supercross THE BIGGEST TEAM

[KABLEXXL Biden 2021]

California will be limiting dirt bikes in the next few years, gas engine off road bikes are on death march, so don't hold your breath.

Edited December 26, 2020 by KABLEXXL Biden 2021

[KTMRider4Life]

20 hours ago, indy rider said:

Yea...that bike landed on a broken KTM that was laying in the middle of the track. 

Yamaha crack welds. KTM's break in half. 

When questioned about broken framed Yamaha's answer was it's normal for frames to break, this has been a manufacturing problem for some time they've failed to address. Shitty robotic welds. is anyone surprised though? Aluminum frames are cheap junk that dumb consumers think are better and lighter than steel. 

Edited December 26, 2020 by KTMRider4Life

[KTMRider4Life]

On 6/6/2016 at 7:14 AM, GBowman said:

Maybe you should Google 2014-16 yz250f frame problems. 

 

20 hours ago, indy rider said:

@MotorBoatin so you want to play. We can do this all day.

 

Garry setting me straight....

[MANIAC998]

54 minutes ago, KTMRider4Life said:

 

Garry setting me straight....

[KTMRider4Life]

1 hour ago, MANIAC998 said:

Many threads here on TT about the broken frame Yamahas and people contracting Yamaha and them denying warranties and practically new bikes.  MXA even did a story on it. 

[MANIAC998]

18 minutes ago, KTMRider4Life said:

Many threads here on TT about the broken frame Orange KTM’s and people contracting them denying warranties and practically new bikes.  MXA even did a story on it. 

Fixed

[KTMRider4Life]

29 minutes ago, MANIAC998 said:

Fixed

Funny if you google MXA KTM broken frame it brings up a link to Yamahas broken  frame problem 😂😂😂😂😂😂! You couldn’t make up a funnier story.  Gary said 14-16 but the problem goes back to 07 at least. 

[mxaniac]

The weld and adjacent zone is often only 25% of the strength of precipitation hardened aluminum.  That's why you shouldn't ride homegrown AF conversions!

I estimated that flat landing a triple could result in up to 19g, not a trivial load in the frame.

Aluminum doesn't hold up to high cycle fatigue as well as steel, and in fact has no INFINITE LIFE CYCLE which means eventually it will ALWAYS break.

I think the transition to aluminum frames actually went very smoothly compared to how badly it could have gone.  It wasn't perfect, but for most people it hasn't been catastrophic either.

[redrider144]

7 minutes ago, mxaniac said:

The weld and adjacent zone is often only 25% of the strength of precipitation hardened aluminum.  That's why you shouldn't ride homegrown AF conversions!

Unless there is post weld heat treating (6XXX alloys), right?

"There is one final alternative to discuss. If after welding, the structure is given a complete heat treatment (i.e., solution treat at 1000°F [540°C], quench, age at 400°F [205°C]), all of the material properties (even in the weld) will be recovered and T6 properties will be obtained. This practice is frequently followed on small structures such as bicycle frames, but it is impractical for larger structures. Furthermore, the quenching usually causes enough distortion of the structure that a straightening operation is necessary before aging."

Link to source

Edited December 26, 2020 by redrider144

[777654321]

5 hours ago, KTMRider4Life said:

When questioned about broken framed Yamaha's answer was it's normal for frames to break, this has been a manufacturing problem for some time they've failed to address. Shitty robotic welds. is anyone surprised though? Aluminum frames are cheap junk that dumb consumers think are better and lighter than steel. 

From first hand experience I feel the aluminum frame issues is a direct result of not preheating along with post cool down procedures. 

[Momus]

On 12/26/2020 at 2:36 AM, MotorBoatin said:

 

These photos appear to be the failure of welds joining two castings, not wrought 7000 series, 7005 most likely, extrusions.

Comments regarding age/precipitation hardening of that material are a bit irrelevant.

Goodness knows what grade of material they are casting, and how they are doing it- sand, metal dies, investment/ shell moulds and so on but likely either/or 355, 356 or possibly 357 in ascending order of strength- and difficulty are commonly used for high performance castings. Casting shapes has much more of an artisan aspect to it than working with wrought material whose composition, impurity level and characteristics can be closely controlled, so issues, particularly iron contamination, can become a problem.

The welding wire grade for joining castings- which may be dissimilar and sourced from different foundries (some in red China?) would likely be work in progress. 

 

 

Edited December 26, 2020 by Momus

[777654321]

24 minutes ago, Momus said:

These photos appear to be the failure of welds joining two castings, not wrought 7000 series, 7005 most likely, extrusions.

Comments regarding age/precipitation hardening of that material are a bit irrelevant.

Goodness knows what grade of material they are casting, and how they are doing it- sand, metal dies, investment/ shell moulds and so on but likely either/or 355, 356 or possibly 357 in ascending order of strength- and difficulty are commonly used for high performance castings. Casting shapes has much more of an artisan aspect to it than working with wrought material whose composition, impurity level and characteristics can be closely controlled, so issues, particularly iron contamination, can become a problem.

The welding wire grade for joining castings- which may be dissimilar and sourced from different foundries (some in red China?) would likely be work in progress. 

 

 

Most commonly aluminum wire used is a 50 series or 60 series strength wire. I know 4043 wiil stick to everything and  will flex better. Ive seen an entire pallet of bad wire usually an innershield type but bad batches happen. It all comes down to quality control. I just hope people aren't getting injured. I will never forget seeing that KTM break off the front stem in SX. Ive seen cracks on several brands. 

[mxaniac]

3 hours ago, redrider144 said:

Unless there is post weld heat treating (6XXX alloys), right?

"There is one final alternative to discuss. If after welding, the structure is given a complete heat treatment (i.e., solution treat at 1000°F [540°C], quench, age at 400°F [205°C]), all of the material properties (even in the weld) will be recovered and T6 properties will be obtained. This practice is frequently followed on small structures such as bicycle frames, but it is impractical for larger structures. Furthermore, the quenching usually causes enough distortion of the structure that a straightening operation is necessary before aging."

Link to source

Correct, and other grades.  I believe in general it's the grades without magnesium.  I heat treated my AF frame after welding.

[MotorBoatin]

40 minutes ago, Momus said:

These photos appear to be the failure of welds joining two castings, not wrought 7000 series, 7005 most likely, extrusions.

Comments regarding age/precipitation hardening of that material are a bit irrelevant.

Goodness knows what grade of material they are casting, and how they are doing it- sand, metal dies, investment/ shell moulds and so on but likely either/or 355, 356 or possibly 357 in ascending order of strength- and difficulty are commonly used for high performance castings. Casting shapes has much more of an artisan aspect to it than working with wrought material whose composition, impurity level and characteristics can be closely controlled, so issues, particularly iron contamination, can become a problem.

The welding wire grade for joining castings- which may be dissimilar and sourced from different foundries (some in red China?) would likely be work in progress. 

 

 

Bla Bla Bla

Yamaha frames broke. That’s all that matters 

[Piney Woods]

Was at the Astrodome SX way back when and just going thru the pits. Was looking at a KTM with the twin/split downtubes and noticed one of them broken completely. This was when practice was going on. The rider was so busy with stuff he hadn't noticed the break. I hated to tell him but didn't want to see him get hurt. The look on his face broke my heart.  He was a privateer from the midwest somewhere traveling in a typical van. Really felt sorry for him, don't know what he did.

Edited December 26, 2020 by Piney Woods

[MANIAC998]

8 minutes ago, Piney Woods said:

Was at the Astrodome SX way back when and just going thru the pits. Was looking at a KTM with the twin/split downtubes and noticed one of them broken completely. This was when practice was going on. The rider was so busy with stuff he hadn't noticed the break. I hated to tell him but didn't want to see him get hurt. The look on his face broke my heart.  He was a privateer from the midwest somewhere traveling in a typical van. Really felt sorry for him, don't know what he did.

Piney, you can’t come in here and start bashing the Orange brand.

Bashing is strictly reserved for the Blue Bomber division here in Pro.

 

 

(You really should have known)

[mxaniac]

 

1 hour ago, Momus said:

These photos appear to be the failure of welds joining two castings, not wrought 7000 series, 7005 most likely, extrusions.

Comments regarding age/precipitation hardening of that material are a bit irrelevant.

Goodness knows what grade of material they are casting, and how they are doing it- sand, metal dies, investment/ shell moulds and so on but likely either/or 355, 356 or possibly 357 in ascending order of strength- and difficulty are commonly used for high performance castings. Casting shapes has much more of an artisan aspect to it than working with wrought material whose composition, impurity level and characteristics can be closely controlled, so issues, particularly iron contamination, can become a problem.

The welding wire grade for joining castings- which may be dissimilar and sourced from different foundries (some in red China?) would likely be work in progress. 

 

 

I have no idea what they are casting with either but many grades of cast aluminum can be age hardened, so I don't see how it's irrelevant.  Obviously your extrusions would have to work with a similar time and temperature if you're post weld hardening.   

[Chaconne]

1 hour ago, 777654321 said:

Most commonly aluminum wire used is a 50 series or 60 series strength wire. I know 4043 wiil stick to everything and  will flex better. Ive seen an entire pallet of bad wire usually an innershield type but bad batches happen. It all comes down to quality control. I just hope people aren't getting injured. I will never forget seeing that KTM break off the front stem in SX. Ive seen cracks on several brands. 

^This^  Exactly right.  The source doesn't matter. They bought the shit they should QA it. A pile of shit from the US, China, India, or Japan is still a pile of shit.

Reminds me of these other corps who source stuff on the cheap and try cheap out on the QC too. And then blame source when customers complain about the shit quality.

[777654321]

22 minutes ago, Chaconne said:

^This^  Exactly right.  The source doesn't matter. They bought the shit they should QA it. A pile of shit from the US, China, India, or Japan is still a pile of shit.

Reminds me of these other corps who source stuff on the cheap and try cheap out on the QC too. And then blame source when customers complain about the shit quality.

If you buy the cheapest filler material there's a reason why its so cheap. How you doing . You gonna try to go to the TKO. 

[Chaconne]

3 hours ago, 777654321 said:

If you buy the cheapest filler material there's a reason why its so cheap. How you doing . You gonna try to go to the TKO. 

Things are better my mom seems to have dodged the RONA bullet. Yes I am thinking of driving down to TKO hope to see you guys.