Dirt Rag Magazine

Introduction to Project 27Plus – WTB Scraper rims and Panaracer Fat B Nimble tires

If the past decade is any indication, there may soon be as many tire sizes as there are gears in a cassette (though that is also growing year after year). 26 is too small. 29 is too big. 3.7 isn’t fat enough. 4.8 is too fat. Where will it end?

Perhaps it never will, but Dirt Rag has a long history of experimenting with new wheel and tire sizes, from 26/24 combos, through early 29ers, and onto one of the first 27.5 bikes.

Rocky Mountain Sherpa

Our first introduction to 27Plus came in the form of the Rocky Mountain Sherpa displayed at the 2014 Sea Otter Classic. Based on a Rocky Mountain Element full suspension 29er, it was outfitted with a set of super wide 27.5 wheels with big 2.8-inch tires from WTB. The wider and taller tires have roughly the same diameter as a 29-inch wheel, so it was able to fit in the Element’s frame and fork.

Fast forward a year and a the WTB Scraper rims and Trailblazer tires are headed to a bike shop near you soon, and a few other brands have followed suit with tires that fall somewhere between a “normal” size and a full fat bike.

We got our hands on a set of the WTB Scraper rims with an internal width of 45 mm—that’s twice as wide as a traditional rim. Built with the same double wall construction as WTB’s other popular TCS rims, it promises to be a simple tubeless setup when the tires become available.

Panaracer's Fat B Nimble tires will be available in 26x4, 29x3 and 27.5x3.5.

Panaracer’s Fat B Nimble tires will be available in 26×4, 29×3 and 27.5×3.5.

In the meantime, we also received a set of Panaracer’s new Fat B Nimble tires in 27.5×3.5. Eager to get this project started, I mounted them to the Scraper rims before the wheels have even been built. One of the key steps in this project is seeing how they will work with existing components, so we haven’t yet decided on which hubs to build them with. Out of the box the pair weighed in at 693 grams and 673 grams, so their weight is significantly lighter than fat bike tires and competitive with many cross-country tires.

First we mounted them up on the Scraper rims and grabbed the Feedback Sports calipers: Panaracer Fat B Nimble 27.5×3.5 on WTB Scraper rim (45 mm internal width) measured 71 mm wide and 73.3 cm in diameter.

UPDATE: Since I first posted this story the Fat-B-Nimbles have stretched out a noticeable amount. They now measure 74.3 mm wide.

Panaracer Fat B Nimble 27.5x3.5

If that seems small, it’s because it is—71 mm is about 2.8 inches, well short of the 3.5 inches marked on the sidewall:


Up against a normal 27.5 wheel and tire, however, they are quite a bit larger. A Schwalbe Hans Dampf 27.5×2.35 on a Easton Haven rim measured 57.5 mm wide and 71.4 cm in diameter.


27.5 Schwalbe Hans Dampf left, Panaracer Fat B Nimble 27.5×3.5 right.

So how does it compare to the other “mid-fat” size? I grabbed a 29×3 Surly Knard mounted on a Stan’s NoTubes Flow EX rim (25.5 mm internal width). It measures 73 mm wide and 77.4 cm in diameter:

Panaracer Fat B Nimble 27.5x3.5 vs. Surly Knard 29x3.

Panaracer Fat B Nimble 27.5×3.5 vs. Surly Knard 29×3.

For the sake of comparison, we also installed the Hans Dampf on the Scraper rim and the Fat B Nimble on an Easton Haven rim (21 mm internal width):

  • Panaracer Fat B Nimble 27.5×3.5 on Easton Haven rim: 65 mm wide, 72.5 cm in diameter
  • Schwalbe Hans Dampf 27.5×2.35 on WTB Scraper rim: 67 mm wide, 71.6 cm in diameter

As you can see from the numbers, the rim makes a bigger difference in the tire’s ultimate width, though it also dramatically changes the shape of the Hans Dampf, creating a flatter, more square profile than it was likely designed for. The Fat B Nimble is also much taller.

The Fat B Nimble is also far from optimal on the smaller rim, with its profile rounding off so far that the side knobs become essentially useless. However it did fit easily in a 27.5 Fox 34 fork when mounted on the smaller rim, and I have no doubt it will fit on the larger rim as well.

Panaracer Fat B Nimble 27.5x3.5 tire, Easton Haven rim, and 27.5 Fox 34 fork.

Panaracer Fat B Nimble 27.5×3.5 tire, Easton Haven rim, and 27.5 Fox 34 fork.

So what’s next? Step two is getting the Scraper rims laced up and see which bikes the wheels will fit in. A 29er with good tire clearance should be no problem. Will he bigger tires on a smaller rim perform well on the trail? That’s what we hope to find out. Stay tuned.



Frostbike gallery and tech roundup, Part 1

Quality Bicycle Components is the largest bicycle products distributor in the U.S. and is the brand that supports nearly every bike shop in America. It owns several of its own brands and distributes dozens of others. We traveled to QBP’s home office and distribution warehouse in Bloomington, Minnesota, for FrostBike, its annual dealer show, to see what was new.

We first saw the new Salsa Warbird and Powderkeg at their official unveiling, then toured the halls. Here is what we saw:

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Belgian helmet brand Lazer was showing off the new Magma and Blade cross-country helmets, which are essentially the same thing with and without a visor, respectively. The both use the latest version of Lazer’s Rollsys fit system which adjusts 360 degrees around your head. It’s available in three sizes for $95 or $100.


Wolf Tooth Components

Based right down the road in Minneapolis, Wolf Tooth Components is expanding rapidly and had several new products in the works. The first is a stainless steel version of its SRAM direct mount chainring in tiny 24t and 26t sizes. Designed primarily with fat bikes in mind, the stainless steel should last longer in super terrible conditions.


They were also teasing this 3D printing of a new ovalized chainring, which should be available soon. Unlike the BioPace chainrings of old, the current oval designs help to redistribute your pedal stroke’s natural surges into a smoother motion. Many claim it also increases your power. Wolf Tooth says there will be a direct mount version of this oval ring as well.


Other variations include this 64 BCD chainring ($64) to mount to your crankset’s granny gear position, and there’s a nice bash guard ring that can go with it.


If you’ve got your hands on the latest 11-speed XTR and you’re looking for an aftermarket chainring, Wolf Tooth is one of your few choices ($75) so far that matches the XTR’s 96 BCD.


Is 11 speeds 10 too many? Wolf Tooth has your singlespeed needs covered with a growing collection of cogs.



QBP created Cogburn for hunters and other outdoors enthusiasts as a way to get further into the backcountry than they ever could on foot.

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The 2015 edition of the CB4 ($1,999) is available in two new camouflage patterns: a safety orange version of RealTree camo and the new Verde camo pattern from the outdoor brand Kuiu.



The Saris Bones was first launched in 1996 and has since sold more than a million units, making it likely the most popular bike rack ever. While the shape looks good and is easy to use, the one complaint Saris wanted to address was keeping track of all those straps. The new Super Bones was designed with this in mind, and features ratcheting, retractable straps that store inside the arms themselves, leading to a cleaner look and easier storage when not in use. Also included is a theft-deterrent system that locks the bikes to the rack and the rack to the car. Even the straps have steel cables inside them that make them harder to cut through with a knife.

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The Super Bones isn’t on sale yet, as Saris wants to thoroughly test its real-world durability before its release, but expect to see it on store shelves later this summer. The price will be “less than $500.”



Lauf is expanding its line of carbon leaf-spring forks with a new fat bike model. It looks similar to the 29er version but is completely new, with much larger legs. Lauf says it should be on sale this summer for about $900.

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Spotted in the Panaracer booth were the new line of Fat-B-Nimble tires that include 26×4, 27.5×3.5 and 29×3.0 versions. They will be available soon in both wire and folding bead versions with very competitive pricing: $50-$60 for the wire bead and $80-$90 for the folding. Because of the west coast port slowdown shipping has been delayed, but Panaracer is hoping they will be available in March.



When Shimano stopped selling its pedals through QBP, the distributor saw an opportunity to create its own line of high quality clipless pedals aimed at Shimano XT level. Introduced last year, the iSSi (pronounced “eee-see”) design has already been updated with a new release point that results in a more positive snap when disengaged. They’re also available with a standard spindle or with wider spindles—pictured at the left—in +6 mm or +12 mm for riders looking for extra clearance for big shoes (read: fat bikes in winter).


The Trail version has a larger pedal body, and both standard and Trail versions are available with upgraded sealed bearings.


Like many bike components these days, they are available in a range of colors to personalize your ride, including this limited-edition Radiant Gold.


DT Swiss

One of the largest and most well-respected wheel brands is getting into the fat bike market as well, with the introduction of the Big Ride series of hubs and rims. The hubs are only available in 190/197 mm versions for now, though we were told 170 mm is coming. The front hub is only 150 mm with a thru axle. They use the 350 level ratcheting internals. Retail price is $270 for the rear hub and $90 for the front.


The BR710 rims are a single wall fat bike rim with a 76mm internal width. The name is derived from its 710 gram claimed weight. They aren’t tubeless ready out of the box, but DT Swiss said it is working on an aftermarket tubeless kit.


Because DT Swiss also makes spokes, naturally they offer the hub and rim combo as a complete wheelset, laced with straight-gauge Champion spokes. The BR2250 tips the scales at 2,250 grams (natch) and will retail for $1,250 when they hit stores in May.

Keep reading

Watch for Part 2 of our tech roundup tomorrow.

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