Final Review: Rocky Mountain Thunderbolt BC Edition

The Thunderbolt was a hoot to throw around fast singletrack.


Expectations can be tricky. High expectations are the perfect setup for a letdown or disappointment. Expectations need to be shelved well before embarking on a number of endeavors, and reviewing a mountain bike is certainly one of them… especially if one hopes to maintain objectivity. Having said that, there was simply no way I could un-see what I have seen, un-know what I have known, and un-experience that which I have experienced.

Having had such an excellent two months last year with the Ride 9-equipped Rocky Mountain Instinct 999MSL, I couldn’t help but transfer that experience to my expectations for the Thunderbolt BC Edition. Having reviewed the spec sheet on the Thunderbolt BC Edition in my On Review article only further enhanced my expectations.  I knew it was unfair, but I am human, and couldn’t help but approach the review period with some bias; but at least I was aware of that bias, so I knew I could compensate. So let’s look at two months and roughly 300 miles on the Thunderbolt BC Edition and see how it matched up against expectations.

The T-bolt was as much fun in the rocky, tight and twisty as it was out in the open, maybe even more so.

The Middle Wheel Size: Just Right

When the 27.5″ wheel first appeared, it was supposed to be the best of both worlds, combining 26″-like maneuverability with 29″-like rollover and momentum. My experience was that I preferred either 26″ or 29″ wheeled bikes depending on the type of riding I was doing. Never did I find a 27.5 that began to bridge that gap in a meaningful way–until now. The Thunderbolt BC edition is the first rig I’ve thrown a leg over that made me feel like I had 26″ spirit and 29″ momentum. I could maneuver the Thunderbolt through the tightest of rock gardens, steer it around the tightest switchbacks both up and down, and then open it up, quickly building momentum and then maintaining that momentum when the hill turned into a roller coaster. Expectations? Greatly exceeded.

Although not evident in the picture, this little maneuver is a test piece that drops most riders/bikes pretty quick. It cannot be approached straight on–there is a mandatory 90-degree right turn right before the stepover. The T-bolt took it in stride; even easier than my 26″ bikes.

Climbing: Beyond Stellar

I’ll cut to the chase here: the Thunderbolt BC Edition is far and away the best technical climber I’ve ridden. Every ride, I wanted to head for the rockiest climbs I could find. I just wanted to go up, up, up, and never stop. Rocky’s claims of making the stiffest carbon frame on the market are hereby validated in this rider’s opinion. That uber-stiff frame combined with surprisingly light weight that rides far lighter than its actual weight (under 26.5 lbs–which is shockingly light for a bike with this level of gnar-capability), seems to vault the bike up hills, and no obstacles are cause for concern. That light, stiff frame also made even mundane fire road climbs–something I usually look on as a necessary evil required to get to the good stuff–something I actually enjoyed. Expectations? Greatly exceeded!

The T-bolt was truly in its element in extended, uphill rock gardens.

Ride 9: The Same Yet Different

With my time on the Instinct, I always rode it in the setting for the heaviest riders and split my time on the geometry scale at about 10% steep (climbing oriented), 60% middle, and 30% slack (downhill oriented). With the Thunderbolt, I ended up leaving it in the slackest setting all the time after experimenting with all settings. The steering on the T-bolt is so sharp and precise, I never felt like I was giving up any maneuverability on even the tightest singletrack, and I loved the way the slacker setting exploited the bike’s desire to move up the gnar scale. The other thing that surprised me was my ultimately settling not on a setting for the heaviest riders, but rather the medium setting. Granted, I have lost about 25lbs since testing the Instinct, but I’m still a little over 200 lbs with a loaded backpack and I expected to continue needing the stiffest platform, but the Thunderbolt’s suspension didn’t come alive until I backed it off a bit. I attribute this to both some differences in geometry and the use of the RockShox Monarch on the Thunderbolt versus the Fox suspension on the Instinct. Expectations? Met.

My usually challenging switchbacks were a snap on the T-bolt.

Suspension Performance: Trial, Error, and Success

This is the one area where the T-bolt gave me some troubles. I must have been lucky with the Instinct last year as one setting of the sag and the suspension was a dream from the first pedal stroke. I wrestled with the T-bolt for a half dozen rides over at least 30 miles before I got the suspension dialed in. This was in part due to my lack of familiarity with the RockShox setup and partly due to the need to match the suspension settings with the Ride 9 settings to fully exploit what the bike is capable of.

Switching the Ride 9 chips takes about 60 seconds, so it is something you can do mid-ride if you live in a place like I do where the rides tend to go up, up, up for miles before plunging down, down, down for more miles. The bad news is that, to fully reap the benefits of the bike’s performance, it may be necessary to reset the sag after changing the Ride 9 settings. The good news is the Monarch has sag settings etched on the shaft, making it easy to do so if you’re carrying a high pressure pump. For me, I chose to find my favorite setting and leave it there for an entire ride. In the end, I never got the suspension as plush-feeling as I’m used to with my Fox setups, but that never affected the astonishing ability of this bike to hold a line, or my ability to thoroughly enjoy the ride. Expectations? Met.

The T-bolt was more than happy to transition from trail to all mountain mode.

Component Performance: Beyond Reproach

With every bike I’ve ever ridden, including last year’s Instinct which I loved overall, I find the bike would be better suited with a few components changed. Like the wheel size dilemma I described above, that has always been the case–until now.

Each and every last component on the Thunderbolt BC edition was purposely and perfectly chosen for its intended purpose. The Stans Flow wheels rolled fast and free, but refused to flex or complain at any level of abuse. The RockShox Reverb dropper post responded quickly and smoothly as did the Shimano XT brakes. The SRAM 1×11 drivetrain shifted smoothly in all conditions. The wide handlebars and short stem provided excellent control without sacrificing playfulness. The Maxxis Ardent tires, while not the most aggressive tires in Maxxis’s line, sacrificed very little in aggressive capability in exchange for fantastic versatility and surprisingly-low rolling resistance. Expectations? Exceeded. (And I had very high expectations going in here.)

The ultimate suspension test; unevenly placed steps around corners and for a long distance–this is when I knew I had finally dialed in the suspension on the T-bolt.

Just One Nit to Pick.

With the Ride 9 chip in the top middle setting, there is little clearance between the frame and the air valve on the shock, making it hard to add air. I have two high pressure pumps, one of which has a bit of a flare on the fitting which screws onto the shock, and I simply couldn’t get it to mate with the shock in that setting, so I would have to undo Ride 9 to adjust sag and hope for the best when I reinstalled it in that position–a rather tedious task when testing, but probably not such a big deal once the best pressures are known and again, only an issue for a heavy rider looking for the slackest geometry.

I just couldn’t help but want to take the T-bolt out again and again on tricky steps-ups and technical climbs.

Bottom Line

Despite potentially unrealistic expectations setting up the Thunderbolt for failure, it far exceeded them overall. This bike is fast–I mean really fast. Up, down, or across, the Thunderbolt BC Edition slays all manner of trail–and can be expected to do so all the time in the hands of an experienced or confident rider. Because the bike zooms away with such ease, it could easily get ahead of the novice who is constantly looking right in front of his wheel, but for anyone else, this bike should be a complete joy.

The Thunderbolt is, in my estimation, the rarest fulfillment of the inflated promises every trail bike makes. It can handle the most impressive range of terrain; while it is most at home in the middle of the gnar continuum as a dedicated trail bike, like most Rockys it “cheats up” and is an admirable all-mountain ride as well.

Amazingly enough, even with its ability to reach up the gnar continuum, it also does quite well going the other direction; it is light and stiff enough to be a spirited cross country ride as well. I can’t imagine any competent rider not falling in love with this bike on just about any trail, from your buffed out home town track to your next Moab adventure.