Crack in Frame
 

While having my shock rebuilt, I took a look at the frame I'm about to build up and found this little beauty (by the screw on the bushing).
http://img.photobucket.com/albums/v1...Bike/Crack.jpg
It doesn't go all the way through to the other side, but it's a crack in the frame and not just the paint. I'm kind of pissed because I just paid $100 plus shipping to rebuild the shock, which is pretty much only good for this specific model of frame, and bought a fork, headset and seatpost for it. Trying to consider what would happen if that part did let go, and I think it would be annoying but not dangerous. I was thinking of putting everything but the drivetrain on and taking it for some slow but hard bunny hops and curb jumps to see if that doesn't finish it. What do you think?

Bummer. Bunny-hops likely won't break that. It's under compressive stress. Looks like one of those things destined to fail 6 months from now and when you least expect it. Sadly, it could be the result of overtorque on that bolt.

At worst get it welded. Is it aluminum? I wouldn't ride it if so.

I'm sure you could find someone to fix it for like.. $70. Hopefully less, doesn't look hard to fix.

Can you order a new seatstay (?) for that frame?

Hmmm, what do you think will happen when it does fail? Catastrophic hospital trip or just a boring hike home?


Yes, Aluminum. I'm not sure if such a small area can be welded, but I can ask. Heck, my dad has a welder and knows how to tig (I think).


Since the frame is from 2001 and the company has been bought out since then, I doubt it. It's a miracle there's even a company that can service the pull shock that comes on it.

K2? Both sides of the push-unit would need to fail for anything significant to happen. Then the bike would squat down in the rear. The sharp aluminum would be pointing rearward.
To me that sounds a lot more benign than, say, a front fork or stem failure. But more malevolent than a flat tire.

Welding is the easy part. The real problem is that the heat soak from welding weakens the metal around the weld area, so it really should be heat treated after welding to re-temper the frame (although a lot of companies simply over-build the frame rather than heat-treating, because it's cheaper). I have no idea what that costs.

Yes, it's a K2 Razorback frame. That's what I figured, looking at it. The part that's cracked takes a small amount of the load. I imagine the screw could fall out if it cracked through, but I'd notice something by the time it works its way out.


Well, it was designed as a lightweight XC racing frame, so I'm not sure how over-built it is. Are you saying that not heat treating after a little weld could cause other nearby parts of the frame to fail? I don't like the sound of that. However, it's such a tiny area I wonder just how much time has to be spent. What kind of welding would be required?

man that sucks, sorry to see.

pay someone to test ride it for you...no sense in a needless injury to impact your road cycling.

That's my understanding, yes.

I wish I knew, UK. I'm hoping an experienced welder will chime in.

So someone else can get injured instead of me? That doesn't sound very nice. :D


It's alright. If I go that route, I'll ask my dad (he has limited welding experience on cars) and the welding shop. For now, it looks more promising to just buy another frame on craigslist... and inspect it more carefully this time!

Interesting poll results. Either a lot of people have mild faith in the frame, or there are a lot of sadists on this forum :D

Keep an eye on the 'bay for a replacement stay. I've seen 'em.

sell it to a nub :)

I'll keep an eye out, but it seems like the newer versions and conversion versions (for Fox Float) would be more likely to pop up, and that once again makes my shock rebuild useless.

I'm considering a frame on C-list right now, then I'll sell the shock, and maybe the front triangle if someone wants it.


I see you have 70 posts. How much are you offering? ;)

I am disturbed how many people want you to bunny hop it, myself included. I would try to order a seat-stay... if not ride it until it breaks. Depending on the suspension design the seat-stay takes a lot less force than the chain-stay.. though if your seat-stay is already cracked the frame may be of a design which stresses the seat-stay. Either way, i'm not sure how spectacular this failure will be, if you keep an eye on it you should be able to see it really breaking.

Don't spend another dime on it though.

Now why in hell would anyone want the K2 Razorback and unique shock in the first place is my question... :)

I wouldn't ride it, if that fails further the chain stay could follow the seat stay very quickly, or maybe not, but I wouldn't want to be the guinea pig.

Why would someone send shock out for rebuild and acquire fork, headset, & seatpost without taking time to first inspect a new old used full suspension frame? These are mysteries to some of us and hopefully valuable (albeit somewhat costly) lessons to others.

I personally wouldn't feel comfortable riding with a crack like that any further than what it took to get out of the woods. Although with the inherent lack of lateral stiffness in that design I would likely tear the back off that bike even if it were not broken.

I did not vote in the poll as I do not fully understand the choices, but I do wholeheartedly support the OP's right to weld (JB or otherwise), duct tape, or popsicle stick & elmers glue it back together. Might as well get the most out of this exercise.

Man UK! That sucks and blows at the same time. They can do alot with Al now days but I voted to scrap it for the money you have invested and try and recoup some of the greenbacks.

But depending on where most stress is centered on that particular bike frame may persuade me to keep it. I have no idea and speculation alone would not be enough for me. I would contact the frame builder to see. Is it a new frame you bought or a used one? If new I am sure you would send back for replacement so I take it that it is used**********

Yeah, I had done a quick inspection when buying it and hadn't noticed the crack. Not sure how I missed that one, but I did. Lesson well learned.

Yes, it was a used frame. I got it cheap, but not cheap enough for a cracked frame. Since the shock is hard to come by, I might be able to recover most of what I'm out through ebay.

Put a decal over the crack it and eBay it.

Can't. I have too much of a conscience.

http://www.energyquest.ca.gov/teache...ny_140x143.gif

... note to self avoid k2 frames on ebay :D

Don't worry. I'll sell the shock and maybe see if anyone wants the main triangle, but not the broken strut. Maybe someone out there has a good frame but wants a different size.