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Recentering H1 and PVC bead locks

Tech Article

  1. clarkjw24
    Article/photo's courtesy of:
    clarkjw24
    main.png

    Recentering H1 and PVC bead locks
    Here is my version of how to recenter your H1s.

    H1 info:
    H1s are military beadlocking rims. They are two piece rims, an outer and inner bolted together. In order to be a beadlock you must also have an insert that goes between the insides of the tire's bead. It can be the factory style rubber runflat, mag runflat or an aftermarket piece of pvc. They measure 8.25x16.5, as far as I know there are no other sizes. All of them come with the 8 on 6.5 lug pattern. There are two versions of the rims, 8 bolts and 12 bolts. This is refering to the number of studs and nuts that bolt the two halves together.

    Parts and equipment needed to recenter your H1s consist of:
    H1s
    Beadlock inserts
    New centers
    New orings
    studs and nuts if needed.

    Torch or Plasma cutter
    4" side grinder
    Impact and sockets
    Stick or mig welder
    Vertical Bandsaw or portaband

    Here are pictures of the H1s and mag insterts in their stock form. One of the rim bolted together and then the two halves with the studs and valve stems removed.

    1-pvc.png

    2-pvc.png

    3-pvc.png

    4-pvc.png
    The idea is to cut out the factory center which is set at 7" backspacing and weld in a new center at a more functional backspacing around 3.75". I'm also going to cut the "backbone" out of the mag insert, leaving just the beadlocking part. The mag inserts are bolted together inside the tire. From the picture of the bottom half (2nd picture) you can see an outline of where you need to cut out the old center.

    I usually cut it out about an 1/8" wider. You can use a torch or plasma here just be careful lot to booger up the studs if you're not planning on replacing them. After you've cut the old center I use the grinder to clean up the cut edges. Now you're gonna need to flip the bottom half over and clean up the inside where the new center will be welded in. Remember these are military rims so there is prob about 20 layers of paint and crud on them. Also at this point you'll need to remove any of the stick on weights so the new center will slide in. I usually use a wire wheel or grinder and just clean where I'm going to weld. Mainly because if you want the rims powder coated or nicely painted you're gonna need to have them sandblasted. It would take days with a wire wheel, trust me I know.

    I've only used the USA6x6 pressed centers. They drop right in and sit nicely on a ridge in the rim. Sitting on this ridge it will give you about 3.75" backspacing. Now you can change your backspacing to less but you will have to build a jig in order to get it true. It depends on how much you really want a 1/4" to 1/2" less backspacing to go through the extra work. Here is a new pressed center.

    5-pvc.png
    The pressed centers fit really nice with less than a 1/64th play. The large holes in the centers should line up with the 8 bolt studs. That way you will still be able to replace them if necessary. I usually do about 5 quick tacks on the new centers. This keeps you from drawing the centers up and off center. Now you can weld these all the way around but I usually put 5 long beads in a star pattern. Here is a picture of the new pressed center welded in.

    6-pvc.png
    Once you have all of the centers welded in and the rims cleaned up from cutting its time to have them ready for paint. Once again you can have them blasted, wire wheeled or do like I do say "to hell with them" and just paint them. If your going to have them blasted and you're reusing the studs you may want to slide a piece of rubber hose over the studs or remove them if you have new ones. Here is a finished recentered H1.

    7-pvc.png
    Now to the mag insert. I used a vertical bandsaw to cut the backbone out. Now remember magnesium if flammable, but if I remember correctly its only the dust when mixed with water and ignited. It takes a while to cut them but most of the time when you get a set of H1s these inserts come with them. Your options are to buy the PVC inserts which will run you around $50 a rim. Backbone cut out.

    8-pvc.png
    Tire installation is easy. If using the mag inserts place the two half's in the tire, bolt them together. Take the bottom half of the rim and sit it on a 5 gal bucket. Pick up tire and insert and slide onto back half of the rim. Now is the time to install your new o-ring or used o-ring. Now take the outer ring, top half of the rim and align with bolt studs. Put nuts on and tighten them down. An impact is really nice here, it takes a lot to get these outers to seal, because you're pinching beads on your new monster meats.

    9-pvc.png
    Here is a PVC insert being installed on my spare

    10-pvc.png
    O-ring in place

    11-pvc.png
    Bottom half of rim sitting on a block or 5 gallon bucket

    12-pvc.png
    Squeezing insert in the tire between the beads

    13-pvc.png
    Finally in

    14-pvc.png
    Tire, insert, O-ring on bottom half

    15-pvc.png
    Stud nuts going on

    16-pvc.png
    Running them down with the impact

    17-pvc.png
    Now you're ready for air if you want, I run about 5lbs in mine, no issues

Recent Reviews

  1. rockin kw
    rockin kw
    5/5,
    Good article