Tandems of the forum

Me and the other half have joined the club, just sitting in Manchester Piccadilly station waitin for my train back to laaandan after picking up a motobecane inter club that's had one owner from purchase in 1980, they even had the original ma fac tools that it came with. I'll post some picks later.

In other news, it cost me a fiver for a bottle of black sheep in the pub, bloody Manchester the London of the North (says cheap Yorkshire man)

Love <3

Love <3

Nah, he hates me so much he could only stand to be on it for a bit under 21 minutes.

Edit: Showed that pic to miss.ua and she said it "looks almost intimate" :-|

It was a bit longer than that after you missed the turn back to the HQ...

you missed the turn back to the HQ

What happened to your pace notes then?

So this is the (not so) little beauty I picked up from Manchester on Friday afternoon. Needs new cables and a little attention to some chips in the paint, but otherwise it's in fantastic condition. Looking forward to a first ride!

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wheee another member of the early '90s Super Galaxy club.

Had a ride on a friend's last weekend, it was glorious! We were this close to a similarly old Orbit (531 too) but the prevalence of the Dawes makes me more confident doing weird things to it.
What brakes are people running on these - canti, side pull (probably dual-pivot) caliper or the centrepull caliper (a la Weinmann)?

V's on mine.

Mini V's or full size with a travel agent?

What's the best tandem frame design? Yesterday we had 4 different basic patterns on show.
Double Marathon:

Double Diamond:

Direct Lateral:

Marathon:

full size, with long-pull levers. Tektro RL520 I think.

I've been wondering this lately, for reasons. What is your thinking?

BC appear to use double diamond

What is your thinking?

It's clearly not a problem with a unique solution, all four of those designs plus ones with no lateral tubes at all can be built into good frames.

BC appear to use double diamond

Or Marathon, or Direct Lateral, or no lateral, depending on which crew and event you look at.

Excellent. Then any hypothetical thinking will instead be informed by the cost of S&S couplers...

Ah ok. Bar-end shifters then? Was going to go with STIs.
Anyone on here got experience of V brakes through travel agents/a spare set I could borrow to try out?

I've got mini Vs and they work ok-ish with regular pull levers (tektro RL340). Got the drum brake on the back for extra peace of mind.

I would think a double diamond would be stiffer vertically, but less stiff laterally than the other variants. I'm tempted to knock out some quick FE models to find out.

awesome haha!

I'm tempted to knock out some quick FE models to find out

Good luck with the optimisation. You have up to 15 tubes, for each of which you can choose the diameter¹ and wall thickness². You have at least 5 different main topologies to dispose these tubes. All that's left then is to find the least amount of material required to achieve a given stiffness.

¹Major and minor diameter separately for elliptical tubes, plus the option of having the major axis vertical, horizontal or transitioning from one to the other along the length of the tube.

²Which can also be varied along the length of the tube either as a continuous taper or a series of butts.

³There's a footnote 3‽ Yep, the tubes can be tapered in diameter too. Or they can be shaped in almost any way other than circular/elliptical, possibly varying along the length.

Ha. I was just going to use the same nominal tubing for all of the arrangements using a beam model...

In which case, my money is on the heaviest one (double marathon) being stiffest :-)