Snapped spindle

[Webbo2]

You don't know how right you are.
I bought a second hand frame (for the record: the seller was in Germany, not in Belgium). We agreed that he removes cranks (square taper!) and bottom bracket and sells it seperately. I paid the frame and shipping and waited. So far so good, but then that ... guy destroyed the threads in the left (square taper!) crank while trying to get it off. That was his problem, not mine. Then - without confering with me - he took an angle grinder, cut off the spindle with the crank and of course he hit the bottom bracket shell with the running angle grinder. 🤦‍♂️
Fortunately it was only roughly one millimeter and the left side and my plan was to use the frame with a cartrige bottom bracket for square taper cranks. Fortunately again I have a face milling tool for bottom bracket shells and know how to use it.

And the moral of this story: https://www.cyclechat.net/threads/snapped-spindle.309571/post-7603307

E.

I posted that think no one in their right mind would go near a bike with a grinder. It must be a European thing.😏

 

[silva]

So you keep on throwing OFC in because this thread is about Shimano? You threw it on other threads that weren't about Shimano.

So I'll refer you back to my question, why?

You keep on throwing your question, so I'll refer you back to my answer:
https://www.cyclechat.net/threads/snapped-spindle.309571/post-7602947
https://www.cyclechat.net/threads/snapped-spindle.309571/post-7602826

...
if that 29% less deformation would bring it under the endurance limit of the steel wall of the spindle, metal fatigue would not occur, no crack initiation, and ofc also not growing until Shimano Spindle Snap Story Day.

Safety Reserve.
No cracking spindle section, no cracking spider section, no cracking crank section, no cracking of left crank around pincher bolts, and So On, as proved by the numerous pictures over the years that people posted on Instagram @thanksshimano.
Until it became a so ugly sight https://www.roadbikerider.com/the-shimano-crank-recall/ that Shimano was finally forced "to do something" instead of keep denying the safety shortcomings of their design.

Next time you throw your question, I'll politely re-throw my answer.

 

[classic33]

You keep on throwing your question, so I'll refer you back to my answer:
https://www.cyclechat.net/threads/snapped-spindle.309571/post-7602947
https://www.cyclechat.net/threads/snapped-spindle.309571/post-7602826

Safety Reserve.
No cracking spindle section, no cracking spider section, no cracking crank section, no cracking of left crank around pincher bolts, and So On, as proved by the numerous pictures over the years that people posted on Instagram @thanksshimano.
Until it became a so ugly sight https://www.roadbikerider.com/the-shimano-crank-recall/ that Shimano was finally forced "to do something" instead of keep denying the safety shortcomings of their design.

Next time you throw your question, I'll politely re-throw my answer.

Well you explain why Orbitofrontal Cortex is relevant then!

Simple really.
You must know as you keep on throwing it in to your answers, whichever thread you're replying to.

 

[silva]

Don't forget 'tuning' sprockets with an angle grinder

That's just an own made-up story you tell here.

Loose chainring and loose rear cogsprockets, on a table grinder, to make the valley's abit rounder and the teeth abit lower = making it easier for the rollers of the chain to disengage, thereby eliminating a number of flip on their mount - jobs in order to minimalize the sharkfin shaping.
That's what I did, and the experience with such shaped chainring and rear cog proved that it works.
Chainring mounted new begin 2019.
A number of flips on its mount.
Same for the rear cog, which is also a demand of Velosolo, its producer:
https://www.velosolo.co.uk/shopdisc.html

...
*Guarantee applies to the original owner only, cog must be run in both directions evenly and flipped frequently,
...

Once ring and cog reach the wear state that a max chain wear causes, they proved as not wearing further. Since 4 years I don't bother flipping the ring anymore - no sharkfin shape - not needed. The chains rollers disengage effortless.
And the same proved for the rear cog.

So, what you call "tuning" here, is just evading the cost of new, and, evading the work/hassle of flipping regularly, ON FOREHAND.
And ofcourse, also, the chain, see, if rollers have to overcome the sharkfin hook, they have to roll over a steadily longer trajectory, under an increasing pressure, so chain wears faster too.

 

[EckyH]

That's what I did, and the experience with such shaped chainring and rear cog proved that it works.

Wrong.

Anecdotes prove exactly nothing.
Or, more scientific: The sample size isn't big enough to have any statistical relevance.

E.

 

[silva]

Well you explain why Orbitofrontal Cortex is relevant then!

Simple really.
You must know as you keep on throwing it in to your answers, whichever thread you're replying to.

These are the 2 calculators I used for the weight +20 grammes / torsion resistence +29%
https://www.profilebendingmachine.com/steel-pipe-tube-hss-weight-calculator/
https://amesweb.info/Torsion/torsion-of-shaft-calculator.aspx

These are technical and reporting sources I gave:
https://machiningpartner.com/demystifying-strength-of-materials-for-engineers/
https://www.bicycleretailer.com/ind...rankset-recall-settlement-officially-approved
https://www.cpsc.gov/Newsroom/News-...t-Bicycle-Cranksets-that-Posed-a-Crash-Hazard
https://www.hambini.com/shimano-crankset-failures-an-engineering-analysis/
https://weightweenies.starbike.com/forum/viewtopic.php?t=176295&start=60
https://www.ptsmake.com/the-complet...does_metal_fatigue_occur_below_yield_strength

So Please Ask Yourself Your Relevance?

 

[classic33]

These are the 2 calculators I used for the weight +20 grammes / torsion resistence +29%
https://www.profilebendingmachine.com/steel-pipe-tube-hss-weight-calculator/
https://amesweb.info/Torsion/torsion-of-shaft-calculator.aspx

These are technical and reporting sources I gave:
https://machiningpartner.com/demystifying-strength-of-materials-for-engineers/
https://www.bicycleretailer.com/ind...rankset-recall-settlement-officially-approved
https://www.cpsc.gov/Newsroom/News-...t-Bicycle-Cranksets-that-Posed-a-Crash-Hazard
https://www.hambini.com/shimano-crankset-failures-an-engineering-analysis/
https://weightweenies.starbike.com/forum/viewtopic.php?t=176295&start=60
https://www.ptsmake.com/the-complet...does_metal_fatigue_occur_below_yield_strength

So Please Ask Yourself Your Relevance?

What you're saying then is you don't why you keep on inserting it into your posts.

 

[EckyH]

What you're saying then is you don't know why you keep on inserting it into your posts.

The funny thing is: Some of the sources show that his assumptions how things work are just complete and utter b...lah.

E.

 

[classic33]

The funny thing is: Some of the sources show that his assumptions how things work are just complete and and utter b...lah.

E.

Only some?

 

[fossyant]

Cycle forum's Voldemort is back....

I replaced my square taper cartridge BB last night on my commuter (not hollowtech so the best-est.... ahem) , it was 'slightly' wobbly and worn out... bin job for me, but our 'highness' would have made it last. £15 new, had one in stock, will order another. Looked at possibly replacing the bearing, and went - nope ! Waste of money/time.

 

[EckyH]

Only some?

Didn't read all of them and I only write about things I know.
Perhaps some of them don't cover eg. fatigue failures and so - formally speaking - they don't show that the assumptions are wrong.
Therefore I only refer to one or the other and not all of them.
But if they would cover that topic, they would show that the assumptions in question are wrong.

E.

 

[SpokeyDokey]

Mod note:

Enough is enough thank you. This slightly bad-tempered thread has run its course and is now closed.