These are hub adapters to allow you to use larger tires on the stock Razor Dune Buggy.
You will not need to modify your cart at all or use any additional hardware with these parts.

The existing hubs slide into each of the halves and then bolt together.
Raxor_dune_buggy_rear_inner_rim_extension and Raxor_dune_buggy_rear_outer_rim_extension for the rear tires.

dune_buggy_front_inner_rim_extension and dune_buggy_front_outer_rim_extension for the front.

I recommend PETG or some very stiff TPU. I have been using PLA for testing, however, and it seems to be holding up ok.

You can ignore the spacer files unless you need them. The plan is to add spacers as well so you can use wider wheels easily. This would require modifying the spindles and axle as well as using longer hub bolts.

Tires I used can be found here:
https://www.amazon.com/dp/B08R87DHRL

Any tire that isn't too wide of a similar size should be able to be used.

OLD INFO:

4mm spacer that allows you to more easily use larger tires for the Razor Dune Buggy.

Just discovered that the front and rear on some carts hubs have different bolt spacing.
Uploading files that reflect that.

The razor_wheel_spacer_front files have 43mm spacing between the bolt holes while the razor_wheel_spacer files have 45mm.

There is a flat version and a recessed version.
The recessed version mirrors the locking design of the standard hubs, but as the hubs themselves are terrible tolerance wise the flat version may be easier to use.