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
![Mad :x](./images/smilies/icon_mad.gif)
) , 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.