Video by Dan Barham, Vernon Felton and Seb Kemp

Editor’s Note: Bike Magazine's Seb Kemp has been the only person outside of Santa Cruz Bicycle's inner circle to have extensively ridden the Bronson. Since last September Kemp was riding one of the raw metal, raw design mules and since December he has spent time on a pre-production, carbon fiber version. Somewhere between those two bikes a radical change was made to the Bronson.

The story behind the Bronson is more interesting than that of most bikes because during the early stages of prototype testing, 650b wheels reared their head and made Santa Cruz Bicycles take a long, hard look at the actual benefits of the middle wheel size.

One thing that this behind-the-scenes look has given Bike Magazine is an intimate look at how a bike goes from raw, rideable concept to full-blown finished product. This is the personal account of one rider's struggle to accept the new wheels and the story of an entire company trying to make the right choice.

No, it's not an April Fool's joke: the Bronson is Santa Cruz's latest bike and it sports six inches of travel and 650b wheels. The Bronson will be available in both carbon and aluminum. Carbon bikes (starting at $4,150) roll out this month (April) and aluminum bikes (beginning at $3,400) will become available in May. The Bronson is also available as a frame only. Carbon frames will sell for $2,700. Aluminum frames retail for $1,925.

By Seb Kemp
It was almost exactly 13 months to the day that Joe Graney, Santa Cruz's head of engineering, indicated that they were working on something completely different and, to me, utterly confusing.

It was during the launch of the Tallboy LT models in Sedona last year that it became clear that Santa Cruz already had some new irons in the fire. No one would have expected Santa Cruz to rest on their laurels and quit coming up with new bikes—redesigns and rolling refinements are part of the evolution of mountain bikes—but what I didn't expect was Joe to let slip that part of the testing, research and development of this other, future bicycle centered around that bastardly other wheel size: 650b.

Santa Cruz has already invested a great deal of time and energy into making 29ers that are actually enjoyable to ride. The original Tallboy, it’s fair to say, was perhaps the first full suspension 29er that really worked – both as a high-performance mountain bike but also as a conduit to massive amounts of fun. Santa Cruz then painstakingly worked on the Tallboy LT for a considerable amount of time to magically meld big-wheel monster trucking and long-travel confidence with an impressive amount of maneuverability.

On top of this Santa Cruz had produced the 26er Blur TRc, a bike that had the kind of manners that a trail bike should have but could dance into both the all mountain and cross-country categories and still come out winning. Between these three particular bikes it seemed that Santa Cruz had nailed the best of both 26 and 29-inch wheel sizes. Why even bother with the middle-of-the-road 650b size? The very notion seemed to smack of compromise.

It was widely expected that the next bike Santa Cruz would develop would be some kind of revised Blur LT, getting the long travel 26-inch wheels back up to speed. I think that's what Joe and Co. expected too, but then 650b started to gain some traction.

Members of the Santa Cruz Syndicate will be racing the Bronson in their Enduro World Series campaign.

Actually, at this stage the rapid rise of the 650b wheel was merely a rumor, few people had ridden them, except perhaps a small number of product managers and engineers. However, due to the magic of Internet forums and the inability of their users to base any knowledge on fact and reality, there was talk about 650b being the "perfect compromise", the "best of both worlds" and just straight up "better than sliced bread" (okay, I didn't hear anyone make that last claim, but it sums up the general hysteria for 650b that began taking root in certain corners of the web).

It was this kind of talk that gave Graney enough reason to shod one of the Blur LT mules with 650b wheels and ride it back-to-back with 26-inch wheels in an effort to understand what 650b wheels really brought to the table. What really were the strengths of the third dimension? Nothing conclusive was deduced so Santa Cruz welded up a new mule with geometry and a fork suited to 650b wheels. They then test rode the 26" and 650b side by side. There was still no clear winner, which is why Santa Cruz's decision to produce the Bronson (which is effectively a revised Blur LT) in 650b shape is so interesting.

The Bronson didn't start out as a 650b bike—it began life as a 26er—an updated Blur LT. Our author, Seb Kemp, raced the prototype 26er Bronson in last year's Trans Provence enduro in France. Kemp has also been riding the carbon 650b version on Vancouver's North Shore. Check out our exclusive Blueprint video (above) for the full story of the Bronson's evolution. Photo by Irmo Keizer.

It was February 2012 when Joe first mentioned that they were experimenting. I wasn't able to test ride both those bikes at that point, but I strongly voiced my resistance to the mid-size wheel. My thinking was that 26-inch wheels hadn't done anything wrong. What had happened over the past few years is that 29ers had shown that there were performance gains for some riders, in some circumstances, on some trails, sometimes. Twenty-niners had their downsides too, areas in which bikes equipped with 26-inch wheels had the critical edge.

Twenty six? Twenty nine? It was never about one wheel size being better than the other, but rather a matter of choosing the right tool for the job at hand. I didn't, and still don't, understand why people clamor for 650b, thinking it magically solves the negatives of both 26-inch and 29-inch wheels has and yet has no disadvantages of its own.

Joe and I kept talking over email, me telling Joe that this 650b stuff was just a load of nonsense that was being perpetrated by e-engineers and marketers from companies who needed a golden goose. I was sure that the 650b trend would blow over, but Joe stressed that I should try out their version. I just wasn't keen on it, so late in the summer of 2012 Joe dropped off one of the original 26-inch mules. I rode it throughout the fall, even taking it to race the Trans-Provence in France, and it gave me a pretty good idea of the direction Santa Cruz were headed with this bike.

Once you've ridden with a dropper post, there's no going back. The Bronson, like any new bike worth its salt, provides dropper post routing—both external and internal. Nice.

This was an early mule, made up of welded tubes borrowed from other designs; it lacked the stiffness and finishing touches that the final bike would have. The amount of travel had been bumped up from 140 to 150 millimeters, its geometry took cues from more recent Santa Cruz models (a little longer in the top tube, a little slacker, a little lower), the suspension curve had been changed a little to give some mid-stroke support, the frame had port holes for a Stealth dropper post, room for two bottle cages, and although the mule had regular 10-millimeter slotted quick release drop outs, the production models have 142-millimeter rear through axles.

The mule I rode felt poised, stable, yet attacking and agile. Overall, the bike seemed to be headed in the right direction. Then, in December, a carbon fiber, pre-production frame accompanied by a pair of 650b wheels turned up on my doorstep. I've since spent the winter nudging this bike around the trails.

The Bronson (named as an homage to the old Cannery that housed Santa Cruz Bicycles for the past decade and change) is everything a proper mountain bike should be – beautiful, well made, well thought out, great to ride, stiff in all the right ways, playful and yet ready to rumble. It is fast, athletic, fun loving. It turns great, pedals well, goes in a straight line fast, eases the burden of climbs and makes the downhills worth sweating for. It has no silly proprietary gubbins or speculative bottom bracket standards. This, simply, is a very good bike.

But, and this is just me, I can't quite figure out why it has 650b wheels.

Like most short-dual link bikes, the Bronson consists of two solid triangles joined by, you guessed it, two short links—it's a stout design that doesn't require a rear through axle to reduce flex, but we're still happy to see Santa Cruz equip the Bronson with a 142x12-millimeter rear end. It's a tidier solution to fixing wheels to your frame than the traditional (135-millimeter) quick release.

Since having voiced my original reservations about 650b to Joe Graney, I have ridden six bikes with 650b wheels, including one that can morph between 26-inches and 650b. My conclusion? There are good 650b bikes and bad ones, but wheel size alone doesn't determine a bike's greatness.

To be honest, I still don't understand why 650b has taken such a hold in the market this past year. As far as my experiences go, the advantages that 650b wields over a 26er, in terms of roll over and traction, are fairly negligible. And when it comes to 650b versus 29ers, 650b's one main perk is that it is not as unwieldy as 29ers, and that's exactly what 26-inch wheels already had covered. And then there's this, if you line up identical 26-inch and 650b wheels and tires, the 650b ones are going to be heavier, and rotational weight is key to unlocking a bike's potential, so why add heft there when the traction and rollover gains are so insignificant?

Well, in January we visited Santa Cruz to find out why 650b was the flavor of favor. We wanted to speak to Joe Graney and Nick Anderson, the two guys who designed and engineered the Bronson. After a full day of questions and rebuttals being fired about we were left with the impression that Santa Cruz does't see the size of the wheels on the Bronson being that important to the bike. Joe and Nick would defend the bike irrespective of the wheels, and they have a point – the Bronson is a good bike. But one thing Joe said to us hung heavy on our minds, "You could make the best bike in the world, but if no one buys it, then what's the point?" It's the most fundamental economic concept in the world: supply and demand.

Employees at Santa Cruz told us that they have been fielding phone calls and emails for months from people wanting to know if and when the company would make a 650b bike. And this is where I put aside my resistance to 650b and feel empathy for Santa Cruz, because if I were in the business of selling bikes and if enough people told me they wanted a bike with pink streamers, a glittery sticker job and a leopard print saddle, then I would have to strongly consider satisfying that demand.

Like my imagined chintzy bike, there isn't much really wrong with 650b. The wheels still go around and around, they are fitting to proper mountain bikes, and depending on which opinion you are predisposed towards, you will either love them or you will hardly notice them. Slapping on a pair of 650b wheels doesn't change ride quality dramatically the way shifting from 26 to 29-inch wheels does; this shouldn't be a big surprise, really, but given the amount of hype surrounding 650b these days, you might expect something more.

The Bronson comes loaded with thoughtful details. Examples include the molded, rubber frame protectors, ISCG-05 tabs (easy chain guide compatibility) and a threaded 73-millimeter, threaded bottom bracket. That last bit may not seem like a big perk in this high-tech world of ours, but for those of us who have grown weary of Loc-titing our press-fit bottom brackets in place, it's a thing of beauty.

The Bronson story is interesting; it would be a very good bike even if it came with pink streamers and looked like a member of Hansen, yet this is arguably one of the first occasions when a manufacturer didn't simply choose 650b wheels because they were new and therefore had to be rad – the Bronson's wheel choice came from the demands of a consumer and not the whims of a product manager. Personally, I wish that so many people hadn't taken time out of their day to call Santa Cruz and ask them to build a bike with a wheel size that I am willing to bet 90 percent of them had never even ridden, but 650b is here now and it might just be here to stay.

Weight for the carbon Bronson frame (size Medium) is an impressive 5.3 pounds. Complete bikes can be built as light as 26.2 pounds. The Bronson is backed with a five-year warranty on the frame, a lifetime bearing warranty, and a lifetime crash replacement warranty.

The Bronson is Santa Cruz Bicycle's new flagship trail bike. It will be going into battle in the World Enduro Series, piloted by some of the world's most talented racers, yet this is also a bike that will suit everyday trail riders.

The Bronson is a six-inch (150-millimeter) travel VPP suspension bike with very refined geometry, well suited to aggressive riding and confidence-inspiring trail conquering: 67-degree head angle and 13.6-inch bottom bracket height. It has a 142-millimeter bolt-thru rear axle, ISCG-05 tabs, routing for a RockShox Reverb Stealth (or other internally-routed dropper post), a threaded bottom bracket shell, room for two bottle cages, and even has new, molded rubber swingarm and downtube protectors.

Although both aluminum and carbon-fiber versions of the Bronson are available now, the full flavor, carbon fiber model is going to be the real star– what with a frame weight of 5.3 pounds and Santa Cruz's well-deserved reputation for excellent carbon fiber frame construction and ride quality.

• 142-millimeter rear axle spacing.
• Molded rubber frame protection.
• 2 water bottle cage mounts.
• Forged upper and lower links.
• Double-sealed pivots with grease ports for low maintenance.
• Collet axle pivots and angular contact bearings maximize stiffness.
• Standard or direct mount rear derailleur hanger option.
• ISCG-05 tabs for chain guide compatibility.
• Stealth and external seatpost cable routing.
• 73-millimeter threaded BB


Frame only from $1925 (aluminum) and $2,700 (carbon).

Complete bikes from $3399 (aluminum) and $4150 (carbon).

• The Bronson will be offered in a huge selection of build options, which you can check out by using Santa Cruz’s Bike Builder customization tool at

• Five-year warranty.
• Lifetime bearings warranty.
• Lifetime crash replacement warranty.

Carbon models will begin hitting the streets this month (April 2013). Aluminum-framed versions float into shops a month later, in May.

What do the folks at Santa Cruz have to say about the Bronson? Well, if you’ve already seen Graney curse at us and make the case for why they went 650b in our own Blueprint video, and you are still itching to hear more (we don’t blame you), check out Santa Cruz’s very own video right here.

Check out these other videos from Bike Magazine’s Blueprint series: