I want to say that the titanium Duopart is a piece of trash that should be avoided at all costs, especially if it's going cheap on eBay and I'm the high bidder.
Actually, I have one on a tandem and another on my Paramount P15, which I rode into work just yesterday (in the snow, no less). There were two Doupars, the steel version, which they may have called the "Eco" at times, and the titanium version. There is absolutely no comparison between the two other than they look alike. Both of them suffer from one potentially fatal flaw, and that is that you simply cannot pedal backwards with them. The open cage on the top jockey wheel on the inside makes the chain unship very easily, and then the articulated mechanism can get bent under even light stress if the rider continues pedaling. It can happen in a half-revolution of the crank. Ditto for rolling the bike backwards, since the affect is the same. This weakness, and the way that the more popular steel version wore quickly, gave the changer a bad rap among the unenlightened. You also need to be careful that you've got some decent spoke clearance in the big cog. I've heard the tick-tick-tick of a Campy derailleur kissing the spokes and thought "I've gotta look at that when I get back home." If I ever heard that on a Duopar-equipped bike, I'd freak and hit the brakes.
But that Titanium Duopar is a joy to behold and a bigger joy to shift. I've cranked up on the Sun Tour BarCon too late on a hill, climbing with packs and a stoker, and had that Duopar, at the other end of 7' of cable, drop that chain on the next cog just as sweet as you please. Absolutely amazing.
Proof at http://biketoss.com/
Steve Barner, still have everything in the photo except the youthful build, Bolton, Vermont
> Date: Fri, 12 Nov 2004 09:55:41 -0500
> From: hydelake <hydelake@bcpl.net>
> To: Classicrendezvous@bikelist.org
> Subject: Re: [CR]Hooray for Huret ??
>
> I've been using a Huret Ti Duopar on my Richard Sachs tourer since about
1980
> when I went to a wider setup and removed the Campy Record derailleurs.
The
> duopar shifts a wide range freewheel very sweetly. It can't be forced
like a
> Campy, but if treated gently still shifts quickly and smoothly. When I
> recently switched to a Sachs freewheel, I did run into some problems, but
> managed to track down an old Suntour Winner hub built up to my half step
> spacing and the shifting is back to it wonderful capabilities. Larry
Black
> once told me about shifting a duopar into the spokes on a tandem, but I
used
> one on a tandem for years with Campy barends and no problems. I too have
a
> few of the duopars.
>
> Dan Artley
> Parkton, Maryland
>
> Bikerdaver@aol.com wrote:
> > Additionally, I also had one of the Ti-Duopars I picked up for a special
> > touring project. I ended up going with a Sun tour set up and found that
> people
> > avoided the duopar like ithe plague. I ended up Giving it away to some
> bicyle
> > charity that made bikes for inner city children. Guess that was as good
a
> home as
> > any.
>
> Interesting. My experience with the Duopar has been quite different. I
> replaced a long-cage Cyclone on my touring bike with a Duopar way back
> in 1979 or so when the Duopar was first introduced and was amazed at how
> much better it worked than the Cyclone it replaced. That very same
> derailleur is still on my daily commuting bike and continues to work
> without problems.
> --
> -John Thompson (john@os2.dhs.org)
> Appleton WI USA