Tuners of dirt trackers, road racers and especially motocross bikes work hard to reduce the bike’s weight. Loosing weight is like adding horsepower and improves handling. Pear Shape Pearson went to extremes with his 1947 Harley Davidson “Knucklehead” drag bike. Imagine him is his Kansas City garage back in the 1950’s drilling fins on the engine, perforating the frame, fender,  handlebar, even major parts of the forks! But his fuel drag bike set a record in 1955: 126.76 MPH in the quarter mile. There’s a great grouping of trophies to prove the bike’s performance, event photos and an AMA sanction agreement for the April 22, 1956 day at the track. Interestingly, Pearson’s club was named the Chainstretchers Motorcycle Club!

First produced for the 1936 model year, Harley’s original OHV V-Twin was a hit in performance, put them well ahead of Indian technically. 1936 machines had some mechanical issues and experts will point to running changes, three specific “versions” made that year. But by 1947, the last year for it, the machine later nicknamed the Knucklehead was well worked out. In the 1948 model change the valve train became enclosed and this was the last year for the springer fork except for special order sidecar machines.

When you visit the National Motorcycle Museum you can take in a range of drag bikes built around Kawasaki, Vincent, Yamaha, Honda, Triumph and certainly Harley-Davidson engines, even a double Panhead machine.

This bike was part of the Quarter Milestones exhibit at the National Motorcycle Museum in 2012. It is considered interesting enough that the Harley-Davidson Museum borrowed it for their drag racing show a few years ago, and Iron Works magazine ran a feature on it. Pearshape’s Knuck is graciously on loan from the John & Jill Parham Collection.


  • Engine: OHV V-Twin
  • Displacement: 74 Cubic Inches
  • Induction: Twin Carburetors
  • Controls: Hand Clutch Conversion, Rear Sets
  • Primary: Chain, Open
  • Clutch: Dry, Multi-plate
  • Chassis: Harley, Rigid
  • Fork: Springer
  • Brakes: Drum, Rear
  • Wheels/Tires: 2.75 x 19 / 5.00 x 16 Avon Slick
2 replies
  1. Mark Grochowski
    Mark Grochowski says:

    Once again great article!
    Just wondering if you got more info on the Chainstretchers MC.
    Sounds like an awesome club.


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