Contain the chain in the event of a failure and prevent contact with it.
A rules-required guard around the chain run.
No part-specific design process is documented. The DriveTrain subsystem design process applies: 1. Set gearing from the tractive force diagram, top speed and the event speeds actually seen (autocross top speed 69 mph, endurance 72 mph, gear-limited top speed 82 mph). 2. Design the carriers non-adjustable with a fixed pin, integrated with the engine pins, to reduce assembly complexity and failure points and remove the need for weld-on carrier mounts on the frame. 3. Analyse the carriers at acceleration and deceleration load cases with a 2.0 shock loading factor. CR26I LH carrier at 39 lb-ft with shock: 32.949 ksi peak von Mises, minimum FoS 1.211, 0.013 in average axial bearing bore deflection. RH carrier: 9.432 ksi, FoS 4.229, 0.001 in. 4. Set the half shaft length with a custom measuring jig so the tripod travel range cannot be exceeded, then groove for retaining rings. 5. Validate on track and by inspection of the wear surfaces after testing.
Laid up on a 3D printed mold, printed directly, or formed from sheet.
Aluminium or composite. From the cost report drawings and CAD: From the cost report drawings: 1020 Steel (Chain Guard).
None recorded. This part has no entry in Knowledge_Transfer/Issue Logging/Fault Vault.xlsx, in either Issue Log.xlsx, in CR22/Issue Tracking/Shakedown 7-15-23.xlsx, or in any design review issue list found in CrimsonStorage or Box.
Measured mass, as built: CR25 1.5 g (0.003 lb). CAD mass, CR26E master assembly: 1.683 lb (0.763 kg). CG at X 81.88 in, Y -4.09 in, Z 11.06 in in vehicle coordinates. (CAD component: Chain Guard v1) Dimensions called out on the cost report drawings. These are the figures printed on the drawing, not a labelled specification; open the drawing itself for what each one refers to. Chain Guard (as drawn): 23.11, R14.58, R2.54, 2.62, 0.41, R5.46, 36.25, 26.75 CR25 Chain Gaurd rev1 (as drawn): 227.93, 22.79, 56.08, 5.61, 6.10, 0.61, 44.45, R4.45, 114.30, R11.43 Quantity on the drawing: 1. Source: CR26e Weight Tracker.xlsx, Final IRL Weights (weighed, not CAD) | SolidWorks mass model exports: CR22 (5 May 2024), CR25 (4 Jul 2025), CR26I (30 Jul 2025), CR26E (22 Mar 2026) | Cost report drawings: CR22/Powertrain/Design/X - Cost Report Drawings/Drivetrain Assembly/Chain Guard.pdf; CR25/Powertrain/Design/Y - Cost Report Drawings/Drivetrain/CR25 Chain Gaurd rev1.pdf; CR26i/Powertrain - IC/Design/Y - Cost Report Drawings/Drivetrain/CR25 Chain Gaurd rev1.pdf; CR27i/.Powertrain/Design/Y - Cost Report Drawings/Drivetrain/Archive/CR25 Chain Gaurd rev1.pdf Quantity per car, as costed: 1
Nothing in CrimsonStorage covers these yet.