We're engaged; let's get a tandem

I'm sure you're right about the thudbusters. It's just a shame they only come in one colour: a catastrophic shade of ugly.

Apparently the bump problem isn't awful, so for the time being we're going to try the B66S

And if that's still not good enough, combine it with something like this.

Careful, those heavily sprung Brooks saddles use a double rail so won't work with those seatposts.

Running the risk of making this topic more of an issue than it might be, but there's also this:

Review

Or this

Decided not to change the saddles after all, as Stoker Supercool told me to stop worrying about her and concentrate on avoiding the bumps instead.

Took the tandem for its first proper ride over the weekend - Brentwood to Bury St Edmunds, via Finchingfield. Forgot to take more photos, because I was too busy picking stones out of the brake blocks and repairing punctures after an ill-advised detour down a bridlepath.

The bolt upright riding position is comically un-aero, and combined with a turning circle to rival a London bus, it's a little like driving a dining table. Now I understand why tandems often have drop bars on the front and bullhorns on the back.

Not being able to get out of the saddle easily also means making much more use of the gears, which I'm not really used to. We lose speed remarkably quickly and pick it up remarkably slowly. #physicsinnit

Both massively enjoyed the ride though. Two days in Hampshire coming up next. Might need more luggage capacity than the double Carradice we've got here: Nelson Longflap on the rear, zipped roll on the front.

So cool!

Not being able to get out of the saddle easily also means making much more use of the gears, which I'm not really used to. We lose speed remarkably quickly and pick it up remarkably slowly.

Pretty much sums up my experiences with tandeming too, you really need to keep on top of the gears.

Yup, anything but perfect flat or downhill and we go slooooooooow. Quick variation of terrain, and sharp, small climbs are a total killer for us.

I think I'm living in the wrong country.

That was one reason I tried hard to get STIs on mine - too much shifting to be dealing with downtube shifters! Quick descents and then short ascents are a pain too, I can't find a good gear and it's so difficult to 'feel' whether you're picking up the bike or mashing your stoker's knees...

Good to know that mine are common complaints. The flip-side, of course, is that on a decent bit of flat, it basically feels like we're floating because it's so easy to keep this "bike the size of a sofa" moving.

But what I don't understand is why, on rolling terrain, we lose speed so quickly when starting a little climb after a long descent? On an individual bike, I'd basically use speed gained on the descent to give me a head-start on the hill; on the tandem this speed seems to evaporate into thin air.

Shouldn't being massively heavy mean that we keep this speed for longer? Pretty sure this is GCSE-level physics that I've forgotten. Who is stealing our speed?

Yeah, I know the feeling. I feel like there's a lot more resistance in general, if we are coasting through a flat section the tandem doesn't even come close to keeping its speed like a solo would. I know using Marathons like I do on the tandem doesn't help, but I do wonder if there's not more to it than just rolling resistance.

To talk about the good bits: long stretches of gentle undulation are a blast, we find our tempo and feels like we can keep pedaling forever, the bike roaring along nicely.

All the rest is a bit of a slog, specially loaded. I'm using STI's which do help a lot with gearing but I get why people favour Rohloff on tandems. Chain tension is insane when climbing, downshifting can be a bit scary.

#tandemgrouptherapy

Shouldn't being massively heavy mean that we keep this speed for longer? Pretty sure this is GCSE-level physics that I've forgotten. Who is stealing our speed?

Weight has nothing really to do with it.

Kinetic energy gets converted into gravitational potential energy. If it were perfectly efficient then:-

(We'll ignore the rotational energy of the wheels...)

1/2 * m * v * v = m * g * h

(g = gravitational constant of 9.8m/s^2)

The mass on each side cancels out and you're left with:-

h = 1/2 * v * v / g

So if you're in a vacuum and no rolling resistance then it doesn't matter if you're on a bike, skateboard, tandem or whatever.

But the KE to GPE transfer isn't perfectly efficient, the tandem will have a higher rolling resistance and higher drag coefficient. That's why you don't go as far up the hill as you do on a solo bike.

Something I've pondered is the loss of speed is due to the stoker not really being able to see in front. So changes in gradient don't register with the stoker as quickly as they do with the captain.

What speed gears are you running? Double or triple?

I would love to get STI's but we have hydraulic magura brakes so kinda stuck with the levers we have.

3 x 9, Ultegra cranks and front mech, XT rear derailleur, Dura-ace shifters. Best thing about it is the flight deck, so I always know what gear I'm in without having to ask the stoker to look down.

http://www.chainreactioncycles.com/shimano-rs685-road-disc-brake/rp-prod119977?gs=1&gclid=CjwKEAjw9OG4BRDJzY3jrMng4iQSJABddor1y8MxYRqAVGrEUraKxD3YKWjxf9_tlhF9NgoJZugTFBoCWaXw_wcB&gclsrc=aw.ds No problem

I believe the Maguras @Hovis is talking about are rim brakes...?

There are other terms in there too that have no mass dependence (e.g. aero drag) so you do end up going faster down the hill. It doesn't explain the sensation of losing speed more quickly up hill than with a solo (probably to do with a non-linear increase in rolling resistance) but I feel it's mostly a synchronisation problem. As @Hovis suggested, the stoker doesn't know exactly what's going on and, assuming you spun out down the hill, you both have a reduced sensation of what's going on with the freewheel. Is the resistance you feel the weight of the bike or your stoker? So you can't pick up the work as early as you would on a solo and end up dying a slow and painful death in your granny gear.

Nah, I'm just convinced a headwind blows just when we're on the tandem. As soon as we dismount it stops. As soon as we saddle up it starts again. Magic is my only reasonable explanation.

Yeah. Magura hs11 rim brakes paired with hs66 Road levers. Would love it if there is a compatible set of sti levers that would operate the same brakes

Also 11 speed on a tandem. I don't see that lasting long!

They use mineral oil, so you could use the yet-to-be-released tiagra 10spd shifters with it? No idea if the master cylinder is big enough, and I can't imagine 10spd on a touring tandem is going to last well either.
Maybe get some Kelly Take-Offs? That's as close as you'll get I think.

Oooooohhhhhh

Yeah. Magura hs11 rim brakes paired with hs66 Road levers. Would love it if there is a compatible set of sti levers that would operate the same brakes

Butcher some Di2?

I don't believe Shimano and Magura levers/calipers are interchangeable.

Took the tandem for a two-day trip round Hampshire on the first weekend in May (temperatures circa 10C) rather than the second weekend in May (temperatures circa 25C). Ho hum.

Only failed to climb one hill, where to my immense discredit, I gave up before Mrs Supercool. To be fair, I could see that the hill just wasn't ending; she couldn't see a thing coz she was staring at floor while hanging on for grim death.

Only problem seems to be with the new chain slipping on the new block - but only when riding in the middle ring. Totally confused, coz gear-shifting is otherwise smooth and there are no problems in the big ring or the granny ring.