Originally Posted by
TandemGeek
I didn't include the timing rings since we have daVinci cranks with the one-piece, spiderless rings.
Therefore, you have to compare the weights of the entire cross-over crankset & sync chain to get an apples to apples comparison between MegaExo type cranksets and the daVinci cranks + traditional ST bottom brackets.
My guess is, the total weight difference ends up being somewhere around 100 grams (equivalent of 3.5 oz of water).
Good point Mark. We switched from larger & heavier Polar 26oz capacity bottle to the mid-size 22oz Camelback (verfied by measuring cup test). Yes we lose 4oz fluid per bottle, but the bottle itself weighs quite a bit less too.
The Polars were much taller and a constant source of dripping water and sport drink on the frame. The more compact Camelback bottles have a top that locks & a squirt mechanism takes a bit to get used to while riding, but otherwise seems superior. The smaller bottle size solved access issues for the stoker that she had on both the tandem and her compact single. see:
http://www.bikeforums.net/showthread...1#post14467249
Overall, for the 4 bottles we switched out, that saved equal "empty" weight to the entire CDX setup, and quite a bit more when factoring in the water load.
Polar:
26oz capacity
146gm empty
total full weight each: 852gm
4x 852gm = 3408gm (3.4kg!) = 7.51lbs for full Polar bottles. Yikes!!
Camelback:
22oz capacity
100gm empty
total full weight each: 722gm
4x 722gm = 2888gm (2.9kg) = 6.37lbs <<< still, that weight is near equal to the 2007 Calfee frame!
Camelback weight savings (4 bottles):
empty: 184gm (.4lbs)
full: 520gm (1.15lbs)
Fun factoids:
The 4oz less per bottle in the Camelbacks has not been noticable to us from a hydration point. My take on it: the time it takes my stoker to use up 2 full 22oz bottles is about the max time she can handle between potty breaks
As always, the biggest weight diff is usually body composition. Reviewing photos in the link above will reveal a lot more than 1lb savings in the 2nd photo taken some 3 months later.