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Specialized Fat Boy Trail Pro

- published May 2017

83

2017

RATINGS

Ride Quality
8
Power Transfer
7
Efficiency
7
Handling
7
Components
8
GEAR INSTITUTE RATING
83

SHOP

MSRP
LOW PRICE
$4200.00
N/A
Support Gear Institute. If you make a purchase after clicking on the links above, a portion of the sale helps support this site.

THE GOOD

  • Floats well in snow
  • Dropper post standard
  • Front Suspension

THE BAD

  • Rear tire traction poor
  • Heavy
  • A bit sluggish on climbs

THE VERDICT

The Specialized Fat Boy Trail Pro incorporates aspects of traditional snow-focused fat bikes with a trail bike. The Fat Boy’s list of quality components includes our favorite Shimano XT brakes as well as XO 11 speed shifters and drivetrain spun by carbon Race Face Next SL cranks. Equally at home on the snow and the trail, the Fat Boy Trail Pro does it all well, without showing off in any particular category.

FULL REVIEW

Ride Quality
Specialized knows about making quality aluminum frames, with the M4 aluminum featured on the Fat Boy pre-dating the first Fat bike. The M4 aluminum is renowned for quality, lightness and stability. It is plenty stiff for out of the saddle climbing, but also reasonably compliant for when the tire pressure is maxed out, the ride quality is high. The RockShox Bluto front suspension fork is a nice feature, with 80mm of suspension, it helps level out chattery snow and rocky trails. Crown mounted adjustment is adequate when needing to make a quick switch. 

Stiffness-to-Weight/Power Transfer
The Fat Boy Trail Pro is nothing if not stout, which materializes on the scale at 33 lbs. The aluminum frame does not torque or twist, though the added heft is evident on the climb. Not the most climbing focused Fat machine we tested, the Fat Boy adequately makes its way along the climb and provided you remain seated, won’t slow you down (too much). The Race Fact Next SL cranks are a stiff and able, and the wide aluminum bars and short stem make for a comfy cockpit. The overall positioning seems a bit forward as grab of the rear tire traction was lacking in certain situations causing rear wheel slippage.  

Climbing/Efficiency
The Fat Boy Trail Pro is intended to be a trail riding machine, and it has the characteristics one would associate with a trail bike. A stiff platform featuring a wide Specialized aluminum bar (8 degrees back, 6 degrees up), on a short stem and the Race Face Next SL direct mount cranks with 28T chain ring enable comfortable and reasonably efficient climbing. The drag results from the large tires and heftier set up and the challenges getting good tire hook-up on slipperier surfaces. In fairness, conditions vary widely day-to-day when riding snow and dirt, and tire pressure modulation is an evolving art form on these bikes with different tire sizes and geometry. 

Descending/Handling
Wide bars, 100mm of suspension, aluminum frame on 26 inch wheels with Specialized Ground Control tires: is it the 90’s again!? If so, we're not complaining—dropping in on this bike is a blast. Massive traction on the Ground Controls makes for ridiculous cornering abilities and the suspension is adequate when combined with the substantial cushion provided by oversized wheels and tires. XT brakes continue the downhill joy, where true single finger effort is enough to stop even this substantial, enjoyable bike.

Components: Drivetrain, Shifting and Brakes
XT brakes and levers are a joy to ride. Quiet and sharp, minimal grip strength required, little to no fade, they just do the work. SRAM X01 11 speed drivetrain provides adequate spread and quality shifts. It’s easy to get topped out on a long down hill, but appropriate for the climb (28 tooth up front, 10-42 SRAM X1 on the rear). Command Post Black Lite dropper post comes with the bike. A nice touch, and a light touch bar mounted remote adjust comes in handy. The Command Post is the most consistently functional dropper we've tried. 

Wheelset
Specialized Stout XC 90 32 hole hookless design for the rims spun on Specialized Stout double sealed bearing hubs are an appropriate spec for this bike. Not the lightest set up, but perfectly enjoyable and performance oriented. The Ground Control 4.6 inch foldable tires are top notch for mixed surface riding. 

Value 
At $4,200 the Fatboy Trail Pro is a reasonable value considering you get front suspension and a dropper.  Although the frame is heavy and many would expect carbon for this price.

How We Tested It

The Fat bikes in this test were used over 20-40 miles of mud-and-snow-slopped, baby-head-strewn New England or Colorado trails. Bikes were often ridden one after the other on the same route or segment, especially on climbs or especially gnarly sections or sketchy descents, to compare performance.  Riding varied from longer segments to test ride feel and frame comfort, to explosive climbs and sprints for performance. 

For more reviews beyond this 2017 test, check our our Best Trail Bikes of 2017 and our Best Cycling Backpacks of 2017, along with other related biking gear tests

The products featured in this test have been loaned to the Gear Institute. For more on our policies regarding editorial objectivity and sample returns, see here.

About the Author

Seth Portner

Seth Portner

Seth Portner has been riding and racing mountain bikes since the late 1990s, specializing in XC, marathon and ultra-marathon events. He also enjoys regular multi-day road tours, and is an accomplished ultrarunner and XC skier. Seth, his wife and their daughter all split their time between Lyons and Winter Park.


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MSRP
LOW PRICE
$4200.00
N/A
Support Gear Institute. If you make a purchase after clicking on the links above, a portion of the sale helps support this site.

RATINGS

Ride Quality
8
Power Transfer
7
Efficiency
7
Handling
7
Components
8
GEAR INSTITUTE RATING
83

Weight

33 lbs

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