You don’t win by being the lightest. Or the stiffest. Or the toughest. You win by being the fastest. And that takes a wheel designed specifically for the modern mountain biker. At SRAM, we start with the demands of the terrain and work forward from there—carefully balancing each wheel’s design around five key attributes: weight, inertia, engagement, stiffness and durability. No matter where you ride, SRAM wheels will take you further. RISE higher. ROAM farther. RAIL harder.
Ready to attack, easy to manoeuvre. Built for aggressive All-Mountain descents, RAIL wheels balance the strength and stiffness you need with the lightness to climb quickly back to the top.
With WIDE ANGLE™ rim design providing superior stability, RAIL 40 can withstand the most aggressive All-Mountain / Enduro riding by setting a new benchmark for stiffness in its category. Featuring the perfect balance of strength, lightweight and width for enduro terrain, RAIL 40 delivers high performance ride quality all the way down.
Features
- Available in 27.5” and 29”
- Lightweight but strong aluminium rim, asymmetrical profile with TAPER CORE™ technology. Welded joint
- UST Tubeless
- WIDE ANGLE™ profile—23mm
- SOLO SPOKE™—double butted spokes
- DOUBLE TIME™ ratchet mechanism for durable, quick engagement—SPEEDBALL™ bearings
- Convertible axles:
- Front Hub: QR 9×100, QR Torque Caps, 15×100, 15×100 Torque Caps, 20×110, 15×110, 15×110 Torque Caps
- Rear Hub: QR 10×135, 12×135,12×135 XD, 12×142, 12×142 XD,12×148, 12×148 XD
- Available in XD™ or 10-speed driver body
- BOOST 148 compatible
- Weight: 1810g (27.5”), 1900g (29”) Wheel pair in lightest configuration
Technologies
Double Time
Ratcheting up the smarts. This straight-aligned, 4-pawl design turns the 26-tooth ratchet ring into 52 points of contact. The result: smooth 6.9-degree engagement without reducing tooth size or offsetting internal geometry—which means serious long-term durability.
Speedball
The only adjustment they’ll ever need was made back at the factory. Every part of the ball bearing comes from the exact same supplier—which means that each bearing bore can be precision machined to fit the bearing race exactly. With tolerances this tight, the days of adjusting play after every ride are over.
Solo Spoke
With Solo Spoke, you’re never wrong. SRAM wheel design eliminates the need for different spoke lengths—one size fits the entire wheel. This identical-length design means no longer wondering whether you have the right front/rear/drive-side/ nondrive-side spoke handy.
Taper Core
Strong in the right places. The sidewalls of SRAM rims are reinforced along the wings to withstand major impact. But the sidewalls then taper in along the centre—reducing overall mass. The result is a very light rim with excellent dent resistance.
Wide Angle
Take corners as fast as you want. SRAM wheels have a wider rim profile without significant added mass. This profile holds tire shape better, preventing tire roll and giving you superior
comfort and traction around corners.
XD Drive Body
XD is a cassette driver body design that allows the use of a 10-tooth small cog and provides an improved interface with the cassette.
BOOST
BOOST is a new wheel and drivetrain specification that provides: increased wheel stiffness and durability, better riding efficiency and bike handling precision, improved frame geometry with shorter chain stays, wider and stiffer suspension pivots, wider range of chainring options, more clearance for bigger tires.
International recommended retail pricing
Not much point in SRAM bringing in wheel sets when they don't support replacement of parts.
I have a set of roam 60 wheels. Both rims are damaged but local agents for SRAM say they don't bring in replacement rims. WRF? I support their product but they don't support their customers!