The Chiru Alpin is the ultimate titanium gravel frame for passionate mountain riders seeking thrills on technical alpine terrain. Developed following the Tour du Mont-Blanc record set by Yannick Lutz in 12h27 in 2019, this frame pushes the boundaries of gravel by combining progressive MTB-style geometry, generous tire clearance (up to 700c x 55c or 650b x 2.2") and bikepacking versatility. With its Grade 9 3Al/2.5V titanium featuring hydroformed tubes and refined brushed finish, the Alpin embodies the demanding adventure spirit of this French brand based in Asia.

Technical Highlights

• Ultra-performance Grade 9 titanium: 3Al/2.5V alloy with proprietary hydroformed tubes featuring differentiated sections and thicknesses. The hydroformed down tube ensures increased lateral stiffness and excellent power transfer while pedaling. The triple-butted, horizontally ovalized top tube flexes vertically to absorb shocks while remaining laterally rigid. The ovalized asymmetric chainstays measuring only 430 mm optimize grip and handling.
• T47 x 85.5 mm bottom bracket: Threaded standard developed by Chris King combining the advantages of threading (zero creaking) and a large shell diameter to accommodate modern 30 mm axle cranksets with substantial bearings. CNC machining Grade 5 with oversized center diameter.
• SRAM UDH derailleur hanger: SRAM patented universal standard allowing installation of all derailleur types (Shimano, SRAM, Campagnolo, Rotor, Microshift) including the new SRAM T-Type MTB derailleurs. Easy replacement and optimal stiffness for modern 1x11v, 1x12v, 1x13v, 2x11v, 2x12v drivetrains.
• Exceptional tire clearance: Accepts tires from 700c x 43c up to 700c x 55c, or 650b x 2.2" (equivalent to 29 x 2.1"), allowing you to switch between fast road configuration and very technical terrain depending on the adventure.
• Total bikepacking versatility: 4 standard bottle cage mounts (including 2 under the down tube for 750 ml bottles), eyelets for rear rack, fenders, bolted top tube bag, full frame bag. Internal cable routing for dynamo and rear lighting.

Geometry and Handling

• Progressive mountain geometry: 68° head tube angle (67.7° in S, 68.3° in L) reminiscent of MTB for maximum stability on technical descents. Short 430 mm chainstays (428 mm in S, 435 mm in L) for excellent rear wheel grip and nimble handling in steep switchbacks.
• Balanced Reach and Stack: In size M, 431 mm Reach and 587 mm Stack (1.36:1 ratio) offering a slightly aggressive yet comfortable position for long distances. Deliberately short seat tube to maximize seatpost extension and take advantage of the absorption capabilities of a carbon or titanium seatpost.
• Pronounced sloping: The frame adopts a sloping top tube line to free the rider's movements on committed descents and lower the center of gravity.
• Fork compatibility: Geometry calculated around a 430 mm rigid fork (A-C 427 mm, offset 50 mm) but compatible with short suspension forks with 40-50 mm travel for even more comfort on rough terrain.

Standards and Compatibility

• Headset: Semi-integrated tapered ZS56/44 (1" 1/8 - 1.5"), tall and imposing head tube 290 mm in length, 25 mm internal steerer diameter
• Brakes: Flat Mount 160 mm, internal hose routing on disc side with optimized bend radii for maximum protection
• Rear axle: 142 x 12 mm thru-axle, supplied in titanium CEC
• Compatible drivetrains: Shimano GRX mechanical or Di2, SRAM Road mechanical or AXS, Campagnolo Ekar, SRAM T-Type XPLR MTB. Single chainring configuration up to 44 teeth or double chainring up to 48/31T (47 mm chainline)
• Routing: Semi-integrated routing with internal or external option under the chainstays for easy maintenance. Dedicated internal routing for dropper post, rear dynamo and lighting

Finish and Accessories

The fine and consistent welds, laser marking and brushed finish demonstrate careful manufacturing carried out in China by a trusted subcontractor with whom Pierre-Arnaud Le Magnan (founder) maintains a close relationship. The customizable titanium headbadge is bolted on for a unique touch. The frame is delivered with a complete set of premium accessories: CEC semi-integrated headset, CEC #S32 titanium seat collar Ø31.9 mm, titanium rear axle 142x12 mm, titanium hardware M5x10, rubber grommets and UDH hanger.

Available Sizes

• Size S: Seat tube 420 mm C-T, Reach 401 mm, Stack 576 mm, Wheelbase 1086 mm, Chainstays 428 mm, Head angle 67.7°
• Size M: Seat tube 450 mm C-T, Reach 431 mm, Stack 587 mm, Wheelbase 1118 mm, Chainstays 430 mm, Head angle 68°, Weight 1750 g
• Size L: Seat tube 475 mm C-T, Reach 444 mm, Stack 615 mm, Wheelbase 1145 mm, Chainstays 435 mm, Head angle 68.3°

Who is This Frame For

The Chiru Alpin is the choice for mountain riders seeking a gravel bike capable of tackling the Tour du Mont-Blanc, degraded 4x4 trails, rough alpine paths and steep technical slopes, while maintaining the efficiency of a gravel bike on fast roads. Its exceptional comfort comes from the natural vibration filtering of titanium, amplified by the intricate frame geometry and vertical flex of the seat tube. An exceptional frame for demanding adventure gravelers seeking a unique versatile mount for their finest mountain explorations.