|Aluminum vs. steel frames||Willis|
Aug 31, 2001 4:53 PM
|When all else is equal, a bike with an aluminum frame has the reputation of being faster than a bike with a steel frame. But how much faster? I've ridden both, and know that my decade-old Cannondale may be the stiffest bike I've ever ridden. It sure feels fast, but I don't have any real numbers to back it up.
Does anyone have any real world time-trial numbers that back up aluminum's reputation? Has anyone ridden both steel and aluminum on a favorite course and compared their times? Did the stiff aluminum frame just feel faster? How long was your course, and what was its terrain? What is your level of riding experience? I'm considering a new bike and just wonder what the real-world differences are. I don't race, but I enjoy a sporty bike like I enjoy a sporty car.
|re: Aluminum is faster?||Rusty Coggs|
Aug 31, 2001 5:05 PM
|Doh? I did not know that.And I always Thunk it wuz the guy makin the cranks go round.|
|Willis - Rusty Boy has troubles with basic English Comprehension||Rusty Boy Oh boy|
Aug 31, 2001 5:14 PM
|He obviuosly had difficulty with that complicated term, "when all other things are equal." LOL, perhaps you should have said it in ebonics, then he probably would have likely understood it. Cheers everyone and have a great holiday weekend. :-)|
|Aluminum: not faster, but quicker||Tig|
Aug 31, 2001 6:39 PM
|I don't think you could call aluminum "faster" unless it was full of aero shaped tubes. I think a better description of aluminum would be "quicker". The stiff bottom bracket and the properties of aluminum tubing give the bike a snappier feeling. The energy you put in the cranks is better distributed due to the stiffer frame. This kind of "quicker" comes in handy in a crit race where you have to accelerate over and over. Most steel bikes have more flex and weight. A lighter aluminum bike should climb a little faster on a long climb thanks to less weight to haul up. Realistically, a pound or two off a frame doesn't make all that much difference for us mortals. Lighter wheels will be more noticeable than a lighter frame. The best way to lose weight cheap is to use an enema the night before a hilly day!
I'll take a comfy steel bike over an aluminum on a long ride any day. I've had plenty of both. I used to ride a steel Tommasini for training, and a Cannondale for races.
Sep 1, 2001 5:54 AM
|Unless there is some magical property about aluminum involving warping of the space/time continuum, what could possibly make a material faster? Now if the Aluminum bike is lighter, that will make some difference in acceleration and climbing - we are on solid ground regarding the physics of that. While some folks have suggested that stiffer is faster, I notice that Sheldon Brown's material article (http://www.sheldonbrown.com/frame-materials.html) suggests that flex has no impact of lost energy to forward motion. I can't really argue that either way, but it is somewhat at odds with the folklore.|
|A bad reputation||Kerry Irons|
Sep 1, 2001 4:22 PM
|Your basic assumption is incorrect. Someone may have told you, or the BS'ers at the LBS may claim, or your riding buddies may believe that Al makes for faster frames, but as another poster said, there is nothing in the material itself that makes for a faster frame. And short of weight (especially in climbing) and aero tube shapes, there is precious little that would suggest one frame material is "faster" than another.
Early aluminum frames had the same diameter tubes as steel because all of the components (including shift levers and even brake and derailleur cable guides) were clamp on - you had to use standard tubing sizes. This resulted in flexible, though light, Alan and Vitus aluminum bikes. Therefore "aluminum makes flexy bikes." Then Cannondale moved in, taking advantage of the fact that there were no more clamps, and probably overcompensated to prove that Al didn't have to be flexy. Therefore "aluminum makes stiff bikes." Design is everything, material is secondary and mostly allows you to build a lighter bike if you choose the right material. Due to design parameters, there is much more range within a given material than there is between materials. Look at the design philosophy rather than the frame material.