All,

I'm preparing to convert a 1985 Panasonic to fixed and was hoping to use as many of the original parts as possible. Rear spacing is 126mm and I will likely go with a formula fixed/free in the back.

My question focuses on the front ring. I have noticed in pictures that several riders use a 52/19 or a 53/19 fixed setup. This is a preferred combination for me. I have read on sheldon's site about using the stock chainring during a conversion, but he speaks of using the 42t inner ring affixed with short stack bolts. I am curious: for those running the big ring up front (52 or 53), are you moving it to the inside to replace the inner chainring or are you simply removing the inner chainring and still managing to get proper chainline with the big ring in its normal "outside" position?

I'm guessing that some frames don't have enough clearance to handle a 52 or 53 ring affixed on the inside where the smaller 42 ring normally goes. I don't have the bike in hand yet, but it comes stock with the 42/52 up front, I believe.

thanks

I tried doing a conversion the same way, last year -- I didn't have clearance for the 52t chainring on the inside due to it rubbing against the chainstay. It was a 1976 Raleigh Record, so you could be in a different scenario. Good luck!

For a conversion, clearance for a large chainring is likely to be a problem at the typical 42 mm chainline. Those large chainring setups you saw may well have been on track frames designed with greater chainring clearance. But is there something wrong with the 42 t inner ring? Can't you just use that with a smaller cog and be done?

I converted an 87 Panasonic. I use the smaller chainring on the inside edge of the spider. This
is the only way for me to keep the chainline straight.

if you're really interested in the 52x19 ratio, it looks like 42x16 is going to be a little easier/shorter than you want, and 42x15 is going to be a touch harder/higher than you want.

https://software.bareknucklebrigade.c...it.applet.html

teehee! I just converted my raleigh record and I use the 42 because it let's me have a straight chainline. Plus I don't think I could handle a 52/16 lol (yes too poor to get a bigger cog) but 42/16 is great here.