Results 1 to 15 of 15

Thread: Inner tube installation

  1. #1
    Registered User
    Join Date
    Apr 2011
    Posts
    4

    Inner tube installation

    I'm installing new tires on my 1977 R100S. I've changed many tires over the years, but one thing has been bugging me. I'm using new Metzeler inner tubes. The valve stem has two jam nuts and a conical shaped washer on it. I know the washer goes between the tube and the rim, but does one of the jam nuts go inside the rim between the washer and rim? Or does ONLY the washer go inside the rim and BOTH of the nuts go outside the rim? It seems if I put one nut inside the rim the tube would have to distort to form around the nut. The rubber is very thick at the valve stem, and the nut would put undo stress on that part of the tube. Any thoughts?? Joe

  2. #2
    Registered User
    Join Date
    Jul 2006
    Location
    Fairfax, VA
    Posts
    319
    What was on the old tube when you removed it?

  3. #3
    It's a way of life! oldnslow's Avatar
    Join Date
    Oct 2011
    Location
    Ash Grove, MO
    Posts
    572
    One nut inside, one nut outside. This will keep the stem moving up and down and all around. Some dirt bikers leave the outside nut off or just barely on, giving the stem some 'slack' to go inside the rim if the tire happens to spin on the rim, pulling the tube with it. This hopefully keeps the stem from ripping away from the tube. YMMV
    Mike Davis
    "Old n Slow" It's a way of life!
    1985 K100RT

    1998 R1100RT

  4. #4
    Registered User
    Join Date
    Apr 2011
    Posts
    4
    Quote Originally Posted by queretaro View Post
    What was on the old tube when you removed it?
    nothing on the inside, and a knurled nut on the outside.

  5. #5
    Registered User
    Join Date
    Sep 2005
    Location
    Eastern KY
    Posts
    3,191
    I think this is a great question,r.e.TR-4/TR-6 inner tube metal stems, both of which are metal. The nuts I see on MC's are hex, not knurled like bicycles.
    When I have disassembled OEM tires from old Hondas ,etc., they seem to have the washer on the inside & one nut on the outside. Who knows if they had the tube replaced and when I just checked a parts schematic the stems are not shown. I think the idea is to have the tube stationary if the tire slips. On bicycles there is usually one nut on the outside to keep the tube available for inflation and stationary too-my guess. When you buy most brands of MC tubes these days, you get a washer and 2 nuts. I've wondered the same OP question. I see the washer as staying inside as it's obviously curved to fit concave into the inside of the rim, i.e., not to get :mashed into the outside surface. As for 2 nuts , typically in a mechanical assy when you have 2 nuts it for one to be the lock nut, so why not the same on an inner tube?
    I looked until I lost interest & google was drifting away from topic toward British engine valve stem installation. I did run into other people asking the same question on various forums. I cannot think of a purpose for a nut inside the rim other than as a spacer & why have the washer if that's a need?One guy that worked in his family Brit bike dealership yrs ago said one nut outside but that doesn't explain why they all come with 2 nuts.FWIW, he also commented that it's important to not use a wire wheel on the inside of rims as you take away the edges of the striations that are to keep the tire from rotational slipping-I can see that this would be even more important on airheads as they are alloy , thus softer.
    I suspect Darwin could explain why(two nuts) humans & probably some other primates are so equipped. I have a nephew that has three kids from a "onesy situation" as he sadly got testicular cancer in his late twenties when he was in med school.
    "If I had my life to live over, I'd dare to make more mistakes next time...I'd relax,I'd limber up... I would take fewer things seriously...take more chances... take more trips...climb more mountains...swim more rivers...eat more ice cream." Jorge Luis Borges at age 85.

  6. #6
    Registered User lkchris's Avatar
    Join Date
    Mar 2003
    Location
    Albuquerque, NM
    Posts
    4,725
    Perhaps you'll find the attachment interesting ...
    Attached Files Attached Files
    Kent Christensen
    21482
    '12 R1200RT, '02 R1100S, '84 R80G/S

  7. #7
    Registered User
    Join Date
    Apr 2011
    Posts
    4

    valve stem nuts

    Quote Originally Posted by lkchris View Post
    Perhaps you'll find the attachment interesting ...
    Thanks for the service bulletin attachment! I put the washer on the inside, and both nuts on the outside slightly away from the rim tightened against each other. Another of lifes little mysteries solved. Joe

  8. #8
    Registered User
    Join Date
    Sep 2005
    Location
    Eastern KY
    Posts
    3,191
    Quote Originally Posted by oldnslow View Post
    One nut inside, one nut outside. This will keep the stem moving up and down and all around. Some dirt bikers leave the outside nut off or just barely on, giving the stem some 'slack' to go inside the rim if the tire happens to spin on the rim, pulling the tube with it. This hopefully keeps the stem from ripping away from the tube. YMMV
    You may be old & slow but according to the Kenda inner tube box(I had a new one on my workbench) your on the money. One nut inside other outside the rim. I looked online earlier & read a blurb from Michelin on how their tubes are better due to the splice being a taper , not a butt joint as others.
    FWIW, the Goodyear tubes I watched made were all with tapered splices too. They doped the green rubber with cement after skiving(tapering) the edges with what looked to be the same thing as a tube patch cement then rolled them down with the same stitcher as a tube repair then vulcanized the splice under a heat thing kind of like a shirt press @ the dry cleaners as I recall.
    "If I had my life to live over, I'd dare to make more mistakes next time...I'd relax,I'd limber up... I would take fewer things seriously...take more chances... take more trips...climb more mountains...swim more rivers...eat more ice cream." Jorge Luis Borges at age 85.

  9. #9
    Registered User
    Join Date
    Apr 2012
    Location
    Gilbert, AZ
    Posts
    271
    FWIW, when I changed my rear tire a couple months ago, it had the washer & a nut inside and a nut outside. It had been on the wheel for quite a while with no issues.

    Also FWIW, I had my front wheel into the local airhead guru the other day to have the wheel bearings replaced. He tightened down the valve stem nut mumbling something about people who read BS on the internet. I will probably loosen it before I re-install the wheel. Maybe I should show him the bulletin that Chris posted. Oh well...

    As always, YMMV...
    1983 R100RS (Sold)
    2004 R1150RT
    BMW MOA 181289
    ABC 13558

  10. #10
    It's a way of life! oldnslow's Avatar
    Join Date
    Oct 2011
    Location
    Ash Grove, MO
    Posts
    572
    The nut on the inside keeps the stem from pulling through the hole, and putting stress on the joint between stem and tube. The nut on the outside's only purpose is to prevent the valve stem from being pushed into the hole.
    Mike Davis
    "Old n Slow" It's a way of life!
    1985 K100RT

    1998 R1100RT

  11. #11
    Registered User
    Join Date
    Sep 2005
    Location
    Eastern KY
    Posts
    3,191
    The service bulletin advises a nut placement based on improper inflation-why would you say something like that in a tech publication? I'm thinking a nut placement based on a PROPER!!! inflation makes more sense? The washer is curved in such a way that it allows for the round shape of the tube and rim as well . Having a nut inside & out would keep the pressure of the nuts off the stem base where it meets the tube but having 2 nuts on the outside will allow the locking of the stem in a certain relationship with the rim/tube allowing positioning of the stem.
    Do we go with BMW & assume improper inflation-maybe the person there was a poor writer?
    "If I had my life to live over, I'd dare to make more mistakes next time...I'd relax,I'd limber up... I would take fewer things seriously...take more chances... take more trips...climb more mountains...swim more rivers...eat more ice cream." Jorge Luis Borges at age 85.

  12. #12
    Registered User
    Join Date
    Sep 2006
    Location
    Diamondhead, MS
    Posts
    1,054
    Quote Originally Posted by MARKAZ View Post
    FWIW, when I changed my rear tire a couple months ago, it had the washer & a nut inside and a nut outside. It had been on the wheel for quite a while with no issues.

    Also FWIW, I had my front wheel into the local airhead guru the other day to have the wheel bearings replaced. He tightened down the valve stem nut mumbling something about people who read BS on the internet. I will probably loosen it before I re-install the wheel. Maybe I should show him the bulletin that Chris posted. Oh well...

    As always, YMMV...
    Show him the bulletin. Let us know what he mumbles.
    '03 R1150R, '03 F650GS, '97DR200SE,'78 Honda CT-90, '77Honda CT-90

  13. #13
    Registered User
    Join Date
    May 2008
    Location
    B.P., MN
    Posts
    709
    With one nut on the inside, one on outside, how would it be different for Mr. Tube? Except that Tube would now be slightly pushed away from seating up against the rim hole? Have always pulled the valve stem and thus the tube right up to the rim hole, with hole properly lined with tape all'round. The tube if trying to move in the tire may have more leverage to do so, the further it sits away from stem hole? For the tube/tire to move on/in rim, guess you'd have to be doing massive wheelies, burnouts every day, and drag racing all week long? the never ending saga on the double nuts. 2cents.

  14. #14
    Registered User lkchris's Avatar
    Join Date
    Mar 2003
    Location
    Albuquerque, NM
    Posts
    4,725
    Quote Originally Posted by kantuckid View Post
    Do we go with BMW & assume improper inflation-maybe the person there was a poor writer?
    No, in your case it's rather a matter of poor interpretation.

    If it were my bike, I'd do NOTHING to lock the tube stem into position.

    The nut is there simply to aid in installation. After that screw it up to touch the valve cap as BMW specifies. No nuts inside, either.

    You ever going to reduce pressure for riding in sand?
    Kent Christensen
    21482
    '12 R1200RT, '02 R1100S, '84 R80G/S

  15. #15
    Registered User
    Join Date
    Sep 2005
    Location
    Eastern KY
    Posts
    3,191
    :no on the sand, I ride asphalt,concrete & some gravel all which require normal air
    Hard to figure that as a "sand tech bulletin"?
    Has this become the BMW vs. Kenda thread

    I installed another Kenda tube yesterday. I had one in a red box & another in a white box. The red box instructions are worded a bit differently & suggest that the way the nuts are used is for "road use" and lacks the specificity of the white box in that regard, sort of leaving it up to the user to decide. Also on the FWIW I'll ad that both sets of instructions are written by someone with exceptionally good English, not the garbled instructions we sometimes read on Asian items. The Kenda tubes do come from Taiwan.
    Last edited by kantuckid; 03-13-2013 at 01:06 PM.
    "If I had my life to live over, I'd dare to make more mistakes next time...I'd relax,I'd limber up... I would take fewer things seriously...take more chances... take more trips...climb more mountains...swim more rivers...eat more ice cream." Jorge Luis Borges at age 85.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •