The Amusement Bike Park

Paul H

Fearless OOS Poser
So, was just the immense power of that one stroke generated by you leg that did it? Do tell...
Fact remains.... you are making a lot of assumptions here without knowing the details and stating them as facts.
You are making an ass out of yourself. Please stop.
 

rick81721

Lothar
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Paul H

Fearless OOS Poser
Ere, I was talking about mine. Didnt we have the same issue? Where our incredible power was too much for the chainring to handle?
Similar.... but my chainring didn't crack... and it wasn't threaded either.
 

TimBay

Well-Known Member
So, was just the immense power of that one stroke generated by you leg that did it? Do tell...
For my experience breaking one, yes. I weigh 230lbs and the ring wasnt threaded enough. The part it was threaded into was about 1mm thick aluminum. If it were threaded into the actual body of the chainring as it is now, it would not have broken...presumably.

Edit: I rode it pretty hard at Harts yesterday and it's fine because I have it threaded fully.
 

serviceguy

Well-Known Member
For my experience breaking one, yes. I weigh 230lbs and the ring wasnt threaded enough. The part it was threaded into was about 1mm thick aluminum. If it were threaded into the actual body of the chainring as it is now, it would not have broken...presumably.
Sorry, not at liberty to speak about this issue, I wasn't there so obviously can't comment on tensile strength of aluminum...
 

TimBay

Well-Known Member
Sorry, not at liberty to speak about this issue, I wasn't there so obviously can't comment on tensile strength of aluminum...
Fuck what Paul says. The other issue is how it was machined and any inconsistent thicknesses or fractures, but all 4 snapped on mine. It was curious that the 2 that snapped fully off were at oposite sides and same gor the om2 that were half off. I'm referring to the built in spacer of the chainring.
 

Paul H

Fearless OOS Poser
Ah, so different circumstances. Thread failure on the jacket? Or did the jackets actually snap/crack?
Nothing cracked
Because the bolts were short, it didn't thread into the female part far enough and stripped the thread.
Bolts were useless but chainring was fine.
 

serviceguy

Well-Known Member
Nothing cracked
Because the bolts were short, it didn't thread into the female part far enough and stripped the thread.
Bolts were useless but chainring was fine.

Full disclosure, I used your picture because you mentioned in an earlier post that @TimBay could use it to show what happened to his chain ring and that yours had the same provenance.
 

Paul H

Fearless OOS Poser
BTW... my bolts were supposedly titanium so no idea what aluminum tensile strength have anything to do with it when the AL chainring was totally fine.
 

TimBay

Well-Known Member
BTW... my bolts were supposedly titanium so no idea what aluminum tensile strength have anything to do with it when the AL chainring was totally fine.
I think he was assuming we had the same issue...so aluminum chainring being the cause of fuckery.
 

Paul H

Fearless OOS Poser
I think he was assuming we had the same issue...so aluminum chainring being the cause of fuckery.
Cause and result was the same but different failure (not sure if you can call it failure if it was user error) pts
But anyways... dead horse here
 

serviceguy

Well-Known Member
BTW... my bolts were supposedly titanium so no idea what aluminum tensile strength have anything to do with it when the AL chainring was totally fine.

Tensile strength of aluminum (9,000psi to 79,000psi) and titanium (25,000psi to 230,000psi) partially overlap, with the best aerospace aluminum alloys being stronger than the lowest grade titanium alloys. So if your chain ring aluminum alloy was 'better' than the titanium used for the bolts the bolts would have given way. So the chainring threads did not get any damage, not even at the beginning of the thread?
 

Paul H

Fearless OOS Poser
Tensile strength of aluminum (9,000psi to 79,000psi) and titanium (25,000psi to 230,000psi) partially overlap, with the best aerospace aluminum alloys being stronger than the lowest grade titanium alloys. So if your chain ring aluminum alloy was 'better' than the titanium used for the bolts the bolts would have given way. So the chainring threads did not get any damage, not even at the beginning of the thread?
My chainring had no threads
It requires both bolt and nut
 

TimBay

Well-Known Member
Saw 3 riders without helmets today. Part of me wanted to say something, but you know...natural selection.
 
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A Potted Plant

Honorary Sod
Nothing cracked
Because the bolts were short, it didn't thread into the female part far enough and stripped the thread.
Bolts were useless but chainring was fine.

You only need engagement of 3 threads to be able to apply enough torque for Soviet bolts comrade
 
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