Harley Swingarm Numbers – What Do They Mean?

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I am traveling this weekend, but figured I could still squeeze in a quick post from my phone – I am just as addicted to this little electronic device as everyone else, but please forgive any typos.

In particular, I thought I would try and answer an esoteric question about vintage Harley-Davidsons: what do those vintage Harley swingarm numbers mean?

Generally, when buying a bike, we are obsessed with the VIN (as we should be), but the swingarm is also typically stamped with a set of numbers.  Mine are 47606-58.

So what do those Harley swingarm numbers mean? Do they tell me the year?

Well, yes and no.

Despite some misunderstanding around the internet, I believe that these are the forging numbers (as opposed to part numbers), and that three numbers and at least four swingarm types existed between 1958 and 1972

-Forging number 47606-58 was outside the right-hand axle clip for 1958–72.

-Forging number 47614-58 was outside the left axle clip for 1958–59, although at least two swingarm types existed during this period.

-Forging number 47614-58 was inside the left axle clip for 1960–62, although again a variety of swingarm types existed during this period.

Essentially, the fact that the ends in -58 means it is original and was first available in 1958 (not that it necessarily came off of a 1958 motorcycle).  The only other thing I know is that 1972 was the last year for the round swingarm.

Personally, I love authenticity to my bikes.  If you are buying a vintage Harley, maybe take a second and check the swingarm numbers – seeing the right numbers back there is a plus one in my book.

Okay, that’s it for my lesson on Harley swingarm numbers.  If you enjoyed this blog post, please like or share on Facebook, tweet on Twitter, or like on Instagram.

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