I have a 1985 Trek 720. Considered by many to be one of the finest production touring bikes of all time. I've made a few changes here and there- Phil Wood/Super Champion wheels, Shimano 600 slotted brake levers, Mathauser brake shoes... and it came with a Sachs/Huret DuoPar rear derailleur. While that unit shifted REALLY nicely- I didn't trust it- so I've been running a beautiful, and badass Suntour XC Pro. It's a great derailleur, it looks really cool, it feels "quality" and it shifts impeccably. Most ordinary people would just keep running that and it would still be sufficiently awesome.

But I've got a bug to swap some stuff around on that bike; and I'd like some help making that decision... I'll be using Suntour barcons for the time being- so with friction shifting- that pretty much allows me to use whatever derailleur I choose to...

I've got a Suntour LeTech that's in really nice shape. This came on the 1984 Schwinn Voyageur SP- and it shifted fantastically on that bike. I wanted to change stuff around on that bike... and swapped it out for an XC Pro (are you sensing a theme?). Anyway, the LeTech is a triple pivot derailleur- it moves in and out- like every derailleur- the cage pivots around- but what makes the LeTech unique is that the cage pivot is on a pivot. This allows the upper pulley to get close to the smaller cogs and back off the larger cogs. It's sort of the same idea behind the DuoPar- but executed much more... excellently. It looks like a rear derailleur should- it has tons of chain wrap capacity and it can take a HUGE rear cog. The super modern computer font screening kind of seals the deal.






I've also got a Shimano M735 Deore XT rear derailleur. This is truly a great rear derailleur. It looks sufficiently badass and it's bullet and bomb proof. It shifts great, it has great capacity for cog size and chain wrap. The Deore XT is really the standard that all MTB and touring bike components are measured against.




Of course, there's also the Suntour XC Pro. IMO the finest RD evAr. It looks perfect- the Suntour branding stands out on the back plate, the springs on the unit are strong and it shifts with authority. Everything about the XC Pro just exudes class and quality. I really love these RDs.




I'd also consider putting the DuoPar Titanium back on. It's a really nifty looking unit- it's the poster child for ultra smooth shifting - it shifted so smoothly, I seriously wouldn't know that the shift went through until I felt the resistance on the pedals.