World Premier: Kuroshiro Enso 685 Ride Impressions- by c_g
I have ridden a few fatbikes in the recent months all of which suffered from one thing: Overly heavy and sluggish tires and wheels that turned me off Fat biking on anything but the typical terrain like sand and snow. With this in mind you can believe that I was excited to hear that tubeless ready technology and lightweight carbon rims were making their way into fat biking, too. Just consider how much weight can be shaved off the rotating mass only by going tubeless, not to mention the potential of light carbon rims as well.
The KUROSHIRO Enso 685 is not the first tubeless ready carbon fat bike rim and it does not claim to be, but it could well be the lightest and the most advanced one currently existing. With a claimed weight of about 420g per rim it already is almost too light to believe already, but the special construction allows it to be converted tubeless with only some sealant, so you can save extra by not having to use sealing tape.
As mentioned in the intro, the KUROSHIRO rim is manufactured and designed by ALCHEMIST as small boutique carbon manufacturer producing cutting edge bike components. Being masters of their trade, the curious ridge zig-zaging of the rim is a structural part of the rim, boosting strength and rigidity while also reinforcing the spoke holes to enable the use of lighter high-tension spokes.
In case you haven’t figured it out – the numbers 685 stands for 26” and 85 mm width.
I have had the chance to inspect a rigid SALSA Beargrease during the Garda Bike Festival this spring and felt like this could be a game changer for fat bikes. To my pleasant surprise when talking to Mauro Bertolotto, the man behind RACEWARE distributions and the KUROSHIRO brand about an upcoming holiday in Italy, I was offered to ride the very first ever pre-production set of Enso 685 rims during this vacation on the gnarly and rocky trails of Finale Ligure.
Riding a fat bike on All-Mountain and Enduro trails worthy of minimum 4 inches of suspension? Hmmmm – immediately my tester instinct kicked in and got me excited!
How would those huge tires ride in such a terrain, where picking your line can be vital? Is it even possible to “pick a line” with 4” or more of tire underneath? Is it still necessary? How would the bike handle in off camber situations. What pressure would work best in such conditions? Would this light as can be set of fat bike wheels prove their trail worthiness?
Being no expert fat bike rider, I openly admit that I had plenty of questions and a decent amount of skepticism with little clue on how it would turn out. In case the experiment went wrong, as insurance I took my own bike along as well ;). So when arriving at the hotel I laid my eyes on this beautiful SALSA Mukluk waiting for me – featuring the Enso 685 rims with 45NTH Hüsker Dü 4.0” tires (127 TPI) converted tubeless. The wheels were built up with light spokes and some NOVATEC fat bike hubs and still came out at an incredible 1780g / 3.95lbs – take a set of TUNE hubs and you can come out lighter still.
The other highly interesting item on the bike, the ROCK SHOX Bluto fork will be covered in a separate report later. All in all the bike weighed around 11,2 kg or 25 lbs.
After setting the tires air pressure at an initial 0.75 bar / 11psi front and rear I set out to a long climb from sea level towards the site of the 24h Race of Finale Ligure on an high plateau some 350 m (or 1100ft) higher. The trail was very broken, rocky and loose at places with some steep pitches that would make every bike struggle to find traction.
Initially I rode the Mukluk like I would any other mountain bike picking my line carefully and scanning the trail for the best traction, but soon I learned that there absolutely was no need for this as the bike simply rolled over the ground almost like a magic carpet ride and found plenty of traction pretty much everywhere. So soon I grew sloppy and simply rode my way up as I pleased not giving a second though whether the ground was rocky, loose over hard pack or earthy soil. What absolutely struck me was how well the bike accelerated.
When seeing the Mukluk and its 1×11 set up I was a bit concerned but honestly, on the uphill it rode as lightly and fast as any other similar weight mountain bike. Judging by its uphill performance the light fat bike wheels have certainly won me over. Next up we rode the loop of the 24h of Finale race with lots of swoopy turns, fast paced ups and downs, and lots of off camber riding. Initially it took me a bit of adjusting riding corners and on angled surfaces because the tire simply would create a slightly different ride sensation.
On this diverse loop I also fooled around a bit with air pressure trying anything from 1.0 bar down to 0.5 bar. It may be only my personal preference or not being accustomed to fat bike riding, but on this terrain I found anything below 0.7bar or 10psi to create a too vague ride and give me more bounce than I wanted to be enjoyable. Pressures considerably higher than 0.7bar (10psi) gave me the steering precision I desired but compromised compliance and exaggerated rebound.
With the KUROSHIRO Enso 685 being the focus of this report I will also mention that at the very lowest pressures I could cause some slight burping between the tires and the rim hook, but not as I first suspected by riding lop-sided over rocks or roots, but simply by compressing the tire. It may have been an issue with the tires not having perfectly sealed and since it only happened at pressures too low for me to properly ride, but I wanted to mention it still, because some riders may want to go lower in air pressure … and just may experience something similar.
After determining my preferred air pressure and simply having a blast on those trails due to the awesome traction and cornering grip the fading daylight forced us to return home for which we chose a Stage section of last year’s Finale Superenduro – meaning we would not go easy on the wheels on the way down either.
The trail was sooo fun! It has a very good mix of rocky high-speed sections with small drops, flowy switchbacks and lots of slow speed technical hairpin corners with rocks and drops of every rideable size and manner. Plain fun. And much like on the uphill, I soon learned to only roughly pick my lines and let the tires sure footed traction handle the rest. Braking grip and cornering were so great that I soon rode as aggressively as I did with my 5.5” full suspension 29″er bike on the same trail some days later.
Much to my personal surprise I never felt like my ride experience was compromised by the wide tires and rims. Besides constantly being astonished how confidently I would be able to ride the sloppiest lines and still have more traction and control the bike pretty much rode like a great handling full suspension trail bike. The only downside to fat bike riding in such terrain was the obvious high rolling resistance even with the tubeless Hüsker Düs that when compared to my standard 29″er with trail worthy tires was noticeably higher on the road. On the trail I felt nothing of that sort and simply enjoyed the ride.
I rode the KUROSHIRO equipped SALSA Mukluk for another 3 days on similar trails in the region and my impressions only got confirmed over and over.
Summary: Riding a fat bike with such light wheels has an addictive quality to it. The lack of rotating mass by the rims and tubeless tires, the resulting great acceleration, and abundant traction, is something that needs to be experienced to be believed. With all my prior experiences with riding fat bikes, I can openly admit that I had never had so much fun riding a fat bike before … and a very good part of this enjoyment doubtlessly comes from the light wheels.
No mistaking – these rims will not come cheap but for a guy like me, whose major complaint with fat bikes has always been the slow ride feeling, they are probably the most effective (and likely the only) means I would ever seriously consider riding a fat bike on my regular trails and terrain.
Oh and in case this needs to be mentioned explicitly again – despite me pushing the bike hard on the trails of Finale Ligure, I never experienced the least peculiarity or trouble coming from the rims or wheels. They simply performed and turned every ride into some extraordinary experience.
Am I a converted to fat biking after this experience? Hmm … so far I have only told one part of the story, so wait for my ride impressions of the ROCK SHOX Bluto coming your way soon.