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.

{ 9 comments… read them below or add one }

AZbiker27 January 30, 2011 at 9:50 am

This is a simple great article that helps explain the weight savings. I for one always seem to get wrapped up in component weight. Its something that I try to get the biggest bang for the buck. For me, the difference in weight of components does not impact me as much, as I’m over 200 lbs. My wife, who weighs much much less, the weight impact is more dramatic. For her, it pays to pay attention to the weight. I’m trying to be more pragmatic with parts choices, but I also like the reliability factor of good quality parts.

FatBob January 31, 2011 at 9:48 am

Azbiker27, you bring up a very good point. the more you weigh the more consideration you have to put on durability then just weight. Also the more aggressively you ride. Here is an example. I was riding yesterday on the Specialized Camber with a set of my DT 240s wheels with Stans Arch rims. I had a set of GEAX AKA tires on set up tubeless. This is a light set up. I bunny hopped a root to change positions in the air. When I landed I lost about half of my tire pressure, the fork got packed down at full compression and wouldn’t rebound to full extension and I felt the front wheel and fork twist. How fast do you think I finished the last 4 miles back to my car? Lighter is only faster if it stay’s in one piece and does not fail.

Your wife, as does mine probably weighs almost 100 LBS less then you. While my wife is very strong for her size, she has never caused a mechanical failure. Her DT 240s wheels laced with light spokes and Stans 355 rims have never even needed truing and she has never burped her Schwable Racing Ralph tires with the standard light casing set up tubeless(I burped this set up 100 yards into a very tame trail by pumping a transition while turning). She is also much more sensitive to weight changes.

So in short, it is always best to look at this on an individual basis, as a general rule though, there is a cut off where weight to cost ratio makes the part a poor value for all but the most neurotic rider.

Tjaard January 31, 2011 at 7:34 pm

RE Wheel weight:
Even in wheel weight the more expensive, lighter wheels don’t make sense for many people. that is because in wheels, almost all high end, lightweight wheels are substantially less stiff than the heavier and cheaper versions. This was measured a year or two ago by one of the german mtb magazines and did not include carbon wheels, or very few. The best Stiffness-to-Weight ratio was on some of the cheaper or mid priced wheels, eg the XT wheels had better STW than XTR or Crossmax.

FatBob February 1, 2011 at 7:20 am

tjaard, the stiffness to weight ratio/ weight to performance may be another article coming soon. At what point is weight a liability and for what type of rider ? Bike designers design super light parts for certain weight riders and for particular styles of riding. 200 plus pound guy’s are outside of the design intent of most light weight parts. That does not mean that a 200 pound plus rider cant ride the light part but you will be pushing them outside of their intended use. On the other side of the spectrum not many people want to lug around a 36 pound bike with downhill tires up a hill. There is alot more then purely weight to consider when buying a part and more factors then weight come into play when you are looking at performance.

In support of your comment we have been testing the Sun Ringle’ Charger 29er wheels. These are $400 a set. They are a little heavy but not bad, the ratchets are not as fast as some, but only the most advanced riders are even paying attention, and they are still round and true. It is really hard to justify over double the price for wheels when these ride so well and wont crumble under a heavier rider that doesn’t want to tip toe through every rock garden. To get the wheels light there is typically some compromise. Do you want to have your dollers last longer with less money put into maintenance ? Then consider other factors besides weight when looking at wheels and other parts.

Rob February 12, 2012 at 1:43 am

Good article. In my local bike shop I overheard a conversation where they advised a customer against going to a full race spec as the gains in weight were not balanced out by increased performance and reduced durability – unless you are actually going to race. Good for them, not often you see a shop talking someone into a cheaper option, honest advice is something good about the biking world we should protect.

I do have a question. How about carbon frames? I am thinking about getting a full suss 29er. I currently ride a 29er HT, but looking for a bit more. I am demoing a Camber 29 next week and have read good things about them. Should I choose to go for a Camber the choice would be a comp spec in alloy or carbon – I understand that carbon has benefits beyond weight saving, but £600 ($1000) worth? Any views in general on value of alloy v carbon?

Rob February 12, 2012 at 1:58 am

. . . I have now just read your article on the carbon camber comp, which covers the point on carbon v alloy. I need to keep up with my reading!

Rob February 12, 2012 at 3:26 am

. . . Just re-reading my lbs anecdote – I meant to say the shop advised againts a full race spec as the gains from reduced weight and improved performance were not worth the reduced durability and increased cost, unless you actually are going to race . . . At work I have someone to proof my copy to make sure the meaning emerges from my garbled prose.

FatBob February 13, 2012 at 11:06 am

Hi Rob. Check back on the main page periodically. We are working on a write up on The StumpJumper Comp 29 and the StumpJumper carbon Comp 29. Both have identical specs, the only difference is Carbon vs Aluminium. This will obviously take some time but as we usually try to do we want to compare apples to apples. The initial write up should be up by the end of the week.

Thanks for reading our little site.

droptop August 23, 2012 at 6:51 pm

I have found that there is a balance on the weight/price/performance scale. I have recently built a lightweight (for me) road bike, at 16.9 lbs. Its aluminum. I carefully analyzed every part, and shopped the sales. I absolutely love my lightweight wheels for the road. they came in at 1450g for the set. I do notice how well they help me accelerate, no nimble they feel when initiating a turn. what I know is they would never hold up to my 185lbs on the trail. A lot of the nimbleness is lost due to massive rubber I run on a mtb (2.2″+ tires).

Im hoping that my new suspension bike lets me run narrower (and lighter) tires, that bite better in hard turns. What it really comes down to is get a bike that shifts well, and crisply. Enjoy it. I will be racing this season on a 28+ lb trail bike (6″ travel bike) because I sold my hard tail to buy the new full suspension.

I have found that if you go too light (after riding years of steel, mid 20lb bikes), an ultra weight weenie bike feels awkward. I have a few friends that quickly sold their 18lb carbon bikes because they didn’t feel anchored to the trail, they felt the bikes were skittish.

I guess the moral of my ramblings is don’t over-spoil yourself. Find good, reliable parts FOR YOU and enjoy riding them while your weight weenie friends spend time in the shop. after years of riding, you will know what you can get away with, and what will or won’t last.

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