Originally Posted by rv5869
2004 co-motion. 1 1/8".
The carbon fork spec'd for that bike is the Wound-Up by Advanced Composites. The rake (45mm) and fork length (387mm) were developed for use on Co-Motion's tandems and the fork is offered in both a caliper and cantilever/V-brake version. It's not the lightest model out there @ 795g w/262mm steerer, but it's certainly durable. About $495 for the caliper version & $525 for the Canti/V-brake version at PrecisionTandems.com. It will slightly alter your Co-Motion's handling to make it even a bit more sporty than it is now.
True Temper makes two tandem-specific forks; the X2 ($450) for caliper brakes with 48mm, 44mm, and 41mm of rake and their beefed-up CX model for Burley ($585) with bosses for cantilever/V-brakes and uses 47mm of rake @ 600g, which is the same rake that your Co-Motion's steel fork is spec'd with. The X2 is superlight @ 465g w/300mm steerer but problematic for some in that it has very short legs (374mm vs. 387 for Co-Motion) which alters the bike's front bottom bracket height, geometry, etc... In essence, you end up with a steeper head tube which necessitates a fork with less rake (e.g., the 44mm model) to net out for handling that is similar to how a Co-Motion would handle with a Wound-Up fork, but with a lower front end (you could find yourself catching a pedal can during corners where you didn't before).
The Reynolds Ouzo Pro Tandem forks come in three different models these days: The original which was designed for Santana and which won't work on your tandem. A 1.125" steerer version w/55mm of rake @ 535g that I wouldn't recommend unless you find your Co-Motion to be too twitchy ($490), and a Canti-brake version at 1.125" with /45mm of rake @ 535g that would work ($490).
There are a few others "floating around" on the Web offered under several different brand names, e.g., Windwood (Nashbar & others), Tange/Santana, and a model from Chuck's bikes that may be produced by Tange. Of hand, I'm not sure what the geometry/specs are for these forks but would note that the Tange/Santana model would be incompatible.
Your best bet for getting exactly what you're looking for in terms of the added benefits of a carbon fork would be to contact either the good folks at Co-Motion (Dwan, Alan, etc...) to discuss your requirements and get their recommendations or to do so with one of the speciality tandem dealers who are familiar with all the various fork offerings and how they match up to Co-Motions, e.g., Mark Johnson at PrecisionTandems.com, Mel Kornbluh at TandemsEast.com, or the folks at Tandem Cycle Works in Colorado. That is, unless you have a great local dealer who's well-versed in the current technology & product offerings.