BannedCR500Riders.com

gen 3 125 frame after mods 22.5 lbs
94 CR500 steel frame (with footpegs) just under 21 lbs

just thought that was interesting.

Honda claimed the Alloy frame was for strength not weight savings.

I guess they were telling the truth.

i think those fourstroke frames can be lighter, i need to weighten mine frames later.

But those steelframes are quite light weight. Especially the ones that is made out of cromo.

I have read that alum frames actually save the manufacturers money in the long run.

As far as the 4 strokes go, the Aluminum frames have made them a fortune!

What about the complete bike? Is a new cr500af lighter than an ol' school cr500?

yota wrote:gen 3 125 frame after mods 22.5 lbs
94 CR500 steel frame (with footpegs) just under 21 lbs

just thought that was interesting.

Does this mean you have disassembled your AF coversion for some reason?

homenf wrote:What about the complete bike? Is a new cr500af lighter than an ol' school cr500?

I have to think the steely may be lighter. same motor, lighter frame, smaller suspension components.

CR500R7 wrote:

yota wrote:gen 3 125 frame after mods 22.5 lbs
94 CR500 steel frame (with footpegs) just under 21 lbs

just thought that was interesting.

Does this mean you have disassembled your AF coversion for some reason?

no I weighed the alum frame way back when and just got around to weighing the steel frame a few days ago.

yota wrote:gen 3 125 frame after mods 22.5 lbs
94 CR500 steel frame (with footpegs) just under 21 lbs

just thought that was interesting.

so the weight of the ali frame would be even closer in standard form without the billet y piece

the billet Y pc is hollow but surely still weighs a little more than the stock pc.

yota wrote:the billet Y pc is hollow .

Not any that I have seen are.

Those things are heavy.

I would love to see one before it is welded in.. Seems like alot of work to hollow out a peice of billit like that.. None the less those frames sure were nice.. too bad everything went the way it did with that guy

AlisoBob wrote:

yota wrote:the billet Y pc is hollow .

Not any that I have seen are.

Those things are heavy.

Bob I'll bow to your experience but when I got the frame I did some tapping on the Y pc and it sure sounded hollow. I also remember a thread where AJ kind of accused Mike of copying his Y pc and Mikes asked AJ if his were hollow? Maybe I'm wrong, Ill go home and bang on it again.

At the very top, where it index's into the OEM down tube... its machined to fit inside the downtube and that pocket is milled out a bit, but the rest is solid aluminum.

no wonder my bike can't wheelie then

On Ya Gregrobo!, thanks for posting these weights!

Quite a few times I've got some hysterical reactions from those that think the alloy frame is lighter and I've said they were mistaken. Depending on how you do it, they tend to be 1 to 2.5lbs heavier, frame to frame.

Add in how all the fuel is carried high above the engine, and I've always chuckled at the claims that they are lighter feeling. Well, only if you have a big IMS or Clark tank on a steel 500, when it's full it may be. Those same 2 tanks with , say, the 7.2(?) litres a LM CRFx tank has, carries that same amount quite a few inches Lower than an AF. My alloy drop tank carries fuel inches again lower- 7.5 / 8litres carried below the cylinder/head junction.

What you do get, especially with the LM 4t chassis, is much lighter ancillaries - that's the benefit you get from all the 4t development and the pursuit of light weight by the factories. A good example is the weight difference between a steelie KS and a CRF450 one: it's been a while, but I think it's over a pound, at the least. and it's made out of better alloy, so it isn't weak. Smaller caliper (rear) , thinner plastics etc etc. To the best of my recollection, I think the swingarm/linkage combo on the steelie is only lighter than a 450 set by a few grams, so probably the same as 125/250F units.

When you have the fact that AF Donors are a dime a dozen over in the US ( not here though ) , and you get a cheap, modern ( if you are using a LM chassis) , hopefully not worn out, upgrade for your old beast. It's an entirely logical way to keep riding the engine you love. But it's complete bullshit that an AF is massively lighter than a Steel 500. You always need to weigh like for like - heavier tyres and tubes can make a difference of almost 20lbs, if you go to extremes, either way, for example. Fuck knows what MXA were doing when they claimed that the steelie they tested against a CRF was 245lbs(?), as the same bike they tested in 2001, they weighed at 233lbs - I think they were leaning against the steelie or just showing their typical level of bullshit. I just started to clean up the IMS tank (to sell it) I have removed for my alloy tank and was surprised that it was slightly lighter than the std 500 tank. So even before the more severe legislation for fuel leaching, Honda made an effort to contain fumes with thick tanks.

This isn't knocking AFs, I've got a Gen1 stored away and a 07 gen3 that I've lent to a mate, and I've made quite a few others. But I'm always left scratching my head about the weight loss people claim for AFs. And they sure as hell don't feel lighter in riding to me, Unless you have the aforementioned desert tanks full to the brim - then they do feel like tanks, as would an AF with a big tank.

good info yota. i do recall the xr650r came out with the alloy frame that was 3kg heavier than its steel predecessor.
and bob, i think some y sections are hollow. ive seen the honda ones reused once the welds are grinded away.but yes, all the billet ones i think are solid.
this makes the justification to keep my steelie all the more worth while, but i wonder what the wet weight for both bikes is "complete" on the scales!

Not hollow....

hey, that was almost a year ago, are all those bikes built????

Yea, their at the "Powdercoaters".....

AlisoBob wrote:

Not hollow....

those are not finished. he did more machine work before assembly.
just sayin...

just noticed those 2 holes in the underside of the Y, need to look at those tonight.