2003 KTM triple clamp failures

[saratogatc]

My dealer called me this morning advising me not to ride my 2002 250 EXC RFS. He says it is in the recall list even though I have the old style forks. It has a 2003 VIN# but 2002 styling and parts. I'm going to do a die-penetrant inspection tonight to see if it's cracked

 

[jboomer]

So, if they are recalling some of the '02's, then that means some of them were given the same parts. I wonder how many failed before this KTM rider at the dealer show broke them? Who knows, lots of people may have been hurt.

 

[chumbucket]

yea this is for real, I was looking at the two that broke. One of them had every single cable and hose riped from the bike when the front broke off, it also had some rear end damage, so it must of cartweeled. The other bike didnt look to bad though.The not so damaged one was a 525mxc, cant remember what the other one was, think it might of been a 450E, not sure though.

 

[Strick]

O.K., but what about the '02 that already HAVE the 48mms. Are these the same clamps as the '03s?? I would think so. Does anyone know for sure?

Never mind the info was right under my nose. ;)

 

[380EXCman]

The only affected 02's were the 250 RFS's. They were an early 03 release. I was told that the cracks may actually be coming from an assembly process.

 

[MoGwai]

Hi,

I bended the original top and bottom clamps on my '01 400EXC and switch to a 18mm Appiled set. While I'm changing to a shorter fork last month, the mechanic found out I've bend the Appiled set too, its just 6-7 months into its usage!
Anyone can recommend a strong set that I can use?

MoGwai

 

[Greek kattom]

Does this recall considers only KTMs in USA or Europe too?
I ride a 520 EXC 2002!
Must tell to my KTM friends if so!!!!!!!

 

[380EXCman]

Your 2002 520 is not affected.

 

[CrazyTed]

There is a vin# list of suspected bikes posted on KTMWorld's home page at www.ktmworld.com . Go there and enter your vin# and find out if your bike is suspect. My vin#is there. Talk to my dealer who was there and he said guy wrecked bad. They stopped all riding and checked other bikes and found some cracks. He also said that the bikes involved had been flogged really good. Like jumping triples and stuff. I don't jump so I'm not too worried about mine cracking but I'll change them as soon as KTM sends replacements. Unfortunately I'm in a points race and next race is this Sunday. So out I go...

 

[dkmccarty5]

The KTM oem lower triple clamp is perhaps an aluminum "equiaxed sand casting". The cooling/solidification in this casting process is somewhat random - and results in a random grain pattern. Looking at some of the photos that have been posted the cracks are eminating from the stem hole - which could indicate a tolerancing issue between the stem diameter and the triple clamp hole diameter. The crack perhaps developed when the stem was pressed in. Once a crack has started in an equiaxed casting, it will typically follow the grain boundaries - and in the case of equiaxed castings, the crack will propagate along the boundaries until the part fails. Since the grain boundaries are small - and plentiful - it doesn't take much for the crack to grow - and the part to ultimately fail. We would all be wise to heed the KTM warning - and not ride the bike until it's fixed. KTM will be expeditious in a remedy.

 

[penguin]

Yeah, what he said. KTM is a standup company and from recent history, they will make this right for all those affected

 

[WoodsRider]

Originally posted by dkmccarty5
Looking at some of the photos that have been posted the cracks are eminating from the stem hole - which could indicate a tolerancing issue between the stem diameter and the triple clamp hole diameter. The crack perhaps developed when the stem was pressed in.

Are you saying the interference between the two components was too great causing excessive hoop-stress around the hole?

Excessive hoop-stress could easily exceed the tensile strength of an aluminum sand casting. However I thought someone mentioned the triple clamp was machined from a forging... I could be wrong though.

 

[Thomas]

Sorry but the triple clamps are not sand casted they are forged !!!

 

[drz mick]

The triple clamps are too rough to be forged. They look like sand cast to me although I am no expert.

 

[chumbucket]

They are forged, bad heat treating caused the problem, I think.

 

[DahlElama]

Originally posted by CrazyTed
Unfortunately I'm in a points race and next race is this Sunday. So out I go...

dood... your DRN handle is appropriate... don't race that thing if those clamps could break!

 

[Matthew]

Check out KTM's website, Holeshot's and Applied's. They all have info. Applieds also has pics of what the cracks look like


Matt