Updated: Mar 16, 2022
I started with a 15 year old Specialized Hardtail...
I used inexpensive parts from China (we’ll see how well they hold up). I used a 780 mm WAKE brand handlebar and WAKE 31.8 mm stem that I ordered from Aliexpress. I also used a KMC 1/8" single speed chain, GPMTER (What kind of a company name is that?) handlebar grips, a Cycling Deal Fixie conversion kit for the rear single sprocket and a BWWNBY (WTF?) chain tensioner. I bought all of these from Amazon. The rest of the parts I had lying around in my parts bin.
The original bike had a 3-sprocket chain ring set and a front derailleur. I used a Dremel tool to remove the smaller and the larger chain ring on the front to make it a 1x drivetrain. I also removed the rear cassette and converted it to a single speed.
I painted a few parts like the front chain ring black and the rear single speed sprocket red. I threw on some matching red/black Crank Brothers pedals. My inexpensive Slopeduro conversion was complete. This bike is actually a ton of fun to ride around the neighborhood.