Yeti AS-R 5 Carbon Review

Yeti's AS-R 5 Carbon blurs the line between what we currently hold true of bike categories. That is, mega light weight is for XC race bikes and skinny types who are usually more concerned with the amount of calories burnt during the ride, and a rig with 5" of travel should sit firmly in the trail bike class with riders who shotgun post ride beers at the trail head. It is obviously a bit fuzzier than those examples, but that isn't too far off of a lot of scenes. But what happens when you combine the two? The forward thinking crew at Yeti did just that with their AS-R 5 Carbon, a 5" travel bike who's frame hits the scales at only 4.75 lbs. It will pay dividends to do your homework if you're thinking about adding this particular Yeti to your stable. There is the 575 after all, that could be used for the same task, and sports .75" more rear wheel travel travel, yet is a very different beast altogether. Yeti themselves state the the AS-R 5 "rides more like a souped up cross-country bike likened to a sports car suspension". In other words, if you're looking for a lazy and forgiving trail bike, look elsewhere because the AS-R 5 Carbon isn't going to be your cup of tea. The carbon AS-R 5, as well as the slightly heavier aluminum version, makes use of firmer travel, especially when in the shock's mid stroke, to deliver a more spirited ride all around. You are going to feel the terrain under you on the AS-R 5, but a good rider can and will use that fact to their advantage on a lot of trails. So, it's light, and Yeti makes no bones about the bike's 5" of taut travel, but the third piece to the puzzle is the AS-R 5's geometry. The 67 degree head angle (with a 140 mm travel fork) is a full degree slacker than the 575's with a longer 150 mm travel front end, although those static numbers will get closer to each other due to the 575 running more sag. Regardless, the AS-R 5 is raked out more than the majority of bikes in its travel or weight class. This is not a bike that will want to doddle around on the trails...

The AS-R 5 is available in two flavors; an aluminum frame that comes in at a very reasonable 5.5 lbs and retails for $2000 USD, and the swanky AS-R 5 Carbon shown here. Yeti uses quality high-modulus carbon that is laid down by hand to create both the front triangle and rear stays, but this more expensive frame still mimics the lines of the aluminum version. Yeti packs an impressive amount of technology into the AS-R 5 Carbon, all of which adds up to a grand total of only 4.75 lbs. That's including the shock by the way, and is certainly an impressive figure considering that the bike sports 5" of rear wheel travel and comes with a five year warranty from the factory. Instead of boasting of the frame's welterweight status as most manufacturers would, Yeti touts the AS-R's awe-inspiring stiffness - it's claimed to sport a rear end that has been measured at 50% stiffer than the previous version when the 12 x 142 mm axle and adapters are employed. Switching out the rear axle adapters couldn't be easier, a nice touch considering that many AS-R 5 Carbon owners will choose to run the bike with their standard wheelset. Hidden from view within the carbon chainstays are lightweight hollowed out aluminum sections, located at both the yoke and rear flex pivot, that further help the cause in the war against flex. Speaking of flex, the AS-R 5 Carbon forgoes using a dropout pivot, instead relying on the flexibility that has been engineered into the carbon just above the dropouts. I'm picturing the more skeptical of our readers out there cringing, but the truth is that very little movement is required at this point as the bike goes through it's travel. Not only can the carbon stays be designed to more than adequately handle the movement needed, but the bike's designers can save valuable grams by not needing to use bearings and the hardware required to hold everything together. At the opposite end of the swingarm you'll find a rather shiny aluminum piece bonded to the chainstay who's purpose is to keep the chain from damaging the carbon when the inevitable happens. Aluminum and titanium hardware holds everything together. Another one of the few pieces of aluminum on the frame is the Dogbone link. This piece has two jobs; it controls the rate of the rear suspension, which is certainly different than on the similar travel 575, and also keeps side to side forces from taking a tole on the Fox shock. Yeti chose to go with a tapered headtube to allow riders to reap the benefits of the system's increased stiffness, a wise choice considering that there is a good chance that the AS-R 5 Carbon will be under some very aggressive riders. Other nice details include machined aluminum housing guides and clean routing of the rear derailleur's housing through the swingarm that incorporates a removable cap to make replacement easier. I'll admit that many readers will disagree with me when I say that the bike should also have built-in routing for a telescoping seatpost, but I can see many AS-R 5 Carbon owners choosing to run a dropping post. Seems a shame to have to resort to zip-ties on such an impressive frame.

Given its weight, you'd be forgiven for assuming that the AS-R 5's geometry would lean more towards bib shorts and bar ends, but you'd be mistaken. Thankfully, the smart people at Yeti decided to go slack and low with numbers that will have aggressive trail riders sporting an evil grin. Make no mistake, much like its suspension, the bike's geometry is for riders who attack trails. In short, this is a go-fast bike. The 67 degree head angle (with a 140 mm fork) is a number that you'd be likely to find on a rig with more weight and more travel, but I have to applaud the crew at Yeti for thinking for themselves and possibly forecasting the future. I'm of the opinion that we'll shortly begin to see many more bikes with geo like the AS-R 5 - low and slack for high speeds, but firm travel for riders who want to feel the terrain, not to mention pump the hell out of it. We added a touch more rake to the front end by employing RockShox's 150 mm travel Revelation World Cup up front - its carbon fiber one piece, tapered steerer and crown seemed like the perfect match for the carbon frame and the relaxed front end suits our local terrain, which is a mix of fast, smooth trails and slower, steeper runs.


Yeti AS-R 5 Carbon details:

- High modulus carbon fiber front and rear triangles
- 127 mm of rear wheel travel
- 4.75 lb frame weight, including shock
- 30.9mm seat post diameter
- 135 mm QR or 12 x 142 mm rear axle compatible
- Hand made
- Tapered headtube
- MSRP $2550 USD (frame only)

Our AS-R 5 Carbon test bike features a make-no-apologies build that errs on the extravagant side and would retail for more than many motorized vehicles, but Yeti also offers three different solid build kits that span the range from reasonable to "your kid isn't going to college" kind of prices. Our custom build would relieve you of $7999 Canadian.

By now you probably get the picture - the AS-R 5 Carbon is a no holds barred trail bike - so why hang anything but the best off of it for parts? SRAM's top tier XX grouppo made sense, and not just because of the high carbon content. A trail bike like the Yeti is going to see all of the elements and will have every sort of terrain under its tires by the end of the season. We wanted a reliable setup that would not only let us climb straight up the side of a mountain, but would also run smooth after a wet Fall riding season. Having had some time on their 2 x 10 system prior to putting our custom Yeti together, I knew that I wanted to go that route with this build. The XX crankset uses 26/39 ring combo and spins on a ceramic bearing GXP bottom bracket. It is mated to an XX 11-36 X-Dome cassette. The result is less hassle with two rings instead of three, but a still suitable gearing range for the trails and mountains that I frequent the most. Slowing the bike down is a set of XX World Cup brakes, with the addition of a bigger than standard 185 mm rotor up front.

The cherry atop the cake has to be DT's extravagant EX 1550 wheels. These hoops are unashamedly over the top: while DT's high-end hubs and spokes certainly play a big part in the story of the EXC 1550's, the real story here is the use of carbon for the rim material. The handmade carbon rim uses a unidirectional (UD) material as opposed to a 3K carbon weave that you may be more used to seeing. That is why the rims do not have the classic carbon look and at first glance look more metallic than anything else. By choosing to use UD carbon instead of a more classic looking weave, DT has managed to shave unneeded grams while still retaining carbon's inherent strength. They also kiboshed the idea of throwing on a cosmetic-only layer of carbon weave to achieve the expensive look that some people may prefer. It's all about the grams here folks, nothing extra that isn't going to make the EXC's lighter or stronger. Taking advantage of carbon's inherent strength, DT has built a vertical rib within the rim that should not only produce a laterally stiffer rim, but also an added amount of vertical strength. The use of carbon, along with the technique used to manufacture the rim itself, allows the final product to be not only incredibly light, but it should also be quite a bit sturdier than its aluminum counterparts. There are quite a few wheelsets out there that are in the same weight category, but nearly none of those can vouch for having the same 29 mm width that works so well with the larger, high volume AM tires that a lot of riders are using. Those wide tires on an equally light, but much skinnier rim, will not have enough support to keep them from folding over on themselves at optimum pressures. There are aluminum options with similar widths that approach the EXC's 400 gram rim weight (a Stan's Flow rim comes in at about 450 grams), but DT would say that their carbon rim is considerably stiffer and stronger in all regards. At the center of the wheels you'll find DT Swiss's own hubs (what else would you expect to see?!) that are equipped with high end, stainless steel, sealed bearings. I have not had much luck with ceramic bearings in the past, although one might expect them to be stock on a wheelset of this price. Inside the rear hub you'll find DT's updated Star Ratchet clutch system that has proven itself time and time again. The latest version of the Star Ratchet has split engagement time in half for quicker pick up and an even louder freehub. As usual, no tools are required to service the hub's internals as everything is a simple press fit. The wheels are finished off with anodized red, aluminum Pro-Lock nipples.

Much like any other tool built to excel at one task, the AS-R 5 C makes no bones about its intentions. The long 23.6" top tube on our medium sized test bike was mated to a short 50 mm long stem to reign the length in, with the result being a comfy, but still roomy cockpit. This was a welcome change from the more cramped reach of some of our more recent test bikes with similar amounts of travel, and was great on long climbs. When the time came to gain some altitude, the AS-R 5 Carbon could ascend the mountain like a scalded cat up a tree. The firm travel, even without the Fox shock's ProPedal engaged, was a asset any time that speed or effort was needed to clear a technical uphill section. The mega light frame turned out to be anything but a noodle when the power was down or extra body English was required, surprising all who rode it with its rigidity. Part of this must surely be down to its massive box section chain stays, but I'm going to give most of the credit to the 12 x 142 mm dropouts. The more muscle required to power through a tricky section, the firmer the rear end felt. While the frame does come with both standard QR and 142 mm dropout adapters, I'd urge anyone who is waffling over which ones to use to make the jump to the larger standard - it's that noticeable. While the rear suspension no doubt provided more traction on trying climbs than a stiffer sprung bike would have, the sporty feeling rear suspension felt like it was not as likely to hold momentum as well when crawling up and over uphill ledges or other square impacts. More finesse was required on the Yeti than on a longer legged bike that one could simply plow through the chunder with, but this is to be expected. Suspension feedback was largely neutral regardless of chain ring choice, but performed best in the smaller of the two XX rings. As suspected, the AS-R's geometry could be more of a handful when the climbing got tight (this was no doubt exasperated by the longer than recommended RockShox Revelation fork), but the key turned out to be carrying as much speed as possible through testing switchbacks, something that is easier said than done when I was already at my redline. Then again, this is a machine that wants to go fast - Maybe I'm not fast enough?

Those same angles that made slow speed uphill plodding difficult at times put a large, shit eating grin on my face when pointing the opposite direction. The AS-R 5 Carbon sits firmly in the trail bike category, not having the extra cush of a 6" travel All-Mountain steed, but its angles beg the rider to push harder and faster on everything from level ground to eye watering downhills. Slack, stiff, and with firm travel, the Yeti can dive into corners with the best of them, especially when the ground is not overly rough. Anytime I got the bike on smooth and undulating terrain I felt as if I had reached my personal zenith - it simply can't get any better. Throw in a few bumps and lumps to air off of and the Yeti was right at home. With 127 mm of rear wheel travel it's never going to feel as confidence inspiring as a bigger bike when the trail gets rough, but a skilled pilot will be able to use the bike's manners to their advantage. Pump when you can, air over the worst chunder, and absolutely rail any and every corner. Your buddies on their heavier and longer legged, coil sprung bikes may gap you on the most white knuckle of sections, but you'll quickly catch up with them at any other point of the ride. The AS-R 5's rear suspension doesn't erase the terrain under you, instead its firm travel, especially in the shock's mid-stroke, takes the edge off without using excess amounts of suspension. There are certainly smoother 5" travel bikes, in fact most other options are more forgiving, but Yeti doesn't apologize for this - if you're looking for a cushy ride, this isn't it. Don't force the AS-R 5 to be anything that it isn't by running more than the recommended sag, you'll only slacken the bike out too much and take away that brisk snap and liveliness that the AS-R 5 Carbon is so great at.

Given the bike's boutique parts spec, I was expecting the shifting to be fast as hell, the wheels to spin up easy, and the brakes to be top notch. I wasn't disappointed in any of those categories. There will always be those who are going to swear that 10 cogs will be detrimental, that the 10 speed system will not perform worth a damn once covered in mud, or that reliability will falter over the long run. Having spent lots of time on 10 speed systems throughout the last season I can say that that isn't the case, especially with SRAM's top end XX group. Not only is the gearing range on this 2 x 10 setup "smarter" than the average home made 2 x 9, but the shifting is no doubt faster. This is to be expected out back where the cog spacing is tighter than a 9 speed cassette, but shifting up front is what really blew me away. Shimano certainly has been able to brag about having the fastest front shifting for some time, but I can confidently say that SRAM is on par with their XX front derailleur and rings. No amount of mud, snow, or trail debris managed to upset the rear shifting, despite the tighter tolerances. This is the third or fourth 10 speed group that I've ridden this season so I was already quite confident in its performance, but no matter how well it works there will be those who swear that there is no place for ten cogs on a mountain bike. Too bad, it works, and it works very well. The XX World Cup brakes also performed admirably, although I did miss having the Contact Point Adjustment that can be found on the only slightly heavier standard XX or X0 stoppers. There is no denying that their 279 gram (160mm rotor, front post mount) weight is impressive though. The no holds barred DT EXC 1550 wheels get high marks in all categories, with the exception of their stratospheric asking price of $2675 USD. Once past the initial sticker shock, I got on famously with the carbon wonder wheels. Not only are they still perfectly true and tensioned despite a full season of abuse, I also never once suffered a pinch flat, regardless of tire choice. Would I personally shell out for their asking price? Probably not, especially considering DT has some great aluminum rimmed options that come in at a much more reasonable price, but if money wasn't an issue, the EXC 1550's would be at the top of my wish list. The RockShox Revelation World Cup proved to be a smooth fork, although I had some trouble getting into the last 20 mm of travel, even when running questionably low air pressure.

The AS-R 5 Carbon is not a bike for the masses. If you make a mistake or get lazy on challenging terrain, you'll be punished. But if you are a fit rider with strong technical skills, you'll be able to make this sporty bike work for you. The reward is more speed and more grins. Just as driving a Lamborghini to get groceries doesn't make a whole lot of sense, the AS-R 5 Carbon could be squandered under the average Joe, weekend rider. That's not to say that a weekend warrior won't have fun aboard the carbon Yeti, but just like watching a gifted driver make his way around the track, the AS-R 5 Carbon being ridden by a fit and technically astute rider is a thing to behold. We all would like the Lambo in our garage, but most of us know that we wouldn't do it justice. When considering this speed machine you'll need to be honest with yourself about your abilities and whether or not you can take advantage of AS-R 5's impressive trail prowess.