Model A - Primary chain

 Today I have fitted and tensioned a new 1/2" x 0.305" primary chain, which for the record has 80 pitches. If you recall, this bike has a new 23 tooth engine sprocket:

The 23 tooth sprocket I've fitted is the largest one Ariel offered in 1930:

This appears to correspond with an 80 pitch primary chain, though I'm sure 79 pitches would fit as the chain is nearing the end of the adjustment. Perhaps the 80 pitch chain is designed to suit the Burman clutch.

A 79 pitch chain would need a half-link which I believe are available from Simply Bearings. I might investigate that, but I don't fancy having two spring links in the chain.