Reusing sprocket mounting screws?
Seasoned HDF Member
Joined: Apr 2008
Posts: 10,135
Likes: 4,780
From: Sandpoint, Idaho
That sucks that they would back out
It sure is interesting...what would a new bolt have that an old one doesn't? They don't wear, they are the same size and pitch...why would the instructions say to toss them and put new ones in, other than the obvious....profit. There is some science here that is over my head. Is it because they have locking teeth on the head? The chrome ones I have are just chromed hex head bolts with a chrome washer, nothing more.
SDozier, do the bolts on the old sprocket look like something special? Thread forming or something?
We need Bill Nye the Science Guy on this one...lol
It sure is interesting...what would a new bolt have that an old one doesn't? They don't wear, they are the same size and pitch...why would the instructions say to toss them and put new ones in, other than the obvious....profit. There is some science here that is over my head. Is it because they have locking teeth on the head? The chrome ones I have are just chromed hex head bolts with a chrome washer, nothing more.
SDozier, do the bolts on the old sprocket look like something special? Thread forming or something?
We need Bill Nye the Science Guy on this one...lol
Bill Nye doesn't seem to realize that air pressure in an object will change with temperature. That is why tires are checked when "cold".
Seasoned HDF Member
Joined: Jul 2011
Posts: 27,096
Likes: 4,673
From: Frozelandia, Minnysota
If they'd been over torqued previously, the threads could be warped and not give a proper torque reading next use - reach the value on the torque wrench but not be tight - I've even seen bolt heads not touching yet when the wrench clicked, after some gorilla put them on previously. Old locktite left on threads can throw off the torque reading - on new bolts, too, if the holes aren't cleaned out. This business of not re-using Harley bolts bothers me, so I don't; I get good grade 8 bolts and re-use them as many times as I want, always using a torque wrench, too. If I didn't put them in first, I usually get new bolts.
Road Master
Joined: Feb 2008
Posts: 887
Likes: 133
From: Upstate NY
Bolts are designed to "stretch" when they are torqued properly. Once they stretch they lose the holding ability that that "stretch" provides.
Bill Nye doesn't seem to realize that air pressure in an object will change with temperature. That is why tires are checked when "cold".
Bill Nye doesn't seem to realize that air pressure in an object will change with temperature. That is why tires are checked when "cold".
HAHAHAHA Footballs either!
Road Warrior
Joined: May 2010
Posts: 1,593
Likes: 11
From: Mass/NH
Apparently, I have saved several hundred dollars in "special" bolts over the years...LOL. Better to spend it on some Guinness...so it's not wasted...LOL.
Ride safe.
Extreme HDF Member
Joined: Dec 2007
Posts: 13,402
Likes: 941
From: Illinois
HD says one use for grade 8 bolts. Engineers in the fastener industry say three uses for grade 8 bolts. By the way all bolts stretch that is the what the torque measurement is for. The amount you stretch the bolt.
Even the 3 times is precautionary. I have always reused grade 8 bolts and never concerned myself with the numbers of times.
All of HD's critical fasteners are grade 8.
Even the 3 times is precautionary. I have always reused grade 8 bolts and never concerned myself with the numbers of times.
All of HD's critical fasteners are grade 8.
Last edited by lh4x4; Jan 26, 2015 at 11:15 PM.
Seasoned HDF Member
Joined: Nov 2009
Posts: 15,705
Likes: 22,718
From: Farmington ,MS
"A torque to yield fastener is mounting hardware which is torqued beyond the state of elasticity and therefore undergoes plastic transformation, causing it to become permanently elongated."
Road Master
Joined: Feb 2008
Posts: 887
Likes: 133
From: Upstate NY
Does anyone know what the size and pitch of the sprocket bolts that are on a 2008 softail? I would like to get a bottom tap and at least clean the threads up. If you look at the chrome bolt set instructions it says to tighten them to 23 ft lbs with red loctite. Then you do the 60 degree finish torque. Does not seem like a lot of torque. Also the red would make it a lot harder to work on in the future.
Seasoned HDF Member
Joined: Jul 2011
Posts: 27,096
Likes: 4,673
From: Frozelandia, Minnysota
Does anyone know what the size and pitch of the sprocket bolts that are on a 2008 softail? I would like to get a bottom tap and at least clean the threads up. If you look at the chrome bolt set instructions it says to tighten them to 23 ft lbs with red loctite. Then you do the 60 degree finish torque. Does not seem like a lot of torque. Also the red would make it a lot harder to work on in the future.
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Seasoned HDF Member
Joined: Jan 2011
Posts: 157,463
Likes: 57,022
From: Michigan 15 Minutes East Of Hell
I've seen it happen twice ... and both times it was a big deal before it was over. Just because it didn't happen to you doesn't mean it won't happen. Buy some bolts and do it right O.P. Geez!
