Bent Subframe..........

[kartras]

Anyone got any ideas on how or who to straighten a subframe rail?

Just got my hands on a ZX6r subbie for the ole '93 GSXR 750 wp but the frame is bent was hopin to get it straightened before trying to fit to the ole girl.

I am on the Sunny coast if any one can recommend anyones services or if it aint to difficult I'll give it a go.

Any ideas??

[Mishdog20]

Chuck up a few photo's on here mate so we can get an idea about how bent it is Pretty hard to make an assessment without seeing the damage.

[BANDITROD]

i swear zx6r's are made from paper machae

[ozzy1100]

throw up the pics, there is a place at loganhome that is good from what i hear they are doing my frame as i dont want to wait till
i finished sharky's swing arm to put in in my jig and learn how to do it
or there are a few of us on here that could do it for beer money or parts for old kwaka's lol

[kartras]

Here is a piccy...any ideas? I reckon both Top and bottom rails are bent http://i1153.photobucket.com/albums/p504/kartras/ZX6rearend002.jpg

[kartras]

And another:
http://i1153.photobucket.com/albums/p504/kartras/ZX6rearend009.jpg

[kartras]

Do ya reckon I would have to open that long weld and straighten both rails individually and then get the weld re done?

[Mishdog20]

I'd probably just try bending it back gently, but i am a cheapskate...lol

[BANDITROD]

lol i tried to straighten the zx6 one i had a while ago and it didnt end well i ended up buying another one as it was cheaper than getting it fixed

[Kramer]

I think i have a subframe that looks similar too that in the shed.

[Kramer]

if you want it you better grab it now cos im gonna chop it in half in the morning ay.

[kartras]

Hey Kramer, PM sent

[kartras]

Yeah gettin a professional job done is gonna be exy.I reckon I may have to try straightening it myself. Lets hope it end better than it did for Banditrod....unless........anyony got an 03-04 ZX6r subbie lyin about they want rid of.......:)

[RevHead]

1657id try twisting it to try and pull these out 1st so both rails line up , with the front mount work on the lines ,bends first if you get the back out thatl be most of the problem solved

[kartras]

With or without heat??? I can kinda see where the bend is on both rails . the bottom is bent a bit more , twistin the top one slightly.

[RevHead]

dont heat itl fuck the alloy do it cold .

[Kramer]

yeah sorry dude im thinking of keeping it now.

[kartras]

dont heat itl fuck the alloy do it cold .

I spoke with a guy in brissy who straightens frames, subframes et al and he said to try and apply heat, just enough and then try to bend???? I am confused but I confuse easily

[ozzy1100]

if u use heat there are two old tricks to use to control heat
one is a soap mark and the other is to sout the ally with acetiline only before adding the oxxy
both you heat to they begin to disaper thats thats as hot as u dare go
i have never done it but just the way i was told and that was long ago so goggle is your friend

[kartras]

Yeah ozzy1100 I heard something similar. Mark with a black texter and when it dissapears its hot enough...no hotter

[Redmohawk]

The good news is your bent frame is most likely 6000 serise ali (heat treatable for hardness) So If you heat it to bend it the anealing (hardness can be retained) to soften your piece to straighten :-

Use an oxy torch with a small heating tip (you want broad heat not intense consentraighted) light torch no oxy carbon flame wave it over where you want to aneal till ally is black with carbon soot

Turn on oxygen and get a good balanced neural flame then heat using a waving motion similar to putting paint on , to spread heat evenly (Ali will soften at 370 deg c ruffly and melts at about 650 deg c so be gentle go easy) work heat over piece till carbon black you deposited with gas only flame is burnt off and you should be at about the right temp.

Now let it cool for an hour , waste of time trying to bend it hot as Ali doesnt go plastic at temp (well it does about 20 deg below melting but I know I cant get it just right with a lazer noncontact thermo so using a crayon or carbon black will do fuck all or give you a puddle lol)

Once its cool it will be as soft as its going to get, bend it. If your worried it will be to soft once you've straightened it to ride , I wouldnt bending it will most likely bring it back to close to what it was before ! And over time it will reharden anhow.

If by chance its work hardened ali (not likely on a bike frame) same deal really. You just wont be able to reharden it with heat , time and vibration riding it on your bike will though.

Good luck.

On a side note an elcheapo heatgun with heat control on the back (mine is a ryobi) Has a dial heat set on the back and thermo couple tells me the output them and cost $35 I think it will go to 420 deg c so easy way to heat to about the right temp and no risk of a puddle of ali on the floor with a oxy set ! Cheaper to buy than oxy to if you dont have !

[kartras]

Great info Redmohawk...thanx.. Yeah I have one of those heat guns(no oxy set:( ) so I reckon i'll give it a go .

So in recap heat to about 370 deg C and let cool and try to bend. and fingers crossed

Cheers matey

[Redmohawk]

thats it mate

[kartras]

Thanx for that matey...despite what everyone says I reckon your alrite

[Redmohawk]

I'm a cunt , just ask my ex's

[bluedrags]

http://www.ebay.com.au/itm/Handlebar-and-Subframe-Straightener-Tool-/300412120066?pt=Motorcycles_Parts_Accessories&hash=item45f1f52c02#ht_1490wt_689