upgrading mid80s schwinn traveler : question
 

a friend asked me to help him upgrade his mid-80s schwinn traveler - to 9 speed. I'm switching out the derailleurs, brakes, shifters, wheels, but I have a question about the crankset - it currently has the stock sugino crankset.

I assume i have to either replace the crank (and probably bb) for a set compatible with a 9 speed crank OR could I just replace the chainrings with narrower (modern) ones? if this is possible, what spacing is the bolts for the chainrings (i don't have it in front of me and my friend isn't a bike person... so i dont know if i'd trust his measurements).

http://lh5.ggpht.com/_lME3N8JWpjQ/TH...cture%2037.png

what type of shifter are you using? the BCD is likely 130, but you will likely have to change cranks as the spcaing of the rings, which is set by th spider, is narrower on a 9spd crank.

if you replace the cranks with a newer set tou will need a new BB. newer cranks have less 'dish' on the spider. the BB shell is likely english thead 1.37x24 and 68 wide. the length of spindle is determined by the cranks.

this sounds like a huge investment for '80s travel. what year and what frame materiel? is there a RD hanger on the drop?

http://www.trfindley.com/flschwinn_1...985Ltwt19.html

it's an 85 with chrome-moly double butted tubing - tubing is ok, but the parts are definitely lower end. i'll be using 9 speed STI ultegra shifters. would these shifters + 9 speed chain work at all with the 6 speed crankset at all? or is it new crankset time?

basically I have all the parts i need to do the upgrade except for a rear derailleur and a crankset.... so that's why i'm asking... seeing what I can save on.

Correct me if I'm wrong, but I don't see why you can't just use the existing Crankset.

That's what i wanted to know!

I think it may be a try and see type thing. who knows if the chainwheels will work with the 9spd chain and if the ultegra shifters wiull index with it. it is something I would try but if the OP already bought a full ultegra kit he may as well use the new parts and save some aggrivation