biggest cog

what’s the biggest cog size that’s generally available?
askin cause i’ve got a 52t chainring but wanting a fairly low ratio.
any problems with big cogs? are they hard to get?

I’ve seen 18t and 20t’s getting about.

That should give you a low enough ratio.

Not too hard to find online. I think.

I have a 19 tooth cog which I got from Abbotsford.

I’ve got a 21 tooth surly on my polo bike and i believe soma goes up to 23.

But unless you want silly low a 19 or 20 should be good (72 + 68 gear inches). and a bit easier to come by

Human Powered cycles sell a 24t.