happened while out on my ride tonight. now time to sell my spare parts so I can try and pick up a replacement. doubt I'll find another altron. maybe I should settle for steel? *sigh* lots of great memories on this guy. gonna miss it baaaaaaaaaaad

Heartbreaking. That's a pretty brutal crack/break. What was that like while riding? Like, how sudden/severe was the failure from your perspective up on top?

Those really are nice bikes. Suntour Sprint equipped? Big Nishiki fan, and Sprint is a great group. Sorry for your loss .

Sad. That color is even less common. I'd go with steel in the meantime. What size do you like?

I'm assuming that the crack had started a few rides ago judging by the wear on the sidewall of the tires that I hadn't been able to explain until now. When it finally broke completely I was mashing up a slight incline at 20-25 mph when all of the sudden I heard/felt a soft pop. I figured it was the chain that I had messed up and was able to ride it another mile home before I was able to give the bike a through inspection. Not severe at all.

I was actually lucky enought to get a full Sante equipped bike! but I traded the Sante for a 9spd Dura Ace / Ultegra mix and other parts necessary to build up my track bike.

I know! although I definitely wouldn't mind a purple one. Partridge Family scheme would be cool too as I believe it's even more uncommon.

58cm c-c seems to be my happy size. what sucks is that I don't think I've come across any other bikes with a 58x58 c-c/tt bike like this one and it fit perfectly! I suppose that's why they make different length stems, but still!!! haha

It stinks for sure but at least you were riding and enjoying it when it broke.

That is a sad thing..

what a beauty she was..

My condolences go out to you and your components.

that totally sucks... i'd be very depressed if that happened to me, i've never seen a nishiki like that and in that colorway.

FIX IT!!!!

strip down the frame.

remove all paint about 2 inches on both sides of the weld.

take it to an aluminum welder with a TIG welder.

the way i would do it is:

replace the tube or

get the measurement recorded.
cut straight thru the crack so a good penetration weld can happen
slip a short piece of aluminum inside the tube from the bb hole to create a liner.
drill some holes before and after the crack-in these holes the liner can be attached by welding
this also re-inforces the area
weld up the crack and smooth it down.

should be one hour of a welders time.

I am sure frank the welder will be around soon-ask him!

It would be interesting to do the forensics on why the crack developed. Could the chainstay bridge next to it had something to do sith it? What does it look like from the other side of the stay, next to the wheel? Is this something that happens to other Al frames?

Chombi

Wow, you at least have a frame to show someone that does not believe your "I was mashing so hard up that hors categorie climb I snapped the stay" story. That is a beautiful frame/bicycle.

+1 for investigating the cause of the failure. I'd like to see the stress pattern and the propagation pattern of the riser(s) and I'll wager a good welder could weld that stay very well. Let a skilled welder TIG weld it with a good wire and gas shield and really good preparation/measurements. I am with Puchinfinnland on letting Frank see this thread and the pics. I would trust his judgement without reservation.

Bill

There is another crack forming on the other side. You can actually kind of see it in the picture forming from the topside working its way down. I'm a pretty big guy and generate a bit of power. My bet is the constant flex caused that point to fatigue until cracking. This isn't the first frame I've broken in this manner. I had a Lemond Nevada City that I cracked at the dropout on the driveside chainstay. Perhaps the Altron was just too rigid...

interesting
I was under the impression that repairing aluminum frames wasn't a great idea and the repaired area was likely to fail again. Even with it cracked on both sides right at the bridge is this feasible?

I think the aluminum frames are bit too stiff for your weight.

have you considered talking to a frame builder about the situation that is going on?

now that you say you broke 2 frames its something to consider.

as for fixing I had another thought.

as you have nothing left to loose in this frame and it is highly likely to happen to your next frame....

find an aluminum welding specialist locally (not hard to find at all)

or ask a frame builder about heavy duty alloy lower tubes, and explain why they are broken-

the 2 lower tubes can be completly removed and new ones built in-stronger then before.

send a pm to frank the welder about this

You have broken at least two frames this way?

1. You must be one heckuva powerful masher.
2. You might want to consider a different frame material.

I'm wondering if the developing crack on the drive side chainstay only started when the non drive side started to fail (and was fine before that happened), thus putting much more load on the drive side stay at the same area. So there's a possibility that if the non-drive side had some sort of defect on it to start/propagate the crack, The failure cannot be attributed to a rider that is too heavy or powerful for the frame.

Chombi

How does this even happen?

no offence black bullet...

Aluminum is just a stiff material, and its brittle

you should look into a lightweight cr-mo frame possibly
much more strength and flex.

That's what I've been thinking about too. The chainstays and indeed the entire BB are in fact under tension by the rider's weight acting on the rear triangle.

However the chain would be pulling the rear axle forward, and since the chain is on right side that side's tension would see a lower maximum than the left side, and probably lower average tension too. Hence a tension separation is more likely on the left.

No matter how hard the rider cranks on the pedals or pulls upward on the handlebar, the rider's weight on the BB as far as the rear triangle sees it will never exceed his/her downward dynamic load. If the rider is more or less stationary vertically that load will be just the rider's weight. However a rider could bounce up and down dynamically to generate more force on the pedals. The bigger the rider the more dynamic load is possible. (Little 160lb guys like me can't do much in that regard.)

Twisting forces on the BB might also be a factor. One would think the ST and DT would take most of that sort of stress, but perhaps it can alternately compress one chainstay and tension the other.

So one must conclude that TBB pedals with vigor.

Mr. Bullet, a question. Do you recall where in your pedal stoke this failure occurred? That might be a clue.

Please do not try and use "science" to understand this unfortunate accident. The Lord does not condone aluminum frames. That is why this happened.

Why don't you tell us how you feel about aluminum frames, Colonel.

I like riding aluminum....I'm a heretic.

Maybe a Cannondale Al frame might have had a better chance of surviving whatever caused this Nishiki to fail....

Chombi

They look nice, but I don't ride them because I don't want to burn in hell's fire.

The Right Reverend Lloyd has spoken.

but I love the stiffness! it's the responsiveness of aluminum that I just can't get enough of.

interesting idea.

will do


non taken. I'm a 6'4" 230lb 21 yr old that spends too much time out of the saddle haha

and fwiw the first frame that I broke was Reynolds 520. it broke on the driveside chainstay near the dropout but during similar circumstances.

BB flex would seem to be a likely cause. crank was at 180 degrees with my dominant foot forward and I was out of saddle

I don't know why but I've never been too fond of Cannondale's in terms of aesthetics. definitely wouldn't mind getting my hands on another Klein though!

hahahahaha