Specialized introduced its women's Rhyme full-suspension 27.5+ bike back in May, but sightings of the plus-sized bike in the wild have been rare. I finally got my hands on the top-end carbon Expert model at Crankworx in Whistler earlier this month, and I immediately hit the chairlift to find out if all that extra tire makes a difference when the rubber meets the trail.
The Rhyme 650b uses the same frame as the venerable Stumpjumper, and both bikes are also available as plus-size builds. The Stumpjumper and Rhyme 6Fattie (Speclialized refers to 27.5+ as ‘6Fattie’) bikes are based around a carbon-fiber frame with an alloy rear triangle that utilizes 148-millimeter rear-axle spacing to increase stiffness and allow room for a 3-inch tire. On the Rhyme version, the 135-millimeter-travel Fox Float DPS shock is tuned specifically for lighter riders–Specialized calls this Women's Rx Trail Tune–and uses the Autosag function to guide riders in properly setting up sag. Front-end suspension is handled by the 150-mil-travel Fox 34 Plus Performance Elite fork with 110-millimeter front-axle spacing and a 15-mil QR.
When I picked up the bike at the demo tent, I went through the Autosag process, which requires pumping the shock to 300 PSI (a floor shock pump is handy for this), then weighting the bike and releasing the correct valve to free the excess air. This should automatically set the sag at an ideal 25 percent or thereabouts. It put my sag at a too-firm 10 percent, which is the same result I've gotten with Autosag in the past. It's any easy fix–just use the shock pump for additional tweaks–but it makes me wonder whether that defeats the purpose of Autosag to begin with.
Next up was tire pressure. One of the benefits of the wider tire is that it can run at super-low pressure, thus increasing traction. Initially, I set the 3-inch Purgatory Control in the front and Ground Control in the rear at about 18 PSI, but I ended up lowering it to about 15 when it still felt too firm on the trail.
I could immediately feel the benefits of the lower tire pressure combined with the fairly wide 29-millimeter (internal) Roval rims on which the tires were rolling. Cornering felt amazing. Gaining the confidence to carry speed around corners without brake-checking at exactly the wrong point and losing all momentum has been a weak point of mine, and this 6Fattie was a welcomed crutch–the tires latched onto the dirt as perfectly as a snowboard's edge catches the snow while arcing a turn.
Descending felt just as ego-boosting. The Top of the World trail at Whistler is a spectacular high-alpine 2,350-foot singletrack descent from the 7,110-foot summit of the Peak Chair, through the bike park back to the base of the mountain. The drop-in is steep and rocky with a few tricky moves required around tight corners. The improved rollover of the plus-sized bike was apparent here, especially on the steepest chute, which I felt confident enough to commit to and, ultimately, clean.
I felt sure enough in the bike, and my ability to handle it, to keep my speed through rocky sections that had given me pause in the past, and the bike seemed to float through the chunkiest bits effortlessly, as though the rocks had been smoothed over with a giant butter knife.
The trail was still wet from the previous night's storm, but the slick, loamy switchbacks and wet roots and rocks proved no match for the Fattie's superior traction. By the time the trail dumped us into the rock rollers and jumps of the No Joke/Freight Train trail in the park, I felt as if the Fattie and I had known each other for years.
Credit this to the Rhyme's spot-on trail geometry–17.2-inch chainstays, low 13-inch bottom-bracket height, 67-degree head angle and 23.2-inch toptube–struck an ideal balance between descending capability, playfulness and climbing prowess.
During my short test time, I admittedly didn't get as much sustained climbing in on the Fattie as I would have liked, but on the surface, the bike's abilities going up didn't appear to suffer greatly from the tires' girth. The bike felt quick and responsive upon acceleration, and the small 28-tooth front chainring paired with a 10-42 rear cassette on the SRAM one-by drivetrain offered a more-than-generous range on ascents.
I went into this test a skeptic of 3-inch wheels, but I had a genuinely good time on the 6Fattie–the kind of fun that leaves you with muddied and worked, but wired to see what you can do next. I've heard of others having issues with excessive flats on plus-sized tires because tire manufacturers tend to sacrifice meat on the sidewalls to keeps weights competitive with narrower rubber. This wasn't an issue for me–I don't flat much in general–and I suspect that tires will continue to improve as plus-sized bikes take hold in the market.
So what's the rub? I couldn't quite kick the feeling that I was cheating. It kept running through my head that if I were a stronger rider, I wouldn't need extra-wide tires to mask my weaknesses. But, is that a bad thing? I suppose you could relate all the sport's technological advancements the same way. If I were really rad, maybe I would still be rocking a fully rigid steel bike with 1.9 tires and V-brakes. Oh, but the torture. In the same way that most innovations in the industry have garnered initial resistance, plus-sized bikes will undoubtedly have their naysayers. But why not welcome another option that could potentially advance riders' skills and provide the confidence to progress quicker?
Specialized is offering the Rhyme 6Fattie in three models. For $6,500, the Expert I tested comes decked out with Shimano XT brakes, SRAM XO1 rear derailleur and a full SWAT package–a door cut into the down tube that stores a tube and pump, a chain tool-integrated topcap and a mini-tool tucked under the toptube. My money would be on the Carbon Comp version, which, for $4,500, gets you the same carbon/alloy frame, a mix of Shimano Deore and SRAM GX components and Fox Performance suspension. For $3,500, the Comp offers the same spec package as the Comp Carbon, but with an alloy frame.