IpIp Biker

Hairline crack from chainstays and travel towards bb

Guerciotti / Alan Frame with Campagnolo Triomphe Groupset
Need Advise on Guerciotti /Alan Bike..Hairline Crack discovered on BB😣..Is it Still Ridable ??
After a Ride with the Peeps last Sunday.. I decided to do a tuneup on my Guerciotti.. upon removing the Crank to do a BB clean/tune up..I noticed a hairline crack line going horizontally from the chainstay to the bottom bracket.. the crack doesn't travel/ reach to the fix cup thread and doesn't open up when I tried pinching the chain stays together or pushing the bb to flex…Is this Alan frame still Ridable??.. the bike frame survived a 50 mile trek last Sunday.. I only detect this crack when I removed the Crank as its concealed from view by the Drive Chainrings.. I really liked this bike and hopefully it still has structural integrity from its 40+ years existence..

nlerner

Toast. Hairline cracks only get worse.

AdventureManCO 

10/10 wouldn't ride. Pretty though! Hang on a wall? Still has artistic value.

abdon 

A TIG welder could put a couple of dots along that line. It would not take much to stabilize it. You want somebody with a ton of experience laying welds, they can lay then with machine-like precision.

dddd

It could be stabilized with a clamp, but what kind of clamp is the question.

I repaired an "identical" frame where the seat lug had the same sort of crack going out towards the top tube. I used an external-type, cast-aluminum seatpost clamp, "mangled" in place to fit well and clamp tightly. The frame went on to provide years of riding.

Just over two years ago, I made a very heavy steel clamp to support a bracket that spared a bb-shell brazed joint from crack expansion, has survived many CX races since then with no further issue other than the significant weight of this repair. Your repair would seem to be much simpler to execute, depending on the materials at hand, your imagination and engineering acumen.

Steel Charlie

That could have been there for years. I say ride it and watch it.
if you want it welded look up Hill's MicroWelding. They can fix AnyThing

Kabuki12

That would be a gamble and I wouldn’t do it. The BB shell has a huge load when climbing or accelerating . I would talk to some expert welders who specialize in aluminum work. That is a beautiful bike and worth a try. I used to live on a sailboat and the boat yard had a machine shop. The guy who ran it could weld, machine , straighten , repair almost anything in aluminum or SS . I’m pretty sure it would be your best shot at saving that bike. You would be ill served to keep riding it .

fabiofarelli

In case of welding, check this:
response 90

OldForerunner

Pardon my ignorance, is this frame different from the Vitus bonded frames? I recall there were some guys that repaired Vitus frames and sold the lugs separately too (BB shell, etc.)

If different, then in the immortal words of Gilda Radner, nevermind...

bulgie 

To those who say "don't ride it", I have to ask, what is it that you think will happen? I'm not able to imagine a scenario where the rider could be hurt. Lack of imagination on my part? Seems to me, the worst thing a chainstay coming loose can cause is a long walk home. Remember, the chain tension tends to hold the stay into the socket, as does the stay on the other side.

I'm not enough of a welder to know if it can be welded, but aren't there alloys that are considered not weldable? Are we sure the Alan/Guerc metal is weldable? Most if not all weldable Al alloys need heat-treating after welding to get best strength. I believe I have heard that 6061 will eventually return to T4 with only natural aging, but that takes time. Full strength (T6) definitely requires a heat treating oven. What does the temperature do the glue used in those joints?

That's assuming there's glue, but it seems likely. Unless "screwed and glued" is only an expression?

Anyway, rather than risk ruining the frame by trying to fix it, I would definitely ride it. I have ridden at least 3 frames until they completely broke in two, with cracks in DT and TT near the HT, a more dangerous place to have cracks, more likely to dump the rider on the ground. But those were steel frames and they were extremely difficult to break! Even when the cracks went almost all the way around, there was still a strip connecting the pieces, and I had to do many repeats of a nose-wheelie (aka 'brakie') followed by a bunny-hop, to bend the HT back and forth. It was satisfying when I finally managed to break them in two. Yes I have done this 3 times over the decades, all on frames that had bulges underneath the TT and DT from a front-end collision, that eventually cracked many miles later.

Aluminum doesn't have that mellow, slow failure mode, but a chainstay won't dump you on the ground. I think! Please don't sue me if you take my advice and get hurt. I am certifiably a lunatic, so don't listen to me.

MooneyBloke

Scary in a scary place. Now I have broken a crank on a climb, and I didn't crash, but I still am very unhappy thinking of a frame failure as something I want to risk. I'd take the conservative position, and not ride this frame if I were you.

Spaghetti Legs 

Worst case scenario I can imagine if it goes suddenly is it opens up when you’re out of the saddle and throws you off balance and maybe wheel gets jammed into the chainstay. Likely though it won’t go suddenly and bike becomes harder and harder to ride. I would relegate the bike to city bike duty or short rides you don’t mind getting stranded on. My only expense with an aluminum crack is in the seat mast of my old time trial bike, which has been relegated to indoor trainer duty for several years now. I’m sure the out of the saddle pedaling in the fixed position contributed to the crack. I drilled a hole at the end of the crack and then cinched the post down tighter and last half of last winter, no slipping or new crack.

Lamont Cobb

Totally keep riding it. Just keep on eye on it after every ride, and make sure to take your cell phone with you on all rides (which you should do anyway).

daka

+1 to what @bulgie said about welding. Aluminum is fussy and, if weldable, the weld-affected area will be weak unless heat-treated afterwards. Consider also that it may be a fatigue crack from lots of miles. Even if you were to fix that one, the rest of the part is similarly fatigued and you are likely to get another crack nearby in short order. The fatigue curve for aluminum is not encouraging - it goes to near zero in the order of ten to the fifth (100,000 to 999,999) stress cycles. Aluminum frames and components are not "forever".

repechage

These are screwed and glued.
no matter how fast a welder is, the local heat will do its thing.
it would have me not trusting it.
ride to rupture or retire.
I would retire it sooner as currently it will be wall art. After any rupture, not really. Who wants to display it showing the non drive side?


right now, always ride with a Cell phone and a Uber or Lyft account app loaded.

Markeologist

…as well as your medical insurance card and the phone numbers of your next of kin.

repechage

my hunch a failure won’t result in a bodily injury. But of course will occur in a no cell service area.

davester

on the plus side, this gives you a great excuse to buy another bike. You can then relegate this one to a rotation that includes wall hanger and around-town putterer.

Bad Lag

I was looking and looking and looking, then I saw what was there all along.

WOW! I guess he found the creak.

fabiofarelli

Complete different lugs, outside and inside.

OldForerunner

Cool, thank you!

fabiofarelli

The problem with a crack is always in the casted lug, not in the tubes. And yes, there's glue. You would not say it but this was, after heating, very hard to loosen.




And this weld did it very well, not nice to see but there were many rides made with it in the field, cyclocross. Edit: wrong, this is a road bike, many miles were made but on the road.

IpIp Biker

Since I’m loving this bike....I

went full ( Macgyver)commando …After drilling a hole to stop the hairline crack to reach the bb fixed cup thread hole..I opted on applying high strength (JB weld)epoxy on the Fixed Cup thread, screw it back tight on the bb lug, totally fusing it together.. with that making them a more solid/strong bond piece. I don’t think this bb would even split open now if ever the hairline crack reaches the thread..Sacrificial piece for the Campy Triomphe fixed cup..As some mentioned the stress force generation at the chainstay is pushing towards the Bb lug.. it’s less likely for the chainstay to pull away and yank off the bb lug. One mechanic mentioned a customer who wanted his old Schwinn re-cabled and he notice it’s bb totally split open and only holding it was bottom bracket thread cups fused from the rust😳😝..but they were still riding it..
Anyway.. Test rode the Guerciotti after the fix about 20 miles… and so far..hairline crack not progressing.🙏
I confess that this bike I bought as an Incredible Barn Find ($200) at CG.. complete bike with Campagnolo groupset Cinelli bar and stem and Classic Ambrosio Wheels from the seller.. If frame was a write off.. I guess I still had a great deal from acquiring all its classic components..

sbarner 

I'm with Bulgie on this one. The crack dissipated stress in the joint and should stop once it reaches the BB opening. If another crack should start elsewhere in the BB shell, that might eventually lead to problems, but it's hard to envision any kind of catastrophic failure, or even a "ruin your ride" mishap. It's not likely to fail like a snapped crankarm. Welding would create at least as many problems as it might solve. I would have no issues with riding it, as long as it doesn't start creaking. I hate creaking. If you accept the fact that it's not dangerous, and won't strand you, what do you have to lose by riding it and seeing how long it lasts? It may never fail more than it already has.

Up here in Vermont we carry cell phones because they have cameras built in. If you're out far enough to make a ride interesting you don't have cell service, but you still might want to snap a pic of a covered bridge, or the moose you spotted in the beaver pond..

Chuckk

I bet there's room for a hose clamp around it as well.