I used 2pc of 'C' channel with a 1/2" in the middle to hold them together, and 1/2" holes in the ends with 4" x 1/2" bolts to push the 'lock ring' down. Also drilled 4 1/2" holes to match the 'lug' holes in the rims to 'pull' it all down. JUST MAKE SURE THE AIR IS OUT FIRST! Cost about $25.00 for it all. I think the 'C' channel was 18" overall, and I bolted them 'back-to-back', so they made a cross (+).
