The Arch MK4's 28mm internal width and patented lightweight, low-profile design is not afraid to climb, while being an absolute monster on the descents. With a welded seam, reinforced spoke bed, and durable 6069 aluminum construction, the Arch MK4 rims give you the confidence to ride everything.
When it comes to a consistent and reliable airtight tubeless seal, nothing beats Stan's patented Bead Socket Technology. The Arch MK4 rims feature an asymmetric design with offset spoke holes to improve spoke angle and create a stronger all-around wheel. Unlike most asymmetric rims that suffer from difficult inflation and poor tubeless performance, Stan's BST-Asymmetric design delivers all the advantages of a stronger wheel, with no compromises in tubeless performance.
Nobody likes downtime, so the Arch MK4 wheelset is built with traditional J-bend spokes based on their proven strength, ride quality, and easy serviceability. Stan's has always made it easy to find replacement spokes should you ever damage your wheel, and now we've made it even easier. MK4 front and rear wheels of the same diameter all use the exact same very common spoke length, both sides, front and rear. Serviceability doesn't get any easier than that.
M-PULSE HUBS
The M-pulse hubs at the heart of Flow MK4 wheels combine an absolutely bombproof magnetic locking engagement with incredibly smooth rolling. Based on the original innovative Project321 engagement system, the speed and durability of this system is unmatched. Unlike weaker pawl and spring designs, the M-pulse features six pawls with Neodymium magnets that offer virtually no resistance when coasting, but lock the pawl teeth into place far more reliably and consistently than springs.
Each detail of the M-pulse hub was engineered to systematically eliminate weaknesses found in other designs. The 17mm axles are made of 7075 aluminum and roll on Enduro brand bearings, including a double-row freehub bearing tested to be far more durable than two individual separate bearings. The entire hub is also shielded, meaning no bearing seal is visible, offering superior protection for all conditions.
With only 1.66°of rotating required for the M-pulse hub to engage, power is always instantaneous. Multiple tooth engagement provides a greater surface area to distribute load to improve both durability and speed. The angle of the pawls was even optimized to distribute stress away from the rotating bearings. Beyond the strength and speed of engagement, M-pulse hubs feature adjustable preload, allowing a tremendous decrease in drag for less resistance and more speed.
Versatile 28mm internal rim width optimized for 2.2-2.5” tires
Durable 6069 aluminum with welded joint and reinforced spoke bed
BST Asymmetric design combines Stan’s legendary easy tubeless inflation with a stronger, more balanced wheel build
New high-end premium M-Pulse hub with 216 points of engagement (1.66º), magnetic-sprung pawls to reduce drag and improve response, Enduro bearings and external preload adjustment. US-made internals in partnership with Project321
Matched wheelsets use traditional J-bend lacing and share a single spoke length for easy serviceability