dsb137

How much do you think that would reduce the weight of a bike? ....

***DISCLAIMER*** I'm at work and _VERY_ bored...

Soooo.... I went to CC's website and did their extra stupendous configurator thingamabob and put in _exactly_ all my pieces parts and low and behold:

C-50/Record -> 6784.8g (14.9#)
on my scale it weighs 18.1#

Marcelo/Chorus -> 7471.8g (16.4#)
on my scale it weighs 19.25#

Gotta be helium....

Mind you, I couldn't care less... Bikes are for riding, not weighing, I just find it curious that the're _that_ far off...

Trogon

You're not suggesting that the bike part weights used in online configurators are incorrect, are you?

Because if you are, I'd have to say you might be on to something.

dsb137

I know... I know... Just call me Captian Obvious...

Trogon

I think you and I should work together to report this to someone. But who?

dsb137

Can't you just hear the phone call?

Hello CC?
-Yes...
You sent me the wrong bike...
-Really? let me check...
-It says we sent you yada yada yada, isn't that right?
No, I ordered the 15# yada yada yada, you sent me an 18# yada yada yada... I'd like to exchange it for the 15# yada yada yada...
- <crickets>

Trogon

I had a huge disagreement with a guy on line over the CC calculator. We both had the same lugged steel bike with identical builds. His was one size larger I think. He was going on and on about his 18 lbs. lugged bike and I'd actually weighed mine in at 20.2 lbs. I wasn't trying to be a porker, but I pointed that out. He printed out the entire CC work up to prove I was wrong. In the end, I let him go away happy in the knowledge that he had the lightest 58cm lugged steel bike in the US.

dsb137

Let's hope for his sake that he never puts it on a scale... It's hard to dispute imperical evidence...

spinnaker

You're assuming that your scale is correct. If you are using a standard bathroom scale, they can be very inaccurate. There is a 2-3 pound difference between my scale an the one at the gym.

If it is another type of scale then when was the last time it was calibrated?

Retro Grouch 

Every bike has three weights: What the manufacturer says that it weighs, what the person who owns it thinks that it weighs, and what the scale says that it weighs. That last one is almost always greater than the other two.

khuon

One thing to note is that weight does not necessarily equal mass. You are decreasing the weight slightly because helium atoms are less massive (4 gm/mole) than the atoms of other molecules that make up air (28 gm/mol) but the volume is small so the actual amount of mass reduction is not all that great. However, you are decreasing bouyancy which is partially what's being measured by a weight scale.

DannoXYZ 

And decreased bouyancy can have a negative impact on cornering-traction as well. You'll lose traction at a faster rate than you lose mass...

dsb137

Good point... I like that... I just got one of these Ultimate scales, which is what started all of this mess... You should never ask a question you don't _really_ want to know the answer to...

cydewaze

Maybe you're forgetting to weight each component, then round down to the nearest pound.

dekalbSTEEL

Grease......you forgot about the grease. That $hit weighs a ton.

dsb137

Sort of like 'the whole is greater than the sum of the parts'?


Nah, I use lithium grease... cuz lithium is 3rd on the periodic table, only helium and hydrogen are lighter...

cyclintom

EXACTLY.

My C40 with all carbon parts, Lance saddle, Kysriums SSLs and carbon bar and stem weighs in at 17.9 lbs.

I could make it a little bit lighter but not without starting to use parts too light for my 200 lb body which I do have rather high regard for.

I suppose that using all the right components - the latest Look frame and fork, Record components save for the Zero Gravity Brakes, CARBON BARS (which are a little heavier than Aluminum bars but a bit safer), that silly carbon-only saddle, those silly wheels with kevlar spokes that break spokes all the time, and some other really expensive and not very reliable but ultralight parts - and you could probably make a 15 lb bike.

And it would cost at least twice as much as my C40. And truth be known, the FASTEST bike I have is the steel Merckx Corsa 0.1 which weighs in at 24 lbs. And when you're coming down a superfast, twisting, bumpy hill on the Merckx you don't have that nagging doubt in the back of your mind. Same with the steel Basso Loto which comes in at 21 lbs.

Don't be fooled by weight. After building that light bike you still put another 5 lbs of water bottles, pump, saddle pack and speedometer on it don't you? I'm betting that you buy COMFORTABLE shoes and not light ones. Do you second guess the weight of your clothes - especially on a cold day?

And I don't know about you but I LIKE a donut and cup of coffee in the morning. My weight swings from 200 in the Winter to 190 in the best of Summertime dreams. And my best climbing weight is below 188 so I haven't seen a good climb in 10 years.

When weight weenies start talking about the weight of their stuff just smile and nod.

munkyv22

OK, so I checked it out.

My bike weighs 16.9 Lbs with air and 16.9 Lbs with helium.

What a waste of helium.

stea1thviper

my bike weighs 17.3 lbs with air and -1.2 lbs with helium. gotta say that helium really does make my bike lift off the ground. am i still uci legal?

mollusk

You gotta ride with the tires absolutely flat so that you minimize weight. Instead of a floor pump I use a vacuum pump.

The G

100% Nitrogen is a far better gas for tires. The tubes as less permeable to it's molecular size, and it has less temperature variabilties. We've used this for years in Stock Eliminator drag racing. It maintains more stable pressures throughout the day mainly because it's usually a drier gas, without humidity. However, it's no better than watching your tire pressures and not worth the effort. The gas weight differences even in a 30"x9" drag slick on a 15" rim aren't even measurable.

Don't forget, Sea Level pressure ambient air is about 78% N. About 2-4% of the total weight of this air is water vapor depending on where you live.

5 more pulls per group ride = burning more kj

NJWheelBuilder

WHAT? Since when are carbon bars "safer" than aluminum? Have you uncovered some safety data that none of us are aware of?

I_bRAD

Did you include fasteners in your calculation?

My bike weighs less in Mexico city than it does in San Fransisco.

spinnaker

????

Grams vs. pounds????

Altitude**********

Cheap Mexican scales???

I_bRAD

Gravity gets weaker as you get farther from the center of the Earth

michaelmc

There would only be a 6g difference in measured weight of a nominal 9072g (20 lb) bicycle between San Francisco (60 ft elevation) and Mexico City (7240 ft elevation).