The F80X suspension fork is the pinnacle in technology for a racing cross-country mtn. bike suspension fork. The F80X damper with automatic intertia-vlave technology coupled with the F80 chassis makes this the ultimate XC racing fork. The F80 chassis used onthe F80RLT and F80X uses specially designed lightweight chassis and internal parts throughout the fork.
NEW Lightweight Chassis Parts:
-Lightweight Optimized double-butted steerer made from Easton EA70 material
-NEW forged 7075-T6 crown with external Scalloped machining and hollow Double-barrel machined internal features
-Lightweight F80 specific Uppertubes made from Easton EA70 material
-Lightweight Lower Leg with machined fork brace
NEW Lightweight Damper Parts
-Polished Hard Anodized Aluminum Damper shafts made from Easton 7075-T6 material
-Lightweight Rebound Adjuster Rod
-Lightweight Hard Anodized Cartridge Damper Tube
NEW Lightweight Air Spring Parts:
-Lightweight Air Shafts made from Easton 7075-T6 material
-Lightweight Air Piston
NEW F80 SLT Air Piston Seal:
-This new air piston seal is an advanced low-friction air seal that is designed with Scraper Lip Technology to retain FOX Float Fluid in the air cylinder
a Weekend Warrior
from Concord, CA, USA
Date Reviewed: June 29, 2009
Strengths: Looks, Technology, Fit, Name Brand Reputation, takes a beating.
Weaknesses: No cable guide (Jagwire helped the lack of cable guides, which came a year later)
The top of the line offering for the F-series, Fox made famous the Terralogic auto-lock function, aka now Specialized Brain, and I have the the last year to have Terralogic technology. It's a silver/red/blue 2006 disc only F100X fork that was spaced down to 80mm by Fox.
When Fox went to the white forks in 2007, I picked up an F29 80mm for my 29er - sick fork as well, but the lack of Terralogic was noticeable! The remote lockout knob on the F29 wasn't up to task. The Terralogic is something many Fox owners want to retrofit into their new F29 forks, MTBR has a couple forum posts about the successful swap of internals. I have been happy with this fork, it does not leak, it does sag and there is a bit of a clunk fore and aft which I believed to be worn seals. It was sent into Fox HQ for the full 9 yards and came back feeling exactly the same with exactly the same fore aft motion. I suppose that is normal? And not many bike parts can get a "that's sexy" from the ladies, but this fork has!!!
Bike Setup: Single speed steel 26" bike suspension corrected for 80mm fork.
a Cross Country Rider
from Venice, CA
Date Reviewed: August 2, 2004
Strengths: Rigid. Great handling. Easy to set up.
Weaknesses: Terralogic is inconsistent. Brand new, I was amazed. Now, fully broken in, it's mushy, and this is after factory work which I paid for.
I ride more staircases and curbs on this bike than I do dirt. No question the fork tracks beautifully and soaks deflections like a sponge. Whenever I do hit the dirt on this bike it flies like on rails, and the fork's design is certainly part of the reason.
My problem is with the TerraLogic valve, the part that makes this fork cost so much. When I first installed it, locked out meant locked out - no bob, no squish, just rigidity until I hit a bump (as small as a centimeter-high join between sidewalk slabs) and the fork would open up and suck it up.
Now, a year later, the fork sags into its travel and bobs through the top inch or so continuously. (The pressure is exactly where it's always been.) I do a lot of standing and hammering on this bike (as you'd expect riding primarily on the road), and I bought this fork because I figured auto-lockout would be a great match. The squishiness has pretty much negated that idea.
And this is after sending the fork to Fox to fix right-side leaking seals. Enough oil had leaked out that the fork wasn't locking out at all. Having bought on eBay I had no warranty; Fox charged me $100 for the service and I got it back squishier than ever. And the seals still leak.
Worst of all, I keep dialing the knob to make the fork less and less sensitive s it'll stay locked out when I go to bunny hop an obstacle. Picture you're going for a hop - you grab and pull. If you've got no lockout, no problem - you know this and you compensate. Or if you're rigid, you know this and you work accordingly. But when you expect to be rigid and you compress... sometimes you're lucky to clear whatever it is you're hopping.
I like the way the fork tracks. I'd consider another Fox. But only if I got it with a warranty. And even then I wouldn't buy another Terralogic until I knew for sure they'd perfected it.
Similar Products Used: A Marzocchi Z-3, which cost a quarter as much and is hardly similar but has performed flawlessly going on 3 years
Bike Setup: 24 lb steel hardtail
from syracuse, ny,usa
Date Reviewed: February 24, 2004
Strengths: the automatic lockout works for a time. Mine got progressivley mushy.
Weaknesses: Loses oil. Weight. Not black
Fox made me pay to fix their fork, and a shock that had less than 20 hours. They claim quaility, but don't back it up. I'm selling their junk in favor of Manitou SPV. Manitou has better response on the high frequency chatter bumps, and less weight. Skareb Platinum here I come
Strengths: Predictable handling, solid responsive tuning, no brainer lock out, plush unlocked suspension, incredable stiffness, good looking.
Weaknesses: some oil leakage, weight,
Yes the fork does leak some oil which is silly for the price. Would I by this fork again? In a heart beat. Bottom line you dont buy a Porshe, and complain about the money it takes to keep it in excellent running condition. This fork while a little on the heavy side is a powerfull tool in any racers bag of tricks. And worth every penny, in its performance. If you can climb good with 100mm consider the fx100 but I find it a bit choppered out for my head tube angle. This fork may not be for you weight wennies. But it is my cup of tea at 6.03 and 185lbs. I have never felt this fork give to the point I was afraid this fork inspires confidence once it is dialed to your taste. My advice if you have the means buy it.
Bike Setup: trek 9.8 tru/stylo, xtpods, raceface TI/sigBB, thompson stem and post, king hubs on mavic 819's w/stans juice in tube tires,fox fx80.
Date Reviewed: December 5, 2003
just a follow up to my last post - i was very impressed that a representative from fox actually came to this site, read my post, and followed up with me to ensure my satisfaction. just a couple weeks later, i am sitting with a repaired shock already back on my bike. I must say I am very pleased.
Strengths: Extremely Stiff arm and lockout is amazing! Works perfectly
Weaknesses: Oil Leaking on Right arm.
Great working shocking. Amazingly stiff and the inertia valve works perfectly. BUT it will not stop leaking. LBS is absolutely no help. 4 calls to them on this already and no answer back from Fox. Not great service/support for a $800 retail shock! The oil leaking and lack of support drops this , in my opinion, to only a 2!
Similar Products Used: Rockshox Judy xc, Pace Rc35, Marzocchi Z1(x2), x-fly 80 & Marathon
Bike Setup: S-works Epic 2003, Full XTR, Hope, king, easton bars, Mavic
from San Jose, CA, USA
Date Reviewed: October 13, 2003
Strengths: Fast! Works as marketed Very Precise Terrific race fork
Weaknesses: More small bump vibrations - hard on the wrists till tuned....leaked on right side
I have gradually learned to like this fork - although I have reduced the air pressure so that it starts movement on even small bumps....I ride every day - and noticed that my hands and wrists got beat up at first - just like riding pre-shock....but now it is sucking most of them up...
But - I had the same leakage problem on the right side - and my fork had to be sent back to Fox. I hope they get it fixed right!
May get another fork for everyday riding and use this for races.
a Cross Country Rider
from Pocatello, Idaho
Date Reviewed: October 9, 2003
Strengths: Amazing stiffness/steering, plush on big hits, active when you want it and rigid on smooth climbs. Exactly as advertised, terralogic is seamless. All I notice is a major performance improvement over my 2001 OEM Sid. The Sid was way too flexy and I lived with for 3 seasons. This fork is incredible.
Weaknesses: None so far.
My fuel is quick and an incredible ride though the SID was holding me back. I am not a racer but an epic rider. The uphill performance is better and the downhill is confidence inspiring - absolutely no comparison. Fantastic 80 mm fork. I demo'd a Fox Talas but even at 85 mm in affected the geometry and handling of my bike. Performance of the Talas was amazing and I new I had to get a Fox and I got the F80X instead - no regrets, worth every penny. Point and shoot! Totally recommended for cross-country race, cross-country adventure and epic riders.
Similar Products Used: Rockshox SID, Fox Talas RLC
Bike Setup: 2001 Trek Fuel 100 with many after market upgrades - best of which is my Fox F80X
a Cross Country Rider
from Portland, Or
Date Reviewed: October 8, 2003
Strengths: I have about 6-rides on the F80X and it performs as stated. On & off function is seamless, with noticeable improvement in efficiency on smooth surfaces while maintaining an extremely plush ride when needed. Weight is very reasonable considering the precision steering one gets from the stiff design. The minimal weight penalty is well worth the performance and hopefully longevity. Dollar amount was not reported as it was a comlete bike deal.
Weaknesses: None that I have found yet.
I would never go back to a standard fork, with or without a lock out. The terralogic works so well and seamless that all you have to think about is hammering. Combine this fork with a 5th Element air shock and you have a true cross country competitive ride that is plush when needed. Epic riders would also benefit from this Fork or the F100X.
Bike Setup: 2004 Yeti ASR-5th Element air, XO, Marta SL, Crossmax SL, XTR cranks, Easton, Thompson
a Cross Country Rider
from Mission Viejo
Date Reviewed: October 2, 2003
Strengths: The Fox F80X Automatic (inertia) lock-out really works! The fork easy to adjust and set up. It really wont compress with heavy front braking which allows you to have a lively feel on single track. Its fairly light, and its also stiff which provides a lot of confidence. Its far better than any of the competitors.
Weaknesses: Some reviews say it will leak oil, however i am having success with mine and with Fox. Takes a while to dial it in, But then Your Golden! You Will look down on these other brands!
It gives me more confidence on the trail! Thanks to the guys at BeyondBikes.Com for the awesome custom build, and the perfect set up with my Spider/F80X I am railing single track like no other! I was originally going to do a different model, but decided to go with the Fox after some convincing! Now I wouldnt have it any other way! This fork really improves a top of the line xc bike!!
Similar Products Used: Fox Float RLC 100's, Rock Shox 02 Sid Carbon's, Mantiou Black Elites 80/100 02 model
Bike Setup: The Ultimate XC Bike Setup: Frame in Iron with red decals, Fox Forx F80X, All Shimano XTR, 03 Dual brakes/shifter controls, 03 XTR Disc brakes, Thomson Elite Stem (Black), Mavic UST X3.1 Wheels Hand Built Buy a Pro, Easton Ec 70bars, Thomson Seatpost, WTB Rocket V Laser Saddle, panaracer 2.1 meats!
from winter park, fl
Date Reviewed: September 16, 2003
Strengths: Exactly as it is billed- the ultimate XC fork. Super rigid stantions- NO lateral flex, super plush and very cool... Fox's service is outstanding, as is their tech support at NCS events
This fork is exactly what it was billed to be- soak up the bumps and lock right back out for the most efficient XC ride out there. I love my 80RLT and actually switch back and forth between forks depending on the course!! I used the 80X last weekend in a race and it rocked. You can blaze out of the turns because the handling is spot on and the fork immediately locks out when you get off the roughage. It worked great, and provided a super smooth ride, yet locked out on the flats and ups (as its supposed to). I used 2 clicks firmer than the factory set up (which is 6 clicks) and I'm getting progressively higher (for the bump threshold) as time goes on. I have been amazed by FOX forks and rear shocks. These guys build amazing, no nonsense shocks. Thanks and keep it up!!
Similar Products Used: Fox 80 RLT, Rock Shox SID carbon, Rock Shox SID SL
Bike Setup: Trek Fuel 100 (carbon) with King headset and disc hubs, FOX 80X up front, Fox RL in the rear (super nice also), Bontrager cranks, bar, stem and seatpost, Hayes disc brakes.
Date Reviewed: September 6, 2003
Strengths: Super Super stiff! TIV is awsome! Light!
Weaknesses: I've herd that FOX has seom awfull customer service
After 3 months of use i have concluded that this fork is awomse! TIV is so great! it takes some getting used to at first, but once you do you relise how much faster you go! High points Super Super stiff Smoothest slider i've ever used, very plush and linear TIV Light! Lows Price is very high
Thats about it. I was lucky enough to get the 04 version and i havent experienced any of the problems the others have been talking about. And for gods sake, Dont use Rock shox world cup!! it may be .35 lbs lighter, but this is SOOOO much stiffer, has TIV, actly gets advertised travel (you cant get more then 63mm from any of the 02-03 sid line) and you dont have to worry about a carbon crown craking(Though it looks cool as hell) From reading past reviews I reccomend trying to get the 04 model if you can!!
Similar Products Used: Rock shox world cup (Light, yeat so crappy!) Rock shox judu SL (not bad for a fork that is 3 years old!)
Bike Setup: Trek 9.9 03 xtr group, F80 TIV
from Grand Junction
Date Reviewed: September 1, 2003
Strengths: This is a follow up from my below review.
I totally agree with c.j. below, the fork leaks oil from the right (damper) side. I called Fox about this and they gave me the same line of crap that is in their service manual. That is, that the fork has sponges under the seals to hold the oil and lubricate the slider tubes (hydrodynamic lubrication). OK, that’s fine, but the demonstration that there is something wrong is the fact that the leakage is asymmetrical. That is, the left side (air spring side) weeps little oil, but the right side leaks excessive amounts. If it were nothing more than simple hydrodynamic lubrication than both sides should weep oil at the same rate, but they do not. Here's what is going on. The left side of the fork only contains 35cc of oil, but the right side contains 160cc of oil. Oil in the right side is being forced out of the fork by hydraulic pressure produced during the compression stroke (the seals are not strong enough to hold back the fluid). This does not occur on the left side because the left side contains much less fluid and, therefore, produces much less hydraulic pressure. The fork is fundamentally flawed and Fox refuses to admit it. You cannot service this fork on your our own, so if you ride a lot, you will need to return it to Fox once or twice or more a year. This is ridiculous from a $700 fork. The problem is that are basically no good forks on the market by any manufacturer.
a Weekend Warrior
from Steamboat Springs, CO
Date Reviewed: August 30, 2003
Strengths: When it works, this is a precision fork, slicing through turns with great accuracy, and ridding bumps in the trail with ease.
Weaknesses: This is an update to two earlier reviews; my second F80x just went "active" full-time and I give up - I am no longer willing to be an unpaid beta tester for Fox. Dealer sent it back, they repaired it and I sold it. Purchased a 100RLC - fairly proven product from them.
I am sure Fox will solve this problem sooner or later as I see the trend in shocks moving toward interia valve type suspension. Next year's Specialized upper end ($$$) bikes are all coming with inertia valve suspension on the rear - they call it the IQ Brain.
The rear Brain shock on this Epic has worked well for me after a 1000 miles of riding on it, so I think they will get this technology right on the front shocks, too.