Custom Chainrings.

Here is a list of models and designs that are available in custom sizing.  I am really proud that I have been able to offer custom chainring designs made in Australia for over fourteen years.

If you don't see anything you want here or have something else in mind please let me know.

The Classic Twelve.

  My original custom chainring design that have been available for over fourteen years.  These designs are available in pretty much all the BCD ever produced. I cut these one at a time and finish them in a variety of finishes.


XL series.

 These designs are for chainrings sizes above 60t. the largest ring that can be cut is 96t. These are available in most newer BCD sizes.


  Simple chainrings to work with two different bolt patterns. I have these available in a few different BCD combos




Cycleunderground has been around for over 22 years.

A lot of customers are surprised to find out that it is a one man machining and fabrication shop.

My name is John Bosevski and I have been servicing, repairing bicycles and building  frames, tools and bits for bikes for over 30 years.

I now concentrate on my components and tools and slowly develop new product and tooling to increase my offerings.

I prefer to concentrate on the bespoke side of bicycles, putting my effort towards products and tools that have been forgotten or overlooked.

 My workshop can be found in Taren Point,  Sydney,  Australia.