Gen 1 Supercaliber/eCaliber Fox IsoStrut, Small Frame, 235mm x 32.5mm,Remote PTL

etailed Specifications:
Brand: Fox Racing Shox
Model: FLOAT IsoStrut Performance Series A Remote PTL (Push-to-Lock)
Series: 2021 Performance Series — Black Anodized Finish
Part Number: 972-61-257
Example Serial Number: 1012985-0030-T (example only – may differ per unit)
Frame Compatibility: Trek Supercaliber and eCaliber Gen 1 (Small frames only)
Shock Length: 235 mm (Strut length)
Damper Length: 135 mm
Stroke / Travel: 32.5 mm
Outer Diameter: 36 mm
Rotation / Eyelet Angle: 60° (specific to Small frame geometry)
Spacer Configuration: 0.1 Spacer
Damper Type: Performance Series FLOAT IsoStrut Air Spring with Remote PTL Lockout
Adjustments: External Rebound / 2-Position Remote Compression (Open / Lock)
Axle Configuration: Proprietary Trek IsoStrut mount system (non-standard eye-to-eye)
Material: Forged aluminum body, black anodized finish with hard-anodized stanchion
Intended Use: XC Race / Marathon / Light Trail
Additional Features:
Performance Series tuning: Same internals as Factory Series but with a durable black-anodized finish (no Kashima coating) for maximum reliability.
FLOAT air spring system offers tunable progression and excellent small-bump compliance.
Remote PTL lockout enables rapid transitions between full-open and firm lock for climbing or sprinting.
Integrated IsoStrut design mounts directly into the frame’s top tube for increased lateral stiffness and power transfer.
Factory-valved specifically for Trek Supercaliber/eCaliber Gen 1 geometry to deliver balanced rear-end response.
Performance-grade wiper seals and bushings for improved durability in mud and dust.
Serviceable through any authorized Trek or Fox service center.
Important Usage Notes:
Fits Trek Supercaliber and eCaliber Gen 1 (Small) frames only.
60° rotation/eyelet orientation is specific to Small frames — not interchangeable with M/L sizes.
Requires a Fox Remote Lockout Lever and cable (sold separately) for function.
Not compatible with Gen 2 Supercaliber or any standard eye-to-eye rear shock.
Installation must be performed by a qualified Trek or Fox technician to maintain alignment and warranty coverage.
Riding Impressions:
The Fox FLOAT IsoStrut Performance Series transforms the Supercaliber/eCaliber Gen 1 platform into a race-tuned XC machine. Riders benefit from the FLOAT air spring’s smooth stroke and the Performance Series’ durable finish, ideal for dusty race courses and all-season training. The remote lockout delivers instant pedaling efficiency while the integrated strut layout preserves Trek’s signature rigid-frame feel with controlled traction.
Disclosure:
This listing includes one genuine Fox FLOAT IsoStrut Performance Series A Remote PTL Rear Shock (235 mm).
Example serial number shown for reference; actual number may differ.
Non-retail packaged — includes only what is shown in photos.
Designed for Trek Supercaliber/eCaliber Gen 1 Small frames only.
Remote lockout lever, mount hardware, and bolts not included.
Professional installation recommended.
$119.95
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