Trek Scratch Air 8 - Tested

This is the follow up to the 2011 Scratch Air 8 Preview we featured this spring. Coming in just a hair under 34 lbs and at a retail price of $3,879.99 USD, the Scratch Air 8 packs quite a punch into the one-bike quiver category. The Scratch Air is the product of Trek's Scratch freeride frame platform mated with little brother Remedy's all-mountain components. Although the versatility is almost immediately apparent, the practicality of such a niche-specific mountain bike may be confusing to some.



The Scratch Freeride Platform

The heart of this bike is the Scratch freeride frame, made with Trek's premium Alpha Red aluminum. The Scratch, like all modern Trek frames, utilizes a hydroformed tubeset to maintain smooth flowing lines without turning the frame into one big curve ball of tubes. Everything fits together purposefully and aesthetically on this frame, such as the junction of the top and down tubes to the 1-1/8"-1.5" tapered E2head tube. It's clean, strong, light, and if you want to get overly techy, aerodynamic. Coupled together around a large main pivot bearing and backed by a 3-year warranty, this frame is ready for battle.

While the infamous all-mountain assault Remedy has been gaining popularity in the do-it-all segment, if air mail is how you want to send it, Remedy isn't for you. Scratch is thicker all over, so it can handle the big drops, high-flying acrobatics, and hard-charging dh punishment that Remedy isn't designed for. But what if Scratch, with its coil shocks and slack geo is too much in the freeride direction and you still pedal to the top? That's where Scratch Air comes in. Trek basically took two winning categories, the Scratch and the Remedy, and combined them into another segment of bike altogether. It's smart on their part because they already had the frame, and already had the components, so it's cheap to produce a Scratch with Remedy parts.



Bike Metrics

Trek uses 'virtual' sizing to help riders find the right fit, while actual size measurements allow for frame size identification. For example: my 'Virtual XL' test bike measures as a 19.5" at the seat tube, but Trek suggests that this 19.5" bike fits a little big for freeride use, so they call it Virtual XL, rather than a typical 19.5" Large bike. It's a little confusing, so you're going to have to learn a bit about bike metrics if you're not able to go try one on.


Virtual sizing aside, sizing the Scratch is not the same as most bikes you are used to. Freeride bikes run a bit smaller for technical maneuverability, but Scratch runs even smaller still. At 6'2" in height, I have always, without exception to this point, run a size Large (19") bike. A typical Large bike has somewhere around a 24" effective top tube, which I know I like. Scratch's geometry has the 'Virtual XL' (actual 19.5") bike with a 23.4" top tube. By any standard, the Scratch runs small, which borderline works for me since I like small-ish bikes for technical maneuverability. If you're thinking of buying a Scratch, ignore the 'Virtual sizing' and go with the actual measurement.



Component Spec

Right out of the box, the Scratch Air 8 seemed a bit confused. The Bontrager cockpit parts, while visually appealing, seemed incorrectly proportioned to the handling characteristics of a bike with 170mm travel. The stock 80mm riser stem and 28" handlebar is the result of borrowing component spec from the all-mountain Remedy, and although it makes sense from a financial standpoint to keep the cost down, I did one test run and felt like the bike was VERY held back by these components alone. The spec may work for a taller rider than myself since this XL-sized test bike is the largest size offered in the Scratch frame, but a 170mm bike with a 66-degree head angle is most likely not going to reach its full potential with such a long stem.

After switching to a 60mm stem and 29" bar I had laying around, the bike now feels ready to take advantage of that slack geo and long travel. Most Trek dealers will work with customers to achieve proper bike fit by trading out custom-fit items like stems and handlebars for a nominal fee. It's nice that Trek threw in over an inch worth of steer tube spacers under the stem so the rider can adjust their stem height to their liking without having to worry about not having enough. It can always be cut down.

Specifications
Release Date	2011
Price	$3879.99
Travel	170mm
Rear Shock	Fox Float RP-2
Fork	Fox 36 Float R
Headset	FSA Sealed Bearing
Cassette	Shimano HG8110 11-36, 10 speed
Crankarms	Race Face Ride
Chainguide	MRP LRP
Rear Derailleur	Shimano SLX
Front Derailleur	Shimano SLX
Shifter Pods	Shimano SLX, 10 speed
Handlebar	Bontrager Rhythm Pro, 31.8mm, 50mm rise, 9 degree sweep
Stem	Bontrager Rhythm
Brakes	Avid Elixir 5
Wheelset	Bontrager Cousin Earl Disc
Tires	Bontrager XR4 Expert, 26x2.35
Seat	Bontrager Evoke 2
Seatpost	Bontrager Rhythm Elite, 31.6mm

The Shimano SLX 2x10 drivetrain is a dream come true! 24/36 chainrings on Race Face cranks are more than adequate for any mountain pursuit, and with 10-speed 11-36 in the back, I can climb walls yet still not be spun-out on the commute to the trails. Spring this year was particularly nasty weather-wise here in Northwest Washington, so if 10-speeds can hold up to my 200 lb weight grime-grinding cogs in the wet, I reckon it's here to stay. The SLX line as a whole has held up phenomenally, without a glitch. Cable routing on the frame is well thought out and avoids kinks and exposure to contaminants where possible. Both front and rear shifters and derailleurs are perfectly in sync even after a season of hard abuse. It didn't take long to bend the MRP LRP chain guide, but it's not really designed for bashing in the first place. The long, thin aluminum guide arm bends back into place easily and functions great to keep the chain where it's supposed to be.

Less can be said for the Avid Elixir 5 brakes. The brakes, with their 200mm rotors, offer superb stopping power and good modulation, but have a sporadic feel. Pad life was less than to be expected, and without pad contact adjustment, ergonomics were a bit lacking and pad replacement was overly difficult. Overall the brakes were fitting both to the nature of the bike and the retail price, but I would prefer something with more adjustment and a more consistent feel.


Bontrager parts have always been synonymous with quality and value, and the array of Trek's in-house components on the Scratch Air 8 are no disappointment. Most impressive is the Cousin Earl wheelset with 20mm front hub and 12x142mm rear. These wheels can take a beating! During the entire course of rigorous testing, I checked and re-checked wheel tension and trueness, yet never once had to make an adjustment. VERY impressive. The wheels are pretty light and very strong. I did get a bit of hiccup out of the rear hub with a defective freehub pawl, which was probably due to riding in the muck all spring. Trek is quick to acknowledge any relevant problems with their 2-year warranty on Bontrager parts, so I would go so far as to say that if you're not riding in the wet, the Scratch Air 8 is a much better value than the Air 9 which is mostly more expensive due to the more durable DT Swiss hubs.


The Bontrager XR4 tires on the Scratch Air are a real love/hate scenario. Sized at 2.35 with soft rubber, these tires hold an edge to a certain point, and then slide endlessly. It took me a few rides to get used to them and to be able to predict the traction in corners. Overall, they climb great, roll fast, have a long wear life, corner decently, but are mediocre in the wet. The hate part comes with the soft sidewall that detracts from the stiffness of the Scratch frame. I was forced to run high pressure in the rear tire, around 36 psi, to keep from pinch flatting. The tires are tubeless compatible, but as a 200 lb lover of hard cornering, I didn't want to risk a peeler. Eventually I put in a thicker freeride tube that not only decreased my flat threats, but also stiffened up the sidewall profile of the tire significantly. Trailside flat fixes will almost certainly result in the frustration of an unseated tire bead with the XR4's. Proper bead seating requires either soapy water or a high-pressure compressor, or a combination of both. Improperly seated, the XR4's are rideable, but with a noticeable wallop on flat ground.

Scratch Don't Need No Shuttle Rig

Trek's full-floater suspension design is very apparent on the climb. The rear tire sticks to the ground when sitting, and also does pretty well when standing on the uphill steeps. I never found myself in need of the Fox Float's lockout lever for the rear suspension, although sustained flat ground such as pavement commutes to the trail certainly warrant such a feature for most long-travel trailbikes. Scratch Air pedals exceptionally well with minimal pedal-induced bob or chain-actuated pedal feedback over technical uphill terrain. Again, Shimano's 2x10 drivetrain setup was an ideal choice for this bike, easily conquering every lung-buster en route to the good stuff.



The Good Stuff

Scratch Air, as mentioned, is based on the Scratch freeride platform, so downhill orientation is where it really shines. The trails in my testing grounds included a wide variety of terrain and conditions. The test began with a solid month of downpour, pedaling for hours through wet, slow, technical, root-laden and big rock terrain. With its low-range climbing gear, Scratch Air acted as the commute vehicle for many days of pedal-accessed trail building, waiting patiently in the rain like a good hound serving on cougar patrol, anxious to release all that pent up energy on fresh loam at the end of a long day. Once summer finally arrived and things dried out, Scratch was ready for dust-buster duty without a single repair.


With air shocks mounted fore and aft, it did take some trailside experimentation with the included Fox shock pump to arrive at the proper pressure for my weight and riding style. Trek also has just debuted their new online suspension calculator, meaning that you are running out of excuses for not being in the ballpark with your settings. 160mm front travel and 170mm rear travel is a pretty close match, but I could feel that 10mm difference, and it forced me to ride a little more backseat on the downhill for optimal balance. Once adjusted, I found that with both shocks set for 25-30% sag, I was bottoming on hard corners. Rear air shocks currently lack any sort of low-speed compression, so I had to compensate with just a tad more air pressure. The added pressure was favorable to bigger hits, but made riding over choppy root and rock a bit bouncy.

You can't have it all, and in general the trails around Bellingham are comparatively smooth to anything north of the border, so I am pretty content with Scratch Air set up for riding jumps, drops, and corners, with less emphasis on smoothing over the rough stuff. And that's not to say it does nothing to tame normal trail terrain, it's just that for my weight, low speed compression is noticeably lacking for giving the bike the uber-plush feel most would expect from 170mm travel. Less air time will result in decreased air pressure and thus a more supple ride, but if you're going big, avoid constantly bottoming the rear shock as this will eventually lead to frame damage.

The bike handles high-speed, smooth trails with ease, pumping rollers, gapping doubles, and gaining momentum through undulations in the terrain. Set up stiff as mentioned above, the Scratch Air has lots of pop for those seeking air time, and secures very solid landings. The weight of the bike when flinging it around off medium sized jumps is awesome if you're used to bigger bikes, offering a more nimble feel in the air. It also makes for more solid landings if you're used to smaller, lighter bikes. Overall, the Scratch Air is balanced well for airtime, which is what I would say the bike excels at most.


With two geometry settings via Trek's Mino-link, Scratch can be trail-tuned to most any riding area. For railing berms and dialing in jumps, I found the low setting, with its 66 degree head angle and 14.2" bottom bracket height, to be most fitting. Many will complain that even at the low geometry setting, Scratch is a tad high in the bottom bracket department. It really depends on your terrain and personal preferences, but I ride a lot of technical climbs and prefer to avoid pedal-strikes with rocks and roots, so I'm willing to give up a wee bit of cornering prowess to have a more versatile rig. In my opinion, considering the sag of a 170mm trail bike, the bottom bracket height on the Scratch Air is ideal. However, short of serving as a non-airtime, heavy-duty all-mountain machine for heavier riders, I can't think of a situation where the 'high' geometry setting would be preferred. Perhaps the Mino-link could be improved upon by making the current 'low' setting into a 'high' setting in the future, and offering a 'low' setting of sub-14" BB and 65.5" head angle.

Scratch Air's frame is stiff and solid, tracks straight, and holds down a line really well, thanks largely to the stiff one-piece Evo link and 12x142mm rear axle. Rear suspension is as smooth as when it was new, without a creak in any part of the frame, so reliability is foreseen as excellent. Active Braking Pivots (ABP) in the rear of Trek's bikes keep the suspension moving over bumps on steep terrain when the rear brake is on, and it is noticeable compared to seatstay-mounted brake caliper bikes. The bike certainly offers confidence to riders progressing up from typical all-mountain rigs. Fox's 36 Float up front, with its tapered steerer tube and 20mm axle, keeps the front wheel on track through chunder and doesn't dive in hard corners despite its lack of compression adjustment. Its no coil spring, but the Float R is fairly progressive and has the same highly-adjustable rebound control of the more expensive models.





Pinkbike's Take on Trek's Scratch Air 8

Trek's Scratch Air 8 fills the niche for a healthy freerider on a budget. Pedaling to the top is the idea, though the reward in descent is of far greater value. Airtime, tech-gnar lines, and backcountry dependability are a good way to sum up the practicality of Scratch Air. With a 3-year warranty on the main frame, 2-year on the chainstay, and 2-year on the Bontrager hard parts, Scratch Air doesn't have to be a stranger to truck or bike park shuttles, and certainly excels on uneven, gravity-fed terrain. It's not as supple as a coil-sprung freeride or DH bike, and not as light for climbing as an XC bike, but if you're stuck somewhere in between categorization as a rider because you ride up, down, and all around, the Scratch Air comes in very close to being 'the one bike' capable enough to handle it all.

While the Air 9 is built like Schwarzenegger if he could run, the Scratch Air 8 is nearly as capable, minus the expensive steroids. Air 9 upgrades to Shimano XT-level parts spec, a very high-end DT Swiss wheelset, and a remote-actuated dropper seatpost, all in a package estimated to drop less than 2 lb's, for another thousand plus bucks. Is it worth it? If you don't need extra adjustments and dials, and perhaps a little more wet-weather durability, Scratch Air 8 gets you all the heavy-duty, all-mountain, technical-trail basics in a package just a tad heavier than the elite model.

Though the mesh of capable freeride bike with notorious all-mountain slayer may appear slightly experimental at first glimpse, under intensive review it's quite obvious Trek is onto a viable sub-genre of mountain bike with the Scratch Air series, which is why it came as s surprise to learn that they are being replaced in 2012 with the promising looking Slash lineup. Having said that, as much fun as I had aboard the Scratch, I'm looking forward to some time on the Slash, a bike that has the potential to take this sub-genre to the next level.


For more information, visit your local Trek dealer or check out Trekbikes.com.

Special thanks to Kulshan Cycles in Bellingham!