Death Of a Weight Weenie By: Writer Bob

by FatBob on January 29, 2011

My Spreadsheet Killed My Dream

I have always harbored secret dreams of becoming a cycling weight weenie. I have never been into racing (the name Slow Bob was already taken), where it can be argued losing grams to gain seconds can be the difference between victory and defeat. Still, it seemed like a lighter bike would ride and perform better and, I'll admit it, have a higher cool factor.

What started as an abstract exercise to see the relationship between cost and weight for potential upgrades became more real and immediate when a deal on a frame popped up and I began figuring out how to build up my own bike from scratch. Then, my secret desire met my spreadsheet. Blast you spreadsheet for bringing cold numerical logic into things!

Having a super light bike still has a mystical cool factor. However, I can no longer find much room in my heart for it once money enters the picture. Simply put, once you take the frame out of the picture, the difference in weight between building up a light bike and an average bike is too small for me to justify.

My spreadsheet is pretty simple and not easily swayed by cool factor or long held secret fantasies. Basically, it shows the weight difference between going low end vs high end and the corresponding cost difference. For example:
High end derailleur - $168 and 180 grams
Lower end derailleur - $42 and 260 grams
Difference = $126 and 80 grams
High end carbon handlebars - $130 and 135 grams
Basic aluminum handlebars - $30 and 300 grams
Difference = $100 and 165 grams

To make a long story short, based on the components I selected, it costs $1,800 more to use high end, light parts compared to heavier, average to low end parts. The total difference in weight? A little over a pound and half - a dozen Crispy Creme Donuts that get eaten in no time flat. Wow. I’m sure one could quibble over my high and low selections. Still, even if you doubled the weight savings (unlikely) and cut the extra cost in half (maybe with used stuff), you are still looking at $900 for  a tad over 3 pounds in savings. Double wow.

What about lighter wheels? There is a good argument that wheels are an exception, and, as such, durable, light wheels are worth serious consideration. Spending an extra $800 for higher end wheels (1,750 grams, $1,000 wheels) over basic wheels ($200, 2,400 grams) can save you almost 1.5 pounds. That’s the same as the weight lost in our high end component scenario for less than half the cost. Because wheels are rotating weight, losing 1.5 pounds there provides a greater benefit than weight lost elsewhere.

Even with wheels though, the benefit, when quantified, seems underwhelming. Here is what I found in an article on Wikipedia. “The formula for power suggests that 1 lb saved is worth 0.06 mph (0.1 km/h) on a 7% grade, and even a 4 lb saving is worth only 0.25 mph (0.4 km/h) for a light rider.” Check it out of you want to delve deeper and are not scared off by formulas with strange symbols: http://en.wikipedia.org/wiki/Bicycle_performance. The article does point out that lighter wheels aid in acceleration. However, since I don’t know anybody that does standing start drag races on their bike, this is probably pretty hard to quantify in a way that is meaningful.

A liter of water weighs 2.2 pounds. I don’t typically drain my 3 liter hydration pack, so by the end of an average ride, I have probably lightened the load by maybe 4 pounds and have 1 or 2 pounds worth in reserve. So, if I planned my water consumption a little better, I’d have room to stuff the $1,800 I saved in my pack. Money is pretty light; I doubt it would slow me down.