The modern Thunderbolt name has been in Rocky Mountain's catalog since 2014 (but, as a few clever Pinkers have pointed out, goes as far back as 1989) when it was introduced as a 27.5'' wheeled cross-country and/or trail bike, and since then it's been everything from a wallet-friendly, alloy-framed do-it-all rig to a carbon dream machine. Rocky has spent the last few years re-vamping their range of full-suspension bikes, with everything from the Element to the Slayer getting shaken up, and now it's the Thunderbolt's turn.
Rocky's add more rear wheel travel to the Thunderbolt – up by 10mm to 130mm on the normal models, and 140mm on the BC Edition – and there's a completely new frame that sports the ubiquitous ''progressive geometry,'' a tweaked suspension layout, and a host of details already found on the company's other fresh platforms.
Are you sure it's new? Looks similar to me...
Yup, the new Thunderbolt is fresh from axle to axle, even if it sports similar lines to all the Thunderbolts that came before it. That's kinda the same story as Rocky's other re-designed bikes; the silhouette is comparable, but the frame, features, and geometry are all completely new. The intentions are the same, though: even with the added travel, it still straddles that line between capable cross-country and trail terrorizer. Somewhat surprisingly, it's also still rolling on 27.5'' wheels rather than Rocky bumping up to bigger hoops, with them emphasizing their goal of keeping the baked-in playfulness that the Thunderbolt name has long been associated with.
All four models of the new Thunderbolt can only be had with a new carbon frame that sports blind pivots, bearings all around (including the lower shock mount), and metric-sized shock compatibility. In other words, it had the same treatment as the Altitude and the rest of the family.
Like many new bikes, you won't be attaching a front derailleur to the Thunderbolt, but Rocky says that you can run a dropper post, Di2 drivetrain, and Fox Live suspension all at the same time. Batteries won't get in the way, it seems, and neither will the bike's chainstays or seatstays - 27.5'' x 2.5'' and 26'' x 2.8'' rubber will fit without issue, and you can even run a 3'' rear tire if it has a reasonably low profile. Short-travel and big tires is often a fun combo, isn't it? Unlike the longer-travel Instinct, the Thunderbolt isn't compatible with 29'' wheels.
More and better suspension
Other details include shorter seat tube lengths so riders can run droppers with more stroke, a 2-bolt ISCG 05 guide mount and Rocky's own 'Spirit Guide' bolted onto the top of the bike's chainstay, and room for a bottle inside the front triangle regardless of if you've fitted a piggyback shock or not.
Frame weight is a claimed 5.63lbs for a medium, including the shock, protectors, chain guide, and axle. A complete Carbon 70 should come in at 26.0lbs, too.
Travel on the three ''normal'' Thunderbolt models have seen a 10mm bump up to 130mm, but that doesn't automatically mean that it's a squishier, slower ride. Rocky says that they've also upped the anti-squat number – in simple terms, how much the drivetrain's influence stiffens the suspension under pedaling load – so that the new bike can still get a move on when it needs to. All of Rocky's new bikes have been impressively efficient, so I'm inclined to think the Thunderbolt will perform likewise.
''We’ve flattened out the rate curve to directly increase the amount of usable travel,
'' Rocky says in the press pack, ''while maintaining mid-stroke support and making small-bump performance even more sensitive.''
Just imagine being a 130mm-travel bike and having to be good at everything; it wouldn't be an easy life.
The geometry and rate-adjusting Ride-9 system is still present, but just like on their other re-designed bikes, it's been moved from the frame's forward shock mount to the rocker link in order to drop some grams and gain some sleekness. It does look a lot cleaner than the old version. Want more travel?
In true Rocky fashion, they've also created a BC Edition of the Thunderbolt that follows the same recipe as their other souped-up models: more suspension front and rear, a Fox 36 instead of a 34, slacker angles, and a burlier parts spec. So instead of the normal 130/130mm combo, the BC-inspired package gets 140mm front and back, and a head angle that runs from 65.9/66.6/67.1-degrees (depending on the Ride-9 setting) instead of 66.4/67/67.6-degrees. The static numbers aren't massively different but don't forget that the increase in travel will also result in additional sag as well, so the BC Edition should be more at home on the steeps and at speed.
Rocky says that a medium-sized BC Edition frame weighs 5.63lbs, which is the same number as the normal version that has 10mm less travel. The claimed weight for the top of the line Carbon 90 BC is 27.7lbs for a large, or a bit more than a pound and a half heavier than the non-BC Carbon 70, a difference that's down to the stouter fork and select components. 2018 Thunderbolt Pricing
Over the past four years, the Thunderbolt name has been attached to everything from reasonably priced, aluminum-framed models to Di2-spec'd dream machines that dip into five digits before you get to the decimal point. Rocky has the new Thunderbolt sitting in the middle of the cost spectrum, with the lowest-priced model, the Carbon 30, seeing a $3,499 USD price tag. The Carbon 50 gets a $4,499 MSRP, while the 70 can be had for $5,399 USD.
The big daddy of the range is the Thunderbolt Carbon 90 BC Edition (pictured below) that has 140mm out back, a 140mm-travel Fox 36 up front, and a selection of stout components. That'll cost you $5,999 USD, or you can pick up the Carbon BC Edition frame for $2,599 USD. Rocky isn't offering the standard, 130mm-travel Thunderbolt as a frame-only option, however. Enough with the numbers. How does it ride?
I think I might have spent more time on different Rocky Mountain bikes than any other brand. That list includes the big-hitter Maiden DH sled, the last three versions of the Slayer (including the new 165mm bike), both the old and new 150mm Altitude, the latest Instinct, and even the old and new Element cross-country rockets. It's been interesting to see their line develop from the heavier, arguably less refined older bikes to the latest models that are much sleeker, sport more forward-thinking geo, and have become some of the most efficient machines across the board.
So, where does the new Thunderbolt fit into that picture?
I'll need more time on the red and black bike before I can call it a review, but the handful of rides I have put in is enough for me to share some early impressions. If I'm honest, I was a bit bummed at first to see that Rocky's stuck with small wheels for the Thunderbolt - I'm a big fan of the good things that 29'' wheels and tires do - but the 27.5'' wheels and 130mm of rear wheel travel do set the Thunderbolt miles apart from the 29'' wheeled, 140mm Instinct. Both bikes fill the role of a capable trail rig, but the 27.5'' wheels of the Thunderbolt definitely lend it more of a perky personality. It might be a tired idiom these days, but smaller wheels do often make for a more playful ride, and this is one of those cases.
It certainly doesn't feel like a cross-country bike – it's not intended to – but it does have the pedaling potency that Rocky's bikes are quickly becoming known for.
I think I'd still prefer big wheels if I were looking for an all-day kind of bike that has a sporty feel, but I can see a rider who's coming off a longer-travel, 27.5'' wheeled all-mountain rig really jelling with the Thunderbolt.
Rear suspension is efficient, as expected, and it feels a lot like 130mm should feel; it's supple on top despite the on-power competence, but is much, much more forgiving than bikes sporting just 10mm less squish.
So, early impressions are good. Strong (and predictable) points include the efficient suspension and frisky disposition, but I'm not sure it's as capable as the 10mm longer-legged Instinct. In other words, no surprises yet, but you'll be able to read more about the new Thunderbolt's performance down the road when it's been ridden enough to receive a proper review.