Bent subframe on MX bike [Archive]

Stylo

18th February 2016, 16:17

Crasherfromwayback

18th February 2016, 16:57

I've got a rear sub-frame of a KX500 that is quite badly bent, all in one piece just needs straightening, not cracked at all.

Everything hangs on it or under it, seat, muffler - like a big triangle on both sides you know how it goes ..

Don't have the tools to do it myself. Is there someone who could do this if I took the bike in ? I live in CHCH.

It's actually quite easy to do yourself. Strip all the bits off (sidepanels, muffler, seat etc etc), lie bike on its side...big bar through the subframe...bend away.

Stylo

18th February 2016, 17:19

It's actually quite easy to do yourself. Strip all the bits off (sidepanels, muffler, seat etc etc), lie bike on its side...big bar through the subframe...bend away.

Problem is it looks like this one has landed on the r/h side rear end so, that side has been pushed forward so it's actually bulging outwards on the muffler side as well as being twisted. The air box is now completely out of square.

I guess new parts are out of the window seeing they stopped making the bike 12 years ago ..hmmm

Crasherfromwayback

18th February 2016, 17:59

Problem is it looks like this one has landed on the r/h side rear end so, that side has been pushed forward so it's actually bulging outwards on the muffler side as well as being twisted. The air box is now completely out of square.

I guess new parts are out of the window seeing they stopped making the bike 12 years ago ..hmmm

Still no problem. Post a pic, and I'll describe where to put the bar etc.

F5 Dave

18th February 2016, 21:37

I got a wrecking bar from bunnings for not that much. Its totally straight about 2M long with a flat chisel point at one end. So much leverage that you can do some subtle things. The flat is kinder on the tubes, but some ally can spread the load.

Worst case cut out irreparably damaged tube and weld in a new section after the rest is straight.

Stylo

19th February 2016, 07:12

Here we go ...

F5 Dave

19th February 2016, 07:48

. . . shhika shhika shhika. . .

. . . bbzzzzzz. bbzzzzz.

flashg

19th February 2016, 08:16

Is it removable ? If so, take it off and get someone to do it. Take some measurements of the anchor points, to give them a reference. Any small engineering company could straighten it as long as they have a tig to weld any cracks that might appear. Good luck.

Crasherfromwayback

19th February 2016, 11:02

Here we go ...

Ummmmm...that's actually fucked! How did ya do that? We could straighten it, but you may fuck it doing so. May be cheaper to find one on Ebay.

Stylo

19th February 2016, 15:42

Ummmmm...that's actually fucked! How did ya do that? We could straighten it, but you may fuck it doing so. May be cheaper to find one on Ebay.

Yeah I'll explore the getting fixed option before I look at E-bay etc. Think my chances of finding another one anywhere will be pretty slim though.

How did I do it ? Throttle jammed on full in 4th, you can guess the rest ....

Stylo

19th February 2016, 16:43

Another pic .....

flashg

19th February 2016, 16:58

Can't see a better angle of that sub frame. Not a fan of those two piece handlebars though.
Are you ok Mark ? Hope you bailed in time

Stylo

19th February 2016, 17:30

Can't see a better angle of that sub frame. Not a fan of those two piece handlebars though.
Are you ok Mark ? Hope you bailed in time

Everything's fixable thanks Flash, no time to bail the wheel came up as I realised my throttle wouldn't respond to the off command.

Bike decided it didn't need me anymore so I was dumped at a good rate of knots. I'm now on ACC for a little while .....

flashg

19th February 2016, 17:45

Everything's fixable thanks Flash, no time to bail the wheel came up as I realised my throttle wouldn't respond to the off command.

Bike decided it didn't need me anymore so I was dumped at a good rate of knots. I'm now on ACC for a little while .....

All true about things being fixable.
I hope you mend well and quickly.
My time on ACC is over, I got the all clear, knee is 100%. Back to work Monday

nzspokes

19th February 2016, 18:16

Do you know anybody with a portapower? Looks to just need stretching back out. But if its steel I would just get that bit on tube replaced.

Crasherfromwayback

19th February 2016, 18:25

. But if its steel I would just get that bit on tube replaced.

They're alloy.

bogan

19th February 2016, 18:26

I'd be looking to cut out and replace that piece entirely if the rest of the subframe is pretty ok, wouldn't be too difficult as long as you can get it back into shape so a fabricator can just make a bit to suit and weld it in situ.

Do you know anybody with a portapower? Looks to just need stretching back out. But if its steel I would just get that bit on tube replaced.

If it's anything other than steel, it's probably fucked from going passed the fatigue point. And it looks like ali.

Stylo

19th February 2016, 18:49

All true about things being fixable.
I hope you mend well and quickly.
My time on ACC is over, I got the all clear, knee is 100%. Back to work Monday

God for you mate, enjoy your work on Monday.

I'm good apart from a dislocated AC shoulder joint and a leg broken in two places, ankle included. Cracked ribs and internal bruising.

Could have been a lot worse as my Doctor said :yes:

F5 Dave

19th February 2016, 19:03

Stylo

19th February 2016, 19:14

Yeah just fixed up from stuck throttle, quite unpleasant. Two operations.

On my dirt bike I had stuck throttle but I'd saved it in time being lucky where it happened a few times. Do you know what caused it? Most likely is cable, or duff throttle esp those whirlpool ones (which finally got me on the track) but the dirt bike had some grit perhaps and it got between the needle and jet. Replaced needle and it did it again. Look for scratching on needle. Nothing should cause that.

Thanks Dave, I'll get the bike up on it's stand sometime soon, strip it down and have a look at the cause.

Can't do it for a while until I get the cast off my leg and the arm out of the sling

The bike I was riding had only around 47 hrs from new but very little ride time in the last 5 years ...

flashg

19th February 2016, 19:50

God for you mate, enjoy your work on Monday.

I'm good apart from a dislocated AC shoulder joint and a leg broken in two places, ankle included. Cracked ribs and internal bruising.

Could have been a lot worse as my Doctor said :yes:

Ouch mate, you're a mess. No more rides for you for a while. Hope your recovery goes to plan. Keep your chin up.

Stylo

21st February 2016, 16:07

I see AC Racing in the US have them for $240 = around $365 in NZD, the freight on top would be the killer plus any GST that might apply.

Will still explore the getting fixed option first ...

http://acracing.com/product/ac-racing-kx500-subframe-607.htm

Stylo

21st February 2016, 16:13

319843319844
Ouch mate, you're a mess. No more rides for you for a while. Hope your recovery goes to plan. Keep your chin up.

Thanks but it could have been a lot worse mate . The good thing about the disabled scooter thing that ACC has provided is it has a basket on the front. Great for throwing bit's off the bike into today as I crawled around the garage floor with my socket set and tools in a bag beside me ;)

These pics are better ..

Crasherfromwayback

21st February 2016, 20:50

[
These pics are better ..

I did say you'd be better off to buy one.

http://www.ebay.com/itm/88-1988-KX250-OEM-ALUMINUM-SUBFRAME-REAR-SUPPORT-CHASSIS-/262260061456?hash=item3d0feaf510:g:PHEAAOSw3KFWfzZ p&vxp=mtr

http://www.ebay.com/itm/KX500-KAWASAKI-1988-KX-500-88-SUB-FRAME-ALUMINUM-/400916724115?hash=item5d587fb993:g:iNsAAOSwqu9VTlf Z&vxp=mtr

http://www.ebay.com/itm/1992-92-Kawasaki-KX-500-Subframe-Sub-Frame-Rear-Frame-Free-Shipping-/321960182139?hash=item4af652817b:g:-gkAAOSw3KFWgKXx&vxp=mtr

Stylo

22nd February 2016, 19:05

I did say you'd be better off to buy one.

http://www.ebay.com/itm/88-1988-KX250-OEM-ALUMINUM-SUBFRAME-REAR-SUPPORT-CHASSIS-/262260061456?hash=item3d0feaf510:g:PHEAAOSw3KFWfzZ p&vxp=mtr

http://www.ebay.com/itm/KX500-KAWASAKI-1988-KX-500-88-SUB-FRAME-ALUMINUM-/400916724115?hash=item5d587fb993:g:iNsAAOSwqu9VTlf Z&vxp=mtr

http://www.ebay.com/itm/1992-92-Kawasaki-KX-500-Subframe-Sub-Frame-Rear-Frame-Free-Shipping-/321960182139?hash=item4af652817b:g:-gkAAOSw3KFWgKXx&vxp=mtr

Thanks Crasher, I'll have to wait until I get this cast off my leg and my arm out of the sling before I take it any further.

Might start with a set of bars first then strip it right back for the re-build. Only about 48hrs on the bike since new so it's worth doing it right. Agree ?

F5 Dave

22nd February 2016, 19:27

Yeah trying to work in a sling just results in you using the bits you are trying to heal.

But you can surf for new bits.

Crasherfromwayback

22nd February 2016, 22:35

Thanks Crasher, I'll have to wait until I get this cast off my leg and my arm out of the sling before I take it any further.

Might start with a set of bars first then strip it right back for the re-build. Only about 48hrs on the bike since new so it's worth doing it right. Agree ?

Yeah trying to work in a sling just results in you using the bits you are trying to heal.

But you can surf for new bits.

Aye. Waiting for shoulder surgery myself. Been five months now. As Dave says though...still surfing/buying...

F5 Dave

1st May 2016, 20:31

Now you get to think of good ways to bend it again.

Askor

3rd May 2016, 09:33

I may have a subframe in my garage you can have..

Askor

3rd May 2016, 13:24

Something like this?

321307

Crasherfromwayback

3rd May 2016, 16:32

Something like this?

That looks correct!

Asher

3rd May 2016, 20:29

If you want to try and get it straightened talk to Corey Taylor (https://www.facebook.com/davinci1nut/?fref=ts)

The guy is a magician at fabricating and fixing bikes.