Review: RockShox Bluto Fat Bike Fork

A review of the Rockshox Bluto fat bike suspension fork.

Meet the RockShox Bluto. If you own a fat bike or are thinking of purchasing one, you should stop what you are doing. I’m going to tell you why you need to get a second or third job and buy this fork.

You can seriously boost it up a notch with this fork
You can seriously boost it up a notch with this fork

In case you missed it, Rockshox literally revolutionized the fat bike world with the introduction of the Bluto fork. With stealthy black aluminum uppers reminiscent of the Pike, the Bluto borrows technology from the Reba and Revelation forks to offer fat bike enthusiasts the first-ever definitive, reliable, and affordable suspension fork. Before the Bluto, front suspension could be had, but it was costly, hard to come by, and let’s be frank: t’was downright sketchy.DSC_0206

The Bluto was essentially designed for the Salsa Beargrease and vice versa, before it was launched as a standalone product, helping to catalyze the fat bike revolution that occurred last season. Gone are the days of heavy fatties slugging along in the snow: newer bikes equipped with, and designed around, the Bluto are made to be rippers year-round, in every condition.

Things can get pretty wicked when you slap a Bluto on your fatty
Things can get pretty wicked when you slap a Bluto on your fatty

Offered with 80mm, 100mm, and 120mm travel options, the Bluto was engineered to fit modern fat bikes with tapered head tubes and slacker fat geometry. The 150mm hub spacing can accommodate up to a 4.8-inch tire, but it can also wear a 4″ fat bike tire and a 29×3.0″ tire with the proper wheel. The sturdy but light aluminum crown, magnesium lowers, and 15mm thru axle give this fork the optimal torsional strength to handle heftier fat bike wheels and tires hauling down the trail.

The rebound on the bottom of the lower makes adjustment very easy
The rebound on the bottom of the lower makes adjustment very easy

RockShox made sure that customers would experience the same feel with the Bluto that you get with any modern mountain bike suspension fork. Incorporating infinitely adjustable RL Solo Air damping via the 32mm stanchions allowed RockShox to manufacture a supple fork with a familiar feel. The crown lever, also designed for an optional Pushloc remote lockout, allows the rider to turn and tune the damping, down to a near lock out position.

For a fat fork that tips the scales at less than 4 pounds, the Bluto seems too good to be true. I was happy to be tapped as the guy to put this product through the wringer.

Borrowing from Reba/Revelation platform, the Bluto features are very familiar and easy to setup and use
Borrowing from Reba/Revelation platform, the Bluto features are very familiar and easy to setup and use

The Deets (from RockShox)

TRAVEL80/100/120
WEIGHT1,796g (3.96lb)
DAMPINGRL
AVAILABLE SPRINGSSolo Air
ADJUSTMENTSRebound, crown or remote lockout
STEERER OPTIONSTapered
CROWNForged, AL66 TV aluminum
UPPER TUBES32mm aluminum, Fast Black
LOWERSMagnesium
MAXIMUM ROTOR SIZE200mm
COLOR OPTIONSBlack, White (OEM only), Diffusion Black (OEM only)
REMOTESPushLoc Sprint (optional)
OTHERAxle: 15x150mm Maxle Lite, Offset: 51mm, Brake Type: Disc
This fork excels when things get rowdy
This fork excels when things get rowdy

Testing

Living in central Colorado, I ride my fat bike year round, and I ride it hard. I tested the RockShox Bluto in the winter and spring, with temperatures ranging from the single digits to a comfortable 70-ish. I climbed up steep, dry singletrack, with the sole purpose of turning around to ride back down like a madman. I pulled my kid around in a Chariot. I tested this fork in the snowy Rockies, with everything from choice packed snow to profanity-inducing-post-hole-hike-a-bike powder. In short, I beat the crap out of this fork as best I could, and as I sit here staring at it, I can’t deny my overall reaction to it: the Bluto is probably the best thing that has ever happened to fat bikes.

The Bluto performs well even in adverse conditions, but I'd recommend locking out the fork if it's below freezing

Impressions

Before I tell you why this fork impressed me so much, I want to answer a question many of us skeptics posited months ago: who needs a fat bike with suspension anyway? If you only ride your fat bike on flat boring trails in the snow, or really care about how much your bike weighs for a race, then the Bluto is definitely not for you. Stop reading and go lick an ice cream cone. If, on the other hand, you want to turn your already awesome fatty into an indestructible trail killer, then you should get your credit card ready as you keep reading.

The Bluto worked well even when it was locked out
The Bluto worked well even when it was locked out

I’ll be honest: when I pulled the fork from the box it was almost love at first site–RocSshox did a great job of making this a work of art. However, despite its relative light weight, I realized that I would be adding about 3 pounds to the front end of my bike–and I was not sure it would be worth it. Why? Because I felt that I could already rally pretty hard with my rigid 25lb fatty, so how could a heavier fork with “only” 100mm of travel and 32mm stanctions change that? The answer became apparent from the very first ride, that there was no going back.

Getting used to the extra weight in the front end may take a little getting used to...but it's worth it!
The extra weight in the front end may take a little getting used to… but it’s worth it!

Here is what I immediately observed on the first few rides: the extra weight, whether I was climbing in the snow or on dry trails, was essentially unnoticeable. The extra weight up front did make it more difficult to maneuver the front end of the bike over life-altering obstacles, but I quickly got used to that. What I really did not expect was for the 100mm of suspension to provide tremendous gains in performance and speed, on par with a longer travel bike.

With the Bluto, pretty much the only thing hold you back are the relative size of your cajones
With the Bluto, pretty much the only thing hold you back are the relative size of your cajones

One of my first dry dirt descents was also one of the most memorable. Coming down the fast technical section of one of my favorite trails, Mount Falcon, my Bluto-equipped bike felt like a big, fat, dirt jumper. I was launching the bike in the air and soaring over rock gardens like never before, allowing the suspension to soak up the trail, staging myself to pop off the next kicker. I could not wipe the grin off my face–and I honestly could not believe how high I was jumping, and how fast I was going down this trail… only about 10 seconds slower than my fastest time on my six-inchtravel bike. Needless to say, I was impressed.

I burned though all of my travel on that ride, as I have on most rides since then, but I have continued to ride my fat bike faster and jump off of higher obstacles. My only concern now is blowing the seal on my makeshift tubeless tires and eating it. It’s no fun to eat “it.”

Compress that fork! It's easy to burn through travel when riding hard on rocky trails...but the Bluto can take it!
Compress that fork! It’s easy to burn through travel when riding hard on rocky trails… but the Bluto can take it!

Special Considerations

Despite the aforementioned accolades, there are several things you will need to take into consideration if you add a Bluto to an existing fat bike (bikes that come equipped with a Bluto already have this done).

I used the existing Salsa hub with spacers, and re-dished the wheel 7.5mm
I used the existing Salsa hub with spacers, and re-dished the wheel 7.5mm

Since the Bluto uses 150mm hub spacing, and most fat bikes use traditional 135mm hubs, you will either need to buy a 150mm hub and re-lace your wheel, or use a Bluto-approved 135mm hub (like the Beargrease hub) with aftermarket spacers, and redish your wheel so that your disc rotor lines up with your caliper. If this is Greek to you, I suggest you talk to your local bike shop mechanic, because most bikes can be converted very easily.

Dampening and lockout is a breeze with turn of the crown dial
Dampening and lockout is a breeze with turn of the crown dial
A built in sag scale helps in setting up the suspension out of the box
A built in sag scale helps when setting up the suspension out of the box

I also found that setting sag can be somewhat tricky. RockShox included their handy scale stamped into the stanchions on most of their forks, but I found that I had to add 10-15 psi more than the 20-25% sag in order to keep from really bottoming out the suspension on bigger hits. Apparently I am not the only one who experienced this–it is a pretty consistent complaint on common internet forums. One way around this is to add one or two black 32mm bottomless tokens (originally designed for the Pike). This reduces the air volume and changes the air-spring compression, creating greater ramp up at the end of the stroke.

I found that adding about 10psi above this scale was more in tune for technical riding
I found that adding about 10psi above this scale was more in tune for technical riding

You can also add or subtract bottomless tokens to make the Bluto 80, 100, or 120mm. Some riders have also swapped the stock damper for the RT3 Charger Damper for a “Pike feel.” Most of this information can be found in the updated 2015 Service Manual, consulting Dr. Google, and/or asking a qualified mechanic at your LBS.

You can tell by the look on my face that I was doubting the wisdom of this off camber jump, but the Bluto did not let me down
You can tell by the look on my face that I was doubting the wisdom of this off camber jump, but the Bluto did not let me down

The last thing I noticed was that I needed to run higher tire pressures. Before the Bluto, I rode aggressively on about 6psi in the front and rear, what I found to be my personal sweet spot for traction with a fully rigid bike. Running 5-6psi with the Bluto makes the fork feel sluggish and wallow in its travel. I found 10psi to be the perfect pressure when using the fork, allowing the fork to do most of this work instead of the tire pressure. Setting up the rear is trickier: this fork allowed me to ride harder, so I needed to increase the rear pressure to keep from dinging my rims. This also decreased traction and made the rear feel bouncier. I settled on 8psi. You will have to tinker with your setup to if you have a Bluto.

Here is the landing on that jump in the photo above. Note the fully compressed fork, the tire deformity soaking up the impact, and chain deflection. This 3ft huck to flat felt really smooth despite landing it on a hardtail. In case you have not noticed by now, I did slap on some custom aftermarket decals to jazz things up a bit.
Here is the landing on that jump in the photo above. Note the fully compressed fork, the tire deformity soaking up the impact, and chain deflection. This 3-foot huck to flat felt really smooth despite landing it on a hardtail. In case you have not noticed by now, I did slap on some custom aftermarket decals to jazz things up a bit.

Conclusion

More than anything, the RockShox Bluto represents a paradigm shift in the fat bike world and a remarkable upgrade for riders looking to extend their fat biking to all trails in all seasons. At $650, this affordable front fat-specific suspension isn’t for everyone, but I personally think it is the single greatest upgrade that I’ve made to my fat bike since I bought it. I’ve yet to meet anyone who’s converted from a Bluto back to a rigid fork because they didn’t like it.

Bottom line: if you want to ride your fatty more aggressively, you need this fork.

Your turn: do you have a Bluto? What are your impressions? 

Even on long road climbs in the winter the weight of the Bluto is negligible.
Even on long road climbs in the winter the weight of the Bluto is negligible.

Thanks to RockShox/SRAM for providing the Bluto for review!