TC Bros. Fork Tube Kit for Harley-Davidson Big Twin With 41mm ForkTC Bros. Fork Tube Kit for Harley Davidson With 41mm Forks (Select Big Twins including Softail and Dyna Wide Glide) If your Twin Cam era Big Twin needs a fresh look, a set of. TC Bros. fork tubes will help you spiff up your OE front end. Tubes are centerless ground ID and OD match OEM specifications Fork oil available separately Kit contains 2 fork tubes, 2 fork oil seals, 2 dust seals, 2 fork boots, 2 oil seal retaining rings, fork oil cap O rings,