5 mph

Has anyone on this forum experienced a cracked frame?
The bike is a 2005 Specialized Langster I ride iit 20 miles a day., up and down hills..I love this Fixed Gear Bike. Today,I heard a rattling sound I thought was from my drivetrain. I got home and found this crack. in my frame.

If any of you have experienced this:
1. Is there anything special I should know before taking it to an aluminum welding shop? (I have a Gas Mig Welder but not a Tig Welder). Did you take it to a high end bike shop , or did you take it a to a general aluminum welding shop.

2. I was having problems with my chain coming off. I pulled the chain taut when I installed the tire last time. I pulled on the tire hard, to get rid of the slack in the chain. Could this have caused /contributed frame failure.? With the taut chain, did the frame lost its flexibility? Or was it fatigue?

sch

It could be welded, will it hold up?, probably not as you are dealing with thin aluminum with little area to hold
a strong enough weld. Besides aluminum frames are heated treated post weld when made at 750° F or more
for an hour. The weld will most likely weaken the surrounding metal as a consequence. Aluminum frames
are disposable, it has had a good life, now recycle. Chain tightening had nothing to do with this, it was
fatigue.

5 mph

are you sure its recycle time? That was a really good bike. The cross section area of the crack is round and about 1/2" in diameter. The funny thing is I rode the bike home like that for some 10 miles up and downhills. and it didn't fall apart.. At the end of the ride.--.even with that crack., was the first time I conquered a final steep hill without stopping.5 yards short. I really dug into the frame hard, and yanked on it and wrestled with it.

dsbrantjr

The operative word is "was". At least it died doing what it loved, as they say.

alcjphil

The cost to repair that frame, done by a proper frame builder(not a bike shop) who would have an annealing oven would be more than the value of the bike. Buying a replacement frame would be cheaper. Incidentally, your chain should not be fully taut, there should be a bit of slack

5 mph

Somehow I feel it was that chain. What a great bike. Still tempted to get it welded it and use it for a few more weeks.

Just got into biking this year..really enjoy it but already three bikes and three advanced repair lessons., problems others don't get.

Bill Kapaun

You ask a question and then don't like the answers.
Why do you persist?
Ignore list.

Pop N Wood

I wouldn't hesitate to get it welded by any competent welder.

You can weld aluminum with your MIG, but definitely not a job for a first timer.

Have them weld a support brace across it while there are at it.

dedhed

Go to a competent welder. Try motorcycle repair shops, preferably an independent not a dealer, especially guys who do custom work. Or even better a welding shop that specializes in Al.
Make it clear you don't expect a guarantee.

Heat treat etc etc I wouldn't bother. Yeah, maybe it'll crack, then again maybe it won't. You obviously didn't have a catastrophe when it broke this time, and the second time should be the same. Keep an eye on it. Might get weeks out of it, might get years.

5 mph

Hello Bill
Can we please de escalate and see what we have in common and try to be more friendly in the future?
I know you are a good guy because you have answered a lot of my posts.
Last time you meant well and told me I had a taut cable on my Front Derailleur. and that was why it was skipping the middle gear.
A week later I disassembled the shifter and it was jammed and the cable was installed incorrectly by the previous owner... The shifter was pretty complicated and like a Swiss Watch ..After putting it back together the bike downshifts perfectly.
You also made the statement that some people have no mechanical ability., As a parent, I winced at your your choice of words. Never say that to a child.
Just as you have strong views and words at time, I have a stubborn side and I don't like to give up.
Also I have kids and a family and I just can't buy a new bike like everyone else
By welding and sliding a reinforcing cuff over the crack after welding it , and welding the cuff also ,(see below) the bike will hold together until something else breaks in the future, but by then I can save for another bike.

dedhed

Pro Tip - Don't worry about what people on an internet forum think about you.
Wear "Ignores" as a badge of honor.

cxwrench

I was the one that made the 'no mechanical ability' comment. Sometimes people need to hear that so they realize that what they're trying to do is beyond their ability. I don't think we should shield kids from every little negative thing, that's how we end up where we are now as a society.

As for your frame why haven't you explored a warranty w/ Specialized? I'm usually one to say 'no way that'll be covered' but in your case it looks more like 'materials/workmanship' than abuse. I'd give it a try to see what happens.

veganbikes

My 2009 Langster got a crack in the bottom bracket, I reached out to Specialized and they sent a new frame. Granted they aren't making the Langster anymore but still if you are the original owner they offer a lifetime warranty on their frames so it is worth pursuing if so. A credit or going for a different bike at a discount or something could be well worth it


DO NOT WELD IT. Seriously there isn't really a frame on this planet that is worth risking your life to extend the life of that frame for a short while. The Langster is nothing special, they are great bikes and I loved my original and I like my new for sure but as soon as I figured out the crack I didn't ride the bike anymore and don't ever plan on riding it again, it is nice wall art and that is all it needs to be. Plenty of awesome bikes in the sea and plenty of custom builders who could replicate the geometry or build something even better for you if you really loved that. You can also get some fine stock bikes in aluminum (though maybe not right now with the Pandemic)

frogman

If it were me I would have it welded. First have the break welded, then slide an aluminum sleeve over the repair and have it welded all the way around. Might not be a piece of art but hopefully the finished repair will be stronger at the failure point than before.

Russ Roth

Also wondering why you don't just seek out a warranty? Worse case you get a credit you can use towards something else then head on over to ebay and find a matching frame for practically the cost of the repair.
Don't know what size you have vs this one https://www.ebay.com/itm/Specialized...IAAOSwp2VfcOCU but at least it comes with some spare parts.

Andrew R Stewart 

While I agree that this frame is now "worthless", having come to it's end of life, being such means that any repair attempt has no negative cost but that of the actual repair. So I would replace the bike/frame ASAP then after seek out a repair in a way that I could afford and find.

BTW I have never seen a frame failure that I could say was chain tension related. Too tight a chain tends to be a compressive force on the chain stay and most metals have a fairly high compressive strength when compared to bending or torsional stresses. But I have seen too many BBs, hubs and freewheel bearings work out prematurely doe to too much chain tension. Many people don't understand the forces that a too tight chain can offer the cogs/bearings. Andy

cxwrench

It definitely doesn't have anything to do with chain tension or lack thereof.

frogman

Incorrect.
Not initially with everything in its original state, but If the section of AL frame tubing is weakened by the crack then the chain tension will exacerbate the problem. Thats why he should address it by a weld repair or replace the frame.

5 mph

good idea

dsaul

I build bicycles frames as a hobby and, if that belonged to me or one of my friends, I would weld up the crack and see how long it lasts. The crack is not in a location that would cause a catastrophic failure, if it failed again.

I welded a cracked seat tube/top tube joint on a friend's 6061 frame 2 years ago and it hasn't cracked yet.

CycleCommuter

It is repairable but the cost of a quality repair may exceed the cost of a slightly used comparable bike frame. I too have a beautiful fixed gear ultralight bicycle frame sitting in my bike closet with a cracked frame (the difference is mine is Columbus steel and yours is aluminum). I moved all the tack components to a different bike and used that as my fixed gear, with the hope that someday I might repair repair.

My recommendation would be to bring it to an experienced welder or buy a new frame.

Mr. 66

Put a fork in it, it's done, beer can metal.

Crankycrank

Another vote for getting it welded. Many good welders understand the stresses aluminum can withstand whether it's a bike, motorcycle, etc. Also prices vary quite a bit between welders with expensive ones not necessarily being better. If you have a few to choose from where you live get estimates and have a look at their other work if possible. If, for instance, they just weld alu fencing and have sloppy looking welds look elsewhere. If not bicycles specifically but they do many racing motorcycles, dune buggies, etc. probably a good place to try.

ClydeClydeson

I offer no opinion on welding vs not welding.

But I believe an overly tight chain could have caused this. The chainring and cog are not necessarily perfectly round, and so if you tightened the wheel at a point in the chainring/cog rotation where the eccentricity puts the chain at lowest tension, rotating the chainring and cog could pass through points where the chain is at extremely high tension, which would put a high compressive force into the chainstay, esp. the right chainstay. Aluminum does have a high compressive strength, but the chain cycling through low-to-very-high tension repeatedly while riding could push the chainstay towards a fatigue failure. If there is some defect or notch or scratch or heat affected zone (from welding), failure is all the more likely.

5 mph

okay