18" chunk of 4x12 (easily cut with chainsaw) makes a great drive on for changing a flat tire on a tandem. Doubles as chock. Considering driving a couple screws completely through the tapered edge so it will get a bite on pavement and not slide as easily on drive up. At 18" it will just fit between tires for forward drive on with any tire. Other parts of the trailer travel box are: Fitting tire iron; 1 complete bearing/hub/seal kit; a second set/bearings only and races; spare bearing buddy and small grease gun; ir thermo; spare lights; tools for removing a hub; paper towels/orange gel/disposable rubber gloves; Small tarp to sit on; flares and safety reflector;trailer wiring circuit tester; chain/spare ratchet strap tie downs (for temp. emergency repairs). Please add other suggestions in comments.

18" chunk of 4x12 (easily cut with chainsaw) makes a great drive on for changing a flat tire on a tandem. Doubles as chock. Considering driving a couple screws completely through the tapered edge so it will get a bite on pavement and not slide as easily on drive up. At 18" it will just fit between tires for forward drive on with any tire.

Other parts of the trailer travel box are: Fitting tire iron; 1 complete bearing/hub/seal kit; a second set/bearings only and races; spare bearing buddy and small grease gun; ir thermo; spare lights; tools for removing a hub; paper towels/orange gel/disposable rubber gloves; Small tarp to sit on; flares and safety reflector;trailer wiring circuit tester; chain/spare ratchet strap tie downs (for temp. emergency repairs). Please add other suggestions in comments.