Remember marketing is a thing.
  • + 1
 @whipperman @cougar797:

The piston and shim stack are still "processing" the same volume of oil past - just now, a smaller shaft takes up less space in the system and displaces less of that total oil volume.

When the shaft volume is displacing oil, it's not adding any benefit. It's only moving it to a different place - in this case, the expanded space of the bladder. You very much want as little possible bladder expansion being dedicated to something that isn't providing a performance benefit.

I used to help build shocks for a custom manufacturer and we went with a 1/2" shaft over a 5/8" shaft because we could produce a more sensitive shock this way. Marketing was very much in the other camp --- you know, the old "bigger is better, look at my shaft" story...

It is a balance though. The bigger the shaft diameter, the better the seal and bushing can be, given the same materials and stack height.... Also, you do need some connecting strength usually to keep the system together. We were building mini coil over shocks so the shaft had to support the lower eye and any minor fore/aft forces due to control arm flex, frame flex, bushing wear, etc.

Suspension is a balancing act.
  • + 5
 To elaborate on my previous reply and address the direct quote of "it pushes less oil through the base valve, allowing for less damping" ....

What they're probably TRYING to say here is - a smaller diameter shaft forces less accessory oil around in the system. Since that volume drops, damping used to control those volume spikes isn't needed to be as aggressive.

Think of a tiny little man jumping into a bath tub vs a big fat man. Except the bath tub is sealed with a flexible cover. That cover has to do a whole lot more work to keep the water contained when the fat man jumps in.

(yes - I realize my analogy is impossible if the cover is truly sealing. So instead, the tiny man and fat man must now slide in through a tube of which they are the perfect diameter to seal themselves off as they pass through)

lol this just got weird....
  • + 1
 @agraber: now that makes sense. Larger oil capacity allowed probably means a little better service interval as well.
  • + 3
 @agraber: There is usually no compression circuit on the piston, unless the damper has some sort of mid-valve. On most mtb fork dampers all compression damping is produced by forcing the fluid displaced by the volume of the shaft, through a circuit into the bladder or ifp. The piston at the end of the shaft usually only deals with rebound damping...
  • + 1
 @agraber: I think this explains what you are trying to say better:
youtu.be/ohz8_IafGwE
  • + 1
 As a lighter rider Fit 4 high speed compression has been my issue. I don't see a mention of a change to high speed unless the range of low speed has been adjusted that high speed is affected as well. Anything but wide open is very harsh with high speed compression for us lightweights with Fit 4. Other than a bit less mid-stroke support the basic Grip damper has been lights out better then Fit4 even without the ability to fine tune the settings.
  • + 2
 Vorsprung fractive
  • + 1
 Never been a fan of FIT4. There’s nothing special about it! But those new roller bearings look promising. I would like to know if they would fit in my Knolly Warden carbon tup
  • + 0
 Just super thrilled that no one else ever thought of doing this prior to so 1996... oh wait.. yes I did. Had a bearing kit installed on my '97 GT LTS Team, my 2003 K2, my 2004 Uzzi, and 2005 Hukk (some of you old skool BC rats will remember Andrew and co. for their _massive_ double D-section swingarm). Smoothest ride ever.
  • + 4
 So is revised FIT4 better than grip2, or just different still?
  • + 3
 I'm also a bit confused as the different applications of the two.
  • + 1
 From what I've read, it's easier to manufacture so it's like mid grade in price between Grip and Grip 2.
  • - 4
flag yzedf (Aug 14, 2019 at 5:23) (Below Threshold)
 Grip 2 is set and forget damper. Fit 4 is the xc focused 3 position style damper.
  • + 1
 One thing I've always learned and the industry has always lied about. You cant have a "playful" and "aggressive" fork or shock. It's one or the other. There is no middle ground on that marketing bs.
  • + 1
 Are these new bearing with the same final effect of Enduro needle bearing? I curious about try the Enduro ones and they cost just 10 euro each....
  • + 3
 Just please...bring us affordable coil conversion for 36
  • + 8
 They already have a coil 36, it’s just red and has an M on it
  • + 2
 @BCtrailrider: Am I missing something, or does Marzhocchi not make a coil Z1?
  • + 2
 @BCtrailrider: Well it is not coil and I am not asking for a new fork, but for a conversion kit for a fork I already have which would be cheaper than 400 bucks options available on the market now
  • + 4
 @BCtrailrider: they dont make a coil Z1 either
  • + 3
 @bok-CZ: try Vorsprung for a cheap air solution or Push Industries if you want to convert to coil.
  • + 2
 @mattradical: Push is expensive a bit too much for me and Vorsprung´s coil conversion also. But thanks for the hint, unfortunatelly the air solution from Vorsprung is for FIT4 dampers only
  • + 1
 @rowanlewis: damn. I thought the Z1 was a coil. I guess 2 AM me is a bit of a dunce
  • + 1
 @bok-CZ: Luftkappes are installed on the air spring side, so whether you have a Fit4 damper or something else doesn't affect fitment. Also if measuring in USD, the Smashpots are roughly $315.
  • + 1
 @VorsprungSuspension: thanks guys, will think it thru
  • + 1
 Is this the "new / other" shock a few riders have been trying in the dialled videos but they all go back to their original shock?
  • + 4
 No this is a fork and some bearings
  • + 3
 @scottishmark: well I'm an idiot!   
  • + 4
 @Lewis-pick: don’t be so hard on yourself lad
  • + 1
 @peschman: learnt the hard way not to scim over the article and go to the comments ????
  • + 2
 If I put this new damper in my GRIP 36 will it have a Pink FIT 4 life?

Maybe it's just another case of - Pass.
  • + 2
 Hey, these Fox bearings are just what I need as a bottom bracket for the bike I'm building for my pet rat!
  • + 1
 Seems like the bearing hardware is similarly designed as the ones that come on Rocky Mountain bikes. All you need to remove them is a small diameter blind bearing puller
  • + 1
 Has anybody actually ever said, "My FIT4 damper is too heavily damped in the initial stroke."

I highly doubt it.

Now saving 35g on an 1800+ g fork, finally.
  • + 1
 Safe to assume these roller bearings would also fit the marzocchi bomber cr?
  • + 1
 Real World Cycles as been making needle bearing retrofits for shocks for a long time. I can verify that they work very well.
  • + 1
 Pah, 10 years late Fox. I've had needle bearings in my BOS shocks since 2009.
  • + 0
 I really don't see the need for bearings with the current Igus bushings that some manufacturers (such as Fox already) are using in replacement of DU bushings.
  • + 2
 I don't know what i just read. Will it save my wrists or?...
  • + 17
 Maybe, but it won't save your wallet or your relationship.
  • + 5
 @Waldon83: a smaller shaft might save my relationship. Gwaff Gwaff gwaff
  • + 4
 Putting a coil conversion into your fox 36 will make more of a difference. No arm pump at all in the Alps this year.
  • + 1
 @Waldon83: tell it, brother
  • + 2
 I want an X2 im my smuggler as well!
  • + 1
 Was there any information about price of this kit?
  • - 3
 I must have been riding different Fox forks because through out 2011-2019 VAN/Float FIT models my impression has always been supple in the beginning with excellent midstroke support and quite bottomless feel. Somehow they pulled it off. Since 20fricking11. RS needed 8 years and their ultimate solution deluxe still isn't there.
  • + 1
 An interesting move putting an X2 on a 120mm bike!
  • + 1
 And suddenly your €€€2019 fox fork is worth half its price!!!!
  • - 1
 FIT4? What is it FIT4? Nothing!
  • - 2
 The Fit4 damper sucks.
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