Shop › Speedline Chain Tensioner 3/8" Pro Frames Image 1 of 1 Speedline Chain Tensioner 3/8" Pro Frames $24.95 sold out The Speedline Alloy Chain Tensioners have a 3/8" Axle hole and will work with most 3/8"( 10mm ) hub axles. Sold Out Added! The Speedline Alloy Chain Tensioners have a 3/8" Axle hole and will work with most 3/8"( 10mm ) hub axles.