Progress on Schwinn Twinn Sport 10sp tandem
 

So far so good. The bike is nearing its final stages, for me anyway. There's a limit to how much you can improve a low-end bike like this, and I'm rapidly reaching it. It's already a better bike than its captain is a rider. The bike has gone from 52 pounds to 47. Maybe I should quit while I'm ahead.

Probably the only remaining change to make: Putting on the Shimano Megarange 13-34 freewheel when it gets here from halfway around the world.

Before:
http://www.Little-Acorn.com/pics/tandem33pct.jpg

.

After:
http://www.Little-Acorn.com/pics/TwinnSport10sp0.jpg
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http://www.Little-Acorn.com/pics/altus0.jpg
.
http://www.little-acorn.com/pics/crank0.jpg

. . .cut off that kickstand and you could knock off about another pound?

The kickstand is one of the reasons I like Schwinns. I don't just ride them, I have to park them too, in diverse places and often for long periods. Sure, it's a pound of weight, but it's a USEFUL pound. That's where I draw the line. Besides, it's the best-designed kickstand I've ever used on any bike. Even if it does hang down like that one does.

I decided to go with a 13-32 eight-speed freewheel for its smooth gear range (13-15-17-19-21-24-28-32) and versatility, and change the front smaller chainring from a 39-tooth to a 34-tooth to get that low gear back. With this combination (34 in front to 32 in back), I'll actually have a lower gear than the 39-to-34 combo it used to have. This freewheel is also dazzlingly shiny chrome-plated all over - the first bike bling I've ever put on a real bike.

And with the 52 large chainring in front and the 13 in back, man this thing FLIES down hills. Especially with my 250-pound posterior on the captain's saddle. My 9-year-old stoker loves every minute of it.

Now I'm going to have to get some 40-spoke or 48-spoke wheels for this thing (presently 36-spoke, not enough?), before I kill both of us. I'm watching the spoke tension like a hawk, having had a very bad experience with loose spokes and a steep hill on a JC Higgins in my childhood... when I was about the age my stoker is now. My predictions of "gentle riding around the park" are proving VERY inaccurate... ulp!

I have really enjoyed seeing the progress on your Schwinn. It looks great--Thanks for sharing!

Steve

I had an eye on a 12-32 8-speed freewheel on Ebay, figuring that was the best I'd be able to do. 34-tooth largest cogs seem nearly nonexistent except for those silly Megaranges. And after running out of gears with the current 13-32 8sp freewheel on a screaming downhill, I really wanted to at least get a slightly higher top gear for those long downhills. I figured 12 teeth was the smallest I'd be able to find in ANY freewheel - have to go to a freehub and cassette to do any better, which I didn't really feel like doing.

Was about to bid on the 12-32 8sp, when up popped a 12-34 7-speed freewheel a ways below it. it's a 12-14-16-18-21-26-34. Has ALL the high gears I want, and a slightly more rational path to the low gear.

The seller had indicated a Buy It Now price. It's now on the way. :^) And I guess I'll have to modify my .sig below, to 14-speed soon.

I'm also looking at resurrecting an old child seat for bicycles, that my now-19-yr-old son once sat in when he was two. It's one of those plastic things that mounts over the rear wheel on three struts. Not a bolt-on tandem wheel or a trailer. My other son (now two) might enjoy it.

The Schwinn tandem may soon be the family triple. No, no usage of the 12-tooth cog is planned when the third seat is occupied >:-O

What are you using for a rear brake?

A basic caliper. But the way we've been going down some of the hills here, I may re-string the Atom drum brake hub the bike came with with new spokes and and alloy rim and put it back on.

I originally intended this bike for low-and-slow rides around the park. But my stoker has other ideas, so eventually new wheels and a drag brake (as above) may be in order.

"I originally intended this bike for low-and-slow rides around the park. But my stoker has other ideas, so eventually new wheels and a drag brake (as above) may be in order"

Better hurry on these upgrades or forget them completely.....because......I see a new tandem in your future!!!
Have fun

Bill J.

Well, my stoker is only 10 years old, so I still have 51% of the vote. But it's a weak plurality at best.

My leg strength isn't what it used to be, so the only reason I have to put anything on my tandem's rear smaller than 14 is to go downhill fast. OTOH, going up hills has to be a study in patience for me. But I did run out of gears with the current 13-32 freewheel, going down a long hill on a bike path near my house. Disappointed both me and my 10-year-old stoker son - the pedals was a-whizzin, but we couldn't go no faster. So I started looking for a 12-tooth smallest cog, pretty rare among freewheels.

Other part of the story, is that I wanted a BIG cog for going the other way, up those hills. Turns out to be almost impossible to find a stoker's chainwheel smaller than the 39-tooth POS Sakae the bike came with (118mm BCD, yuck). So now two freewheels are on the way: A 12-34 7sp, and a 14-38 (yes, 38) 5sp for experimental purposes. The 5sp might wind up on my Super Sport, we'll see. But if I run out of gears with that 12-tooth on the rear, I probably didn't want to go that fast anyway.

The 7sp is 12-14-16-18-21-26-34, and the 5sp is 14-17-22-28-38. Not much smooth shifting available from that 5sp with such big gaps, if I can find a derailleur to handle it at all, but if I can't get up a hill with that, then I'm better off walking anyway.

A set of aerodynamic (sort of) tandem wheels is also on the way.

Suntour Alpine Gear Tech derailleur is what you need. Good luck finding one. I know because that's what I eventually put on my Schwinn Twinn 25 or so years ago. I don't have it anymore.