I recently acquired a tribike (Quintana Roo) frame. I know just how I want to build this up but I have some issues that I could use some help with. Principally, I need advise on the drivetrain. My limited knowledge tells me that mixing campy and shimano must be done carefully and, probably, it is best to stick with one or the other to make sure there are no compatibility problems. Is this right?If so I would probably stick with Shimano because of the availability of affordable parts.

One other question I have is how critical is it to match the speed# of the rear derailleur with the shifter gear#? Can these be mixed and matched, or do I need to pick a speed# for this bike and stick with this?

More to come, thanks.

For Shimano, rear derailleurs are indifferent to "speeds" since the indexing is in the shifters and Shimano's rear derailleurs have had the same geometry since the days of 7-speeds. Also, Shimano's road and MTB rear derailleurs are interchangable.

As examples: I'm using a "9-speed" Ultegra rear derailleur with 10-speed brifters and cassette on one bike, a "7-speed" STX rear derailleur with 8-speed 105 brifters and cassette on another and an "8-speed" 105 rear derailleur with 9-speed 105 brifters and cassette on a third bike.

I'm not that familiar with Campy's interchangability but I believe their late 9 and current 10-speed rear derailleurs are interchangable.

Mixing and matching Shimano and Campy can be done and Jtek has made a nice living providing their Shiftmates in various models to let the two makes play together but it's not as straightforward as sticking with one or the other.

Thanks Hillrider. From lurking here and other chat rooms, I really don't think that there is a tangible benefit to deviating from Shimano and since there seems to be more deals to be had with shimano I think I will just go with this company.