IRC Standard Motorcycle Tube 80/100-21 HEAVY DUTY vs SCK 2 Pack 20 Inch Bike Tubes Plus 2 Tire Levers, 20x1.75/1.95/2.10/2.125 Schrader Valve MTB Bike Inner Tubes, Black

No sources that do their own in-depth testing have considered the IRC Standard Motorcycle Tube 80/100-21 HEAVY DUTY to be a good enough purchase for it to earn a spot in their Bike Tube roundups, which is typically a bad sign.

Moving on to the SCK 2 Pack 20 Inch Bike Tubes Plus 2 Tire Levers, 20x1.75/1.95/2.10/2.125 Schrader Valve MTB Bike Inner Tubes, Black: no sources that perform reliable and objective hands-on testing have included it in their Bike Tube roundups, which usually means that a product doesn't make for a good purchase.

As a last step, we wanted to do a head-to-head IRC Standard Motorcycle Tube 80/100-21 HEAVY DUTY vs. SCK 2 Pack 20 Inch Bike Tubes Plus 2 Tire Levers, 20x1.75/1.95/2.10/2.125 Schrader Valve MTB Bike Inner Tubes, Black comparison of their review performance but, unfortunately, weren't able to find any review ratings on either product.