The Surly Krampus represents the next evolution of the 29er, at least according to the folks at Surly. Upon first glance, it looks to be just another fat bike, albeit with slightly different sized tires, a narrower, taller profile. Surly dubs this tire size, the 29er with 3" wide tires, "29+". The stock version of the bike comes with their Rabbit Hole rims, with a 50mm diameter, and 3" wide Knard tires, a combination that gives an incredibly wide footprint, providing great traction as well as a fair amount of float. The wider tires give some of the passive suspension benefit of a fat bike tire, combined with the improved ability to roll over obstacles of the 29er rim.
The bike features standard part sizing, so you can simply toss on parts from your parts bin or older bike and be ready to rock. However, because of the large volume tires, chain rub can be an issue using a crankset with multiple front rings. The bike works best with either a single front ring, or using Surly's own Offset Diameter (OD) crankset.
There are two versions of the Krampus, the "standard", which comes with Surly's ubiquitous track style dropouts, and the Ops version, short for "Options". The Ops features their new Modular Dropout System (MDS), which allows riders the option to use a standard vertical, 10mm dropout with derailleur hanger, rear facing, track style dropouts, a 142x12mm thru axle using different dropout chips, or a slotted thru-axle chip allowing you to run a thru axle single spped. It also has mount points for fenders, should you be so inclined. The paint job on the Ops is a flat black, whereas the standard Krampus has a gorgeous glittery green paint. I opted for the Ops version of the frame, as I knew the bike would split time between a loaded bikepacking rig and a single speed, and I wanted the option to run a standard vertical dropout for bikepacking.
Krampus Spec Sheet
The Krampus has a relatively slack, trail oriented geometry. The head tube angle is a moderate 69.5, a seat tube angle at 72.5 and shockingly short chainstays given the tire size of 446mm. So...that's a lot of numbers, what do they mean? Well, it means you get a ride that is nimble yet stable, and a bike that is surprisingly snappy around corners and not sluggish at all despite the massive tires. The bottom bracket is nice and high meaning there is very little chance of pedal strike even in the most technical terrain, and even with more normal sized 29er tires.
The head tube is tapered, with an oversized bottom but the stock fork is a straight 1 1/8". While it may look a little goofy, the good news is that you can swap it out for a suspension fork, and there are actually a few solid dedicated 29+ suspension fork options. It is also built around a 120mm suspension corrected fork, so with the right suspension fork, the bike has the real potential to be a rowdy, Enduro or even All Mountain hardtail if that's your thing.
The seat tube is 27.2, making it a bit more challenging to find a dropper post, but there are a few options available.
The stock build is as no nonsense as they come. SLX rear mech, Zee crank, with a 1x10 build, BB7 brakes, super wide 780mm Salsa Whammy bar, and of course, the Rabbit Hole, 50mm wide rims and 3" Knards. All parts that do their job and don't break the bank.
I went with a frame and built it up, as I have plans to ride this thing far and wide loaded. I used the Velocity Dually rims, a 39 mm internal width, bomb proof rim that gives me the option of running a standard 2" tire in a pinch, that are laced to Hope Pro II Evo hubs. I got the Surly OD Crankset which allows a double ring, and XT mechs front and rear. The rest is pretty much as stock. This gives me a bit more flexibility in set up and a wider gear range for bikepacking.
So, enough with specs and numbers. Does the Krampus deliver on the promise of plus sized fun, or is it all just hype?
Surly Krampus Ride Impressions
Upon first glance, the bike looks massive. The tire/rim combination gives a very tall profile, it feels almost like a 29er on stilts. It gives the feeling of riding on a tractor, particularly in slower, technical sections. The wider tires are incredibly stable, and the larger 29er wheels roll over anything in their path. The bike simply rides up and over anything and everything. It is a very confidence inspiring ride.
The trail oriented geometry of the Krampus also delivers in a big way. Simply put, the bike absolutely rips. Rather than try and pick a smooth line, I head straight for the biggest shit I can find and barrel over it. If that doesn't work, I'll just hit the biggest rock in the way and jump over everything else. The short chainstays make it a breeze to get the huge front wheel off the ground, great for clearing uphill stairs and obstacles. As mentioned, the reasonably slack head tube angle keeps the bike from being twitchy, it really hits a sweet spot between being responsive and sluggish. Wide bars are a must with the bike as they really help maneuver it around.
Just as with a fat bike, tire choice and pressure play a huge role in the ride quality of the bike. The Knards are a decent tire for hardpack and roll quite well on pavement, but when it comes to chunky stuff they are sorely lacking in side knobs. The Dirt Wizard or Chupacabra really bring out the best in the bike and transform it into an absolute monster truck of bike. I haven't measured the exact tire pressure I've been running, but probably around 11-12 tubeless. Any more and the tires bounce around like pogo sticks, and any less and you risk bottoming out the rims, especially in technical stuff. Too low in the front and the bike suffers from auto steer.
Simply put, this is the most fun bike that I have ever ridden, period. It put my full suspension out of commission. It makes me feel like I'm a kid again in the best way possible. The bike is at home in just about every environment. I have not ridden it with a dropper post and suspension fork, but I am absolutely dying to. And don't think just because the tires are so big that the bike is slow, it is not. I've had no trouble keeping up with friends on their XC racing machines. The bike just eats everything you can throw at it and begs for more.
Bikepacking on a Surly Krampus
While not specifically designed as a bikepacking bike, the Krampus truly shines as one. The plus sized tires give the bike extra stability, which is crucial when riding under load, as well as the aforementioned passive suspension benefit, particularly when run tubeless. This provides a more cushioned ride than a standard rigid 29er, but without the headache and potential risk of running a suspension fork.
When loaded with overnight gear and food, the bike handles much the same as it does when unladen. The handling is a little slower, but the bike still retains a playful quality. It begs to be ridden hard through technical sections, to rip around corners through flowy sections and even, if you are so bold, to catch some air. I often found myself forgetting that I was riding a loaded bike, and was able to ride technical sections with confidence. At slow speeds, the bike is stable, thanks again to the large tires, allowing you to ride at slow speeds as you pick your way through technical sections or up steep inclines. It behaves like a tank, rolling over anything and everything in it's path. I've taken it through dense, brushy trails at 2 mph with no issues, as long as you can pedal, the bike will continue to move forward.
One downside of the bike as a bikepacking bike is the lack of fork mounts and downtube mounts for Salsa Anything cages or standard water bottle cages. There is an aftermarket version of the Krampus fork that has Anything cage mounts, but I wish it was available with the frameset. However, Salsa recently came out with a carbon version of their Firestarter fork, which matches the geometry of the Krampus fork almost exactly, contains Anything cage mounts, and saves nearly a pound in weight.
Thoughts on "29+"
The bike industry as a whole, both mountain and road seem to be adopting the idea that wider rims and tires are better. The larger footprint offers better grip and traction as well as a more stable, comfortable ride, on and off road. The 29+ size takes that to an extreme. The massive tire size transforms the ride of the Krampus into a unique experience. Incredibly stable at low speed, it also lacks maneuverability at those slow speeds, making it cumbersome and awkward on narrow, tight trails, and especially switchbacks. The wheels are slow to accelerate, but once at speed do hold speed well and roll over anything in their path.
It seemed for a time that 29+ was going to become the next big thing in mountain biking, with many custom frame manufacturers, and some mainstream companies jumping on the bandwagon with their own 29+ offerings. There are more tire options now available than a year ago, when it was basically Knards or nothing. As mentioned, there are now a few dedicated 29+ suspension forks, which is great.
It seems that the bike industry is instead leaving 29+ behind a bit, moving on towards 650B+ instead, which I think is a shame. A 27.5+ bike does look very nice, giving almost the same size diameter of a standard 29" tire, with the added benefits of the smaller wheel diameter. This gives the increased maneuverability of the smaller wheel, with the wider tire for added stability, but I think there is something to be said for 29+ as a very viable option. The ride quality and handling characteristics are unmatched by anything that I have been on. It is a unique experience, and one that is particularly suited to technical riding under load.
The benefit of 29+ can really be seen in longer gravel, dirt, or even paved road sections. Once you get the wheels up to speed, they maintain that speed quite well. The Knards are a very capable paved road tire, pumped up with enough pressure, they rest on the two center knobs and hum along nicely. You wouldn't get the same ride benefit from a B+ wheel size. Plus, you get the benefit of the larger diameter wheel in technical terrain. The wheels just roll over pretty much anything in their path.
Overall, the Krampus is an incredible bike that pushes the boundaries of current bike technology, and has really helped usher in the idea that wider, bigger tires have a place in all forms of cycling. When thinking of your next mountain bike, either for a playful single speed, rigid geared bike, or off road, singletrack touring bike, it deserves a real, hard look.
Check out the updated, upgraded Krampus. The closest thing I'll get to having a super bike!