my solution to a old problem

[butthead]

after loosing two sprocket nuts , the original oem and recently the thicker nut , my brother who is a good engineer/ mechanic came up with this.  it IS possible to drill into the end of the output shaft and tap a thread , in our case an  8 mm allen head bolt to hold a washer to prevent further loss of sprocket nuts , along with obligatory thread lock .  have to say it wasnt easy drilling into the case hardened shaft deep enough to take a thread , lots of patience not to go too deep in one go it is resistant to drilling and tapping but with careful application and patience it can be done . took most of the day to accomplish and its possible for the nut still to work loose but now it sits tight against the washer now , so cannot come off again.

[unfazed]

I did the same over 5 years ago, but added a circlip also to be safe. See the downloads section

[butthead]

yes i saw that , so we decided on our bolt and washer instead as we knew it could be done 

[unfazed]

What type of bolt are you going to use, someone on here did it also sometime having seen my fix and went with out the circlip, but for some reason the bolt head sheared. He didn't say if it was an normal or high tensile bolt he used or if it was over tightened.

[agricola]

Since the sprocket is splined onto the shaft, would it not be easier and secure enough to drill through the nut and into the sprocket. Then remove both, clearance hole in the nut, threaded hole in the sprocket, reassemble and bolt up?

[butthead]

What type of bolt are you going to use, someone on here did it also sometime having seen my fix and went with out the circlip, but for some reason the bolt head sheared. He didn't say if it was an normal or high tensile bolt he used or if it was over tightened.

we used a standard allen head 8mm M8 bolt to secure , see photo , it doesnt need to be anything special , its merely preventing side float, kind of belt and braces , new nut torqued up just fine in the end 70nm , could have gone tighter but chose to stop , thread lock on , then this bolt thread lock and tight , SHOULD  be the end of the matter, cant see how it can happen again now .

[butthead]

Since the sprocket is splined onto the shaft, would it not be easier and secure enough to drill through the nut and into the sprocket. Then remove both, clearance hole in the nut, threaded hole in the sprocket, reassemble and bolt up?

maybe ,but we have successfully done it this way and its more than fine , i can change sprockets at will without re doing what you are suggesting every time you need to change  , there are many ways of achieving this though , this one was favourite for me. once done its back to  a state of normal use , even if i wanted to sell it on ( but i wont and dont intend to ) it can only ever be seen by anyone as an improvement in the least affecting way over the standard arrangement, even looks better and is easy to change sprockets still, there's no downside , its better than the original set up .

[agricola]

Since the sprocket is splined onto the shaft, would it not be easier and secure enough to drill through the nut and into the sprocket. Then remove both, clearance hole in the nut, threaded hole in the sprocket, reassemble and bolt up?

maybe ,but we have successfully done it this way and its more than fine , i can change sprockets at will without re doing what you are suggesting every time you need to change  , there are many ways of achieving this though , this one was favourite for me. once done its back to  a state of normal use , even if i wanted to sell it on ( but i wont and dont intend to ) it can only ever be seen by anyone as an improvement in the least affecting way over the standard arrangement, even looks better and is easy to change sprockets still, there's no downside , its better than the original set up .

Good work