Snapped spoke tackling 900ft climb

[raleighnut]

No, in your model (I'm making assumptions about what you say), if torque is evenly transmitted, then stress on both sides will be equal. Remember, stress is just force in the spoke. Tension in this case. That's the corollary of what you say above.

Stress can only be more on the right if less than half the torque is transmitted to the left. You can't have it both ways.

Shimano actually tried to get around the un-even tension thing by designing the 'Parrallax' series of rear hubs.

 

[Yellow Saddle]

Shimano actually tried to get around the un-even tension thing by designing the 'Parrallax' series of rear hubs.

View attachment 344825

I don't think that's the problem they addressed with that series. Parallax appeared in the 1990s as a "solution" to flex introduced by suspension forks.

Either way, a larger diameter torque tube transmits more torque than a small-diameter one by a large factor. On hubs like Dura Ace with a slender tube, less than 20% of torque was transmitted by the left flange.

 

[raleighnut]

I don't think that's the problem they addressed with that series. Parallax appeared in the 1990s as a "solution" to flex introduced by suspension forks.

Either way, a larger diameter torque tube transmits more torque than a small-diameter one by a large factor. On hubs like Dura Ace with a slender tube, less than 20% of torque was transmitted by the left flange.

I always thought you insisted it was Fork rather than forks and that is a rear hub.

 

[Yellow Saddle]

I always thought you insisted it was Fork rather than forks and that is a rear hub.

Forks, multiple, plural, in this case.

Yes, I know it is a rear hub but like I said, Shimano introduced Parallax as a remedy to suspension flex. Either the rear one was made to match the front one's looks or they anticipated rear suspension flex as well. I don't know. I can't remember the exact BS published at the time but it wasn't torque transmission.

However, you are skirting the issue and strewing red herrings. You still have not given an explanation for your notion of right side spokes being under more stress from pedaling forces but simultaneously that hubs transmit torque without twisting under load.

 

[raleighnut]

Forks, multiple, plural, in this case.

Yes, I know it is a rear hub but like I said, Shimano introduced Parallax as a remedy to suspension flex. Either the rear one was made to match the front one's looks or they anticipated rear suspension flex as well. I don't know. I can't remember the exact BS published at the time but it wasn't torque transmission.

However, you are skirting the issue and strewing red herrings. You still have not given an explanation for your notion of right side spokes being under more stress from pedaling forces but simultaneously that hubs transmit torque without twisting under load.

If you look at where the flanges are on that hub you will see that the NDS is further away from the dropout than usual. The tension on the spokes is almost equal when the wheel is laced instead of the large difference found on a standard rear hub.

 

[Yellow Saddle]

If you look at where the flanges are on that hub you will see that the NDS is further away from the dropout than usual. The tension on the spokes is almost equal when the wheel is laced instead of the large difference found on a standard rear hub.

You have not answered the question.

However, according to my hub database the left flange is 32mm from the hub centre and the right flange 20mm from the hub centre. That's a big difference. Cite a "standard" hub and I'll compare. I'm sure to have the hub in my database of of 973 hubs we measured over time in my wheelbuilding business.

Let me ask you straight out. What percentage of torque do you think goes from right to left through that hub with 3X laced spokes on the right? Take a guess.

 

[Dogtrousers]

I'll probably regret saying this but I have never, ever, had a spoke break.

It must be because my dainty featherlight frame applies less stress when the spoke is under tension at the top. And because I pay such assiduous attention to maintenance.

 

[Yellow Saddle]

I'll probably regret saying this but I have never, ever, had a spoke break.

It must be because my dainty featherlight frame applies less stress when the spoke is under tension at the top. And because I pay such assiduous attention to maintenance.

Did I just hear you say that bodyweight puts a spoke under tension when it arrives at the top of the wheel?

 

[Dogtrousers]

Did I just hear you say that bodyweight puts a spoke under tension when it arrives at the top of the wheel?

(Hears Yellow Saddle rattling his sabre and preparing his arguments)
Me? No!
I never said anything of the the sort!
(Decides to deflect attention by making a pun)
I spoke too soon

 

[Yellow Saddle]

(Hears Yellow Saddle rattling his sabre and preparing his arguments)
Me? No!
I never said anything of the the sort!
(Decides to deflect attention by making a pun)
I spoke too soon

That's a relief. For a minute I thought I heard something but I must be mistaken. Probably just a little vein popping in my brain or something.

 

[Yellow Saddle]

OK, I see I'm not going to get an answer to my question. In the spirit of kao o tateru I will let it go.