Category Archives: Product Weight

Metolius FS Mini, Black Diamond Neutrino

. Product Weight

Back to business, measuring mass.

Carabiner weight matters to climbers. Sure, if one biner is 10 grams heavier than another, it’s no big deal. But, if you multiply by 20, that’s almost a half pound. The BD Neutrino, and later, the Metolius Mini carabiners have both advanced the cutting edge of lightweight climbing hardware. I like ’em both enough to have a few. Everything measured here was purchased in or before 2010.

These biners are lightly used, so they will be slightly lighter, and have more variation, than new.

Neutrinos:

Neutrinos individually:
36.9 36.9 36.7 36.9 36.9 36.4 36.7 36.3

Weighed together: 294.1 g.

Correcting for finite sample size, these numbers give 36.8±0.3 g. 

The lighter two biners are not anodized, and were purchased in 2009. The other 6 were from a “rack-pack” purchased in late 2010 and are anodized. It’s possible that anodization or a manufacturing change added a tiny amount of mass.

Black Diamond claims 36g. With these few measurements, 37g would be more appropriate, but there’s not enough resolving power here to tell the difference between 36±1 and 37±1.

It’s a go-to carabiner. Thanks for making it, BD.

Metolius mini FS

Weighed individually:
25.3 25.2 25.2 24.5 24.9 25.2

Weighed together: 150.4 g

Correcting for finite sample size, these numbers give 25.1±0.3 g.

Purchased in autumn 2010.

Metolius claims 25 g. Right on.

Ski Evolution

. Plots, Product Weight . ,

At the Northwest Snow and Avalanche Workshop this weekend, Off-Piste Magazine handed out free copies of the October issue as usual. Thumbing through the ski review, I couldn’t help but wonder: How have things changed over time?

Thanks to Off-Piste’s deep archive of back issues, only tedious retyping was needed to find some answers.

This is the money plot:

The absolute scale makes the scatter part of the plot small, but you can see by exactly how much skis have widened and lightened over time.

For zoomed in plots and more, head down the rabbit hole. Continue reading →

Atomic Kailas 185cm (drilled/used)

. Product Weight . , , ,

These are the green ones.

A friend gave a wonderful deal on nearly pristine and well loved skis. They’re about to get mounted, so it’s time to weigh ’em. These skis have been drilled once for dynafits, and for Voile ski crampons. I think the previous owner stone ground them at least once. I expect them to be lighter than new.

My scale is designed for calibration with a 4 kg standard, but I only have a 2kg standard. So, I do the correction by hand. Actual mass = ( measured mass  x 2000/2006).

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Corrects to 2000g.

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Corrects to: 1881 g

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Corrects to 1862g.

Average mass 1872g.

Couldn’t find the manufacturer’s spec for the 06/07 year, but 07/08 had a claimed weight of 3750g/pair, or 1875 g/ski.

Edit: 3/14/2013

I’ve finally gotten a few days on these skis, after mounting them with inserts. They’re a rather neutral ski. They like to be driven, but will tolerate small quantities of backseat driving. I’m accustomed to slightly shorter (~177 cm) skis, so tricky conditions require a little more forethought. The previous owner kept the bases and edges in pristine condition, so edgehold is excellent. As with Kongurs in the same length, I haven’t yet found a speed limit, even on ripper groomers. Nice skis.

Michelin Kromion

. Cycling, Product Weight . ,

New tires came with the saddle. Manufacturer spec is 230g.

231.7 g and 235.5 g. At worst, 2.4% off spec. Drawing the same inference as in the previous entry (with no extra conservatism), this yields (with some uncertainty about the 3.4): 233.6 +/- 3.4 g, easily consistent with a 230g spec.

I saved less weight than I’d expected simply because my worn tires were lighter than specified by the manufacturer. I’m looking forward to lightening these Kromions further by riding!

Folding tires are a really inexpensive way to pull a little mass (and moment of inertia) out of your bike. Wire beads are heavy.

Nashbar R2 Saddle

. Cycling, Product Weight . , ,

New saddle arrived. Feels nice, feels light, looks cool, magnet doesn’t stick to seat rails.

Nashbar claims 191 grams. I get 205.8. That’s 7.8% high. Weighing, as before, used the AWS Blade scale calibrated using the 200 g weight.

I wanted to put this in perspective, so I looked up the prices of the other saddles that Nashbar sells.

My first takeaway is that old-style riveted leather saddles are heavy. The second is that, while the R2 remains a value, I’d be very unhappy with Nashbar’s claimed 191 g weight if I manufactured the 190g saddles priced at $50-55.

I see 8% less weight savings than expected using the R2, but how much less attractive does that make the saddle?

As shown in green, the claimed weight netted me weight savings at $87.57 per pound. In reality, it cost me $95.35 per pound, and my bike’s mass is 15 grams more than expected.

Reviews at Nashbar.com state that the saddle weighs 214, 208, 209, and 220 g.  Averaging them together with the measured 205.8g yields 211 +/- 5.7 g. With only 5 samples and normally-distributed data, the uncertainty in the variance is considerable, and is slightly underestimated (by 7 %). Call it 211 +/- 6 g. Since Nashbar has lawyers, we don’t have very many samples, not all scale users know what they’re doing, and process variations aren’t always Gaussian, let’s double the variation, to 211 +/- 12 g (that’s almost an ounce variation, peak to peak).   Using these data, if the saddle masses are “normally distributed”, less than one in ten saddles will have mass at or below 191g. 

Weight-wise, the R2 remains a compelling value for budget-minded buyers, just not the exceptional value 191g presents. If the R2’s mass is consistently higher as than 191g, as reviews indicate, then the saddle is improperly labelled and advertised. If the manufacturing process yields saddles that are 176g as often as it does 206g saddles, quantified variation (expressed as 191 +/- 15 g) would be a straightforward consumer resource.

Crank Brothers Eggbeater 1

. Cycling, Product Weight . , , , , ,

Over the weekend, we went on a long bike ride. It was fun, but I was slower than I wanted. So, in addition to resolving to get more exercise, I took a look at the weight of my bicycle.

Lots of disassembling, weighing parts, and playing with spreadsheets ensued. Ultimately, I decided to replace my worn tires (wire beads add 100g per tire!), rattly clipless pedals, and saddle. If manufacturers meet spec, I’ll have dropped about a pound from my 24 pound bike for ~$100. This isn’t the optimal weight/dollar way to get to a 18 lb bike, but it’s a way to spiff up a favorite bike.

The first package arrived in the mail yesterday – Crank Brothers pedals from REI. Listed as 256 grams per pair,  these should save 110g over the old pedals. Opening up the package, they look and feel great.

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Here’s what arrived. 280.2 grams.

Nearly 10% high. For a weight quoted to three significant figures in an industry obsessed with weight, that’s a letdown. In real terms, it’s the weight of an extra granola bar per pair. Or, if you’re a triathlete, three quarters of a pack of GU. As a customer, I saved 22% less weight than I expected with this purchase.

It’s not a gross manufacturing inconsistency; the two pedals mass 140.0 and 140.3 g (+/- 0.1 g statistical uncertainty).

Balance is an American Weigh Blade 400, calibrated with an American Weigh 200g calibration mass. At present, I trust the calibration mass to about a gram. The manufacturer specifies at least 0.1 g. I haven’t yet checked it on a superior balance.