Aluminum vs Steel. Which is better and why?

[bigred455]

Originally posted by Patman
If I'm not mistaken I think the CR frame runs maybe 4 pounds less than a KX. If I owned a KX I'd just call Jenni Craig and make it a moot point :)

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Are you saying the kx's have a thyroid condition. :think: All this weight savings is find and dandy,as long liability is not sacrificed in the process. Richard simmons has been working with KAWASAKI R&D FOR THE 03 KX 250 he got the kx to drop 4lbs.. :silly: ARE YOU GUYS STOKED I AM STOKED. :scream: :scream:

 

[bigred455]

Originally posted by marcusgunby
bigred my 01 did need to have protection from the rad scoops-i havnt done this on the 02 and so far so good.

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Thanks for the reply marcusgunby,I was just curious. ARE YOU GUYS STOKED I AM STOKED.. :scream: :scream:

 

[XRpredator]

Whether aluminum is better than steel is a moot point with Honda. They'll never go back. That would be admitting they were wrong in the first place. Plus, I think after 6 years now, it has become as much a part of Honda as the wing. It is the corporate image.

 

[FasterNU]

Has anyone touched on the thought of lower center of gravity? It always seemed to me the AL framed hondas felt a bit less top heavy. Does the perimeter frame drop the CG? Are the cast in sections at the bottom of the frame the heaviest parts?? Just curious if anyone knows or feels if the steel frames are more "top heavy"

 

[chuckketchum]

I read an article in 2002 in either Cycle World or Cycle Guide, I think Jimmy Lewis had something to do with it. But they took all these bikes apart and weighed all the parts seperately. The Honda aluminum frame weighed more than the KTM chromemoly. If it doesn't weigh a lot less what could be an advantage. The fatigue to the frame made from aluminum just can't last as long as chromemoly.

 

[TerrorFirma]

I used to work in the MTB industry and we used Titanium, Aluminum, and Steel.
The Aluminum [Al] is usually 7005 or 6061 because those are the ones you can weld and they need to be heat-treated after welding. The problem with Aluminum was if you even got a scratch on the tubing it would cause a "stress-riser" which would increase the likelyhood of it breaking at that location. Also Al has a fatigue memory so everytime you jump/crash your bike you stress the frame and eventually you'll have a catastophic failure. I've seen one of my buddies go through 8 Mountain Bike Frames in one season [warranty replaced thank God].
Never buy a used Al bike unless its been barely riden.
The reason I think they use Al is it is cheap [pop cans] -- [tubular chromoly isn't as cheap as u think it is] and it's a good marketing tool.
Are there any Mech or Materials Engineers out there that can back me up pls.
However, a good design can overcome alot of these inherent risk with Aluminum.

 

[WhKnuckle]

Without a shread of physical evidence, I'd offer these opinions (ignorance isn't a sufficient reason to dodge a debate):
(1) No other manufacturer is doing the aluminum frame deal because it's really hard to get the frame to have the right combination of torsional rigidity and bump flex;
(2) Since steel frames flex more, they "feel" better naturally, without magnum R&D;
(3) Since steel frames flex more, they're also subject to fatigue;
(4) Which is why most freestyle guys ride Hondas.

My CR500AF is the best handling, most confidence inspiring bike I've ever owned, and I've owned bikes from A (AJS) to Z (Zundapp-Rickman). If anybody could make a bike that good from a steel frame, let 'em go at it.

 

[jmics19067]

I wouldn't doubt that Honda wanted a perimeter frame but didnt want to be considered a copycat of Kawasaki so they made theirs out of aluminum.

along with most of the other reasons.

 

[markthomps]

My 2 pesos: a distinctive look (Honda loves being the first to do something so that the rest get to follow) and weight savings. The aluminum frame is somewhat lighter, and since Honda tends to use better/heavier (slightly) components overall, they needed to save ounces where they could. Besides, aluminum is what crotch rockets and bicycles have used for years, so mx was an obvious choice. And nobody confuses a Honda with anything else out there --- hell, that's a good enuf reason right there.

 

[Jaybird]

When I was a kid, and a machinist apprentice, my boss was into building top-shelf bicycles. I can't remember all the specific details, but he concluded that chrome moly steel was by far the better choice for all of his custom builds.

I do remember that chrome moly is pound-for-pound much stronger than aluminum and as far as cost...try to buy some chrome moly tubing...you will buy it by the inch.

 

[DougRoost]

had to resurrect this thread. I agree that chromoly makes more sense for dirtbike frames. After all, Kawasaki invented the perimeter frame and uses alumnium versions on their street bikes but steel for the dirt bikes. GasGas does the same thing on their perimeter frames.

But in the end those Hondas are a thing of beauty and they're winning the marketing war. Look at the latest DirtRider and you'll see a preview of the 2005 Yamahas with aluminum frames (still traditional design, though). They are much more refined than the previous works bike that had been run overseas, looking close to production pieces.  Rumor is the 450 4-stroke Suzuki will also use an aluminum frame.

Also, the Hondas have been around long enough now that we surely would have heard of failures. If they've been having them they've sure managed to keep it quiet.  Anyone here have one fail?

 

[muddy226]

I know of 2 CR250s that broke at the headstock, but they were being used as "stunt" bikes. ( This was the second year of the ally frame )


I think that alu is probably cheaper than chromoly, it is after all the most abundant metal on Earth, and I also read somewhere that Honda have a patented extrusion process, and have therefore invested heavily in the necessary production facilities. It is this process which the others don't have which gives H the advantage in costs, and why they will use it whereever they can.

 

[snb73]

I was at my local dealers today, eyeing used bikes. There were two CR-500's side by side. A 1997 and a 2000. The 1997 had an aluminum perimeter frame, while the 2000 had a steel (cromolly?) one.

I tried to search for a picture of the 97 to verify it has an aluminum frame, but couldn't find one. All the pictures I found showed the 97 had a "steel" frame.

The tenth digit in the VIN is a "V", so it's a 97. Any Ideas? That seems odd to me. Maybe someone switched the frame?

Thanks, Steve

 

[muddy226]

As far as I know ( not far ) no CR500s were produced with ally frames, but quite a lot have been made up by people putting the motor in a 250 frame, and I think you can buy them new from Service Honda.

 

[CR500AF 99]

Rumor is the 450 4-stroke Suzuki will also use an aluminum frame.

I have seen the pics!!! yes it is true

 

[DonkeyPower]

I think aluminum vs steel is a matter of what your going to do with the bike... When it comes to MX I preferr aluminum... Just for looks though...Im not shure if you actually save enough weight to make that much of a diffrence... I used to work at a shop that sold titanium fasteners to race teams... They would buy 2 - 5k worth of fasteners just to save 2 to 3 lbs on their race bike... For that much why not just ask your (professional) rider to make shure to go to the bathroom first..... You might save that 3lbs right of the bat for free!

 

[kdxtaz]

:laugh: :laugh:

 

[PETE525]

My take on honda persuing an aluminum perimeter frame is all about rigidity.To help a race mech. to tune the bikes suspension, having a stiff frame[not too stiff 97-99cr]takes it out of the equasion, making the suspesion work independantly from the frame stopping flex/twist at mount points[swing arm pivot and head stay with triple clamps].Cliff white,long time honda guy also was involved in rc racinig and most likely r&d for associated racing,he was the man back in early 1990s in rc.Back then all the off road rc trucks/buggys where going to carbon graphite frames to isolate the chassis and make the susp. work.I know its 1/10th scale racing but the principles the same,Just watch a unlimited class truck run through desert at 90 mph with 20+inches of wheel travel,with the wheels pumping up and down so fast there a blurr, while the chassis and driver float along isolated from it all.I would be suprised if cliff was not involved in the new frame.Same theory applys to a CR250 blitzing into a nasty whoop section.I only road an alum. CR once but read the that the new CRs handle excellent.I'll bet the other brands will follow out of the need to be competitive. MY TWO CENTS, PETE