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bboyce

Bent my subframe...

13 posts in this topic

I crashed pretty hard at my local track, I got sideways off a big double, and landed on the very edge of the landing, in really soft crap and it sent me tumbling over the bars.

Its not to bad, but its enough to make my fender sit fairly crooked and when i took my fender off, I could barely get it back on. I tired to bend it back, but no go. I guess I just wanted to vent...:applause:

Oh, and last time I pulled off my Twin Air air filter, I had a film of dust in my airbox boot. I am stumped. I checked the airfilter seal, and it was good and sealed. I pulled it off and it was oiled well. I still can't figure it out. Is this because im riding in very dusty conditions? I normally slightly over-oil my filters to be sure, so I thought it was very odd that some dust was still getting through.

Well thanks for reading.

BBOYCE

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The layer of dust is usually due to one or more of a few different things. Foam filters work by forcing the air to make a series of turns as it passes through the media. The assumption is that the dirt, being heavier than air, won't be able to make the turn, and will collide with the walls of the foam. As long as there is something sticky there to catch and hold it, it will be removed from the air stream. But if the oil is already coated with dirt, it can't hold, and the dirt goes deeper in search of something to stick to.

So that layer of fine stuff is the result of:

> An air filter that wasn't serviced often enough, or,

> A filter that wasn't oiled well enough,or with a tacky enough oil,

Or, it might also be simply a matter of the dust being so fine, and the air velocity that carried it in was so low, as under part throttle situations, that it actually was able to navigate the filter without getting caught. Not as likely as the first two causes.

One of the things I noticed about the '06 compared to the '03 is that the air box gets much dustier much more quickly, and it's to where I change the filter about twice as often as I do on the '03. That seems to have gotten rid of that little haze on the air boot for me.

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You can bend the subframe back with a 2 x 4 most of the time. Take the fender and airbox off and lean bike against a tree and start prying away at it. Ussually you can get it pretty close to normal. I have also used a car jack to lift it back into place but just be careful not to over do it.

Lastly,a be sure your exhaust is not hitting your rear brake caliper on full compression of the shock. If it is it will result in some more costly damage.

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You might also want to familiarize yourself with what "straight" looks like. The '06 sub is a little bit asymmetrical in the first place.

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I bent the subframe on my 07 and after trying just about every way to get it straightend, I finally ordered a new one. I bent my subframe several times on an 01 YZ250 and was able to straighten it successfully. This YZF is a biach! when it comes to the subframe

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Yea, I noticed yesterday as I tried to bend it back. I got it so the fender and everything looks straight, but it appears that I actually crushed it in just a little bit.

I guess its just something I am going to have to live with...:applause:

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I guess its just something I am going to have to live with...:applause:

Yep...if you haven't bent your subframe then your aren't riding hard enough. It happens...that's why we wear helmets!

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Thanx guys, good advices. I have the same problem after a crash doing hill-climb. Bent the exhaust header and the subframe(YZ450 2006). I will try to bend my subframe back tomorrow. A second hand header will arrive soon by mail...

I wish I could finally find a left radiator to fix my YZ426 2000 and RIDE when my 450 is grounded !!!

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what ever you do dont buy an AC racing unit. Never heard them fitting anything.

I know the YZ is hard to not center the filter cage on the airbox, but it could happen. be sure to grease the filter lip also. inspect your filters for tears also.

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what ever you do dont buy an AC racing unit. Never heard them fitting anything.

I know the YZ is hard to not center the filter cage on the airbox, but it could happen. be sure to grease the filter lip also. inspect your filters for tears also.

So true AC racing sub frame is crap....get one off of e-bay. Not sure what yr you have but 06 yz250\450 through 09 will fit.

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If you guys want a tip, to bend aluminum, heat up the bent area with propane, and bend it ONCE and once only ! The aluminum softens up and will bend easier with heat. The heat process also unfortunately will make the aluminum more brittle thereafter, so before you do this make a judgement call as to if heating is the best solution in your peticular case...

I remember years ago getting a tip from a seasoned pro buddy of mine about bent radiators.... his tip was to LEAVE them bent and don't try to bend them back into shape.

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Today I used 2 pieces of 2x4 between my subframe's rear end to keep the correct spacing. With the fender and airbox off I leaned the bike against a tree and started prying away at it. In fact I had to bang the subframe pretty hard against the tree several times to bend it back to normal. I placed my rear fender into position to check if it looked straight. I used a string with a weight to check if the middle of the fender was in line with the rear tire in vertical position for fine tuning with the final hit...

My rear fender was 2 inches to the left, the muffler was touching the rear tire under compression. Now everything is straight and normal, NO DAMAGE !!!

Thanx for your good advices .

BRRRAAAAAAAAAAAAAAAAAPPPPP !!!

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Today I used 2 pieces of 2x4 between my subframe's rear end to keep the correct spacing. With the fender and airbox off I leaned the bike against a tree and started prying away at it. In fact I had to bang the subframe pretty hard against the tree several times to bend it back to normal. I placed my rear fender into position to check if it looked straight. I used a string with a weight to check if the middle of the fender was in line with the rear tire in vertical position for fine tuning with the final hit...

My rear fender was 2 inches to the left, the muffler was touching the rear tire under compression. Now everything is straight and normal, NO DAMAGE !!!

Thanx for your good advices .

BRRRAAAAAAAAAAAAAAAAAPPPPP !!!

Just be watchfull of newly developed stress cracks right near the welds when persuading aluminum back into position...

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