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Help me lose a little weight(9 posts)

Help me lose a little weightPsychler
Aug 29, 2001 6:00 AM
I just built up my bike, I had hoped that the frame would weigh less than it does, but...purchase made, bike built...Some details:
Dean El Diente frame 56cm
Helium wheels
Axial pro tires
Ouza Pro fork
TTT stem/ bar
Full Ultegra w/ 12-27 rear (this I think is unnecessary)
I need a new post and seat...current is a cheap alum post with Vetta seat.
Can a lighter rear cog, seat post and seat make a major diff?
I weigh in now at 19.5 lbs...
re: Help me lose a little weightcyclopathic
Aug 29, 2001 6:49 AM
you can loose at least 1/2-3/4lb if get USE seatpost and Selle Italia SLR
going to 12-23 would save you weight too, but I don't think you'd get 1g/1$ return on it.

Other weight saving ideas:
- Dura-Ace BB (I assume you have doubles)
- Easton carbon Hbar
- Conti GP3000 supersonics (they last only a few rides, race only)
- ITM the Stem (ouch!)
- lighter pedals (Speedplay or Bebob)

will it make major diff? no it's not the bike it's engine.
USE seatpostTig
Aug 29, 2001 7:47 AM
I'll try one of these on my next bike. I would be cautious if I was a big rider since it looks a little fragile. It's the lightest weight stem for the buck ($130). I'm not a weight-weenie, but I do like trimming unnecessary mass. Here's the yada-yada from Excelsports.com:

The ultimate strength to weight ratio, it is quite possibly the lightest seatpost on the planet. Made from a superior quality fiber and using a weave pattern designed specifically for its application. Utilizing the new Alien clamp that offers ample lay-back and micro saddle adjustment. The finish is the natural fiber weave with a matte resin.
130 grams
re: weightcyclopathic
Aug 29, 2001 8:06 AM
I think people get too paranoid with extra weight.
According to analyticcycling.com 1lb less on 1.5mi 8% climb for 190lb rider (rider+bike+cloth+warter bottles etc) would make only 3sec, or ~35'.

Understood for some that would mean being dropped off peleton, still you only need to increase your power output by 0.5% to compensate it!

Said all above I lust for those beautifully made parts, sigh :-(
Bike weightSamDC
Aug 29, 2001 7:09 AM
Just curious, how much is the frame alone?
some advice...SamDC
Aug 29, 2001 7:25 AM
Dura-Ace cranks instead of the BB. I've heard the D/A BB wears out faster than the Ultegra. Just what I've heard, however. CF or Ti seat post would save a few grams. Ksyriums or Nucleons for the wheels. The K's are really cheap at probikekit.com (in England). Also, unless you're 1% body fat, you may consider losing some weight too. Realistically, though, the laws of diminishing returns are working in your corner. You're going to have to drop a lot of cash for a few grams.
Zaphros say:Zaphros
Aug 29, 2001 11:53 AM
must use light water in bottle. Also, Zaphros think that CO2 in tires too heavy. CO2 have molecular weight of 44, air only 29! Zaphros think nitrogen better-have molecular weight of only 28! Fill tires with nitrogen only!
Zaphros say:SamDC
Aug 29, 2001 4:55 PM
Actually, I think helium (He) would be the best; density of 0.1785 g/cm^3 vs nitrogen with 1.2506 g/cm^3. Also, non-reactive, however, maybe expensive...
It's Academic!!!!SamDC
Aug 29, 2001 5:41 PM
Well, being the academic engineering that I am, I decided to crunch a few numbers to see how much mass one would save if he/she rode with helium in their wheels.

Assumptions:
Tube is a torus with a cross-section radius, r, of 1 cm and center of tube to center of hub radius, R, of 35.05 cm.
Volume of torus is, V=2*(pi)^2*R*r^2, which turns out to be 691.859 cm^3
(See this site for more info on the torus.)

Mass density of helium is 0.1785 g/cm and for nitrogen (which is the majority component of air) is 1.2506 cm^3.

Therefore, after some math, the total mass for two wheels filled with helium is 246.994 g whereas for nitrogen is 1730.478 g. The difference is 1483.484 g or 3.27 lbs!!!! This is assuming one atmosphere of pressure (14.696 psi). Given more pressure there would be heavier wheels, but it was only an academic endeavor. Now it's up to all the REAL engineers/chemists to correct my mistakes/feux pas. Flame on!