badgnome

I put in a warranty request since I am the original owner. I believe there is one local bike shop that has welding service.



Not crashed. 9.5 years old at the time

mstateglfr 

Probably due to the chainstays being dented from the kickstand.

I kid.

That's an insane crack! Cant imagine what forces or poor welding could have caused that.

Did it happen downtube to seat tube, or did it happen seat tube to down tube?
I'm guessing it cracked at the back of the seat tube at the weld and the crank moved forward. Just guessing based on where else could the crack start?

Did you feel it slowly fail? Cant imagine it just separated completely without notice...to shear a downtube apart like that it would take a lot of sudden force.

djb

If it was on a rear car bike rack and was hit from behind, or if in your garage someone accidently pushed a car against it, there will be physical evidence of this, including the outboard bearings showing stress etc.

You would think the same with vertical stress onto seat and seat tube etc

Something funny happened here, and no matter what it was, it should be fairly easy by knowledgeable people in person to determine was force and from what direction caused this---or if it was something else.

Btw, that is rather spectacular.

badgnome

Last crash was over a year ago and it was pretty low impact and its only been on a bike rack one weekend in its life

The crack on the down tube goes almost entirely around it, but hard to see the extent of the crack on the seat tube, I never noticed anything before today and this bike was in the shop 10 days ago.

indyfabz

IDK. BITD my first real road bike was a Trek 660. It developed a sizeable crack in the head tube. I am talking more than 1". It became my indoor trainer bike. One day I dialed it up to 400W and snapped the right chainstay clean through.

timdow

Wow you gotta wonder what happened here. Maybe the bike got dropped before you got it and it has been cracked all along and it finally broke?
Curious how much welding would be compared to purchasing a new or used frame? Guess you might have to answer that question if they don't replace the frame under warranty.
BTW: Might want to replace your granny ring while you have it apart.

Tourist in MSN

I think you will get a new frame. I know someone that got a new 520 frame a couple years ago, he was perturbed because he wanted a disc frame but the cracked frame was a rim brake version so that is what they gave him.

Happy Feet

Curious if there was standing water in the BB to rust it through from the inside? Otherwise, as noted that's a fairly strong point to crack like that. Do you stand and mash like a monster?

indyfabz

Good catch. It does look a bit shark toothed.

badgnome

It does get ridden in the rain but nothing extreme. Don't really stomp on it aside from the one switchback on the local trail.

Trek said to bring it to a local dealer with proof of purchase. Do they even make this frame for V-brakes and bar end shift routing anymore?

Tourist in MSN

I was curious myself, yes they do, bottom of page. But the rim brake version only sold as a frame, not a complete bike.
https://www.trekbikes.com/us/en_US/b...es/520/f/F251/

The friend of mine that got a new 520 frame did not need proof of purchase, but I am sure if you have it that it is less trouble free.

KC8QVO

That is a pretty spectacular failure. Can you get pictures all the way around it? Im curious what the hole separation looks like.

Let us know what happens on whether or not you get a replacement. If not - find someone that can TIG weld. A lot of people that work on cars TIG weld, you don't necessarily need to go to a specialized fab shop. Depending on what the metal is on the frame having appropriate filler material available for whoever to do the work would speed things up. If it is Chromoly steel and a place just has a filler for mild steel, for example, it will "work" but isn't the best solution. For that kind of repair I'd make sure it was done with the right material.

Torch welding is another option. That's real old school - but it can work well. Same as with TIG, though - you need proper filler.

seeker333

You may be out of luck on that warranty, since the bike is a 2009:

https://www.trekbikes.com/us/en_US/trek_bikes_warranty/

If it's not warrantied, you could buy a Surly LHT frameset (new or used) and transplant the components from the Trek. Current Trek 520 frames are disc-brake-only.

Tourist in MSN

Check out
https://www.trekbikes.com/us/en_US/b...olorCode=green

badgnome

The bike is already at the shop. The warranty manager was going to be away for a couple days so I got it in before then. I told him it was my main bike and he said he would try to expedite it.

There is a custom frame builder in town, maybe they could weld it:
https://www.chumbausa.com/made-in-usa-road-bikes

CliffordK

My guess is that it started in the heat affected area along the bottom of the seat tube, and was stressed by the side to side motion of pedalling. Then propagated into the downtube.

One might be able to tell the age of the crack by looking for corrosion along the crack (especially if cut up and disassembled). I see some fresh metal along the downtube, but that could also be from abrasion after the fact.

djb

That was my thought as well, and that visually one could plot the corrosion, although it's hard to imagine that this could happen gradually and not be noticed, visually or by wobbly feel.

Re welding, if it were me, I'd be inclined to start looking at used bikes, and just transfer all the bits over.

Hate to say it, but I wonder if the bike stand clamp could have put a stress on the weld area, and it went from there following this line...couch metallurgy on my part of course...

CliffordK

All of my bikes were purchased used, so I'd probably try welding myself. But, in the case of the OP, it will probably be a warranty replacement. Then it depends on whether he gets a new frame or a new complete bike. Upgrades?

You are right, there are lots of good used frames available, often for very cheap depending on the exact bicycle.

I don't think anybody clamps a bikestand down near the bottom bracket. And, clamping at the top fo the seat tube is unlikely to have significant effect that low.

That area gets quite a bit of protection from the crankset.

I think it is simply fatigue (although perhaps compounded by welding problems).

It is possible a double butted tube was cut outside the butted area, although seat tubes are often designed a bit differently than the other tubes.

Wilfred Laurier

Funny that people are so shocked about this... The myth that steel frames will last forever is being tested now that a significant number of cyclists have gone back to steel. BITD of all bikes being steel, frame failures were not uncommon.

There is another active thread right now about an almost identical failure of a Surly frame.

The difference is that if OP can prove they are the original owner, Trek will almost certainly give them a new one, while the Surly is out of warranty, and we have yet to hear what is going to happen with that..

I was concerned for OP that Trek would only have disc-only frames to replace it, but I just looked on their website and they still offer a canti-brake 520 frame!

Edit: The thread about the Surly.
https://www.bikeforums.net/bicycle-m...s-check-2.html

It is entirely possible that these bikes came off the same production line.

CliffordK

Just looked at the Surly thread. I should have opened it earlier.

Looking at the two cracks, for the part of the crack that we can see, the two cracks are very different.

On the Trek, the crack propagates around the top of the weld in the heat affected zone around the seat tube (thin tube).

On the Surly, the crack propagates around the bottom of the weld between the weld and the bottom bracket (we can't see inside the bottom bracket). That may well be a weld penetration problem.

Of course, one should at least pull off all the parts and take a dozen photos at different angles, and even try to peer between the parts of the crack to try to determine where it started.

It is quite possible that the crack propagation on the right would be different than the left, and likely started in one place and slowly progressed around the entire tube, perhaps over months or years.

badgnome

I took it back to the same shop I bought it at, Melllow Johnny's in Austin, and they said I didn't even need a receipt. I guess they have a database of everything they've sold since they opened in '08.

If they don't warranty the frame I might go with a Salsa Marrakesh or Fuji Touring Disc. I still dig the bar end shifters.

badgnome

Trek offered a new frame (and fork?) in deep green which is most likely this:

https://www.trekbikes.com/us/en_US/b...olorCode=green

They are not paying for labor to move over to the old components, however. I'm guessing Trek will not offer cash and the bike shop probably will not offer me credit/cash, so I may just rebuild it myself or sell it.

djb

offering a new frame and fork seems rather reasonable.

chrisx

rebuild it yourself
best choice.

9.5 years old at the time?
and a new frame?
really?

fishboat

+1..yah, I'd say so. Would seem to fulfill a lifetime warranty.."it breaks, you get a new one..". Not covering the cost of swapping parts is also in line...as warranties go.

A bike shop can swap the parts for 2 hrs work..locally (here) they charge $100-$150 to build up a bike. Rather modest compared to selling it(for not a lot)..finding another bike & paying for it.