MTB Review: Fox F29 Terralogic Fork

Back in March I post an On Test article where I covered the technology packed inside the 100mm Fox F29 Terralogic suspension fork. Now that I’ve put a bunch of miles in I’m ready to post my final review. Did it live up to the performance claims and marketing hype? Is Terralogic the next best thing since sliced bread? Read onto find out.

Install and Set Up

Installing the fork was easy – no issues.The crown race pressed on nicely, the brake mount was faced, and the threads were clean and smooth. This was my first time using a thru-axle, and Fox’s 15mm QR was very easy toset up and use. The axleslides inon the left side through the fork leg and hub and into the right fork leg. In the right fork leg there’s anut the axle threads into. You thread it in until it starts to snug up, then flip the lever closed. How that nut is positioned will determine the orientation of the lever. You should set the nut up so that when you close the lever it is pointed up parallel to the fork leg, easy to use but tucked up out of the way. Once you get this dialed, it will always close in the same position, and it’s very easy and fast to install or removethe axle. No tools are needed to remove or install the wheel in the fork.

How this nut is positioned in the drop out determines the QR lever’s position when it’s closed. That black clip holds it in place, making the Fox QR15 a tool-free thru-axle.

To get the fork’s suspension settings the way I wanted I firstturned the Terralogic function off (more on Terralogic later) and used the air pressure guidein the owner’s manualas a starting point for setting the sag and spring rate. The guide was pretty accurate – I ended up using only about 5psi more than it suggested for my weight. Next I set up the rebound. I wanted the fork to rebound quickly, but not so quick that it seemed like it was fighting back. My initial rebound setting turned out to be a little too slow (too much rebound dampening) and the fork packed down on repeated high speed hits. With a few turns of the red knob on top of the right leg, everything was gravy. I settled on 5 clicks from full fast (there are 15 settings).

The red knob on top of the right fork leg adjusts rebound. The air valve is hidden beneath the blue knob on top of the left fork leg. An o-ring on the left fork leg lets you see how much travel you are using.

Lastly I set up the Terralogic threshold. I found asteep hill in my neighborhood and hammered up it out of the saddle. With the Terralogic knob in position 1 the feature is basically turned off so the fork bobbed a lot. I started dialing up the Terralogic until I got no more bob, which for me was position9 of 15. Then it was time to load up and head to the trails!

Terralogic is adjusted using the knob on the bottom of the right fork leg. It’s not easy to get to while riding, but doesn’t need to be. It is a set-it and forget-it setting.

Terralogic on the Trail

I have a hard time explaining how the Terralogic feels when riding. The problem is this: it doesn’t feel like anything. You never notice it working, locking or unlocking the fork – it just does it. When you’re out of the saddle climbing there is no bob. When you push down on the pedal all of your effort goes toturning the cranks, not compressing the fork. When you hit a bump the fork soaks it up. It climbs with the efficiency of a rigid fork, but glides over rough terrain like a suspension fork. It’s pretty awesome really. And when the fork locks or unlocks you can’t feel it. There is no clicking noise, or vibration, or anything. It just happens.

When you first get on the bike the fork will sit down into its sag like any fork will. But then the Terralogic keeps it locked there until you hit a bump hard enough to overcome the threshold you have set.At speed, that means any bump bigger than what your tires can’t smooth out on their own. At low speed however,sometimes the fork won’t soak up stuff that a normal fork would. If you hit something hard when climbingit will soak it up, then lock out again. It does all of this without you ever needing to flip a switch or turn a dial. Just ride.

The Terralogic setting is something you’ll rarely need to adjust – I left mine on the same setting 95% of the time. I did soften it up by 1 click when I did the Snake Creek Gap Time Trials though, because the course is super technical with an 8-mile long rock garden. I went 1 click stiffer for a 10-mile XC race and a few local3-mile time trials because I knew I’d be out of the saddle really hammering hard a lot. Other than thosefew rides I left it alone.

No bob, even when hammering out of the saddle.

On my other suspension fork (a Manitou Tower Pro) I have to use a lot of compression dampening and a really high spring rate to keep it from bobbing when I’m out of the saddle. That doesn’t work all that well as far as soaking up trail irregularities – the fork is a lot stiffer than it needs to be. But Terralogic allows you to use a softer spring rate formore plushnesswithout losing any pedaling efficiency.

Bump Compliance

The faster you go the betterthis forkfeels. Thecompression dampening feelsa little slow at low speed, but once you pick up some steam the fork feels great. It’s super smooth on medium to big hits, and never bottomed out hard enough for me to notice. In years past Fox forks were known for not using all of their travel, well not anymore – I used all 100mm every ride. The F29 doesn’t do a great job at smoothing out small bumps, or ‘chatter’, however. To improve small bump compliance Fox has started using a different seal/wiper on their 2012 forks – and the new parts will fit many older forks as well.

Stiffness

This fork is plenty stiff for XC and trail riding. I never felt any flex under braking or cornering. The thru-axle does an incredible job of stiffening things up for cornering – it’s noticeably better than a standard 9mm quick release. It’s a night and day difference,way more so than I expected. There is a much more “connected” feeling between the handlebars and the tire’s contact patch on the ground. The front wheel doesn’t get knocked off line as easily either, and this is especially noticeable on mid-corner bumps. I really noticed the difference when I went back to another fork with astandard quick release axle after riding this Fox fork for several months. The standard axle felt like the front wheel was trying to fold over when pushing hard into corners. It actually scared me and I stopped several times to check and make sure everything was tight!

I don’t ever want another suspension fork without a thru-axle – the added stiffness and control is amazing.

Other Good Stuff

The gold Kashima coated stanchions are really good looking, and they are slick! They’re very easy to wipe off. The coating is durable too: I’ve got no scratches at all, the stanchions still look brand new. I also really like the brake hose routing, and the bolt-on guide that keeps the hose in place. The fork holds air extremely well: I never needed to top mine off. I checked the pressure after about three months of use just to see if it had lost any air, and it was still good. All adjustment knobs are decked out in anodized aluminum, no cheap plastic here.

The QR lever is strong and beefy, and actually takes less force to close than a regular 9mm quick release.

The Bad

For starters, this isn’t the lightest fork out there so weight weenies beware. Also the seals on top of the fork chassis aren’t the greatest – I started getting oily grease on my stanchions after about 400 or so miles. I didn’t notice any change in performance, but if left alone for too long there could be issues. Fox’s seals have been one of the few areas of complaints about their forks – hopefully the new seals will be better.

Speaking of seals,the Terralogic knob could use an o-ring seal or something. Since it’slocated at the bottom of the fork and is shaped like a thimble it can fill up with mud (which dries to rock hard dirt) and makes it difficult to turn the knob. It happened to meafter one of the Snake Creek Gap races – I had to remove the knob and knock the dirt out.

To some this fork may seem expensive. Although it’s not out of line when compared to the top end offerings from other suspension companies, still, $900 is a lot of money. Of course, the best is never cheap – you gotta pay to play! That being said, this is a great fork, and whether it’s a good value or not is something everyone will have to answer for themselves.

For 2012 Fox is using new seals which will hopefully keep this from happening. I have some Enduro seals coming in the mail, so look for a How-To article and a review later this summer.

Who is it for?

This is a fantasticfork for the right type of rider who doesn’t mind paying for performance. I don’t think the Terralogic would work well on a full suspension bike; it might feel unbalanced unless the rear suspension had a similar auto-lockout feature like Specialized Brain equipped bikes. Those of you who like to sit and spin your way up the climb, you don’t need the Terralogic function either, so check out theless expensiveFox RLT version of the F29 instead. But for hardtail XC racers, single speed riders, and anyone who likes to get out of the saddle and hammer – you’ll love this fork.

See it in action!

Want to see for yourself how well the Terralogic works? Check out this short video clip I took riding at the Long Cane Horse Trails. The first part of the clip is mostly climbing – notice how there is little to no pedal-induced movement when I’m out of the saddle, yet it still soaks up bumps. The last part of the clip is going downhill, with a bit of full-on panic braking at the very end to keep from missing a turn.

I would like to thank Fox Racing Shox for providing this fork to review.

Components

9point8 Fall Line R is Reportedly the Lightest MTB Dropper Post Available [Review]

Mountain Bikes and Gear

Review: RockShox Bluto Fat Bike Suspension Fork

Mountain Bikes and Gear

Shimano XTR Di2 Test Ride Impressions

Mountain Bikes and Gear

Review: Felt Virtue Nine 1 Carbon Trail Bike