Split-Rim Tyre Repairs.

That feeling of gloom is back, the familiar woosh - bump that indicated another flat tyre (tire) can be heard. You pull over and there it is, a piece of Mulga (Acacia aneuria) protrudes from the sidewall of the tyre. tire --> You reach for the baseboard, jack and wheel brace and toss them at the side of the truck. You put on your Akubra (broad brimmed hat) and have a long drink of water. The temperature is 45 Celsius in the shade of the truck. You change the wheel and drive on to the night camp. You cannot take the wheel to the nearest service station; you are 400kms from an Aboriginal community and another 400kms from a small township. You are at least 3 days away and the terrain is still as unforgiving as ever. You make camp early, you have a drink of water and start thinking of the wheel repair. Your second spare wheel is intact but you never know what the morrow will bring. Out comes the bead breaker, the tyre levers, the puncture repair kit and the tarpaulin. Time to start comes when it is cooler!

B u m m e r !

This is, for me, a common scenario. Fig 1. --> A classic puncture, this one unrepairable for use on the road! It is still worth repairing this hole with a sidewall patch and a gaiter, it may last another 100kms in an emergency.

How to repair?

1. Mark the position of the valve and split in the locking ring with chalk or similar. This will help retain the wheel balance after the repair. Remove the valve stem, and ensure that there is no residual pressure in the tyre, for safety.
   
   
2. Using the bead breakers (I use Tyre pliers, right), break the bead on both sides of the tyre.
   
   Fig 2. -->
3. Depress the locking ring with a lever and insert the end of the second lever in the recess cut in the right hand end of the locking ring. Lever up.
   
   Fig 3. -->
4. Using the levers, work your way around under the ring until it is free.
   

   URL - 4wd.sofcom.com/Wheels/Split.html

   
   Fig 4. -->
5. Taking care not to damage the valve stem, remove the wheel rim from the tyre. Remove the dust band and tube from the tyre casing. Examine the tube for damage.
   Fig 5. -->
6. This tube is ruined and calls for a new tube from the stock in the truck. However, a small hole would need patching and the cause identified and removed from the casing. Usually this is easy, however, a small nail, for example, may not be readily visible. By using the valve as a marker, you can trace the area of the casing to search. Run your hands along the inside wall of the case, find the problem and remove. Check then the remainder of the casing for inner wall damage. It may need a patch.
   
7. Clean out the inside of the casing and put the case on a tarpaulin.
   
8. Insert the tube and the dust band into the casing, ensure the valve lines up on the mark placed on the casing. This is all done on the tarpaulin. Replace the valve core. I put a little air into the tube to help remove the wrinkles.
   
9. Replace the rim. Pass the valve stem through the slot in the rim as the first step in this procedure.
   
10. Now for the fun part: Place the locking ring on the top of the tyre and line up the split in the ring with the mark on the casing. I do this off the tarpaulin as tearing can occur!
    Fig 6. -->
11. Time for the `split rim two step'! Kicking down and slightly out, starting at the end opposite to the recess in the ring, re-seat the ring. Do this by standing on the tyre initially and after the first segment is seated, stand on that part.
    Fig 7. -->
12. Continue around the rim until it has all been reseated. check the ring is correctly fitted.
    
13. Have a break and a drink of water.
    
14. Recheck the ring is seated correctly.
15. Have somebody else check that the ring is seated correctly.
16. If happy, re-inflate the tyre. I place the tyre away from the truck and with the split ring uppermost, start the pump.
    [The potential danger is due to the fact that a tyre side-wall has an area of perhaps 7x20x3.14=440sq". At a tyre pressure of say 30psi, that is about 6 tons of force trying to tear the wheel apart. If the split rim is unseated, it will become a dangerous projectile.]
    I watch from a few feet away! If there is a convenient forked tree, Fig 8. --> I would try and use that as a cage. Re-inflate to a working pressure (25psi) and check the wheel. If all looks O.K. continue the inflation to the correct pressure.
    
17. Return the wheel to its carrier. Clean away the tools and put them ready for next time.
    

Tube repair. This is similar to a bike tyre. Perform on a clean flat surface.

1. Clean the area with tube buffer and roughen the surface.
   
2. Apply rubber cement and allow to become tacky.
   
3. Apply a suitable sized patch after removing the foil.
   
4. Smooth it down with a roller. Leave to dry.
   
5. Remove cellophane wrapper to patch.
   
6. Tidy up.
   

When this is all done, have a beer or something similar and enjoy the evening. As you are dozing in your swag, you hear a gentle hissing sound. You know a slow leak has occurred in another tyre, you have a choice, do it now or first thing in the morning! You reluctantly get out of bed and start.

Comments.

This is a safe procedure if done carefully! I have never seen an injury due to a separating split rim off a light vehicle rim. Big Rig wheels are a different format and it is these that cause concern.

Some folk wrap a chain around the wheel as it is inflated, I don't. My kids (19, 17 and 13) are all able to repair a wheel. I check the 13-year-old's work before inflating the wheel. This way, we can repair several wheels quickly - when necessary. In the bush, you have to be self-reliant. The RAC (AA) will not make a call into the desert for a flat tyre. We carry 3-5 tubes and puncture repair patches and cement for another 50 flats. If it is really hot (50 Celsius and above), and we have several punctures, we will replace the punctured tubes with new ones and have a mass repair session in the evening.

- Nigel Buxton © 1998

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