Product DescriptionThe FOX Performance RE:aktiv Thru Shaft rear shock is a genuine Trek replacement component custom tuned by the Trek Suspension Lab for compatible Trek Fuel EX suspension platforms. This Trek-specific shock features a 210mm eye-to-eye length, 52.5mm stroke, EVOL large-volume air sleeve, and an ultra-responsive RE:aktiv damper with FOX Thru Shaft technology. The design provides efficient pedaling support while reacting quickly to trail impacts for improved traction, control, and suspension consistency. External rebound adjustment and a three-position damper allow the rider to tune the shock for changing terrain and riding conditions. This specialized shock uses Trek-specific trunnion mounting dimensions, so exact frame compatibility should be confirmed before purchase. Key Features Genuine FOX Performance rear air shock Custom tuned by Trek Suspension Lab Designed for compatible Trek Fuel EX models 210 x 52.5mm eye-to-eye and stroke RE:aktiv with Thru Shaft damping technology 9mm Thru Shaft EVOL large-volume air sleeve External rebound adjustment Three-position damper Trek-specific trunnion mounting configuration Factory 0.4 volume spacer Black finish New Specifications Brand: FOX Model: Performance RE:aktiv Thru Shaft Series: 2022_20 Series Product Type: Rear Air Shock Eye-to-Eye Length: 210mm Stroke: 52.5mm Configuration: 210 x 52.5mm Air Sleeve: EVOL LV Spring Type: Air Damper: RE:aktiv Thru Shaft Thru Shaft Diameter: 9mm Compression Adjustment: Three-position Rebound Adjustment: External Remote: No Volume Spacer: 0.4 Shock Finish: Black FOX Part Number: 972-61-233 Trek SKU: 588634 Example Serial Number: 1030141-0078-T FOX Description Code 2022_20 9mm Thru Shaft A 3-position Trunnion EVOL LV Trek EX130 210mm 52.5mm 0.4 Spacer CL RM RaM Mounting Dimensions Upper Mount Mount Type: Trunnion Width: 54mm Hardware Diameter: 10mm Lower Mount Mount Type: Trunnion Width: 50mm Hardware Diameter: 10mm CompatibilityDesigned for compatible Trek Fuel EX frames requiring all of the following: 210mm eye-to-eye length 52.5mm stroke Trek RE:aktiv Thru Shaft suspension design 54mm upper trunnion mount 10mm upper hardware diameter 50mm lower mounting width 10mm lower hardware diameter Compatible Trek Suspension Lab tune This is a specialized Trek-specific Thru Shaft shock. A standard 210 x 52.5mm rear shock should not automatically be considered interchangeable. Rear shock fit depends on the exact bicycle model, model year, frame size, mounting configuration, stroke, and suspension tune. Please compare the FOX part number, Trek SKU, dimensions, and original shock specifications before purchase. Included FOX Performance RE:aktiv Thru Shaft 210 x 52.5mm rear shock Factory-installed 0.4 volume spacer Includes only what is pictured and described Warranty and Notes Genuine FOX and Trek replacement component Custom tuned by Trek Suspension Lab 1030141-0078-T is an example serial number for model reference only The serial number on the item received may differ Frame mounting bolts and additional hardware are included only when pictured or stated Professional installation and suspension setup are recommended Confirm exact Trek Fuel EX compatibility before ordering Condition New Genuine FOX and Trek product Includes only what is pictured and described