Thats a steal.

No wheels?

So it's just the frame, headset, bb and shifters?

See my first post in this thread. $50 is okay but not great.

Everything except the wheels!

I'd hit it.

So:

Centurion > Univega I take it?

Yep, cuz that Univega is HUGE. It's a mid range Uni too, the Ironman is top notch

I got the Dave Scott Centurion today for a whopping $40, it has some rusty spots and looks like it was used/loved a lot. It came with Shimano 105 gear and these cool ellipsoidal chain rings by Shimano called Biopace. Should I opt for round chain rings or just keep these? Since I didn't have shorter bolts to hold the chain ring on I "machined" some washers to fit where the smaller chain ring was so I could tighten on the larger one. Ghetto rigged that hardcore. I have the original chain but something makes me think I should buy a fixed-specific chain. I took it apart and cleaned it and then put it back together, now it's sitting in the garage awaiting wheels.

You can read about the biopace debate. It's hot and cold.

https://tinyurl.com/Biopace

Biopace and fixed is less than ideal.

There is a very definite "lash" at certain points in the crank's rotation that can be felt, similar to a loose crank arm or uncentered and out of round chainring. Which is essentially what Biopace is to the fixed rider.

*lash is when the chain is loose and the cranks can move up/down a few centimeters even though the wheels are stationary. This translates to an odd sensation when riding. If you've ever used a fixed 2/3 speed hub you may be familiar with said sensation.

Sell the rings on eBay and buy a proper fixed ring.

I'm on it. Getting a 44 tooth chain ring.

My latest snag: I'm going to need to either space my cog or get a shorter BB. The problem with spacing is that my cog would stick out a bit because the threading on my hub is short, is that okay? Problem with a shorter BB is that it costs money. What should I do?

I just read this thread and having done a couple of conversions was waiting for this kind of response: anything you change will take a little bit of thought and knowledge. Sizing quirks, those biopace chainrings, etc.

Not sure why you need to change the BB... are you using a fixed-specific wheelset? Is the chainline not working?

44T? What gear ratio are you using?

As for chain, I'd just go with a 3/32" cog and 3/32" chain.

If I had a pretty, geared Centurion and everything worked well I'd just put a set of Nitto flat bars and Shimano flat-bar brakes on it and call it done. Sacrilege, I know, but I couldn't ghetto-rig -- I had to actually get bolts that worked, a new wheelset, etc.

You don't user spacers on a cog.

If that's the original bottom bracket you can most likely solve the chainline issue by mounting the ring on the inside of the spider or if it's a cup/cone type flipping the spindle.

Then buy the new bottom bracket.

If moving the ring to the inside does not get you there, you can use spacers in the chainring bolts to move the ring inboard more. You'll probably need double stack bolts.

What are you using for cranks and wheels?

A list of you parts will go a long way to prevent the likely flame war.

The stickler. It's not going to get my chain line bang on, but it will help. How much does it matter that my chain is super straight? I didn't mind spending money to get a decent frame, having one, I no longer feel the need to spend money.

I like this idea, I have tons of extra washers, I probably should buy some spacers though because I doubt my washers would keep my chainring true. Shimano 105 cranks, Vuelta Zerolite (cheapies).