Its that time for new chain and sprockets, still have the originals so that includes the 9mm nut, kept an eye on it due to known problems but all was well.
Sooo ordered a new nut and locking washer from my dealer and a new 9mm nut turns up. Apparently its all up to date, but why a 9mm nut and not the 12mm nut if there are known problems.
Shall I get a 12mm nut from wemoto?
28-10-18, 09:28 PM (This post was last modified: 28-10-18, 09:35 PM by fazersharp.)
Quote:Shall I get a 12mm nut from wemoto?
Yes.I am the same as you with no problems but keep an eye on it. I already have my 12mm nut brought from webmoto ready for when I change sprocket and chain. Odd they send the 9mm nut, I think you have to request the 12mm when you order otherwise you get sent the standard I think. Especially if the dealer is clueless or useless, you will get "no mate that is standard" then you have to explain the whole situ.Search on here as you will find the correct part number and they may be able to swap it for you.
I don't do rain or threat there of. dry rider only with no shame.
It seems that Yamaha don't bother to update the database for part numbers. Perhaps this was understandable in the days when dealers had to look up the details on microfiche, but these days there is no excuse. Anyway, if you want the 12mm nut (which you should) you have to tell the dealer the correct P/N.
07-11-18, 07:46 PM (This post was last modified: 10-11-18, 09:55 AM by limax2.)
(07-11-18, 07:19 PM)His Dudeness link Wrote: Nice drawing That must have taken some careful measuring. What program did you draw it in?
It was done on Autocad 2005.
It does illustrate the extra thread engagement.
Interesting that the counterbore in the new nut is 1mm deeper than the old nut. Made me wonder if with unfavourable build up of tolerances you could get a situation with the old nut where it tightened on the end of the shaft splines rather than on the sprocket. Same would happen if an aftermarket sprocket was a bit thinner than original. Maybe I overthink these things.
So I've got my upgraded nut and it is the right thickness overall, but I wasn't expecting it to be hollowed out in the middle making the thread thickness basically the same as a 9 mm nut. Is this right?
(04-12-18, 06:07 PM)Skippernick link Wrote: So I've got my upgraded nut and it is the right thickness overall, but I wasn't expecting it to be hollowed out in the middle making the thread thickness basically the same as a 9 mm nut. Is this right?
From memory the new nut is flush with the end of the shaft, including the threaded part.
I'm sure it's meant to have more threads otherwise it's all a bit pointless.
More people are born because of alcohol than will ever die from it.
Yes it is meant to be hollowed out so the nut pushes on the sprocket and doesn't push on the end of the splines on the shaft. The 9mm nut is also hollowed out so you get about twice the threaded length with the 12mm nut
(04-12-18, 06:07 PM)Skippernick link Wrote: So I've got my upgraded nut and it is the right thickness overall, but I wasn't expecting it to be hollowed out in the middle making the thread thickness basically the same as a 9 mm nut. Is this right?
Look at the drawing I posted earlier in this thread. You will see the following.
The 12mm nut is hollowed out 1mm more than the 9mm nut, but when fitted this is all in the are of the undercut on the shaft thread so doesn't effect the thread engagement. On the 9mm nut the nut thread overlaps the shaft thread slightly where the shaft is undercut.
At the outside end the 12mm nut comes to the end of the shaft whereas the 9mm stops short. so you gain about 2mm to 3mm thread engagement above the original approx. 5mm engagement.
