frame weight steel vs alum

[AlisoBob]

Thats the upper section I told you was milled out, the holes are prolly' vents to let trapped ( expanding) gasses out while being welded....

[thestuz]

Not hollow....

sorry bob, i didnt make it clear. i said some people were re using the genuine honda y section which appears to be hollow (which would be my prefered option) and not using billet ones.

http://www.bannedcr500riders.com/board/ ... highlight=

[thestuz]

on the subject of frame weights,i dont suppose some one with a complete steely and a complete af could put them on the scales and compare.?

just weighed my steelie. with barkbusters on and an empty tank, it weighed

2001 STEELIE = 107.5 kg

this was done on very accurate digital scales.


AF = ?

[AlisoBob]

Its not just the weight, its where its located.

Steelies weight more, and the height of that weight exaggerates it even more.

[thestuz]

yeah i understand that the geometry,suspension,layout etc is better. but i was always under the impression the afs were much lighter too. but now im thinking there might only be 1 kg in it.

[AlisoBob]

2001 STEELIE = 107.5 kg

Steelie = 237 lbs + Gas ( 2.5 x 7 =17.5)= 254.5

I put Uncle Crackers (Gen 3) dry bike on two bathroom scales when we built it... Together they measured 218lbs. The bike has no "bells or whistles"....

218 + Gas ( 2 x 7 = 14) for 232 lbs. I Jumped on the scales first, and they seemed accurate.

[gregrobo]

Thats the upper section I told you was milled out, the holes are prolly' vents to let trapped ( expanding) gasses out while being welded....

i would have thought it was for the web on the inside of the extrusion (down tube)

[thestuz]

fuck me! its hard to believe you can save that much weight through the forks,tripples plastics and rear swingarm. i kinda figured the beefier crf swingarm would of been heavier along with there twin cartridge forks(as opposed to the crs light swingarm and one cartridge system).
anyone else got a af with an empty tank they wanna throw on the scales!

[AlisoBob]

soliD brO stole me bike. I'm going to repo it this weekend, I'll weigh mine then.

[thestuz]

tank empty if possible.
when i weighed mine i just put it on the race stand then weighed it all on the electric scales with nothing touching the ground and no balancing issues so it gave me a very accurate reading.
tared the stand of course.

[AlisoBob]

fuck me! its hard to believe you can save that much weight through the forks,tripples plastics and rear swingarm.

Theres a few pounds, just in the seat!

[homenf]

2010 crf250: Curb Weight 226 pounds (Includes all standard equipment, required fluids and a full tank of fuel-ready to ride)

2010 crf250x: Curb weight 253 lbs (Includes all standard equipment, required fluids and a full tank of fuel—ready to ride)

2010 crf450: Curb Weight 234.8 pounds (Includes all standard equipment, required fluids and a full tank of fuel—ready to ride)

2010 crf450x: Curb Weight 269 lbs (Includes all standard equipment, required fluids and a full tank of fuel—ready to ride)

For weight comparisons

http://powersports.honda.com/offroad.aspx

[yota]

all of the manufacturers lie about weight and horse power.

[thestuz]

all of the manufacturers lie about weight and horse power.

x2.

[bearorso]

fuck me! its hard to believe you can save that much weight through the forks,tripples plastics and rear swingarm.

Theres a few pounds, just in the seat!

Your not wrong there! I've got an ultra high seat (it would be perfect for a big bastard like Bob ) that I use when my knees don't bend far enough for my normal, high seat, and it probably weighs an extra 2lbs over that lower seat.

Unless you've got exactly the same sort of accessories from one bike to another ( re my example of tyre/tube combo's) weights from one bike to another are pretty pointless. I do know, that when Dirt Rider had the internet bike builds, the AFX they built up , weighed, according to their scales, 266lbs without fuel. My steelie, with it's massive muffler, huge bash plate, Scotts, side stand, axle pullers, lowered and widened pegs, top bar clamp mounted bark busters, extra shock reservoir ( doubles the oil capacity) shark fins for both disc and change guide, steel rear sprocket, heavy O'ring chain,pipe guards, fans, rad cages ,lights,blinkers, extra wiring loom, Rekluse etc,etc weighed 266.5lbs, without fuel. And I guarantee I had a lot more Enduro equipment on the steelie than the SH AFX. The only thing missing was the rear brake lever & reservoir, that would have been partially made up for by the long brake hose and master cylinder plus clutch lever on the LH bar.

AFs certainly feel very different, but , to me they aren't any lighter. Plus , with the same amount of fuel in them, a steelies 'pannier' style tank, holds the fuel much lower. So, to me, an AF, feels more top heavy.

As I've said, I'm not knocking AFs, but some claims for them are a bit over the top. They are just a modern version of a classic motorcycle, which Honda should have bloody well made.

[thestuz]

Not hollow....

http://i216.photobucket.com/albums/cc24 ... ble022.jpg

was looking at att the builds and found this. looks like mike used to hollow out the top section after all.

[AlisoBob]

looks like mike used to hollow out the top section after all.

Thats what I keep repeating

[AlisoBob]

..... to me, an AF, feels more top heavy.

I have the complete opposite opinion.

[nmdesertrider]

It's a shame he's such a flake- all 3 of our ho-made bikes have problems with cracks( I am completely redoing mine) but the tt bike has held up.

[bearorso]

..... to me, an AF, feels more top heavy.

I have the complete opposite opinion.

Fair enough - one persons feel from a bike can differ entirely from anothers.

I do know that the steel frame is lighter in itself - Gregrobo's picture and testimony are a good illustration of that. Many AF peripherals are lighter, though.

Late model steelie frames are not tanks - geeze, the top tube is the same dia. , yet thinner in the walls than the downtubes on the DH frames that I make. Just using the rough guide of weight differences between Aluminium & Steel (4130 is no lighter than mild steel, just stronger, so less metal can be used) alloy being approximately a 1/3 of the weight of steel, when you compare the dimensions / amount of material in an AF frame, you will see it isn't a feather weight.

And the mass present up high, re the backbone/perimeter rails and HT sections in both frames, has the AF frame by itself being more top heavy. Add in how all the fuel is carried above the engine ( yes, a quantity of fuel on a steelie is carried a bit higher than an AF, but that's when filled with the full 10 litres - the majority of AFs, with the original donor tanks, plus mods to clear the 500 engine, hold a lot less than a std steelie tank) and steelies carry probably at least 4 litres ( more than a US gallon) below the low point of an AF fuel tank. Desert tanks make the fuel height difference even more pronounced, as so much of the extra fuel is held even lower on a steelie, yet the AF desert tanks can only go out & up.

AFs radiators are a bit lower. so they gain a bit back on that front.

I went for a ride today with my steelie, which is heavy with all its off road set up, and my mate who currently has possession of my 07 gen 3, which is set up purely as an MXer for his uses. I'd say that it Is at least 35/40lbs lighter than the CRE, purely because of having nothing added to it. It's a great bike, and I love to ride it every now & then, but if it were to become my one ride, as the CRE is for the foreseeable future, it too would become a tank with all the gear I fit for my riding.

I'd like to have 2 identically set up CRs, 1 AF, 1 steelie, to check the centre of gravity with. I'd say the AF would be slightly higher , without fuel, which combined with the more rigid frame, gives you the feeling of quicker / easier flip flopping, so to speak. A slightly higher centre of gravity is not necessarily a problem, ( though a considerably higher one will be!) it can be a benefit, depending on the feel the designer is after. Centre of mass / concentration of the mass nearest to that centre is yet another thing, and we will be seeing pretty much all manufacturers concentrating on it. That is why I'm so eager to get a few of my own projects finished , so the Gen4 I did for a mate recently can come back in for a airbox /tank position swap. That should be an great thing to ride, and remove the top heavy feel I feel with AFs with a full tank. If you go back when Honda first introduced the Pro Link, their advertising pushed the centre of mass point Much harder than the suspension action.

With how cheaply you US blokes get Good rollers, if you have an old bike, you'd be mad not to do your own AF. Just try to get as young a roller as you can - I prefer the gen 3s as a ride, personally, but even 07s are getting long in the tooth, so it's hard to get a good one. And of course, you'll get gen 4s & 5s in damned near perfect condition from all the idiots who don't take care of their CRF/CRFxs . But I had a fellow recently come to me, with a pristine CRE and a trashed gen1 for a conversion - a 13 year old piece of junk, that was worse than a steelie of that time to ride ( gen 1s are held up quite often as one of the worst handling bikes in recent times - they do work better as a 500 though. And I'm writing this as an owner of one - we made quite a few of them in 97/98 as a bunch of mates , each one took only an afternoon and a few cases of beer to make, dependent on the amount of blokes 'helping', and all except one of us put our engines back into the original frames fairly quickly) so I told him that there was now way I'd do it, and to go away and have a think about getting a much later chassis, in Much better condition. The poor bugger had payed a shit load for the bloody thing and it was trashed.

As I've said, I'm not knocking AFs, they're a good thing, but a L/M , well set up steelie, is far from being a dog, especially as an off road / enduro bike.

[drtrdr]

Besides the weight factor, the componets are newer, parts are easier to come by(frame&suspension) and the plastics look waaaaay better.

[Kuma]

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

just thought that was interesting.

I may have missed it, but did anyone notice that the AF has the swingarm pivot bolt in and the not on the steely? still not going to make up the diff but will put them a little closer together.

[2strokeforever]

i weighed my bike with a questionable heavy duty bathroom scale, i checked to see if it was close and if its out its less than 5 lbs
i put a 2x6 on the scale then balanced bike on it, came up with 146lbs (+ the board) with a full tank of gas, and it washed clean heres what i have on my bike:
2010 500AF
PCpipe+type296
TGT subtank handlebars
cycra handguards
eline carbon fiber kevlar skidplate
unabiker radiator guards
radiator fans
Magura hydraulic clutch
tubliss front and rear
new D952 front, and rear 952 just worn till the grooves (1/8 " wear)
99 250 ignition
full revalve + spring by Ian Mckill
non o ring chain 14/48 aluminum rear sprocket

im guessing it holds 7 liters so 1 liter = 2 lbs
so i figer it weighes 232lbs dry
and i think the Y is solid, and the bottom rails are billit, i dont know if there drilled out, but i like how ill never crush them

[Jeff4510]

those billet Ys he built cracked? they look thin

It's a shame he's such a flake- all 3 of our ho-made bikes have problems with cracks( I am completely redoing mine) but the tt bike has held up.