Road Bike, Cycling Forums banner

21 - 40 of 43 Posts

·
Registered
Joined
·
18,292 Posts
“supported” I guess meaning it cuts almost the whole tube with a blade
No. You really don't know what you're talking about.
Supported means it eliminates the bending moment so it can... shear. That's why it's called... a TUBE SHEAR and not a tube cutter.

You won’t be doing any calculating of shear strength with formulas for non-tube shapes of alloys you don’t know no matter how many times you post it.
Meaningless argle bargle.

A person with reasonable intelligence can calculate the shear strength of mild steel. Of any shape. Because... mild steel can and will shear.
 

·
Registered
Joined
·
440 Posts
I didn’t say it doesn’t shear. I wrote it’s the least likely.

Let me decode: your videos with formula for shear strength aren’t related to tubes or unknown alloys.
 

·
Registered
Joined
·
18,292 Posts
I didn’t say it doesn’t shear. I wrote it’s the least likely.
lmao Yes you did. Then you EDITED your post... because you were wrong.

Let me remind you what you said before you edited your post.
Mild steel will bend but “stronger” steels with carbon or hardened can snap/sheer.

Let me decode: your videos with formula for shear strength aren’t related to tubes or unknown alloys.
Derp. Now you're embarrassing yourself.
Again.... A person with reasonable intelligence can calculate the shear strength of mild steel. Of any shape. Because... mild steel can and will shear.
 

·
Registered
Joined
·
440 Posts
Even in ur quote I didn’t say mild steel can’t shear. You try so hard though, why?

sure they can calculate the shear strength of a steel tube if they know what it’s made of and use a formula for tubes. Good for you you posted one this time. You’re repeatedly posting vids about I-beams with petulance wasn’t a win.

I assure you your shearing machine is doing a LOT more cutting than shearing. Go to their site and read up if u don’t believe.
 

·
Banned Sock Puppet
Joined
·
12,531 Posts
Even in ur quote I didn’t say mild steel can’t shear. You try so hard though, why?

sure they can calculate the shear strength of a steel tube if they know what it’s made of and use a formula for tubes. Good for you you posted one this time. You’re repeatedly posting vids about I-beams with petulance wasn’t a win.

I assure you your shearing machine is doing a LOT more cutting than shearing. Go to their site and read up if u don’t believe.
tlg is a metallurgical engineer (I think). You're in over your head. Time to quit while you're fill in the blank .
 

·
Registered
Joined
·
18,292 Posts
tlg is a metallurgical engineer (I think). You're in over your head. Time to quit while you're fill in the blank .
Mechanical, not metallurgical.
Which makes this so hilarious.

and here’s my quote.
And again... THIS was your post. Notice your use of the word 'but'.
It is clear you said mild steel will bend BUT not shear.
So not only don't you understand physics, you don't understand the English language.
Mild steel will bend but “stronger” steels with carbon or hardened can snap/sheer.
You made a mistake. Suck it up and move on.
 

·
Registered
Joined
·
4,475 Posts
OK, steel will shear, but on a bike, no! Did you calculate the load required to shear a 1 1/4" steel tube? Lets hear what you come up with.
.... whatever it is, it ain't happening on a bike.

edit: Yes I used the wrong term "shear'. What I meant was fatigue crack, which will not happen so much with with steel (it should start bending a little before failure). I rest my case.
 

·
Registered
Joined
·
440 Posts
I think his hostility is meant for me.


mild steel can shear. If my writing makes you think otherwise I’m sorry.

In my understanding a mild steel might be chosen for its low yield numbers. So more likely to bend than snap or shear. But an alloy or hardened stuff will be stronger and have higher fatigue Strength.
Mild steel is cheap and easy to machine.
it, compared to all other steels, seems to be the safer bet in some safety critical situations, and cheaper, when youre betting on a new design. A good tester metal where you hope it will bend and you realize what shafts housings or whatever needs to be strengthened by just being thickened.​
 

·
Registered
Joined
·
18,292 Posts
In my understanding a mild steel might be chosen for its low yield numbers. So more likely to bend than snap or shear. But an alloy or hardened stuff will be stronger and have higher fatigue Strength.
Mild steel is cheap and easy to machine.
it, compared to all other steels, seems to be the safer bet in some safety critical situations, and cheaper, when youre betting on a new design. A good tester metal where you hope it will bend and you realize what shafts housings or whatever needs to be strengthened by just being thickened.​
You should stop with your 'understanding' .
Mild steel isn't "easy" to machine. It is soft and gummy. Sticks to cutting tools and shortens tool life.
 

·
Registered
Joined
·
1,874 Posts
I rode that exact frame and fork for several years. I really liked that bike, it rode well. Eventually the frame cracked around the seat tube and Cervelo replaced it with a new S2 carbon frame.
Sorry to hear about this happening to you. Thank you for bringing it to everyone's attention. I've never heard of a fork failure like this with a metal steerer tube. Horrible.
 

·
Registered
Joined
·
4,475 Posts
Are those steer tubes aluminum or steel. If they are aluminum, they are much more suspect to failure like this. I had one on my trek which I rode for years without a problem.
 

·
Registered
Joined
·
1,874 Posts
Maybe supporting the steerer with a longer compression plug is safer as it could go the full length of the stem and down through the headtube...and if u need more height use a riser stem instead of spacers

I like that idea for a carbon steerer. Seems to make sense in distributing the load some. In reply to Duriel, I believe the Wolf CL had a steel steerer (not AL).
 

·
Registered
Joined
·
7 Posts
Discussion Starter #38
I like that idea for a carbon steerer. Seems to make sense in distributing the load some. In reply to Duriel, I believe the Wolf CL had a steel steerer (not AL).
Thanks all for the comments. A magnet sticks to the steerer so it's definitely a steel alloy. Will post a sharper pic later.

dk
 

·
Registered
Joined
·
7 Posts
Discussion Starter #39
I know carbon and aluminum forks have succumbed to failure at the location of your failure, but I have never heard of a steel steerer having such a failure. I have also never seen a steel steerer fail due to rust, especially at that location. It had to be a True Temper material issue.

Yeah; I get Cervelo not honoring the warranty without the receipt. But the shop owner wasn't able to look through computer records to dredge it up for you?

You were fortunate in that you'll ride again. Buy another fork, but not a Wolf.
Thanks for the comments. Yup, the bike store changed their Point of Sale system twice since I bought the bike there. They can see records of parts, but not servicing, or the original purchase. I've looked everywhere for the receipt!!! No luck. In the process I actually found the original receipt for a bike I bought in 1987! Still have the bike.
 

·
Registered
Joined
·
4,475 Posts
... so the shop owner knows you bought the bike from him new? .... and he's not willing to recreate the reciept from his & your bank records? ... and obviously it's a cervello? ... and they are not going to honor their warrenty?
Just want to be clear.
 
21 - 40 of 43 Posts
Top