Introducing the Rocky Mounts DropTop, an innovative locking bike fork mount crafted from years of user feedback. This mount uses a TPU overmolded shim, allowing both 12mm and 15mm axles to fit without shim - switching. Based on the DriveShaft series' clamshell design, it enables easy bike loading and adapts to axle diameter and contour differences. The DropTop has mounting holes for both horizontal and vertical orientations, replacing the DriveShaft HM and DriveShaft Track Mounts. It's the only locking thru - axle track mount for truck and van tracks. Compatible with 12mm, 15mm, and 20mm thru axles up to 110mm wide (remove shims for 20mm). It offers vertical and horizontal mounting, and the TPU overmolded shim means no shim - swapping for 12mm or 15mm axles. Its anti - theft feature uses the TPU surface's friction to prevent axle removal when clamped and locked. It can fit QR bikes with a separately - sold 9mm QR with Dummy Axle. The wide - mouth opening simplifies bike loading, and the locking T - Bolt adjusts for a tight hold. It can carry one bike up to 45 lbs, and comes with a lock core, keys, and track hardware. The 24mm x 35mm x 6mm thick track plates with an M6 x 1mm tapped hole can be installed in either orientation.

Using the Rocky Mounts DropTop is easy. First, decide if you want to mount it horizontally or vertically according to your truck or van track and your preference. Install the track plates using the included track hardware. For 12mm or 15mm axles, you don't need to do anything with the shims; just place the axle in the wide - mouth opening of the mount. If you're using a 20mm axle, remove the shims first. After placing the axle, use the locking T - Bolt to adjust and secure it tightly. For QR bikes, you'll need to buy the 9mm QR with Dummy Axle separately and then follow the same steps. When it comes to safety, always make sure the mount is firmly clamped and locked to prevent the axle from being removed. As for maintenance, regularly check the TPU overmolded shim for any signs of wear and tear. Also, keep the lock core clean and lubricated with a suitable lock lubricant to ensure smooth operation. Don't overload the mount; it's designed to carry one bike up to 45 lbs.