Hi all - I'm thinking of putting these two Biopace rings onto my existing crankset. BCD looks to be about the same. Is it possible?

Why don't you try it and see. While you're at it wash your bike, that's disgusting. And maybe you can also start posting in the proper section of the forum rather than putting every damn thing in GD.

Measure the BCD and then tell us. Yes, of course chainring swaps are possible, when the bolt pattern matches.

Will give it a try this weekend at the local bikehub.

Im tired of constantly cleaning the bike just for it to get caked in road grime again shortly after. I'll be installing fenders as well.

I've never seen a biopace ring that wasn't the most common contemporary bolt circle, and have never had a problem swapping them in and out. Every bin of old rings has a few of both.

It isn't necessary to remove the crank in order to change the rings. It can be done with the crank installed on the bike

And try using the search function before posting. Or this thing I’ve heard about called “google.”