Panasonic Titanium eBike frame fail

Timpo

Well-Known Member
Well this is not good, even titanium isn't super durable I guess?

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Timpo

Well-Known Member
I think it was this bike.

2010 Panasonic Titan Flat Road EB
Price: 699,999 yen ($6,607)
250W mid drive
top speed: electronically restricted to 25km/h (15mph)











 

rich c

Well-Known Member
It's not the titanium itself that is not durable, that's a welding process failure when it's that close to a weld. According to the American Welding Society, "Titanium is a reactive metal that forms compounds with less than optimum properties. Heated in air, the part surface contains brittle carbides, nitrides, and oxides, each of which can reduce the fatigue resistance and notch toughness of the weld and heat-affected zone (HAZ). Not only do you need to protect the surface being welded, you also need to protect the back side of the weld, which is just as sensitive."
 

MMC

Active Member
No, the welds held up fine as you can see it didn't break at the welds. The heating process during the welding probably weakened the titanium at those points where it broke.
 

JRA

Well-Known Member
The original pic has a funky weld like thing going on at the joint. If you compare it to the welds on the other bike which is a more classic stack weld. It looks like some sort of flange?

I agree that it got too much heat there that made it brittle. I’ve owned several Ti bikes over the years and seen them made by “hand” (with machines) and never image that could even occur. I hope the owners okay...
 

Sifu Ben

Active Member
I bought my Litespeed titanium bike because I talked to a racer who crashed bike in a race and it came out undamaged and factory straight . I wouldn’t trust that Panasonic ti frame. It looks like they didn’t know what they were doing.
 

indianajo

Well-Known Member
Sounds to me the argon flow was insufficient to keep the air away from the weld arc. Cheapskates. Titanium oxide & titanium nitride don't have tensile strength. Panasonic surely checks one out of a lot of frames for strength, but if a worker forgot to turn the argon on after a break or missed that a bottle was empty a few frames would be sub-standard strength.
 
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That's an old one for sure. Look at the basic aluminum V Brakes as well. If it lasted 10 or more years of hard riding before failing (and it does have MTB tires), that's not terrible for an ultra lite frame. It doesn't look overly cared for.
 

Sifu Ben

Active Member
I had a Litespeed Catalyst from 1994. Maybe because the tubing was straight gauge with no tapers, but it was/is pretty indestructible. My brother has it now. I’ve watched an A-10 with titanium plate armor being shot by a cannon. Hardly a dent on just flat titanium plate.
 

MMC

Active Member
It's also got a mismatch fork. No way that was the oem fork as it looks like it's made of cast iron/steel. The oxidation is totally different.

The OP title says ebike frame fail. Well sorry to disappoint you OP but that Panasonic frame is circa 80's/vintage and not from a ebike.

This may be more-like what it was


Looks like a lug at the back where the end of the top tube and top of seat tube meet
If the OP shows us a pic of this area then will know forsure
 
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FlatSix911

Well-Known Member
Well this is not good, even titanium isn't super durable I guess?

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This is misinformation... Titanium is one of the most durable bike frame materials if fabricated properly.
When you weld titanium you have to shield the metal with an inert gas as it cools, otherwise it can absorb O2 or N2 from the air.
If the titanium absorbs either gas it becomes brittle and will crack over time. Most Ti frames carry a lifetime warranty. YMMV. :)