Is it TRUE...
Road Warrior
Joined: Oct 2005
Posts: 1,448
Likes: 1
From:
RE: Is it TRUE...
There are two different issues at play here: 1) H-D MOCO is just protecting themselves from the liabilities of the off chance that a ham handed mechanic using the German torque system (gutentight) and a bolt manufactured with a defect come together to create a potential failure; and 2) The Dealer is using the H-D position to up grade a modification to maximize the Dealer's profit.
I know from participating in an experiment by Sandia Corporation that stressing and re-stressing bolts and nuts causes a certain percentage of failures only after the cycles the nut/bolt are put thruare consistently over 95% ofthe calculated tensile failure strength of the bolt's shaft. Even then it takes several cycles over that 95% figure before failure was even a possibility. There is one exception: all manufactured items are subject to the variances of the manufacturing process and can be manufactured outside the specified strength requirements.
Bolt threads are engineered to develop slightly more than 100 % of the tensile strength of the shaft diameter of the bolt with the same length of threaded shaft as the diameter of the shaft, i.e. a 1/2 inch dia. bolt will develop holding power equal to or exceeding the tensile strength of the bolt shaft given a thread engagement of at least 1/2 inch.
Translate all this to H-D sprocket bolts: The bolts are so minimumly torqued for their size that they should be able to be reused over and over again during the life of that sprocket/hub assembly. In my opinion the fact that steel bolts are being threaded into a hub of aluminum alloy makes the hub suspect, not the bolts. The aluminum threads are not capable of developing near the strength that steel threadsgiven an equal amount of threads. For total minimumization of liability H-D should require the replacement of the hub every time the drive pulley is changed.
I just reuse the existing OEM bolts and carefully retorque to required amount. ..... BC
I know from participating in an experiment by Sandia Corporation that stressing and re-stressing bolts and nuts causes a certain percentage of failures only after the cycles the nut/bolt are put thruare consistently over 95% ofthe calculated tensile failure strength of the bolt's shaft. Even then it takes several cycles over that 95% figure before failure was even a possibility. There is one exception: all manufactured items are subject to the variances of the manufacturing process and can be manufactured outside the specified strength requirements.
Bolt threads are engineered to develop slightly more than 100 % of the tensile strength of the shaft diameter of the bolt with the same length of threaded shaft as the diameter of the shaft, i.e. a 1/2 inch dia. bolt will develop holding power equal to or exceeding the tensile strength of the bolt shaft given a thread engagement of at least 1/2 inch.
Translate all this to H-D sprocket bolts: The bolts are so minimumly torqued for their size that they should be able to be reused over and over again during the life of that sprocket/hub assembly. In my opinion the fact that steel bolts are being threaded into a hub of aluminum alloy makes the hub suspect, not the bolts. The aluminum threads are not capable of developing near the strength that steel threadsgiven an equal amount of threads. For total minimumization of liability H-D should require the replacement of the hub every time the drive pulley is changed.
I just reuse the existing OEM bolts and carefully retorque to required amount. ..... BC
Outstanding HDF Member
Joined: Sep 2005
Posts: 2,893
Likes: 2
From: USA
RE: Is it TRUE...
ORIGINAL: Big Cholla
There are two different issues at play here: 1) H-D MOCO is just protecting themselves from the liabilities of the off chance that a ham handed mechanic using the German torque system (gutentight) and a bolt manufactured with a defect come together to create a potential failure; and 2) The Dealer is using the H-D position to up grade a modification to maximize the Dealer's profit.
I know from participating in an experiment by Sandia Corporation that stressing and re-stressing bolts and nuts causes a certain percentage of failures only after the cycles the nut/bolt are put thruare consistently over 95% ofthe calculated tensile failure strength of the bolt's shaft. Even then it takes several cycles over that 95% figure before failure was even a possibility. There is one exception: all manufactured items are subject to the variances of the manufacturing process and can be manufactured outside the specified strength requirements.
Bolt threads are engineered to develop slightly more than 100 % of the tensile strength of the shaft diameter of the bolt with the same length of threaded shaft as the diameter of the shaft, i.e. a 1/2 inch dia. bolt will develop holding power equal to or exceeding the tensile strength of the bolt shaft given a thread engagement of at least 1/2 inch.
Translate all this to H-D sprocket bolts: The bolts are so minimumly torqued for their size that they should be able to be reused over and over again during the life of that sprocket/hub assembly. In my opinion the fact that steel bolts are being threaded into a hub of aluminum alloy makes the hub suspect, not the bolts. The aluminum threads are not capable of developing near the strength that steel threadsgiven an equal amount of threads. For total minimumization of liability H-D should require the replacement of the hub every time the drive pulley is changed.
I just reuse the existing OEM bolts and carefully retorque to required amount. ..... BC
There are two different issues at play here: 1) H-D MOCO is just protecting themselves from the liabilities of the off chance that a ham handed mechanic using the German torque system (gutentight) and a bolt manufactured with a defect come together to create a potential failure; and 2) The Dealer is using the H-D position to up grade a modification to maximize the Dealer's profit.
I know from participating in an experiment by Sandia Corporation that stressing and re-stressing bolts and nuts causes a certain percentage of failures only after the cycles the nut/bolt are put thruare consistently over 95% ofthe calculated tensile failure strength of the bolt's shaft. Even then it takes several cycles over that 95% figure before failure was even a possibility. There is one exception: all manufactured items are subject to the variances of the manufacturing process and can be manufactured outside the specified strength requirements.
Bolt threads are engineered to develop slightly more than 100 % of the tensile strength of the shaft diameter of the bolt with the same length of threaded shaft as the diameter of the shaft, i.e. a 1/2 inch dia. bolt will develop holding power equal to or exceeding the tensile strength of the bolt shaft given a thread engagement of at least 1/2 inch.
Translate all this to H-D sprocket bolts: The bolts are so minimumly torqued for their size that they should be able to be reused over and over again during the life of that sprocket/hub assembly. In my opinion the fact that steel bolts are being threaded into a hub of aluminum alloy makes the hub suspect, not the bolts. The aluminum threads are not capable of developing near the strength that steel threadsgiven an equal amount of threads. For total minimumization of liability H-D should require the replacement of the hub every time the drive pulley is changed.
I just reuse the existing OEM bolts and carefully retorque to required amount. ..... BC
Agree 100 %.
Road Captain
Joined: Feb 2007
Posts: 666
Likes: 1
From: Cavendish, Pei
RE: Is it TRUE...
Once you strugle to get those damn torx bolts out, throw them away and get some button head allens . They probably strip them all the time at the dealers so maybe thats why they say to replace them. Can'tthink of any other reason ..Mark...
Road Warrior
Joined: Oct 2005
Posts: 1,448
Likes: 1
From:
RE: Is it TRUE...
Ram: This is to say "Thanks for your comment on my post", but more than anything else to compliment you on your bike and the customization that you have done. Every time I see your signature picture, I pause to admire your bike one more time. I too have a RK Classic in Sierra Red. I have been thinking about going the "Ultra" fairing and windshield route for some time. You inspire me..... BC
Outstanding HDF Member
Joined: Sep 2005
Posts: 2,893
Likes: 2
From: USA
RE: Is it TRUE...
ORIGINAL: Big Cholla
Ram: This is to say "Thanks for your comment on my post", but more than anything else to compliment you on your bike and the customization that you have done. Every time I see your signature picture, I pause to admire your bike one more time. I too have a RK Classic in Sierra Red. I have been thinking about going the "Ultra" fairing and windshield route for some time. You inspire me..... BC
Ram: This is to say "Thanks for your comment on my post", but more than anything else to compliment you on your bike and the customization that you have done. Every time I see your signature picture, I pause to admire your bike one more time. I too have a RK Classic in Sierra Red. I have been thinking about going the "Ultra" fairing and windshield route for some time. You inspire me..... BC
I'm running DeadCenterCycles, detachable and lockable fairing and love it!You can find more pictures of my bike in his photo gallery as well:
http://www.deadcentercycles.com/
Thank you again for your kind words .."Build On"
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