Bicycle Mechanics - Graphic Image - seat tube travesty

Please don't shoot the messenger. I didn't do this, but I bought this bike in hopes of correcting it. PO loaned bicycle to his buddy. Buddy broke seatpost clamp (the one on the bike frame that holds seatpost in seat tube). Then buddy did the unspeakable. He drilled 2 holes through the seat tube lug into the seatpost and mounted two screws into it. Then he tack welded [sic] the seat tube lug in 3 places to the seatpost. Personally, I think anyone with the training/skill to TIG weld aluminum tubing to an aluminum casting should have had the sense to just replace the seatpost clamp, but that was not the case here. I'm guessing that Trek would have made this right under its lifetime warranty, right up until the guy got out his drill and welder!

So I now have a cheap year 2000 Trek 2100 Carbon Series road bike (that's the one with Carbon main tubes and aluminum stays, fork, and lugs joining the whole setup.)

I don't know exactly what clamp it had in the past. Can anyone tell me? Would this bike have come with an attached clamp, or would it resemble the Salsa clamp that I've been contemplating using. I'll try to include a pic along with this post. My thought is to remove screws, grind tack welds off (with a rotary cutting wheel) replace seatpost, and purchase a replacement seatpost clamp, but that will mean using a new clamp to compress an aluminum lug with it's original adjustment split and the weakness of two holes drilled in it. There doesn't appear to be very much lug for the original seatpost clamp to have grabbed in Trek's design. Was is a special clamp that did more than just surround/compress the joint? Can anyone offer constructive advice? Thanks.
-Karl

My constructive 0.02e: take Buddy to back yard and shoot him. Now.

Doubt it helps, though. :D

--J

NOW I have seen it all.... man oh man... good luck

Brendon

Unfortunately, your description did not fully prepare me for the shock and horror of the image that assaulted my eyes when I clicked on the first image link. Personally speaking, I fear for the integrity of the tube-bonding at this point. I'd be concerned that the heat from the welding might have weakened them. I'd also be concerned about the amount of material removed from the lugs in the process of getting those screws in. I'd write the frame off and maybe clean it up to use as wall-art but that's just me.

As far as the original clamp goes, my guess is that it was integral with the lug. It looks like your friend hacked off the binder-bolt ears/flanges (or maybe that was what originally broke off) at the location he inserted those screws.

Quit wasting time on the forums and make him disappear!!!! What gets me is why didn't he call you??? I hope you get it fixed, good luck.

He's fixed that one to death. My advice is to strip all of the components and immediately discard the frame so you don't have to keep looking at it.

Your buddy the moron needs to buy you a new frame ASAP.

I do not loan bikes to idiots and I only loan to non idiots if they accompany me on the ride.

omg!!

how stupid can people be? (referring to your buddy)..

he needs to replace that frame... or I'll "kill" him for you.. :D

Sweet holy mother of God! My eyes, my eyes!!!!

Not to mention that is some of the absolutely worse TIG welding I have ever laid eyes on. I too am a weldor and I can tell you this guy might know what a welder looks like but he cannot use one.

When is he buying you the new frame?

Thanks for the responses, especially the ones with some useful feedback.

I bought the bike as my return from a 16 year hiatus from cycling. I purchased from Craigs List from PO who loaned to his buddy. It was actually one Marine and a long term loan to another Marine. The seller was honest about the problem when I first enquired about the bike, and I knew what I was buying when I purchased it (300 bones). I even got to test ride it, and ironically had it not been for the additional height that I'll probably need when using cleats, the damn thing's welded at the right height for me. I probably paid too much, but my budget's low, and the components are all new enough that they've got lots of life left in them and I may decide to buy one of those $150 7005 frames off of ebay.

But getting back to my question, does anyone know what the original clamp would have looked like? Brand? It's worth buying a clamp to salvage an otherwise nice frame if that'll do it.

I understand Khuon's theory that it had ears a la a traditional steel frame, and it would help to explain the drastic repair. But, damnit people Trek guarantees it for life! Can anyone confirm that ears with a simple bolt is the (or a) technique that Trek used to secure their seatpost on an alloy lug? How much tube should a collar clamp grab if that's the design?

One final stretch (it is a mechanic's forum): might a Trek mechanic be able to remove and replace that whole lug or is Carbon Fiber bondage a one way trip? I'm hoping to get it to a Trek service shop tomorrow if for nothing else, to see the expression on the mechanic's face ;^) Maybe I can get a break on a Trek replacement frame if it was a frame failure that started all of this.

Good luck to you on trying to get Trek to replace that frame, worth a try, but I doubt it will happen. Enlist a friend's help and see if you can get ahold of a mechanic's stethescope. Let him place stress on the frame in different vectors while you listen to the bike where the lugs join the tubing. If you don't hear any creaking it may be worth trying to salvage. I don't see a problem with using a clamp to secure the seatpost, and those welds look like they will pop off the seatpost with a chisel, there appears to be zero penetration. Obviously, this wouldn't be the bike you'd want to use to take on mountain switchbacks at 50 mph, but if the Al to carbon bonds are intact, I don't see a problem with using it for tamer riding....


EDIT: On closer examination there doesn't seem to be room to use a clamp. You might be able to salvage the ears using a helicoil or similar solution.

He does'nt have any children does he?

I'll bet you don't have to worry about having your seat stolen.

:eek:

Not to mention that is some of the absolutely worse TIG welding I have ever laid eyes on. I too am a weldor and I can tell you this guy might know what a welder looks like but he cannot use one.

When is he buying you the new frame?

The "welding" looks to me to be lead plumbing solder, applied after heating with a propane torch. I'll bet it just comes right off the seatpost. The bad news is the way the stays are chewed up. You could do a temporary repair, but I don't know how long you'd have until the stays cracked through.

If you do fix it and ride it, recommend you check the stays and seat post carefully for cracks and integrity of the joints after each and every ride....and stay close to home!

Got my cleats today, and rode on a trainer at the Trek Dealer. Seat height is right (!!!) so this weekend I'll begin riding and try to confirm that Frankenbike stays welded at this height... FOREVER .... MUH-HUH-HWaH-HA-HA. Thanks again for all the comments. Happy Riding Everyone!
-kARL

don't know if you want to spend more money, but a licensed airframe and powerplant (A&P) mechanic will know how to properly cut off the trash and weld new tubing in it's place. Ditto finding a suitable clamp.

betting on a bike frame is risking a broken bone and lost skin. betting on a bad weld on an airplane is betting your life. These guys are good and aluminum tubing is bread and butter work.

and OBTW. how pretty a weld looks is only one indicator of proper welding. it can be gorgeous looking but if the surface prep was poor then the weld will have internal voids, and if the post weld heat treatment after was non existent , then the material (steel or aluminum) will have a crystalline structure that is too soft or too brittle or even a combination of both in layers.

good luck

don't know if you want to spend more money, but a licensed airframe and powerplant (A&P) mechanic will know how to properly cut off the trash and weld new tubing in it's place.

I hope that A&P is also skilled in the art of composite materials repair (given today's advanced aircraft structures, that's a possibility) because that frame is made of carbon fibre tubes bonded to aluminum lugs.

Yeah and you dont have to worry about losing your seat position. I myself was shocked at that pic, I would cut my losses with that bike or sell it for whatever you can get for it.