Jump to content

Sprocket Bolts Stripped The Hub Threads, How To Fix


godzilla
 Share

Recommended Posts

sprocket bolts have stripperd the hub threads, they where m8 but now you can push an m8 in. am gutted but cant afford a new rim or hub. has this happend to you ? how would you fix this? i have got a new set of bolts on there way and have a new sprocket, i was giong to use loctite 243 to keep it together. There is also a lesson to lernt and that is threadlock at

Edited by godzilla
Link to comment
Share on other sites

 

Godzilla ,I'm at work so i can't check but I think my 2005 hub has 'through holes' not female threads?

The bolts are nipped up with nyloc nuts?

What year is your bike?

Link to comment
Share on other sites

 
 

the bike is a 2005 sy. just been to see al the spanner of gas gas ssdt fame, he sold me some new nuts and bolts and sent me to get some bearing fit ( super thred lock ) will let you all know how it goes asap. keep every thing crossed for me guys.

Link to comment
Share on other sites

 

have a look at an m10 bolt and see if there is enough beef round the hole and re tap it to suit m10 .no need to buy expensive taps if you havnt already got a set as its only alloy . helicoils might do short term but they wont last long term on something thats taking a load

Link to comment
Share on other sites

 

Still pondering on how to fix this. i have never used a tap and die set but think this could be a good option. although iwould have to open out the sprocket too. if i put an m8 in you can pull it out without turning itsoam not convinced that nyloc and thread loc will work. keep you thourght comeing as without my bike i am only half a man.

Link to comment
Share on other sites

 
 

I remember my 04 SY used to regularly vibrate loose selected nuts and bolts in particular at the rear sprocket, most were rectified with locktite however the rear sprocket remained a problem I eventually rectified it with longer bolts that actually accepted the nylon lock nuts. Whether this problem is caused by the resident frequenct of the Yammy engine I don't know but I do know at the time it was quite common.

A rider at my local club recently bourght a 07 SY and guess what, every trial he was forever tightening up his rear sprocket bolts! unfortunatly the only time he didn't he gouged a large chunck out of the swinging arm that had to be welded.

At the end of the day I realise its a bit too late now but for every one else fit longer bolts, I still reakon its the resident frequenct of the Yammy engine as both my TYS's have never had loose nuts and I presume thay use the same hubs............

Link to comment
Share on other sites

 

The simple solution is to fit better quality longer bolts with nyloc nuts on the back. The primary cause of the problem is that the original bolts are of poor quality and the 90' seating area on the bolt head does not seat snuggly on the sprocket countersinks - with the constant rocking action of the sprocket it eventually loosens the bolt and wrecks the thread. Its common for the bolt heads to then remove chunks from the swinging arm 'cos there isn't much clearance.

A good engineering machine shop will easily helicoil your hub and the thread should then be better than new - contrary to popular belief, helicoils are not just for repairing stripped threads but are frequently used in the production of alloy parts that require a strong thread. However, helicoils do work better in blind holes rather than thru holes and a badly installed one is as good as useless!

Longer bolts with nylocs is the way forward.

Link to comment
Share on other sites

 

I have just got the finest quality bolts and nuts. i have decided to have the holes welded up and re tapped to the original m8 thread. i will from now on remove the sprocket from every bike i buy, put new nuts n bolts on and threadloc em up. i will advise everyone to do this. will post some pics of the end result if i get round to it.

As for longer bolts there is noway i could use longer ones as there is no room.

Link to comment
Share on other sites

 

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

×
  • Create New...