Cheerock U-Bolt Roof Box Clamps 4-Pack — 85mm Fit with Lock Nuts & Straps, Stainless-Iron Mounting Kit

Cheerock 4-pack U-bolt clamps are a complete mounting kit designed to fasten most rooftop cargo boxes securely to factory or aftermarket roof rails with an 85mm internal fit.

These stainless-iron and plastic U-bolt fittings give you a straightforward way to attach a rooftop cargo box when your original mounting hardware is missing or incompatible. The set includes all the pieces needed to create a durable, vibration-resistant connection: U-bolts, plastic backing plates, rubber gaskets, lock nuts, straps and sealing stickers. Before purchase, confirm your roof box and roof-rail dimensions to ensure compatibility.

How do these U-bolts fit different cars and roof boxes?

The Cheerock clamps are sized to match common aftermarket and OEM roof-box mounting rails. With an internal width of 85mm and a thread center distance of 90mm, they accommodate many crossbar and side-rail profiles. The kit’s plastic back plates and rubber washers adapt to curved or flat mounting surfaces for stable contact.

• Inner width: 85mm (3.34 in) for the U-bolt opening
• Thread center-to-center: 90mm (3.54 in)
• Screw diameter: 7mm (0.27 in) for heavy lock nuts
• Includes rubber washers and plastic plates for varied rail shapes

What materials and durability can I expect on the road?

Constructed from iron and durable plastic with rubber gaskets, the components resist routine wear and environmental exposure. The metal U-bolts are designed not to deform under typical load conditions, while the rubber pieces defend painted surfaces from scratches and reduce loosening from vibrations. This combination helps preserve the roof box’s stable positioning during everyday driving.

• Iron U-bolts for structural strength
• Plastic support plates to spread load and protect rails
• Rubber washers to prevent scratching and increase grip
• Heavy lock nuts to resist loosening on bumpy roads

How simple is installation, and what tools or time are required?

Installation is intentionally straightforward and typically requires only basic hand tools (a wrench or socket for the lock nuts). Most users report a 3–5 minute fit per clamp once the placement is planned. The included straps and sealing sticker help secure and weatherproof the mounting points after tightening the nuts.

• Estimated install time: 3–5 minutes per U-bolt set
• Required tools: wrench or socket set for 7mm screws/nuts
• Supplied accessories: straps, rubber gaskets, plastic plates, sealing sticker
• Installation tips: confirm rail spacing and tighten lock nuts evenly

What comes in the package and how does it support long-term use?

The kit delivers a complete array of parts so you won’t need extra purchases to mount a rooftop box. Multiple lock nuts and protective pieces are included to ensure the clamps remain secure and prevent metal-on-paint wear. If maintained and periodically checked for tightness, the assembly provides a reliable connection for seasonal travel use.

• 4 U-bolts, 4 rubber washers, 4 plastic support boards
• 8 heavy lock nuts for secure fastening
• 2 straps (bandages) and 1 black sealing sticker
• Compact, lightweight pieces for easy storage when not in use

Who is this for? The Cheerock 4-pack U-bolt roof box clamps suit drivers who already have a rooftop cargo box but need universal fastening hardware: owners of older boxes missing original parts, shoppers with crossbars that don’t match supplied brackets, and anyone wanting a compact spare kit for trips. Confirm measurements before ordering to ensure a proper match with your roof rails and cargo box attachment points.