What thread are 8mm cylinder studs?

Discussion in '2-Stroke Engines' started by AussieSteve, Nov 28, 2009.

  1. AussieSteve

    AussieSteve Active Member

    I just stripped a thread on a head nut because with the billet head the studs need to be a couple of mm longer. (And I was too slack to chase up longer studs and better nuts when I fitted it.)
    I went to remove a stud to measure it's length, using 2 x M8 (high tensile) nuts locked together and lo and behold, the thread isn't M8. I tried 2 new M8 nuts on the studs, then an old head nut on an M8 high tensile bolt. nogo.
    Is 8mm metric different to M8?
    I did a search, but all discussions were related to stud strength ratings, not the thread.
    Either way, I'll take a couple of head nuts down to our local bolt dealer, a specialist, and get the right size in a day or two. Just wondering, especially since no one else appears to have had a problem in this area.

    ... Steve
    Last edited: Nov 28, 2009

  2. ibdennyak

    ibdennyak Guest

    I think it is a 8mmx 1.25. I remember having the same problem and had to go through 3 different drawers to get the correct pitch. Could be 8mm x 1 also.
  3. AussieSteve

    AussieSteve Active Member

    So I'm not the only one.
    I always thought that for 8mm metric there was only one pitch, M8 - most are. I've never had this problem before. Whatever I'm working on, I just grab an 8mm nut/bolt and it goes straight on. Not to worry.
    I was looking forward to a good ride later.
    ... Steve
  4. ibdennyak

    ibdennyak Guest

    I think there are actually three in that size range...1.0 1.25, and 1.50. Considering I had enough trouble with SAE course and fine in the US, I was hoping metric would be a little more standard. No such luck. :confused:
  5. Pablo

    Pablo Motored Bikes Sponsor

    As others have mentioned M8x1.0 or M8x1.25.

    A simple way is to measure 1 cm and count the threads. 1.00 thread pitch will have 10 threads in that 1 cm, 1.25 thread pitch will have 8 threads.
  6. AussieSteve

    AussieSteve Active Member

    I could have sworn that I posted a reply yesterday, regarding pitch. Thanks Pablo, I'm a bit slow sometimes, I should have known to measure it. Duh. That's what I did.
    Anyway, the pitch is 1.0mm, on both ends of the stud. I went in to get some M8 x 1.0 threaded rod today from a bolt 'specialist' and they don't have it. Not even any long bolts. There's nowhere else that I know of around here to get it. A PITA.
    I did manage to get some nuts to suit, though, so the billet head is off and the stock head is back on for now, until I get the longer studs. I had a ride today - I want the billet head back.
    I emailed Tony at Rock Solid a couple of days ago, to see if he sells stud and allen-head side-cover screw kits. Waiting for a reply.
    ... Steve
  7. AussieSteve

    AussieSteve Active Member

    Tony got back to me today:-

    My friend in Sydney asked a bolt supplier and got the same - M8 x 1.0mm isn't even in his books.

    Looks like I've got a problem.
    I asked this in another thread, but if any Aussies know of a supplier who will post, please let me know. (M8 x 1.0mm x 1 metre)

    I'm doing a search of Australian sites now, to see what I can find. Next overseas if nothing.
    A bloody nuisance.

    ... Steve
    Last edited: Dec 2, 2009
  8. EnFlaMEd

    EnFlaMEd Member

    Just order from Sickbikeparts like I did. My stud kit from them is top notch. I went through the same **** trying to find a local supplier and came up with nothing. The only bad part about SBP if you are an impatient ******* like me is waiting for the postage.
  9. AussieSteve

    AussieSteve Active Member

    Were the SBP studs longer than the standard ones? My stock studs are 107mm and I need 110mm to 112mm.
    I can wait for postage, I've got the stock head back on for now, so it still goes.
    ... Steve
  10. Pablo

    Pablo Motored Bikes Sponsor

    Unfortunately our M8-1.0 studs are stock length. ~108mm. We could get you some longer studs, but those wouldn't ship until Monday - IF our supplier had material in stock (it's 4:32AM right now)
  11. AussieSteve

    AussieSteve Active Member

    Wow, good stuff Pablo, I don't mind waiting as long as necessary. (I already emailed Jim a short time ago.)

    I've been discussing this with another member who has the same issue with a billet head. (He left two washers off.) You'll probably get more requests for the longer studs.

    If you mention it to Jim, I'll wait for his email reply, then we can arrange payment etc.

    (It's almost midnight here - we both should be asleep.)

    ... Steve
  12. AussieSteve

    AussieSteve Active Member

    Problem solved thanks to Paul and Jim at Sick Bike Parts.
    Air Filter's pretty good, too.
    See here and here.

    ... Steve
  13. 210061741

    210061741 Guest

    There are 2 different thread types.

    PK80-J has 1 type and Grubee another.
    Both the 8mm version.

    I'm not sure about the 6mm version.
  14. AussieSteve

    AussieSteve Active Member

    Yes, in 8mm studs, some are metric fine, (1mm pitch) and some are std M8, (1.25mm pitch.) ie ZBox Australia have 8.0mm x 1.0mm studs, 107-108mm long.

    For others, to check, 1mm pitch have 10 threads per cm, 1.25mm pitch have 8 threads per cm.

    In 6mm studs, as far as I know, all are std metric 1mm pitch.

    ... Steve
  15. give me vtec

    give me vtec Active Member

    yep I agree... my zoombikes motor with slant head took the 1.0 thread pitch and my grubee took the 1.25.