Knucklehead Oil Pump Shirt


Celebrate the difference between making it and breaking it with our 1937 Harley- Davidson oil pump diagram t shirt. If you thinking pumping oil today is tricky, try doing that shit in 1937! This one is a tribute to the people who taught us, the people who fought us, and the people who got us here.

It comes in sizes small – extra large* and features a pre-war Harley motorcycle oil pump diagram that we’ve adapted for print. The design is printed in breathable orange ink and the shirt is made from a 60/40 cotton blend fabric.

*This shirt has a fitted style. If you like a looser fit, or are between sizes, size up.




This design’s inspiration started from a vintage 1940s motorcycle repair manual that was found by a friend in an abandoned house. It’s a neat book: “Modern Motorcycle Mechanics and Speed Tuning” by J.B. Nicholson. Ours is a second edition.


Additional information


XS, S, M, L, XL