Ruth rode in my new cycle-car
In the seat back of me;
I took a bump at twelfth street
And rode on Ruthlessly.

The Phillipian (Enid, Oklahoma), 1919, [p. 167]

Notes by Andrew Guild:
This poem, or variations thereof, appeared in several dozen publications. This version was the earliest one that I could locate. Its origin is unknown, but is possibly American; this version, with its reference to “twelfth street”, denotes a likely American origin.
The following is a slightly different version, from an Australian newspaper:

Ruth rode in my new cycle car
In the seat in back of me;
I took a bump at fifty-five,
And rode on ruthlessly.

Interesting items“, The Northern Standard (Darwin, NT), 24 September 1926, p. 3