Fox Racing Shox 2009

New 15mm thru-axle standard

It's only mid-April and Fox Racing Shox is already debuting its 2009 lineup. The new collection will likely be best remembered for its new ‘15QR' 15mm thru-axle standard which the company will offer as optional equipment for all of its 32mm chassis segment (with the exception of the F29).

Fox doesn't intend 15QR to replace any existing thru-axle format and indeed, the industry-standard 20mm system is heavily utilized elsewhere in its range.  Rather, Fox aims 15QR at cross-country and all-mountain riders who are looking for more steering precision than a standard 9mm quick-release configuration but less weight than a typical 20mm setup.  According to Fox's figures for its 2009 forks, 15QR is 25 percent stiffer in transverse shear and 15 percent stiffer in torsion than the standard open dropout quick-release versions, but only adds about 100g - excluding the hub but including the 15QR axle and standard skewer.

Debates about yet another standard aside (see below), 15QR is well-designed and executed.  Co-developed with Shimano, the one-handed system requires only an initial setup step to ensure the proper final lever position… and that's about it.  Operation is very similar to a standard quick-release and, coincidentally, nearly identical to Rock Shox's Maxle system.  Obviously, Shimano will offer hubs and wheels to accommodate the new size but the standard is open to anyone who wants to adopt it.  According to Fox, both DT Swiss and Mavic already have supporting hubs and wheels ready to go.  

We had the opportunity to ride 2008 model year 9mm quick-release forks in an all-day back-to-back session against the 2009 15QR models at Utah's Gooseberry Mesa and noticed the increased steering precision, especially in trickier situations where the added control can mean the difference between a crowd-pleasing slingshot out of a rutted turn or an (equally crowd-pleasing) expansive yard sale.   Even so, we'll be sure to secure a test sample straight away and report back with a more in-depth evaluation.

Lighter, stronger 32 chassis

The upper assembly of the 32 chassis receives significant updates as well, yielding modest weight savings of 20-70g depending on model (as such, '09 15QR models are roughly the same weight as '08 open dropout models).  New forged crowns and 1 1/8" steerer tubes across the board are said to be stronger than '08 versions; 140mm-travel 32 forks also get a lighter and smoother running set of lower legs.  Last year's well-received F29 will now get a 120mm-travel version as well as lower priced RL versions across the entire travel range.  

The tapered and oversized 1 1/8"-to-1 1/2" steerer tube format used by Trek will be an option across the 32 range, although some will only be available to bicycle manufacturers.   This is fairly interesting news on its own but it also strongly indicates that we can expect to see the size standard used in more of Trek's lineup for 2009, most likely in the new Fuel.  Fox officials weren't able to say whether or not the forks would also be compatible with Specialized's similarly sized front end but the inclusion of the 29"-specific F29 in this grouping tells us that at least one big-wheeled company will use the tapered-and-oversized configuration for 2009 as well.

After years of sponsored rider exclusives, Fox has finally decided to offer consumers a remote lockout lever.  As with 15QR, the inline lever was co-designed and manufactured with Shimano.  Operation on the trail was reasonably intuitive although the release requires a slight hand position shift and some riders may find the lockout lever to slightly interfere with trigger shifter thumb paddles.  Sealed construction promises reasonable durability.  The lever will be included as standard equipment on the new Remote RL 80/100/120 models but the widget will also be retrofittable to other forks with crown-located lockout levers.  Total added weight is approximately 90g.

Chassis updates to long travel platforms and rear shocks

Changes to the bigger-boned 36 and 40 platforms are more subtle than on the 32.  All 36-series forks get a lighter forged crown and lighter steerer tubes across the board.  As with the 32, all 36 forks will be offered in the tapered and oversized 1 1/8"-to-1 1/2" size format.  

Potential buyers of Fox's 40 fork will now be happy to hear that last year's upper crown will be replaced by a direct mount-type version that uses the industry standard four-bolt pattern for integrated stems.  

The popular DHX Air rear shock receives some minor revisions as well, in particular a substantially larger ProPedal lever that now rotates just 90 degrees lock-to-lock.  The angled air valve incorporated into the RP23 last year also finds its way on to the revamped DHX Air for easier inflation.

The air valve on the DHX Air has also been relocated for easier access

Internal changes

Fox's TALAS adjustable-travel air spring system is widely used but has long suffered from criticism that it had too much stiction, especially when compared to the fixed-travel Float air spring.  Fox has thankfully redesigned the system for 2009 with fewer seals for a noticeably more Float-like feel, improved top cap seals for better longevity and steeper spring curves.  The current 100-130-160mm and 100-120-140mm settings carry over from last year but the new dial is now easier to turn.  Field serviceability is also vastly improved - no special tool required - and the revised system is backwards-compatible with existing chassis.

36 and 40 forks also get new FIT cartridges with more compression stroke damping control, improved bottom-out resistance, more tangible distinctions between the low-speed and high-speed adjustments on RC2-equipped models, and new seals for better reliability.  ProPedal-equipped RP23 and RP2 shocks also now deliver more refined mid-stroke compression damping after the platform threshold is exceeded and a broader rebound damping adjustment range, mostly on the faster end. 32 fork dampers remain unchanged from last year's settings.

Will 2009 be a good year for Fox Racing Shox?

The new 15QR standard is undoubtedly controversial and we'll have to wait and see if it truly takes hold within the industry beyond the early adopters.  We're on the fence in the meantime but wholly embrace the other updates as nearly all of them are evolutionary refinements of an already excellent product line.  As added benefit, many of them are even retrofittable to existing models.

Our initial test rides suggest that the updates are genuine improvements, too, and most riders should be able to feel the internal changes themselves.  

Counterpoint: RockShox weighs in

RockShox has taken particular interest in Fox and Shimano's new 15mm thru-axle system, particularly as it just debuted a new, more svelte version of its widely accepted 20mm system at Sea Otter.  The new Maxle Lite will be offered as optional equipment on the updated Reba cross-country/trail bike fork and is targeted at much the same audience as 15QR.

"We are strong proponents of thru-axles, hopefully as evidenced by where we've used it in the product lines in the past and the developments we've pushed through," said RockShox product manager Sander Rigney.   "As we look at where we want to see thru-axles go, which is more of the cross-country, trail and lighter weight all-mountain, what we see as being important is weight and stiffness."

According to Rigney, the new Maxle Lite axle assembly weighs just 84g, putting it about 10g lighter than the comparable 15QR assembly, while its industry-standard 20mm diameter sacrifices almost nothing in terms of stiffness relative to full-blown freeride and downhill versions.  Rigney also insists that "optimised" 20mm thru-axle system weights (which include the fork and hub) are already very competitive.

"If you kind of use that as sort of your foundation to start building your weights from there, we're finding it really hard to find a weight advantage to the 15mm system compared to 20mm," Rigney continued.  "So there's no weight advantage [and] there's not going to be a stiffness advantage.  You're going to a narrower diameter and a narrower stance so you're going to lose in both fork stiffness and torsional stiffness.  You're going to lose in wheel stiffness because of the hub shell width.  We're just struggling to see a benefit in stiffness.  

"Now, absolutely when you compare [15QR] to a standard quick release, the 15mm is going to be stiffer [and] the 20mm will be much stiffer.  But that just brings us back around to weight.  If 15mm isn't lighter, why do we need to develop a new standard for something that isn't lighter and isn't as stiff as it could be?"

That's a good question so we sought to answer at least part of it for ourselves with the assistance of Tom Torrance, a structural engineer in Boulder, Colorado.  Using a somewhat simplified model, 15QR is roughly half as rigid as a 20mm thru-axle in transverse shear (think independent leg movement along the axis of the leg).  Even if 15QR is marginally lighter than the lightest 20mm systems, that's a big hit, although it's still substantially more rigid than a 9mm quick-release setup.  

Is 15QR's decrease in rigidity worth the slight weight advantage it might hold over 20mm?  Maybe, or maybe not.  Ultimately the market will make the final call.

Based on this simplified model, the 15QR is roughly half as rigid as a 20mm thru-axle in transverse shear

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