Chainring sizes?
 

Hi all!

I am looking to get a new chainring for my fixed/single speed conversion.
My cranks are of an late 80'ies Peugeot, but I cannot seem to find a chainring the right
size. Also I am uncertain of which size it is.

When I take a pencil, put it through the center of every bolt hole (of which there is 5),
I then draw a circle through the 5 pencildots, and measure the Ø (diameter) I get 122 mm,
not knowing how accurate this method is, it could be 120 mm. Which of these, if any, is a reel chainring
measure? I can only seem to find Ø130 mm, and Ø110 mm on my local webshops...

And if it is a real measure, is it so unusual that I will be searching high and low for a new ring?
I want to put on a new chain, and I do not want to ruin a new chain, with a worn chainring.

Thanks
Morten

122mm would be a Stronglight 93 or 105; 120mm would be Zeus. All have been out of production for many years, but rings (new and used) still turn up on eBay fairly often. Since you say the frame is Peugeot, I'd lean toward the Stronglight, which is also significantly less rare than the Zeus.