Cool bike! I hope you'll have a lot of fun with it.

Some people wil tell you you need a drag brake in addition to the cantis, but I'm a longtime avid tandemer whose never had a third brake, 2 rim brakes only. Maybe consider V-brakes, especially good ones like XTR or Paul. V-brakes need long-pull levers though, as I'm sure you know, which limits your choices, unless you combine regular-pull levers with Travel Agents that increase the cable pull. But if you use Travel Agents, be sure to inspect the cables frequently where they wrap around the pulley, which is too small to prevent the cables from fatiguing. Luckily cables don't break all at once, so you'll get a little advance warning, just replace the cable immediately when one of the little wires breaks. They're in an easily-visible spot, so inspecting just means looking at it for a sec before every ride (and maybe mid-ride too — the stakes are high).

One thing that I think helps, worth considering, is deep-V rims of some sort, we use Mavic CXP30. That shape is stiff and strong, but it's also better at transferring heat to the ambient air, just from being bigger, more surface area. We use 36 spokes F&R but I know a guy who had good results with 28 spokes on deep-V rims from FIR, even deeper than the CXP30.

Remember if you sit up more, which is fine for slower riding and sight-seeing, it puts more weight on your butt. For people whose 'saddle area' is the limiting factor on ride length, a bit of forward lean and weight on the handlebars might make the longer rides more pleasant. Oh wait, now I'm just talking cycling in general, and you don't need help with that. I can presume you have your own position on the bike worked out. But remember that on a tandem with a short-ish rear toptube (RTT), if you sit up more, it might force her to sit up more too, if her head is hitting you in the back. (It may not be, depending on factors like your relative heights, but this often is the case)


(Not our tandem, hadn't built us one yet, this is a loaner) (You can tell it's early '80s by the Skid-Lid "helmet") (Seattle Times photographer chose this pic over the one where Laurie also sat up and we were both no-hands, but holding hands. I guess he liked the one with Laurie's tongue sticking out. It was used in an article titled "Bicycle Dementia", so...)

On virtually any vintage tandem, a too-short RTT prevents stoker from getting a normal road-bike position. Most high quality modern tandems have finally "gone long" and let stokie stretch out, but I think yours is on the short side. Things that help include a short stoker stem, but that can put the bar into the space occupied by cappy's butt and thighs. One solution I've seen is straight bars, like MTB with little sweep or pull-back, and clamp-on bar-ends (the climbing handles not the shifters). Any sweep or pull-back on the bars is reducing the effective RTT.

Another trick for short rear toptubes is seen on the other 3Rensho pic you shared, a lay-back seatpost for longer effective RTT. It gives the stoker a shallower effective seat tube angle, but most stokers adapt to that no problem. In the extreme case, tandems with very short RTT, stokie might hit her knees on the handlebar if she tries to pedal while standing. I don't think yours is quite that short, but it may be that climbing standing feels awkward for her. Tandem riders tend to stand less, because it requires coordination between the teammates, but being able to, at least for short spells, can relieve the saddle issue. I wouldn't want to give that up, so don't put stokie's bars too far back. You need to lean forward a little to stand on the pedals.

Since I outweigh my wife by a lot, her standing while I sit doesn't affect me much, I don't mind it. I can't really stand without her standing though, because I need to rock the bike right-left a bit for efficient honking. So when I want to stand, I either say so, or more often just use body language: I start to rise, just sort of hover a half-inch off the saddle for a second which Laurie knows means "please stand". Oh and I usually shift to a higher gear first, since standing works better with a lower cadence, so she gets two messages that we're about to stand. Then when we're done standing, I sit first. She tells me when she's going to stand, so I don't do anything crazy while she's not connected to the saddle. But other than while hard cornering, she can stand any time. You guys will figure out what works for you, but don't be discouraged if standing is too weird or difficult. Most tandem teams take a while to learn that trick. One day it'll feel easy and natural.

Stoker seat on a tandem is always a bit less comfortable for a few reasons, so stokie's undercarriage might be the limiting factor in ride enjoyment. Many tandem teams use a suspension seatpost like Thudbuster. That doesn't allow the lay-back post idea though, no sus posts that I know of have a large rearward offset, so you probably have to choose only one of those mitigations

Obviously using the fattest tires that'll fit is an easy way to improve stoker comfort. If you care about low rolling resistance, consider the new Conti GP 5000 in 35 mm, which Tadej just used in Paris-Roubaix. Oh wait, Conti isn't showing that size on their website yet, they say GP 5000 tops out at 32 mm, which is what I have on my tandem. If/when the 35 mm variant comes out, I may consider upgrading, even if it means taking the fenders off. This tandem is a sunny-day bike for us, so it might be worth it for fatter rubber. Of course your bike may allow even wider than that, but alas my tandem was made for racing. Space between the chainstays might be our bottleneck, and if so I'd consider having a framebuilder indent the chainstays for more clearance there. Wider tires are even more of a must on tandems than on singles. And even the pros are starting to use 35 mm tires on singe bikes, then clearly tandems in a perfect world would all fit 45+ mm. But we muddle through with what fits.

EDIT: I see now that Continental does have the All-Season variant of the GP5000 available in 35 mm. If your bike fits 35 mm, that would be a good choice for a tandem, a bit heavier and presumable a skosh more rolling resistance, but stronger and more flat-proof. Probably better for anything other than actual racing.

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