Im modernizing a vintage bike to use brifters. Im only making it use the rear shifter. I found a rear shifter on ebay, but it says it need a new spring. Upon looking at the schematics for that shifter, I found that the only spring in the assembly is the return spring. i searched only for a rear dereailer return sping, but couldnt find one. Anyone know were I would be able to?

Does this shifter have a name, model year, or other designation?

Why would you search for a rear derailleur return spring if what you need is a shifter return spring?

That is what i searched for, i just miss typed it.

but its Shimano 105 ST-5500 right shifter.

have fun with that

didn't mean to sound too snappy, but rebuilding shimano shifters is essentially the holy grail of bike repair

I would definitely skip on that one, shimano shifters are pretty much disposable. It's not meant to be a put down but it's the truth.

yea ive come to that realization after a bit of searching. kinda weird since I found the tool needed to install the spring...

If you are saying the shifter works when downshifting, but when you try to upshift, it won't shift (return) unless you hold the brake lever firm and slightly to the right. If that's your problem brother, you have a totally toast shifter. I gambled and picked up 2 Dura Ace shifters for $15, both right hand, both with the same problem. I spent another $20 having one of them disected by a LBS who has the tools to work on Shimano brifters. The verdict, totally toast. I learned from that experience only to buy brifters that are described as working perfectly. If possible I like to try them myself before buying. I know that's a bummer.

or leave the sweet busted left DA9 broken shifter for those of us running 1x10s