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djconnel wrote:I'm sure the brakes will be adequate. Still....
Oh, I see what you are getting at Dan. Our team mass of 305 lbs. The Captain's 6'0" and Stoker 5'10", with BMI's of 23.7 and 18.9 respectively. So, if our team mass has Dan concerned, it is due to Ritterview, not Mrs. Ritterview.
The eebrakes decelerate a tad more than the Shimano 7900's, and no one would quibble over these.
The brake concern is not over effectiveness but carbon-melting rim heat. If we to be doing the Davis Double or any other hilly rides, the rear ee brake will need be replaced with an Avid BB7 disc (which will add about 370 grams).
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Basically for a given stopping power, deceleration is inversely proportional to total mass. The total mass of the bike isn't double the comparable single, but mass is dominated by riders, and in this case the total mass is comparable to two typical adult riders. So basic physics, you'd expect half the stopping acceleration on the tandem. The EE brakes stop very well on the single, but if you consider it's stopping double the mass, it's stopping acceleration will be less than that of the poorest brake in the VeloNews test (which was AX-Lightness, followed perhaps by KCNC).
So the EE will feel less powerful than AX-Lightness feels on a single.
For Low-Key, though: perfect! I'll see you there !
BTW, I love that you went with the DragonFly high-modulus option. We're in serious $/gram saved territory here. No skimping here, but you only live once...
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Powerful Pete wrote:If you will be doing serious hills (and descents) wouldn't you want a double disc setup?
A tandem with two discs would never be eligible for a post at WW, each Avid BB7 weighs 467 grams, and the disc hub and fork add still more.
A single rear Avid BB7 and a strong front caliper is generally felt to be adequate for hills. For example, uspspro at the BF Tandem forum just finished Everest Challenge on his Calfee Tetra with this set up, and he felt it was adequate.
uspspro wrote:...I installed the Avid Clean Sweep G3 rotor, and got some new EBC pads. I am pretty happy with the brakes now. There was a very technical and steep descent at the top of the last climb of day 2 of EC. The brakes worked fine.
As far as technique, not much different than before, except that I use the rear brake more that I did with full rim brakes. Rear brake does most of the slowing, and front brake provides power for turning-in.
djconnel wrote:So the EE will feel less powerful than AX-Lightness feels on a single.
Which is why I'll eventually get a rear disc, note that the rear hub is a DT240S disc. First I'll enjoy the bike with the two ee brakes on the likes of Canada Road, but as soon as we start doing hills, the bike will sport a BB7.
TheBugMan wrote:That looks like a bullet train Ritterview. Almost as light as my single seater!
Yeah, well that is just the spreadsheet weight. We'll see what the real weight is soon I think, and hopefully it won't be embarrassingly higher. Madcow thought it would be between 23.2-5 lbs.
djconnel wrote:were're in serious $/gram saved territory here.
Don´t forget they can split the bill
Btw it wasn´t my intention to start a campaign against those brakes, if you trust them just ride them.
To see if i still feel
I focus on the pain
The only thing thats real.
my introduction here:http://weightweenies.starbike.com/forum/viewtopic.php?f=10&t=63830&start=0 UPDATED!!
Ruegamer is down, so isn't an option right now.
But Calfee says "with a fame weight of less than 6 pounds, the Dragonfly Tandem weighs in as the world's lightest tandem!" (6 lbm = 2721 g).
added: I'm not able to view the photos anymore. I need my bike porn fix . I believe the problem is flickr uses temporary URLs.... imageshack.us is better. For flickr, link to the HTML page associated with the image.
That is super, super cool! Love in! Congrats on such a fantastic build!
Is it hard to co-ordinate yourselves when you're both out of the saddle? I imagine you have to do it at the same time? And, as someone who has never used one, can the rear person simply kick back and freewheel?? As I'd LOVE one of these at some point down the line....but my gf has a fear on them after stacking one years ago when riding with her sister. Dammit! So now I have psychological scars to try and ally before she would even entertain the idea....
djconnel wrote:A few things: (1) I didn't realize Super Record 11 front shifter ran with a triple crankset.
It doesn't, officially. In fact, I had been planning to switch the SR11 with the Record 10 from my BMC. However, to the surprise of both Madcow and myself, the 11 cassette fits on the DT 240S, and the RD shifts just fine. Not so, however, for the FD, which is a 2006 pre-Quick Shift Record, which doesn't like the QS shifter. I'll have to figure out what to do with that, the default being to use 2009 Campy Comp Triple FD, which is a shame as it is hardly even Centaur level.
The Ruegamer Uberlights were light but we don't know at what stiffness penalty. The more apt comparison is the standard Ruegamers. Probably the ultimate (as in the last) Ruegamer Tandem was Whereswaldo's standard received in April. It weighed 2.68 kg (5.91 lbs) painted.
Making this tandem light would be a lot easier with a 5.91 lb frame. It would project to 21.67 lbs. Edge 45 2.0 tubulars would save 290 grams, and get it down to 21 lbs even. Now, if this were a djconnel sized frame, it would be bordering on sub 20 lbs. But alas, Reugamer is no more, and Calfee has a carbon tandem monopoly. Would Parlee be interested in making a carbon tandem? Nope, I already talked to them. Too expensive to make the molds they say.
The Calfee web page may wax a bit optimistic about their weights. The Dragonfly's weight came in roughly what Calfee had predicted to me prior to its being built. Calfee weighed the frame nude at 2930 gm (6.45 lbs). It was painted, and shipped to Fairwheel, where it weighed 3210 (7.08 lbs), gaining 280 grams. That seems like a lot for the clearcoat, maybe Fairwheel included the 116 gram eccentric in the frame, that'd be nice.
djconnel wrote:added: I'm not able to view the photos anymore. I need my bike porn fix . I believe the problem is flickr uses temporary URLs.... imageshack.us is better. For flickr, link to the HTML page associated with the image.
Geez, I've had problems with these images. Thanks for the Imageshack tip, it seems to work fine and will now be my default.
The bike is a work of art. Super Record? Amazing. But it would look even better were it a Crumpton or a Kirklee. Too bad those guys don't do tandems.
For me, if I get a tandem, it seems like the Ritchey Breakaway set-up is perfect. In fact, you should be able to convert a Breakaway to a tandem with a middle frame segment. Obviously not nearly as light as yours, but much more portable. Mikkelsen in Alameda works with Breakaway couplers. But now we're talking steel, not carbon....
Anyway, you're bike is amazing. I can't wait to see it.