etherhuffer 

Compact triple, Sora 7 speed brifters . I have used an RSX in the past. I think a Claris is my next choice or IRD Alpina. Any other voices from that era that would work?

oldbobcat

Since 7- and 8-speed use the same chain, a Sora 7- or 8-speed or Claris triple FD should work. Others will say that a Sora or Tiagra 9-speed will work, and I'm going to get flamed for saying chain width changes front shifting dynamics, so I will simply leave it as why go there if it's not necessary? I vote for Claris because older Sora and Tiagra FDs tend to break at the nub that anchors the return spring.

Crankycrank

+1. Also, check out Microshift derailleurs. Function is as good as Shimano but usually more durable due to more steel used but only slightly heavier and also less expensive. The R8 Triple is probably what you need for your current triple rings but click the "show full specs" dropdown list for compatibility of the other 3 derailleurs listed. Check the 8 speed + Triple Filter boxes Front Derailleurs | microSHIFT

etherhuffer 

Microsoft is completely foreign to me, but I might give it a try

Crankycrank

Replaced an old Sora 3x derailler for a friend a couple years back. The little nub that oldbobcat mentioned broke off so tried the Microshift R8 and was very impressed. Looks much sturdier and works as good or better than the Sora. Microshift has been around awhile and lots of members here have used them.

icemilkcoffee 

So why not use the RSX FD again? If I remember correctly the RSX FD doesn't require trimming for any position aside from small-small. Somehow the opening is just wide enough, and the 7 sp cassette just narrow enough that basically you never need to trim. Which is a good thing because the RSX 7 speed brifters do not have trim clicks.

etherhuffer 

Good question. I have Sora, not RSX brifters. This set up worked great on several older road frames. Then I tried it on my Surly Long Haul Trucker. No go due to different bottom bracket drop. The tail of the RSX hit the tubing on the frame, not enough clearance. Current bike I am working on has the same and it's really frustrating as the Sora/RSX worked perfectly on the other bikes.

Smitty2k1

Knowing the exact chainring setup on the Sugino would help, I know they sold multiple configurations. Are you running friction shifting or indexed?

I just installed a 48/36/26 Sugino triple on my touring bike with 9 speed indexed shifting. Had a heck of a time finding a compatible FD, finally found some old ~2007 era Shimano models that hopefully fit the bill. Next step is figuring out if I need a new BB to adjust the chainline...

etherhuffer 

This is a Sugino Mighty Tour with same tooth counts.