For Part I, click here.
Driving the bus
Not all tandem experiences are created equal. I once rode a tandem that felt like I was unintentionally courting disaster. (Shepard notes that when Co-Motion started in 1988 their top tubes were 28.6mm in diameter, not the 44.5mm of this bike.) I rode another that was as averse to turning as a school bus. Some feel longer than they actually are. Co-Motion has earned a reputation for some of the best, if not the best handling bikes out there. What this comes down to is how much of the time you’re steering the bike rather than countersteering the bike. Once you’re above about 14 mph on most singles, your direction control comes through countersteering. The longer a bike’s wheelbase, the higher the speed you must go before you countersteer. The upshot is that often when at speeds where you’d expect to countersteer (e.g. 18 mph), you still need to steer most tandems.
Co-Motion offers the Periscope Torpedo in three stock sizes; we went with the medium, which has a 56.5cm effective top tube. Both seat tubes are 73 degrees. The head tube is 73 degrees and is paired with a 50mm-rake fork for 5.17cm of trail; that would be crazy quick for a single, but this is part of what makes the Torpedo handle more like a bike and less like a semi. The long wheelbase offsets the short trail. Bottom bracket drop is only 72mm, but that’s because dropping it more than that makes pedal strikes in turns much more likely.
This bike was, in part, a chance to ask the question, what’s the best way to build a tandem today? Though some options, like triples, have been all but eliminated, there are still a number of gearing options, and as I’ve written elsewhere, a 50×11 is a big gear. You’ve got to be seeking maximum warp to conclude you’re undergeared with that. The bigger problem is finding a gear low enough for the hills. I went with an 11-32 cassette, which gives us a 34×32 low gear—nearly a 1:1 ratio. I think on long climbs this could still be a problem, but until we tackle the Geysers or Coleman Valley, I think we’ll be okay. What we’ve lost in gear range the addition of Di2 electronic shifting has overcome with a near miracle. Tandem shifting has been wonky enough that Di2’s performance advantage becomes that much more apparent.
I’m just going to say it: There’s not a better solution for tandem drivetrains that Shimano Ultegra Di2.
Instead of a traditional timing chain, we went with a Gates belt drive. The reasons why are pretty compelling. It’s quieter, lighter, requires no maintenance, won’t stretch and features lower drag. There’s no downside that I can find.
All these options—S&S couplers, Ultegra Di2 hydraulic, Gates belt drive, da Vinci cranks, specialty paint—adds up. So while the base model was only $3895, what you see here goes for closer to $8600. That’s a lot of dough, but I’ll argue that for the rider willing to make the investment, the satisfaction that comes from seeing the perfectly dialed bike makes the outlay worthwhile. There’s no real substitute for having your kid say, “Oh boy, we’re going to ride the tandem!”
As captain, I have trouble hearing a missed shift, and my stoker doesn’t know enough to be able to tell me when the bike has missed a shift or if I need to trim a derailleur. It’s best if we just leave him out of the feedback loop and go with shifting that will simply perform correctly, always. That’s what Di2 does. And one of Di2’s best and least-lauded features is its ability to shift perfectly when under load and at a low cadence. It’s low-cadence shifting that makes me most nervous. That’s most often when I’ve broken chains. But the Di2 is as flawless as the face of Grace Kelly.
It looks like what?
Without belaboring the obvious, a tandem is a big thing. A whole lot of bike. So any color you paint it is going to make a big statement. You’d better like that color a lot. There are a limited number of standard colors, but as I mentioned, for an upcharge you can go with something outside of the stocks. Co-Motion does all their paint in-house and they’ve got a crack team that can do complicated paint schemes in addition to terrific fades as well as simple, one-color finishes. They’ve got more color choice than most companies, so the problem is less finding something you like than narrowing down which of the things you like most. That was my problem.
I brought Mini-Shred back to my computer one night and asked him to look at the colors and tell me which he liked best. He pointed to an orange and a teal. Co-Motion offers, among their Special Efx schemes, a riff on the McLaren Gulf scheme with a mostly duck-egg blue and some orange stripes. I decided to use the orange where the blue is and then use the teal where the orange is. I was pretty blown away when I opened the box, but the way Mini-Shred’s eyes lit up when I showed it to him told me I’d made the right choice.
Does he like it?
Most of you reading this have known for far longer than I have that kids are as fickle as subatomic particles. You just never know what they are going to want to do from one day—one minute—to the next. I’m fortunate that most days when I ask him if he wants to ride the tandem he says yes. Of course, there are days when I don’t even bother to ask; I just tell him to get his helmet. Runs to school or day camp are far more enjoyable, and they carry with them the added benefit of getting him some exercise early in the day, but that’s the stuff of another post.
I’ve got to be honest and say that communication is a bit harder with Mini-Shred being more than a foot lower than he was previously. With the child stoker kit I could talk with him with relative ease. Now I have to yell a good bit more. Mostly I find myself telling him to wait until we get to a light. It’s not a big deal.
There’s another feature of the Gates belt drive that no one talks about and you can’t appreciate it or even apprehend it until you’re on the road. Thanks in part to the super immediate engagement of the belt, when Mini-Shred turns on the power, I have a finer, more instant appreciation in his increase in effort and that tunes me into his desire to go faster.
To give you a fix on the minimum height a person needs to stoke with the PeriScope setup, Mini-Shred is 45 inches tall (probably 44 when we first started riding this thing), just tall enough to ride most amusement park rides. I had to insert the seatpost fully and insert the telescoping seat tube completely as well. The saddle literally won’t go any lower. Literally.
I’ve yet to really attack any of the area’s descents on this bike. I’ve tried one quick drop on my own, but that’s not the same as having another body in back, even if he weighs less than a big bag of dog food. The big reason I haven’t tried anything challenging is simple: Mini-Shred is intimidated by the combination of steep hills and high speed. As it turns out, 30 on a false flat goes over better than 30 on a steep grade.
I’ve always liked riding tandems because of the way the experience differs from riding a single with a friend. When you share the work, share the same line, the same pedal stroke, the ride becomes intimate in a way that no other form of cycling can replicate. In riding with my son he learns things about cycling that he wouldn’t learn if he was riding a trail-a-bike, or on his own. Being on the back of a tandem teaches him about holding a line, keeping his cadence up and pedaling consistently. On his own bike, he’s apt to pedal a dozen strokes and then pause. Riding the tandem is teaching him to keep pedaling—no sudden stops, either. We can go farther, and go faster, which allows us to see more.
Compared to the other steel and aluminum tandems I’ve ridden, this thing is smoother than 100-year-old whiskey. It is by far the most comfortable tandem I’ve ridden, and that’s surprising considering that it rivals the stiffest tandems I’ve ridden for resisting torsional flex. It’s a bit like budgets and cocaine addiction—one is the enemy of the other.
The Torpedo is also easily the best-handling tandem I’ve ever ridden. Part of the great handling owes to the advantage the PeriScope offers by keeping the stoker’s center of gravity as low as possible. I mean, it also helps that my stoker weighs a whopping 46 lbs., but regardless, the Torpedo carves turns in a way no other tandem I’ve ridden does. The key to enjoying riding a tandem is for the captain not to feel the weight of the stoker with every little course correction.
Final thought: Teaching your kids to ride is the bomb, but sharing the riding with them is even better.