1936 Ariel 4F OHC Square Four on eBay

These rare early overhead cam Ariel Square Four motorcycles do not turn up in barn-find condition very often – actually they are pretty scarce anywhere outside museums. Out of my price range (barns aren’t what they used to be!) but a lot of very clear photos.

This bike looks pretty complete and the numbers match.


Electrical Theory by Joseph Lucas

Positive ground depends upon proper circuit functioning, the transmission of negative ions by retention of the visible spectral manifestation known as “smoke”. Smoke is the thing that makes electrical circuits work; we know this to be true because every time one lets the smoke out of the electrical system, it stops working. This can be […]

Ariel Engine and Frame Number Prefixes

Engine numbers, frame numbers, model designations and engine configuration for Ariel motorcycles from 1926 – 1965.

Letter codes are a prefix to the number which is usually 4 digits. Engine numbers are typically on the left hand engine case just below the barrel. Frame numbers are usually under the seat on rigid and plunger models […]

Motorcycle Safety

I found this 1960s Pathe public service film posted on the Draganfly website. Wonderful lesson on riding your old motorcycle in a world populated by Austin Minis, Morris Minors and no lines on the roads – not even at crossroads! Watch for the little three wheel bubble car. Of course the sensible lad is on […]


I finally got around to investigating what went wrong with the my Ariel NH last time out – very weak spark and general loss of electrical power. The Boyer Bransden unit really is not happy with low voltage. After a lot of low speed puttering I did get home. I assumed that my rewired (again) […]