2009 Rumours-E Start?

i highly doubt the carbon fiber subframe.
One reason such skepticism might be well founded is that the FIM has a rule against CF body work on the grounds that the sharp edges of broken parts are more dangerous than plastic or bent metal.

That CF could be made strong enough is not in question, however. The springs in several GM cars are now made from CF, and have been for 25 years. The 85 pound stacked steel rear leaf of the 1981 Corvette was replaced in 1982 by a CF single leaf weighing about 5 pounds. I've seen 'Vettes dragged into the body shop that had the rear suspension ripped away in a crash and the only thing left where the wheel used to be was the undamaged rear spring sticking out.

Gray, how do you know so much?! :worthy:

He watches the Science Channel :worthy:

How its made :worthy:

Build it bigger :worthy:

Brainman :eek:

Cool Fuel :eek:

It's all Geek to me :worthy:

You know the shows all the know it alls watch.

:crazy::goofy::foul::moon:

I am kidding.

Keep up the good work grey!

Gray, how do you know so much?! :worthy:
I don't remember.

yamaha started the thumper revolution and now they are playing catchup?

RMZ EFI and aluminum tank

CRF 150 and 230

KTM e start.

I guess the combined effort has lead to new generation perimeter frames, high performance 4 stroke engines, twin chamber forks and EFI. a lot of change in 10 years.

If a bike came stock with a carbon fiber subframe, I'd be the first in line to get rid of it and find an aluminum replacement.

I hate carbon fiber, and I think it has no place on a dirt bike.

Doesn't really matter though, since it wont happen anyway.

what would be your objection?

From my experiences and from what I've seen, I just don't believe it to be a very durable material for off-road use.

I had a set of Lightspeed CF case guards on the 250F we had. They held up perfectly. In one instance, my son tagged a rock with one, and the impact knocked him down, broke a chunk off of the rock, and did nothing worth noting to the case guard.

It stands to reason that CF would be more subject to damage in an off-road environment from chips and abrasion than aluminum, or at least it seems to, so I see your point. But in practice, a sub frame really isn't subject to much of that kind of wear, and CF would certainly better resist being twisted into a pretzel in a high side, endo, or a wheelie gone bad.

^^^ Ya CF is some crazy strong sh*t! I tried to modify my CF frame protectors by moving the holes over a bit and it took me a half hour and 3 drill bits. I was VERY supprised... Just my experience though

Does anyone know why the RMZ450 has an aluminum tank? What is the reasoning behind that?

Does anyone know why the RMZ450 has an aluminum tank? What is the reasoning behind that?

Wish I had solid info for you, but I had read on another thread that it was to keep the fuel cooler.

Gray,

I agree that EFI alone "shouldn't" add that much weight, but why does the new RMZ weigh 15 lbs more than a CRF450 or YZ450?

I don't know. What did the old RMZ weigh?

If I remember correctly, the old RM-Z weighed 232 (or 233) lbs.

So, then, is the EFI RMZ 15 pounds up on that?

what's a rumour?

j.k

Wish I had solid info for you, but I had read on another thread that it was to keep the fuel cooler.

it's because the fuel needs to be pressurized.

So, then, is the EFI RMZ 15 pounds up on that?

All the tests I've read say the EFI version is 240 dry.

Also, the fuel has to be pressurized AND the aluminum tank offers a very solid mount (compared to plastic) for the fuel pump (it's housed in the tank).

here are the weights of the 08 big 4s.

CRF 229

YZF 230

KXF 237

RMZ 239

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