On a recent trip to Florida, I rescued this 3Rensho tandem. The seller acquired it in an estate sale and was not a bike collector. He was getting ready to send it to the scrapper because he couldn’t find a buyer. I bought it and had a local shop ship it to my home in New York City, where it’s currently blocking my hallway. I've never owned or restored a tandem before. I don’t even have much experience riding one. My wife and I rode one for an afternoon a few years ago when we stayed at a bed & breakfast and discovered an old trek MTB tandem in the shed behind the house. We enjoyed it and I’m hoping to get this one restored and ridden.

Here’s a photo of a similar one that another collector I know restored and used to ride:


Any build suggestions? It uses canti brakes, but I was wondering if Magura hydraulic rim brakes that mount to cantis would work better. Although, would that spoil the look of the bike? The parts that are on it are a very nice set of Sugino Maxy tandem cranks, Tange hedset, a rusty timing chain, tubular wheelset with 7-speed Shimano freewheel (or maybe a cassette; I didn't look too closely). Definitely going to replace the wheelset, no reason to change the cranks though.

I'm wondering whether it might be better to build this as a "neo-retro" with a 1x wide-range cassette, possibly a SRAM wireless rear derailleur. I'm also considering whether to go with an upright position with swept-back handlebars for the riders. As-is, it looks like this was originally designed and spec'd for road racing. However, my wife and I will be riding this around NYC neighborhoods, and maybe some century rides, but definitely not racing. Comfort and simplicity are the most important build considerations.

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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FWIW the 35mm GP5000 is the tubeless GP5000S TR.
The 5000AS is also tubeless.
No reason not to run a tube but they might be a tight fit on some older clinchers rims.
YMMV

bulgie thank you for the detailed response! I'm hoping to avoid having to install an extreme setback seat post, as it puts the stoker way out over the rear wheel. But, as you can see from the photo of a similar 3Rensho tandem, it has exactly that setup. In my case, I'm hoping my wife, who is about the same height as me, will be able to fit comfortably. I agree that a flat or very very slightly swept-back riser handle bar in the back is probably the best choice for the stoker.

Speaking of tire width, I'm toying with the idea of building this bike up with 650B wheels. I did some preliminary research and it seems do-able, although I will need to install a gizmo that lowers cantilevers a little bit. I'm not going to have a frame builder make any changes to the bike. Other than the canti posts, do I need to worry about the change in BB drop?

We owned a tandem for 10 years back in the mid nineties. They are a particular taste and as a couple we quickly preferred individual bikes again especially as my wife’s confidence and fitness evolved.

My point being is before you sink substantial cost which will very likely not be recoverable, you should confirm tandems are for you. As bicycles have become more user friendly the demand and use of tandems has died off. Now with e-bikes, fitness differentials are no longer an issue either.

i've only ridden a tandem a few times, and with my wife, only once. Every time was a lot of fun, so I'm optimistic that we'll enjoy it. If i'm being realistic and honest, it will probably be a PITA given that we live in an NYC apartment and have plenty of our own bikes to ride. However, between the novelty and the fact that I am a collector of 3Rensho bikes already, I couldn't pass up the opportunity when it came along.

My wife and I are both in our mid-sixties, we were on our tandem-mounted honeymoon exactly 38 years ago, and still ride tandems today. We borrowed a couple hotel bikes this morning as we are traveling, fun but just not as fun for us. E-bikes are great for commuting, schlepping kids or groceries, and carrying a surfboard if you live by the coast, otherwise a bike for poseurs. If you and your wife can communicate effectively, tandems are a blast AND fast.

Contemplated a 3Rensho that was available in SF Bay Area for pretty cheap but had just purchased a Bruce Gordon tandem needing some TLC so I passed. The BG is a lovely mix of lugs and filet brazing. The BG joins the filet brazed Rodriguez that we used on our honeymoon, a similarly filet brazed Ritchey Palo Alto, and our Burley Pub Crawler (christened and labeled as such when new in early 1990s). Tandems are just so cool so advice from folks who couldn’t adapt or lost the joy should be taken with caution.

This is a bike you don't know and a type of bike you don't know. I suggest you ride it a fair bit before investing in changes. It might not need changes. My spouse and I ride a tandem. It has two regular cantilever brakes. I was concerned that they might not be enough but they absolutely are. Maybe it helps that we are both lightweight, with a total body weight of 270 pounds. Even if we were heavier, our brakes would suffice. And we have ridden in hilly country.

I got the tandem in hopes of equaling us out since I have more stamina than she does. Making the pedaling easier should help her last longer in the saddle. Well, it does even us out but not in the expected way. Handling the bike is hard for me, especially my arms and shoulders. I have less stamina on the tandem than on a single bike. But you may not have that experience. I know I need upright handlebars on a tandem even though I like drop bars on a single. Drop bars on a tandem are terrifying for me. I guess I have weak shoulders.

Thanks for the advice, all. To reiterate, I only have the frameset, headset, cranks, BB and timing chain. The rest I must source and build.

any feedback on the idea of using 650B wheels instead of 700c? Beyond the need to throw adapters on the canti posts, of course.

That sounds a lot like our experience. I thought she couldn't get left behind if she was on the same bike. I could ride the tandem alone and it felt like a heavy mountain bike, but when my wife got on, it was a handful just to keep it going straight. We were both much happier when she got her own properly sized road bike. The Mafac cantilevers on our Peugeot tandem have plenty of stopping power. The Atom drum brake is more of a speed attenuator for long down hill stretches, which are very rare in northwest Ohio.

I'm not aware of those adpaters, can you share a pic or a link?

Maybe some, especially if the BB is low-ish already with 700c.
If you can fit 42 mm tires (not likely), then the height will be close to the same as with 700 x 23c.
622/2 = 311 + 23 = 334
584/2 = 292 + 42 = 334 (though that neglects increased sag from lower tire pressure, so the 650 is still a bit lower)

42 mm tires are heavenly on a tandem, but you generally need chainstays that are both indented and longer than modern racing bikes. Unless they're curved like a MTB. The only 700c racers that can be reliably converted to 650 x 42b are older, like early '70s when stays were longer and indents were still common. I have currently in the shop two PX-10s that fit 42 mm, a '69 and a '72, and a '74 Moto Grand Record fit's 'em too. The '71 Raleigh Super Course hanging next to them would not fit over about 35-38 though, despite the long stays, because they weren't indented. (I fixed that, by indenting them.) So you need both long and indented, unless curved, a feature no road racer has.

So it's likely you will top out at 32-35 mm, maybe 38 if you have indents in the chainstays. So you may lower the bike by around a centimeter. Whether that's a problem for you depends on crank length, Q-factor, and whether you like to pedal though corners. Q-factor doesn't have a huge effect but it's worthwhile trying to keep the cranks as narrow as possible, because excess width contributes to pedal-strike likelihood when you lean it over. There's also increased risk of "high-centering" due to the long wheelbase — you may hit from riding up or down a curb, or even some speed-bumps. So level the cranks when crossing them.

My wife hated being a stoker but the kids loved it. I installed a child stoker adapter for when they were 7-10 years old and they took to it no problem.

That said, when the tandem got “misplaced” in a cross-country move, I got a settlement but there would not be another tandem purchased.

bulgie As a test, I will take the wheelset off my randonneur bike (650B with 42mm Grand Bois Hetres) and see if they fit on this tandem. Then I'll check it with a 700C wheel to see what the max tire clearance would be there.

Thank you for the advice - I have a good path to figure this out, now.

OK, Couple of things.

A) really cool. I love the craftsmanship oh Konno's bikes.

2) The idea of a Japanese built tandem weirds me out a little. Tandems were illegal in Japan for years. Santana has a video of unearthing an unridden one and fighting to get the law changed, which they did, in the last 10 years.

C) How is the Stoker's bottle cage attached on the restored 3Rencho? I'd love a close up.

For my Colnago, I used the brackets off 2 aluminum kickstands, filed them a little for fit and lined them with electrical tape as to lessen the chance of marring the frame's paint and GENTLY tightened them to hold a cage. What did they use?

D) When it comes time to fit a stoker stem, please contact me. I've collected a silly box full. I ended up using a Specialized/Santana made by Nitto I'm using. I have plenty more of those in various lengths and angles. Just send back the ones you didn't pick.

You got my number.

I see braze ons I don’t know their use. Like this:

In response to "C" I didn't have a better photo but after asking the former owner, "It was some kind of rigged custom set up…I want to say it was 2 p-clamps looped over the tubes with a bolt through the cage and all 4 holes with a nut on the back." Note that the braze-on you circled above is a shifter or brake cable stop.

On "D" I was definitely be in touch and I really appreciate the generous offer. Figuring out stem lengths is always a process, and having a bunch of options "straight out of the box" will be a huge help. I'll follow up over text or phone.

I fear that those will not work on the 3R, they require the type of canti bosses where the part that goes through the brake is removable. The frame needs to have 10 mm female threads there. Maybe those could be mounted out at the ends of your current bosses, with 6 mm screws, but that would put the brake that much further offset back away from the stays, giving the brake huge leverage for twisting the stays. Maybe a booster arch could take out that flex enough for the brakes to work, but it's going to look Rube Goldberg, and the cable line from the housing stop to the straddle yoke will be suboptimal. And I'd worry about those 6 mm screws doing the job that is supposed to have 10 mm. There will be a bending load on the screws

I'd love to be proven wrong though. Please keep us updated if you make it work.

I think that's for a sidepull brake that mounts to the bridge on the mid-stays. I think I see the round flange on the bridge that would be for a brake.

Maybe that could be the answer to the 650b conversion dilemma. Just ignore the canti bosses, and have your only rear brake be on the mid-stays, something long enough to reach, like a Tektro r559 or Mafac Raid. Dia-Compe 750 centrpulls, since they're Japanese? In front, sub in another fork that doesn't have canti bosses in the way, so you can use any brake you want, bolted through the crown.

bulgie thank you for the sanity check on the extenders. You are correct that they require removeable canti posts and therefore won't work with this tandem. After a little more research, I think a set of Promax v-brakes or Paul Motos will have the extra reach to accommodate 650B wheels on a 700C bike. At least, that's the consensus on the internet. Once I actually mount a 650B wheel to the frame, I'll see the distance and then see whether it's feasible with one of those brake models. As for the center pull / changing out the fork idea, I'd prefer not to make that level of modification to the bike just to get 650Bs to work. If I can't come up with a workable and safe approach with a set of V-brakes, then I'll abandon that idea and stick with 700C wheels.

Hate to break it to you but the internet consensus is wrong. A canti/V with more adjustment range can let you put 700c on a 650b bike, but not the other way. Of course that doesn't happen very often but more often it's using 650b on a 26" (559) bike. But always where the rim is higher relative to the posts, not lower.

You can usually go a few mm lower, like 700c wheels on a 27" bike, which is only 4 mm. But even then, some 27" posts are just too high to work with 700c, without angling the pads funny.

Sounds like this bike is not a good candidate for 650 conversion. I understand your connection with 3Rensho, but if you just want a good tandem experience, you might be happier with something made for bigger tires, maybe a Co-Motion, Santana or Cannondale (ugly but good). Even a Burley, not the old one with the BMX-like loop stays and combined downtube/keel tube, but later when they went to proper tandem tubing, those were an amazing value.

Quality used tandems are ridiculously cheap these days — not good if you're trying to sell one. Some people report not even being able to give them away.
How about this one, Co-Motion on ebay for $269, frame fork headset two stems and two seatposts. Custom adjustable rear stem! Co-Motion is my favorite brand (aside from the ones I made of course).
Or this Santana, complete bike for $199 !?!

Then again, just riding the 3Rensho with whatever 700c tires it can fit will be a thrill. Generations of tandem people have had a ton o' fun on bikes with tires that were too skinny, and they didn't know they were supposed to be miserable, blissful in their ignorance.

There have been numerous attempts to walk you back on this adventure. Tandems are a very particular subset of cycling which needs to be taken in account. As modern bikes have become easier to use and more comfortable, and with e-bikes now readily available, demand has collapsed. Very few people are active tandem enthusiasts, and that number is diminishing steadily for a reason.

My recommendation is to either make it rideable as cheaply and easily as possible, without sinking too much time or money into it, or restore it to its original condition as a collector's piece. If you are seeking a good rider, this is the wrong base to start from.

One last thing, the double crankset is an issue as well, tandems are notorious slow climbers and need low gearing. Unsure if that will be possible with the existing crankset.

Bulgie to the rescue again! Thank you for saving me more trouble. You're the resident expert on 650B conversions, so I trust your advice and will drop this wild goose chase. You're right that 700C wheels will be fine.

I think I can assemble the bike cheaply. i have the brakes and drivetrain already, and just need to add a 700C wheelset, stems, seat posts, saddles, brake levers and bars. Most of this can be acquired cheaply at either the NYC Bike Jumble (next weekend!) or via AliExpress online. I'm not trying to restore it to original condition, just get it rolling and have some fun. The crankset is 110 BCD, meaning I can use very low gearing. As mentioned above, I'm going to go 1X for the crankset (narrow-wide 42T chainring from Velo Orange) and an 11-speed, 12-46 cassette in the back. That should give me plenty of range for the relatively flat roads I'll be riding around New York.

A shop near me has a 3Rensho tandem on the wall. Looks to be built up with Campy 8-speed and a Specialized crankset. I took a few photos for reference...



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Lovely green 3Rensho on display, looks to also have the cable guides on the lateral…as bulgie indicated, looks to be routing for a third brake, an inverted sidepull. Two cable brake levers, Mafac or DiaCompe, aren’t hard to find and putting a brake like that would look cool…and seeing the green display bike, I would be inclined to go more period-correct… but not my bike nor my money.