Can it be fixed!?

[CaPtBlaCk]

Gents,

I had a bit of a disaster today when my mountain bike frame cracked!

It is made from formed 6061 Aluminium and it appears to be a weak spot as later frames had a nice gusset in the region of the break. Here are a few images of the area in question:









For scale the open tube (seat tube) has a diameter of 35mm.

As you can image the frame if I could buy one would be a king’s ransom and the repair has to give me confidence to ride it again so I would pay well for the right person to fix it!

Hence, is there anybody in the West Midlands area that could repair this and perhaps fabricate a strengthening gusset to add strength to the repair area ~ I guess TIG would be the only real option?

Any other advice would be gratefully appreciated!

 

[Sub-arc]

I can't help you with the frame. Someone will be along soon.

Note> Would you mind not using imageshack(or put a warning up) as it's just annoying screen pollution with sneaky gambling s*** coming in the back door.

 

[Wozzaaah]

^ as Sub-Arc says, please upload your pics to the forum server rather than 3rd party hosting sites, advert popups annoy everyone.

 

[hotrodder]

I dunno, spammy image hosting sites and can't even be bothered to clean the mud off before taking pics

Yeah, it's fixable however you should be aware that 6xxx series ally frames are typically 'fully' heat treated* after fabrication and the heat treatment used can cause distortion i.e. getting it re heat treated could cause problems and would probably be uneconomic. Gussetting it could cause more problems... it depends if the wall thickness was rethought when the manufacturers started to add them i.e. if the tubing is butted adding gussets might place the welds on a thinner section which would make things worse (took the bike industry a while to work this out when they first started with ally frames)

My approach would be 5356 wire, keep the heat input as low as possible, leave NO stress risers (bumps/dips/sharp edges etc) and accept that it probably won't be a permanent fix- ally has no fatigue limit and will never last forever anyway. Having said that i'd exhaust warrenty replacement first... how old is it? What's the warranety state etc and as they've redesigned that area it's obviously a known weakness...



* heated to around 530ish C (it starts to melt at ~ 580, molten by 650), quenched and then 'aged' at around 160C for at least 8 hours

 

[CaPtBlaCk]

Sorry gents, I will fix the links when I am back on the PC later today.

hotrodder - many thanks for the very useful information. The frame is from a small American outfit that stopped trading at the start of this year so warranty options are next to nothing. As to cleaning it, then I was too gutted firstly from riding the last 5 miles standing up and then the realisation that replacement is going to cost serious ££!

 

[hotrodder]

5 miles out of the saddle... alright, forgiven for not cleaning it. Narrow down your location to a town and give it a few days to see if anyone local is able to and up for it/can recommend someone. Again, it won't be 'good as new' due to the extra heat cycle. As long as the weld transitions smoothly into the tubes (or is blended in without undercutting/removing material outside of the weld) there should be plenty of warning as long as you stay a little paranoid and eyeball it for cracks regularly.

 

[stuvy]

Iv had mine repaired once or twice in the past, from when I used to ride trials. The rear hanger would regularly crack!

It can be done but from previous experience it will go again in the future

 

[chunkolini]

Is that Maverick ML something or other?
Nice wheels, and I would guess ridden hard. I would pension it off and use it for shopping trips.
That kind of failure could be nasty in action, metal tubes slice flesh a treat.

Chunko'.

 

[stuvy]

Is that Maverick ML something or other?
Nice wheels, and I would guess ridden hard. I would pension it off and use it for shopping trips.
That kind of failure could be nasty in action, metal tubes slice flesh a treat.

Chunko'.

core samples is what happened to me

 

[CaPtBlaCk]

5 miles out of the saddle... alright, forgiven for not cleaning it. Narrow down your location to a town and give it a few days to see if anyone local is able to and up for it/can recommend someone. Again, it won't be 'good as new' due to the extra heat cycle. As long as the weld transitions smoothly into the tubes (or is blended in without undercutting/removing material outside of the weld) there should be plenty of warning as long as you stay a little paranoid and eyeball it for cracks regularly.

Thanks again for the information, I guess due to the hard time the frame gets then it is best to be safe rather than sorry! So it maybe a case of RIP!

 

[CaPtBlaCk]

Is that Maverick ML something or other?
Nice wheels, and I would guess ridden hard. I would pension it off and use it for shopping trips.
That kind of failure could be nasty in action, metal tubes slice flesh a treat.

Chunko'.

It is indeed a Maverick ML7 and after consideration of hotrodder's information and that from one of the ex-employees of Maverick then I am going to pension it off.

Such a shame because it was such a brilliant bike. Now just need to find a replacement....

core samples is what happened to me

The very thought makes me feel sick!!!

 

[stuvy]

well it made me cry! a nice orange P7 should fill the maverick hole

 

[hotrodder]

Just out of curiousity what did the ex Maverick employee say? I would've thought they were originally welded with 4043 or maybe 4643 and then heat treated but that's obviously a guess

 

[CaPtBlaCk]

I sent him the images and he just said it was definitely beyond repair - unless I knew a trusted frame builder who could both weld and heat treat it!

I guess even after that it would always play on my mind so best moving on sadly...

 

[chunkolini]

Just say out loud the word
'Laceration' maybe try a few different accents.
Should do the trick.
Crossed my mind cycling home from work today and thinking about frame failures like this..
Chunko'.

 

[Shox Dr]

So was it the age old problem of the seat post too far out?

 

[CaPtBlaCk]

So was it the age old problem of the seat post too far out?

No.

 

[Shox Dr]

So did the seat post project further down the seat tube past the top tube?

 

[hotrodder]

Used to be nice and simple until everyone started to make frames with a bunch of seat tube above the top tube which made the min mark on seatposts a bit of a grey area. I wonder if the genius that came up with idea of a single size seatpost + shims got what was coming to them (a broken frame inserted into a puckered orifice)

 

[CaPtBlaCk]

So did the seat post project further down the seat tube past the top tube?

Yep.

Looking into it then the rear shock was acting up just prior to the crack. Hence, 80kgs + gear of shock loading due to being on uneven ground coupled with no damping affect probably did the damage.