Steel Bike Weighing 9.6 lbs More Than Titanium BIke Climbs Just As Well!
Did I get your attention with that headline? It was inspired by an article I read in the most recent issue of Bicycle Quarterly, a fantastic, niche magazine published by Jan Heine.
In this issue, Jan tested a titanium bike against a steel randonneur bike. It was a real world test: two guys racing each other up the same hill, one on the ti bike, one on the steel. They swapped out the bikes several times. Both were evenly matched in terms of strength, endurance and weight.
The weight of a steel bike is always of interest. This steel bike was 9.6 lbs heavier than the ti bike, but it climbed as well. It sounds implausible, but as Jan explained, when the weight of the riders was taken into account, the steel bike plus rider was only 5% heavier than the ti bike plus rider, but the steel bike “planed”, helping the rider generate the extra power needed to overcome the weight difference.
Fans of Jan’s bike testing will know there is an advantage to a bike that “planes”. This is a bike that is in synch with the rider and flexes in a way that “gives back” some of the rider’s energy to the drivetrain.
Just for fun, I backed through Jan’s math to calculate that he weighs about 175 lbs. I used my own 100 lb. weight in his calculations and found that the difference in weight plus rider for me is about 8%. Ah, we smaller riders have a rougher road to ride, do we not? A bike that planes is a must!
The important point is that weight is not a big deal. Choice of tires and construction of the frame is though.
Take the road less traveled — not only on your bike, but in your reading as well.
Comments
Looking at gross weight of the bicycle and rider is not the whole equation. The rate a bicycle accelerates is related to three variables, the wattage output of the rider, the mass of the rotational components and the gross weight of the rider and bicycle. In the Bicycle Quarterly (BQ) test both riders were evenly matched in strength, endurance and weight. The difference in weight between the two bikes is about 1.5 lb. which is insignificant. Both bikes use the same tires and lightweight wheel sets, as well as lightweight high-end components. The only difference between these two bikes and riders is a slight weight penalty for the heavier rider and the frame and fork materials. If the frame material were carbon fiber or aluminum, I would expect to see no significant difference in the outcome of the test.
The weight difference between the two bikes was 9.6 lbs.
The article, “Lynskey Helix – Seven Axiom SL,” Bicycle Quarterly, Vol. 11 No.2, Winter 2012 reports the weight of the bikes tested as follows: Lynskey Helix 17.0 lb; Seven Axion SL 18.5 lb. These are the weights reported for the test bikes. The difference in weight between the two test riders is reported at 10 lb. Both bikes in the test are titanium.
The two test riders did make a comparison between a steel randonneur bike with 650B tires and the Lynskey. The randonneur bike’s weight is 26.5 lb. compared 17.0 lb. for the titanium bike. This is the 9.5 lb. differential reported. The test riders’ conclusion is the randonneur bike climbs as well as the Lynskey and the handling of the randonneur bike with it’s wider tires was superior to the Lynskey. This conclusion is surprising considering the wheel set of the randonneur bike has significantly great angular moment to overcome when accelerating compared to the featherweight wheels on the Lynskey.
Bicycle Quarterly does a wonderful job of testing and comparing bikes and bicycle components but they are limited on funds and are unable to run extensive comparative testing using several riders and bikes. This limited test, does suggest well designed steel bikes can match the performance, perhaps even exceed the performance of titanium bikes.
Yes, my blog is about the difference between the steel randonneur bike and the ti bike.
I always look to Jobst Brandt for the final word on the science of bicycling. His comments on rotating mass will be of interest to you:
http://yarchive.net/bike/rotating_mass.html
Georgena:
Thanks,
For more information about “planing”, which is really all about a bicycle deflecting as it’s pedaled and then “giving back” some of that deflection to the drivetrain, take a look at this excellent article:
http://www.bikethink.com/bicycle-frame-efficiency/
Oh, my, this must be my homework assignment. The article looks very interesting and is worth an in-depth read.
Thanks,
Rod
I enjoy the comments as much as the article.
You said it: ” steel is real! ”
Thanks
Great post.
Very informative.