So I’m fixing up a 90’s era Specialized Rockhopper mountain bike with a 3x7 mountain drivetrain. The Specialized branded triple crank has a 42 tooth big chainring. The stock front derailleur is a Shimano and the body has a capital”A” on it. I’m having trouble setting up the front triple index shifting. I noticed that the arc of the cage is not too tight to the big chainring. It got me thinking if I had anything else on hand that might work properly. I remembered that I have a SunTour XC Pro Microdrive front derailleur that fits this frame (34.9/bottom pull).

I was going to give it a try and hope that the cage countours will permit better index shifting across the 42/32/22 range of this crank.

if anyone has tried this with Shimano index systems, I would love it if you could share how well it worked out (or if it does not work I guess I should know the bad news as well).