Shimano105 late 80's-early 90's, Need Help
 

I removed my front chainring (42) and the 53 and need to replace the chainrings. This bike is used in the early spring due to the weather. I would like to know if anyone has any info on where I could purchase new chainrings and hopefully the spacing will be the same. I would like to make the inner a 39 tooth since the bike is an old ALAN frame with a 6 sprocket freewheel. I also have to buy a new derailler pulley wheel, chain, and some cables. Any recommendations on purchases is greatly appreciated.

thanks

Any bike store will have the correct chainrings for that crankset.

you can pick up Biopace II chainrings on eBay for $10 each or so.
130mm BCD for the 105 crank if I'm not mistaken. Easily measured to be sure.
As for cables, chain etc, Nashbar has generics pretty cheap.

Aebike, JensonUsa and similar have tons of bike parts.
Check the chainrings by Sugino.
http://aebike.com/page.cfm?PageID=30...ils&sku=CR1539

Don't forget to measure the Chainring BCD first:
http://www.hostelshoppe.com/tech_bol...e_diameter.php

You can even ditch the biopace for round rings. I was never able to spin biopace smoothly; consequently, a buddy of mine had some campy round rings. (he went to a 53 outer) that he gave me and I've been using ever since..:D

Second GrassWolfs advice. Biopace or not, be sure to check the BCD before purchasing.

http://www.hostelshoppe.com/tech_bol...e_diameter.php

http://www.branfordbike.com/chains/chains1.html
(scroll down to Chain Ring measurements made easy...)

How did you fit Campy chainrings (135 mm bcd) to a Shimano crank (130 mm bcd)?

That's easy. His Biopace had 110mm BCD,
http://harriscyclery.net/itemdetails.cfm?ID=2332
and the Campy chainrings were from a compact crankset.

good answer :)

Even that may not explain it. Campy's compact chainrings had a proprietary bcd with one of the bolts off-set from the standard 110 mm bcd to keep you from using "inferior" chainrings on a Campy crank.

If it was 42 and 53 tooth rings, I'm almost certain it was 130bcd. Yes you can use a 39. It does not have to be biospace.

The aluminum Campagnolo compact cranksets use standard 100mm chain rings, the plastic ones is a different topic.