KTM broke in half.

Luxon MX wrote:

I'm glad the internet engineers have already found the problem and concluded that our product is junk. Can't wait for the internet lawyers to jump in...

I'm glad the internet engineers have already found the problem and concluded that our product is junk. Can't wait for the internet lawyers to jump in too!

I'm not at Atlanta, but from what I can tell at this point is that the pinch bolt at the stem failed, which caused the top clamp to fail, and then the bike to "break in half".

The KTM design uses the top triple clamp to clamp around the steering stem with a pinch bolt instead of the "standard" Japanese bike design where the top clamp is sandwiched between the adjuster nut and the lock nut. It's a pretty elegant design, but if the bolt fails, then the assembly becomes very weak and the clamp will fail. This is the same design that KTM/Husky/GasGas use on all of their stock clamps and factory clamp and multiple aftermarket companies use on their clamps for these bikes.

Here's the actual broken part from today:



You can see the broken bolt on the right, which allowed the clamp to break (on the left). Note the fresh break of the clamp and that there's no fretting or other evidence of a previous crack. That shows this happened all at once and the clamp itself wasn't the problem, it was the bolt. We use bolts that are stronger than the stock KTM bolts (random samples tested to failure for each batch we receive), so either the bolt was over-torqued to the point that it was on the edge of failure, or it came loose and that allowed things to give way.

This is the first failure of this kind for us, but it's not all that uncommon with this general design. Multiple other aftermarket clamps and stock KTM clamps have all failed in the same way. Not because the clamps are bad, but because the bolt failed; most likely because it was over torqued or came loose.

Regardless, we'll take a closer look at the clamps when we get them back to see if there's anything that I'm missing from the photos, but it seems pretty clear cut. If this were a design problem, we'd see this a whole lot more instead of this one incident. Freddie Noren has been on this same setup all year successfully and finished 11th in the 450 class today.

Here's a few examples of the same failure, stock and aftermarket, I'm sure there's plenty more I don't have photos of:

chuckie108 wrote:

Being a generic internet engineer myself- I’d like to know if some of the actual engineers on here have an opinion on this. It appears to...

Being a generic internet engineer myself- I’d like to know if some of the actual engineers on here have an opinion on this. It appears to me that the only way to cause this type of failure would be to load the front wheel with a large force back towards the down tube through the front wheel. Like hitting a wall, or flipping the bike down the track. It’s seams to me, the big forces you’d see during normal riding, casing a triple for example, would load the tripe clamp in the other direction. Point being, all the fear of the Austrian’s “inferior design” may not actually be realistic. Unless you plan on running into a wall anytime soon, or front braking forces rise substantially.

dang472 wrote:

The difference in those factory Suzuki clamps is that they added the pinch bolt as an extra layer of security on top of the normal castle...

The difference in those factory Suzuki clamps is that they added the pinch bolt as an extra layer of security on top of the normal castle nut Japanese way of tightening the steering stem.

MotofactioN wrote:

All I'm saying is, with how communicative Luxon MX is on here with tripleB) clamp questions and situations like this, I will 100% be buying Luxon...

All I'm saying is, with how communicative Luxon MX is on here with triple clamp questions and situations like this, I will 100% be buying Luxon clamps for my new YZ250F later this year. Shows that they actually care about the product and the sport.

wisconsinracer24 wrote:

Werid Suzuki has no problem running a simular design for the factory supported teams.... [img]https://p.vitalmx.com/photos/forums/2022/04/17/544487/s1200_s600_BC4A71D7_A519_4301_9AF0_80972E5F637F.jpg[/img] Makes you wonder, is it the part or the people that...

Werid Suzuki has no problem running a simular design for the factory supported teams....


Makes you wonder, is it the part or the people that are installing/working on the parts that suzuki was thinking about when they went rogue on producing an inferior part according to the internet experts.

Thisusernameisavailable wrote:

Just to screw with your head- when was the last time your torque wrench was calibrated?

suspensionguy wrote:

In no way are those clamps similar. Get your eyes examined. Bro.

Sandusky26 wrote:

Roczen won on OEM Suzuki triple clamps, won a lot.

JM485 wrote:

If you’re going to come into a thread and claim another product is superior and would not have suffered the same failure, I don’t think it’s...

If you’re going to come into a thread and claim another product is superior and would not have suffered the same failure, I don’t think it’s too much to ask for specific reasons why you feel that way. Based on the photos I have seen both clamp designs use the same pinch bolt setup and visually have a similar amount of material in that particular area where the failure occurred, so the only other point of deviation would be material choice. Unless X-Trig is using 7000 series alloys I don’t see enough deviation to make a measurable difference.

JM485 wrote:

If you’re going to come into a thread and claim another product is superior and would not have suffered the same failure, I don’t think it’s...

If you’re going to come into a thread and claim another product is superior and would not have suffered the same failure, I don’t think it’s too much to ask for specific reasons why you feel that way. Based on the photos I have seen both clamp designs use the same pinch bolt setup and visually have a similar amount of material in that particular area where the failure occurred, so the only other point of deviation would be material choice. Unless X-Trig is using 7000 series alloys I don’t see enough deviation to make a measurable difference.

Brent wrote:

1- I never wrote any of the words you claim are mine. 2- it is pointless to share detailed information in this place any more about...

1- I never wrote any of the words you claim are mine.


2- it is pointless to share detailed information in this place any more about anything technical. This forum has become a shit show.

JM485 wrote:

If you’re going to come into a thread and claim another product is superior and would not have suffered the same failure, I don’t think it’s...

If you’re going to come into a thread and claim another product is superior and would not have suffered the same failure, I don’t think it’s too much to ask for specific reasons why you feel that way. Based on the photos I have seen both clamp designs use the same pinch bolt setup and visually have a similar amount of material in that particular area where the failure occurred, so the only other point of deviation would be material choice. Unless X-Trig is using 7000 series alloys I don’t see enough deviation to make a measurable difference.

Brent wrote:

1- I never wrote any of the words you claim are mine. 2- it is pointless to share detailed information in this place any more about...

1- I never wrote any of the words you claim are mine.


2- it is pointless to share detailed information in this place any more about anything technical. This forum has become a shit show.

350ss wrote:

why would ktm design the part asymmetrically like it is? if the bolt fails or is mistorqued than the left side is basically handling all the...

why would ktm design the part asymmetrically like it is?

if the bolt fails or is mistorqued than the left side is basically handling all the load (with a longer torque arm), whereas if it was symmetric and split in the middle like the suzuki pic above, if the bolt fails at least both sides would share the load with shorter torque arms increasing the safety factor. could even go with a two bolt design

maybe putting the split in the middle causes more load to be handled by the bolt as opposed to the clamp

would be cool to see the FEA on this

Luxon MX wrote:

I'm glad the internet engineers have already found the problem and concluded that our product is junk. Can't wait for the internet lawyers to jump in...

I'm glad the internet engineers have already found the problem and concluded that our product is junk. Can't wait for the internet lawyers to jump in too!

I'm not at Atlanta, but from what I can tell at this point is that the pinch bolt at the stem failed, which caused the top clamp to fail, and then the bike to "break in half".

The KTM design uses the top triple clamp to clamp around the steering stem with a pinch bolt instead of the "standard" Japanese bike design where the top clamp is sandwiched between the adjuster nut and the lock nut. It's a pretty elegant design, but if the bolt fails, then the assembly becomes very weak and the clamp will fail. This is the same design that KTM/Husky/GasGas use on all of their stock clamps and factory clamp and multiple aftermarket companies use on their clamps for these bikes.

Here's the actual broken part from today:



You can see the broken bolt on the right, which allowed the clamp to break (on the left). Note the fresh break of the clamp and that there's no fretting or other evidence of a previous crack. That shows this happened all at once and the clamp itself wasn't the problem, it was the bolt. We use bolts that are stronger than the stock KTM bolts (random samples tested to failure for each batch we receive), so either the bolt was over-torqued to the point that it was on the edge of failure, or it came loose and that allowed things to give way.

This is the first failure of this kind for us, but it's not all that uncommon with this general design. Multiple other aftermarket clamps and stock KTM clamps have all failed in the same way. Not because the clamps are bad, but because the bolt failed; most likely because it was over torqued or came loose.

Regardless, we'll take a closer look at the clamps when we get them back to see if there's anything that I'm missing from the photos, but it seems pretty clear cut. If this were a design problem, we'd see this a whole lot more instead of this one incident. Freddie Noren has been on this same setup all year successfully and finished 11th in the 450 class today.

Here's a few examples of the same failure, stock and aftermarket, I'm sure there's plenty more I don't have photos of:

GuyB wrote:

This is an example of one of the things that used to be super-frustrating to me. People want insider info. But then an insider comes here...

This is an example of one of the things that used to be super-frustrating to me.

People want insider info. But then an insider comes here, speaks openly, and spends what was probably a fair amount of time crafting a perfectly reasonable explanation. Then he gets told he's wrong. Eventually, the insider(s) stop responding, and the vacuum is filled with nonsense from people who are speculating, rather than speaking from actual experience.

Meister wrote:

Damn! I totally agree with you for once! Lol

Luxon MX wrote:

I'm glad the internet engineers have already found the problem and concluded that our product is junk. Can't wait for the internet lawyers to jump in...

I'm glad the internet engineers have already found the problem and concluded that our product is junk. Can't wait for the internet lawyers to jump in too!

I'm not at Atlanta, but from what I can tell at this point is that the pinch bolt at the stem failed, which caused the top clamp to fail, and then the bike to "break in half".

The KTM design uses the top triple clamp to clamp around the steering stem with a pinch bolt instead of the "standard" Japanese bike design where the top clamp is sandwiched between the adjuster nut and the lock nut. It's a pretty elegant design, but if the bolt fails, then the assembly becomes very weak and the clamp will fail. This is the same design that KTM/Husky/GasGas use on all of their stock clamps and factory clamp and multiple aftermarket companies use on their clamps for these bikes.

Here's the actual broken part from today:



You can see the broken bolt on the right, which allowed the clamp to break (on the left). Note the fresh break of the clamp and that there's no fretting or other evidence of a previous crack. That shows this happened all at once and the clamp itself wasn't the problem, it was the bolt. We use bolts that are stronger than the stock KTM bolts (random samples tested to failure for each batch we receive), so either the bolt was over-torqued to the point that it was on the edge of failure, or it came loose and that allowed things to give way.

This is the first failure of this kind for us, but it's not all that uncommon with this general design. Multiple other aftermarket clamps and stock KTM clamps have all failed in the same way. Not because the clamps are bad, but because the bolt failed; most likely because it was over torqued or came loose.

Regardless, we'll take a closer look at the clamps when we get them back to see if there's anything that I'm missing from the photos, but it seems pretty clear cut. If this were a design problem, we'd see this a whole lot more instead of this one incident. Freddie Noren has been on this same setup all year successfully and finished 11th in the 450 class today.

Here's a few examples of the same failure, stock and aftermarket, I'm sure there's plenty more I don't have photos of:

McG194 wrote:

Lots of internet engineers out there but some of us actually have a little background. You say you use a better bolt than stock but have...

Lots of internet engineers out there but some of us actually have a little background.

You say you use a better bolt than stock but have you ever considered that may be the problem? A lower grade bolt will elastically deform which means it will flex and distort but a higher grade bolt will hit plastic deformation much sooner which means it shatters and has an abrupt catastrophic failure. The answer isn't always a harder bolt.

Basic engineering 101 if it doesn't shake it's going to break.

philG wrote:

They are disposable items in some places, the cost of calibration , and all that entails, means its more economical to buy a certified new one...

They are disposable items in some places, the cost of calibration , and all that entails, means its more economical to buy a certified new one.

I will be honest, the first time i swapped clamps on the 450 Husky, i was horrified , not having the under clamp locking ring just seems wrong.

And i dont like the pinch bolt on the stem either, although apparently its a perfectly acceptable method to use 3 inches away.

Like Luxon said, its easy to make something that never breaks, but the flip side is, you will never win with it either.

Luxon MX wrote:

I'm glad the internet engineers have already found the problem and concluded that our product is junk. Can't wait for the internet lawyers to jump in...

I'm glad the internet engineers have already found the problem and concluded that our product is junk. Can't wait for the internet lawyers to jump in too!

I'm not at Atlanta, but from what I can tell at this point is that the pinch bolt at the stem failed, which caused the top clamp to fail, and then the bike to "break in half".

The KTM design uses the top triple clamp to clamp around the steering stem with a pinch bolt instead of the "standard" Japanese bike design where the top clamp is sandwiched between the adjuster nut and the lock nut. It's a pretty elegant design, but if the bolt fails, then the assembly becomes very weak and the clamp will fail. This is the same design that KTM/Husky/GasGas use on all of their stock clamps and factory clamp and multiple aftermarket companies use on their clamps for these bikes.

Here's the actual broken part from today:



You can see the broken bolt on the right, which allowed the clamp to break (on the left). Note the fresh break of the clamp and that there's no fretting or other evidence of a previous crack. That shows this happened all at once and the clamp itself wasn't the problem, it was the bolt. We use bolts that are stronger than the stock KTM bolts (random samples tested to failure for each batch we receive), so either the bolt was over-torqued to the point that it was on the edge of failure, or it came loose and that allowed things to give way.

This is the first failure of this kind for us, but it's not all that uncommon with this general design. Multiple other aftermarket clamps and stock KTM clamps have all failed in the same way. Not because the clamps are bad, but because the bolt failed; most likely because it was over torqued or came loose.

Regardless, we'll take a closer look at the clamps when we get them back to see if there's anything that I'm missing from the photos, but it seems pretty clear cut. If this were a design problem, we'd see this a whole lot more instead of this one incident. Freddie Noren has been on this same setup all year successfully and finished 11th in the 450 class today.

Here's a few examples of the same failure, stock and aftermarket, I'm sure there's plenty more I don't have photos of:

McG194 wrote:

Lots of internet engineers out there but some of us actually have a little background. You say you use a better bolt than stock but have...

Lots of internet engineers out there but some of us actually have a little background.

You say you use a better bolt than stock but have you ever considered that may be the problem? A lower grade bolt will elastically deform which means it will flex and distort but a higher grade bolt will hit plastic deformation much sooner which means it shatters and has an abrupt catastrophic failure. The answer isn't always a harder bolt.

Basic engineering 101 if it doesn't shake it's going to break.

#434 wrote:

A higher grade bolt is usually less ductile and will hit plastic deformation later (at higher loads), but can’t tolerate as much plastic deformation before it...

A higher grade bolt is usually less ductile and will hit plastic deformation later (at higher loads), but can’t tolerate as much plastic deformation before it breaks.

Brent wrote:

1- I never wrote any of the words you claim are mine. 2- it is pointless to share detailed information in this place any more about...

1- I never wrote any of the words you claim are mine.


2- it is pointless to share detailed information in this place any more about anything technical. This forum has become a shit show.

GrapeApe wrote:

I'm curious, too. No need to provide details, just a brief description would suffice. You're the one that interposed the X-trig clamp into this thread, and...

I'm curious, too. No need to provide details, just a brief description would suffice. You're the one that interposed the X-trig clamp into this thread, and referenced "a couple specific reasons" why it would have fared better.

I will add I'm not trying to be mean, I'm genuinely curious. I, like many others on here, like to nerd out on this stuff.

Sandusky26 wrote:

Same way positrac in a Plymouth rear end works.

McG194 wrote:

The loads may be later but the point I was making is the bolt will bend less before catastrophic failure. It may take more force to...

The loads may be later but the point I was making is the bolt will bend less before catastrophic failure. It may take more force to break but it will bend and stretch less. It will be nothing, nothing, nothing snap. I lower grade bolt you may have to retorque more often, but I'd rather have a bolt stretch than break.