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WireWorld > Bicycling > Bike Blog > It's about wasted weight, not being a weight weenie

It's about wasted weight, not being a weight weenie

I like the Velo Orange folks. I'm not a fanatical fan of french bikes, but I applaud their interest in offering alternatives to modern carbon fiber disposable racing machines. So I browse their blog sometimes. Recently, Chris posted about weight, and how he suggests that cyclists worry too much about it.

Now, if you compare to the difference in weight between my bike and a carbon fiber racing machine to the amount of weight I've lost since I started biking, the second quantity is larger. So, clearly losing weight has been to my benefit.

On the other hand, I think about weight. Not too carefully, but there's a reason why I ride a hardtail mountain bike instead of a double boingie and use v-brakes instead of disc brakes. On the other hand, if you consider that I carry more spares and supplies than your average guy on the mountain, my bike may not be that much lighter.

And, thus, I've got a better idea.

Cyclists shouldn't care about absolute weight. They should care about wasted weight.

For the most part, a carefully lightened chainring is going to be much lighter than a solid chainring without being flimsier in situations that won't probably wreck the bike anyway. So, the difference between those two chainrings? Wasted weight. The difference between the lighter chainring and a flimsy carbon fiber thing that won't make it through a good hard spring without ending up on the busted carbon blog? That's not wasted weight. Carrying a spare chainring and the necessary tools to fix a flimsy chainring on the spot? That's wasted weight, especially because it's likely heavier than a sturdier chainring.

Wasted weight depends on how you are riding. One person may consider the difference between an aluminum chainring and a steel chainring to be wasted weight, because either one is strong enough, but the aluminum one is lighter. Another person may point out the imposition that having to swap out the chainring every year is, so the steel chainring is not wasted weight. Deep dish wheels are heavier but more aerodynamic compared to lightweight wheels.

Wasted weight requires thought. Maybe a mountain biker gets a bash disk to protect their aluminum chainrings... or maybe they use a stronger steel one that is actually lighter because they don't bother with a bash disk. Wasted weight may not be all the way on the bike. If you are over 200 pounds, that means you need sturdier and thus heavier wheels. If you lose that extra weight, not only have you lost that weight, but you also can use lighter wheels.

Wasted weight requires a certain order of magnitude to be wasted. If I shave ten grams off my bike frame somehow, I won't notice. A few pounds is different. And wasted weight can be in the wallet. Sure I can shave some weight off without giving anything up by getting parts that have been carefully machined to be as light as possible, with expensive alloys, and extra R&D costs. But sometimes I'd much rather have a heavier wallet.

Spares are usually not wasted weight. A bike is awfully heavy if you carry it over your shoulder for a few miles, so spare tubes are not wasted weight. Cars, either to carry you to the part where you start biking or following behind you with spare parts, are giant chunks of wasted weight.

Wasted weight is never good. You may think "Oh, I'll get more exercise in my 40 lb bike" but if a 30 lb bike means that your legs get a little less tired and you bike longer or that you can make it up hills you wouldn't on your 40 lb bike, you are wasting 10 lbs of weight, just like an overweight cyclist who can stand to lose another 40 pounds is wasting both weight and money riding around his carbon fiber frame with clydesdale-edition carbon fiber wheels that he's going to break in two one of these days.

And weight really is a lie. Chris from Velo Orange says that parts can vary 10% or 20% from each other. I was browsing at a high-end cycle place and the guy there had a scale behind the counter because some of his customers want him to pull all of the stock out so they could make sure that, of the different super-lightweight Dura-Ace parts, that they got the lightest one. I, of course, wonder if the lighter one has a hidden void from the casting process or other internal defect that therefore means that something's going to snap when you don't want it to snap. Often times, this is what structural reserve is for. You take the strength of the part that's the one that just barely passing the quality control, add a little bit of a fudge factor, and then design it around that level of strength. And, naturally, you'll claim either the lightest part that passes quality control... or if you want to be at least somewhat honest, the average weight... for when the engineer works out the weight to publish.

Thus, in my mind, it's OK to list the manufacturer's provided figures for weight. Some stores are good and call it "claimed weight" instead of just "weight". I'd be happy if they added a little asterisk and a note on the bottom that says "* weight may contain up to 20% lie" or something like that. Sure, anybody with decent QC can probably give you the weight as a range instead of as a number, which is much less of a lie. And any online store can offer to throw a few examples of the part you want on a scale and give you the lightest one, although I bet that the pain and agony of talking to a thousand weight weenies every day over the phone or email is probably enough to make that an offer any store that wants to stay in business should never make.

The real problem is that we don't have a good gauge for wasted weight. Because of this, products that are heavier in absolute terms but lighter in terms of wasted weight often die in the marketplace.

Myself, I'm somewhat curious. See, I've got a fairly low-end mountain bike with front suspension. There's likely some wasted weight because it's overall fairly low-end and therefore I could get a lighter bike of the same degree of durability. And, in terms of riding on the road 75 miles between home and the pacific ocean, it's got a good degree of wasted weight because it's not a road bike. So I'm kinda looking towards getting a road bike for that sort of long ride. But I'm also deeply suspicious that even if I got a dura-ace racing machine made from carbon fiber, it's going to matter less than I think.

 

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Copyright 2007, Ken Wronkiewicz
Version 4.0
Last Updated: 2009-08-07 10:42PM
Posted: 2009-08-07 10:42PM