Low cost Lug Thread Extender / Shell Bumper

[Joseph]

This is certainly not a new idea. Thread extenders have been discussed before.
I was making thread extenders, and the shell bumpers were a very easy addition.

Thread extenders are small sections of pipe, cut to length, that are placed over the lug threads between the lug plate bolted onto shell and the lug nut. They allow one to use more of the threaded part of the lug.

I’ve got several old Gon Bops, and the lug threads always seem so long. By the time a medium shallow mount is made on a new skin, 30 - 40% of the length of the threads are used up, and end up just hanging out there.

In my case old Gon Bops lugs show wear on the upper end of the threads (towards the hook), most probably from extended periods of time of being left in a highly cranked up condition.

Thread extenders move the nut down on the threads, so that it is grabbing onto the lower end of threads, where threads are usually in good shape, due to lack of use.

Apologies to the metric crowd, as the following is in inches and American pipe size measurements.

Old Gon Bops lugs are 5/16”
I used a piece of 3/8” pipe, cut into ½” long sections.

3/8” pipe measures the inside diameter of the pipe.
If you have 3/8” lugs, you will have to drill out the pipe a little bit to provide clearance for 3/8” lug.

On the outside of each cut pipe section, I stacked ½” rubber grommets, 2 per ½” section.

That’s it!
I used washers on either end to hold rubber grommets “captive” on the thread extender.

Looks reasonably good and functional in two ways.

Best part is price:
10 rubber grommets @ .47 each = $4.70
1 - 6” x 3/8” pipe nipple = $3.50
Total cost = $8.20

Took about 1 hour to cut pipe and file off burrs.
All parts commonly available at a decent hardware store.

You could make these with just a hacksaw and a file, but a vise makes working much easier.

One could make longer extender / bumpers, by cutting longer lengths of pipe and stacking more grommets on them. One grommet for each ¼” length of pipe.

This style of extender / bumper should be adaptable to various brands and lug arrangements, as opposed to the proprietary, brand specific shell bumpers

[Mike]

Awesome device, well done, Jospeh!
I always prefer DIY ideas over usually more expensive
commercial options - and as far as I know there is not
really an alternative to your bumper´n´extender thingo!