Alum frame bending

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velomanct said:

I had a mishap the other day when my rear wheel came out of the dropouts at the start of a sprint. It bent the chainstays apart 1/2inch. It's a CAAD5 aluminum frame. I can still ride it, but wonder if it is going to fail soon. I would expect it to fail near the bottom bracket, the chainstays.
I am a sprint addict and can't go on with life without sprinting.

Am I heading for a major frame failure which will send me to the pavement?

Well Yes.

Take that pull tab off the top of a coke can and bend it in half then straighten it out again. Then do it again and feel how much easier it is the second time. Same principle. A little more extreme but the same idea.

It may last, but I wouldn' t trust it.

I plan I getting a new frame, but for now I am still riding the bent one.

uggg.....

make sure you got your Road-ID on....

you certainly got a "pair"

i dont think i could ride alum. after a bend like that

I think the CAAD5 is 6061 T6 Aluminum, right? If so, I really don't think you should have a problem...

There are a few different kinds of aluminum, as one poster rightly pointed out, a Beer can tab WILL break if you bend it in half, however, Beer cans are made from a 3 series aluminum, a different alloy...so one can't really compare the two...

The only problem I can see is that now your drop outs are 1/2" wider apart you will be inducing inwards stresses by tightening the QR...

Before you go to the expense of replacing your Frame you could contact this place http://www.mindspring.com/~sk8mtb/bicycleframerepair.html

Good luck and let us know what happens...

velomanct said:

I had a mishap the other day when my rear wheel came out of the dropouts at the start of a sprint. It bent the chainstays apart 1/2inch. It's a CAAD5 aluminum frame. I can still ride it, but wonder if it is going to fail soon. I would expect it to fail near the bottom bracket, the chainstays.
I am a sprint addict and can't go on with life without sprinting.

Am I heading for a major frame failure which will send me to the pavement?

Jaguar27 said:

I think the CAAD5 is 6061 T6 Aluminum, right? If so, I really don't think you should have a problem...

There are a few different kinds of aluminum, as one poster rightly pointed out, a Beer can tab WILL break if you bend it in half, however, Beer cans are made from a 3 series aluminum, a different alloy...so one can't really compare the two...

The only problem I can see is that now your drop outs are 1/2" wider apart you will be inducing inwards stresses by tightening the QR...

Before you go to the expense of replacing your Frame you could contact this place http://www.mindspring.com/~sk8mtb/bicycleframerepair.html

Good luck and let us know what happens...

Here is a quote from that frame repair website.

"If your frame needs to have the rear triangle spread to accommodate 8, 9, or 10 speed cassettes we can provide that service. (chrome-moly frames only)"

That is the same idea as what happened to his bike but, I wonder why it says Chro-Mo only. Hmmm... Maybe the beer can analogy does work because aluminum is aluminum regardless of which alloys are added.

jitteringjr said:

Here is a quote from that frame repair website.

"If your frame needs to have the rear triangle spread to accommodate 8, 9, or 10 speed cassettes we can provide that service. (chrome-moly frames only)"

That is the same idea as what happened to his bike but, I wonder why it says Chro-Mo only. Hmmm... Maybe the beer can analogy does work because aluminum is aluminum regardless of which alloys are added.

Aluminum is not a metal that likes to be bent. If it is pushed too far it will crack, and is not very resilient. Steel is easier to repair because of this.

I was planning on getting another frame before the happened, I want to go down one size. I can get a need CAAD5 frame and fork for $300 at the LBS. Not a bad deal.