Tandemgeek, you are correct, for a variety of reasons we did not buy the Rivazza.
To answer the questions you posed:
We are a team that weighs between 300 to 305lbs.
We ride 28mm Gatorskins, no idea what the pressure is (gauge broke) but we pump them up to just below the point where I can't flex them with my thumb. I'm guessing this is pretty close to 120. I did just buy a set of 32mm Gatorskins because we are going on vacation to a place where the roads can be pretty bumpy, but flat!! Most of our vacations lately are to places where the roads are flat, my wife's had two knee surgeries and flat roads don't bother her knees, but hills do a little. You may remember we had to go to 130mm cranks for her to ride pain free, she's got a 30.5 inseam, so these are pretty short.
The feature I value most in a wheel is reliability. I hate to stop in the middle of a ride to fix a flat or mess with anything else.
We don't have a drum brake on the wheels, but that wheel weight did include the freewheel. I hadn't thought about the fact that wheelsets are generally weighed without them. The hubs are Edco Competition, I never see mention of them here on the forum so I don't know anything about them. Maybe the hubs are really heavy, but not the spokes and rims? Anyway they say they are Swiss made on them. Total bike weight is around 42lbs.
I really want a new tandem, my wife wants home improvements done. She loves riding, but never rode before we got married (8 years ago) and likes our tandem just fine. Much discussion here about the merits of both, she's winning so far.
I've got about 1,000 dollars set aside towards a new tandem, looks like it will be between one to two more years before I have enough for a another new/used tandem. I'm not committed to the 160mm spacing, but I do love how stable our bike is. It also seems pretty maneuverable to me, but then again I have no experience with other tandems. I saw the Spinergy's were about 1,000 and thought "hmm, maybe I should just buy those?" but of course then I'd have to start over again towards getting to a new tandem. Decisions, decisions.
Thanks for saying we're not slow. We just always seem to come in towards the tail end of the organized rides we do. We're a 111 year old team. I'm 50 and my wife's 61, so any speed improvements will probably have to come from equipment improvements!!
Thanks again for all the input here, I've ridden singles since the late 70's, but all my tandem knowledge comes from this board.
Back to the OP's question. We mounted the 20/24 Spinerys back at the beginning of April. These are replacing our 40h Velocity Dyads (which will remain our training wheelset). Ancedotal impression without actually getting out a scale was weight-wise, the Spins are about half that of the Dyads. We've only ridden 3 times since mounting the Spins (my stoker-wife had a bad equestrian fall in Jan. & we'd been off the bike for 10 weeks). All of that said, our first "real" ride (and our longest ride this year) was this past weekend -- a 38 mile flat course -- and we'd still managed a 16.1 mph average. Most definitely, the new rims helped. The Hadley hubs are a definite improvement over the DT Swiss on our Dyads. Just guesstimating, but the Spinergys are probably worth about 1.5-2 mph speed advantage.
Thanks a lot!! That's the kind of info I was hoping to see.
A quick trip to Kreuzotter says that, assuming a good cruise at 250 team watts, the additional speed amounts to another 50 watts, i.e. saying that the Dyads absorb 25 watts/ea. more power than the Spins. My guess would be 5 watts. Going to a pair of Zipp 808s might net a 20 watt/ea. improvement over the Dyads at 30 mph. Inertial resistance is such a small factor that it gets lost in tire inflation data noise in the power equation. Not to rain on anyone's parade or anything.
As Carbonfibreboy has pointed out, there is no way you will get that much of a gain with wheels.
Originally Posted by Bornco
Perhaps I'm a tad optimistic. A few years back, I switched out the original Shimano rims that came with our then-Specialized Roubaix & Ruby singles w/ Specialized' Fusee (probably misspelled). My wife & I rode the same 18.5 mile loop under similar conditions -- same tires/pressure, traffic, temp., & zero wind -- and our overall average went from 17.0 to 18.1. It was from that experience that I'd estimated our improvement switching to the Spins on our Speedster. I had a brief chat w/ Mark at this past weekend's Georgia Tandem Rally about this and the conclusion is that Spinergy's (& the Fusees for matter) were effectively extending our speed endurance over distance before fatigue sets in. And in any case, the Spins are definitely quicker off the line and are easier to climb with. At GTR, we still managed average 15.4 (on the 41 mile route) & 15.0 (on the 47 miler) in the hills of central GA.