Advertise on Bikeforums.net



User Tag List

Results 1 to 7 of 7
  1. #1
    Senior Member BikeArkansas's Avatar
    Join Date
    Jun 2007
    Location
    Maumelle, AR
    My Bikes
    2008 Scott Addict
    Posts
    873
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Dura Ace 7800 rear wheel mount problem

    This may be my imagination, but it seems to me it is more difficult to replace a rear wheel with the 7800 Dura Ace components than with most other components. I have not been riding and maintaining road bicycles very long, maybe 5 years. I have had mostly Shimano equipped bikes, which include 105. Ultegra, Tiagra and 9 speed Dura Ace.

    I have not had a problem mounting the rear wheel until a month or so ago when I bought a used Cannondale with 7800 components. Thought it was just me. However, today my wife also bought a used Schwinn Peloton LTD with 7800 components. I replaced the tires for her with new rubber, but when I started to mount the rear wheel I again had a problem.

    Is this my imagination, I am doing something wrong, or is the 7800 contrary?
    I started riding my bike to get healthy. Now I try to stay healthy so I can ride my bike.

  2. #2
    Constant tinkerer FastJake's Avatar
    Join Date
    May 2010
    Location
    Madison, Wisconsin
    Posts
    6,121
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    I don't understand the question. What part of "mounting the wheel" are you having trouble with?
    Why "derailer" is the correct way to spell the gear-change mechanism: sheldonbrown.com/derailer.html

  3. #3
    Senior Member
    Join Date
    Apr 2006
    Posts
    2,207
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Do you put the chain on the smallest rear cog before removing the wheel? As the other poster said you didn't state what your problem is. Roger

  4. #4
    Senior Member
    Join Date
    Apr 2009
    Location
    New Rochelle, NY
    My Bikes
    too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
    Posts
    22,091
    Mentioned
    60 Post(s)
    Tagged
    1 Thread(s)
    I can't see that any one wheel would be significantly harder to mount than any other of the same width.

    The key is to get into the habit of always mounting with the RD shifted to high gear, and the chain on the smallest sprocket. there are also sometimes small differences in hangers which can limit clearance and access to the axle slots.

    Lastly, if you're willing to modify, here's a few tricks from the old days of setting up race bikes.

    If the axle locknuts have very square outer corners, grind a small chamfer (bevel) onto them. Likewise with the areas at the bottom of the dropouts and front of the hanger. The chamfers in the areas where the axle and frame first meet can reduce the odds of the axle hanging on an edge and help guide it into the slot. This is SOP on front dropouts, but often not on rears and is one reason folks sometimes have more grief mounting rear wheels.

    I'm aware that there are many here who would never touch a file to their pristine frames, so the advice is only for those who's sensibilities it doesn't offend.
    FB
    Chain-L site

    An ounce of diagnosis is worth a pound of cure.

    “Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin

    “One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

    WARNING, I'm from New York. Thin skinned people should maintain safe distance.

  5. #5
    Senior Member BikeArkansas's Avatar
    Join Date
    Jun 2007
    Location
    Maumelle, AR
    My Bikes
    2008 Scott Addict
    Posts
    873
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    As the op of this thread, I will try to explain. Yes, I always shift to the big ring and small cassette cog. I have done this many times with my other bikes with Shimano components and the wheels slips easily into place. With the 7800 Dura Ace on both my bike and my wife's bike it is always a struggle to get the wheel to slide into place. It just seems odd that I have not had difficulty with other Shimano components. I do eventually get it done, but it is never easy. My question is: Is the 7800 different in some way which would require something different in mounting the wheel, or is it just coincidence?
    I started riding my bike to get healthy. Now I try to stay healthy so I can ride my bike.

  6. #6
    Senior Member
    Join Date
    Apr 2009
    Location
    New Rochelle, NY
    My Bikes
    too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
    Posts
    22,091
    Mentioned
    60 Post(s)
    Tagged
    1 Thread(s)
    Quote Originally Posted by BikeArkansas View Post
    My question is: Is the 7800 different in some way which would require something different in mounting the wheel, or is it just coincidence?
    Occasionally being harder might be a coincidence. Consistently, on either bike means something is different.

    In my last post I described how to improve mounting ease by beveling the outside of the locknuts (or axle faces). You might compare the shape of the Dura axle faces and your other hub's. If the Dura has squarer corners, or even flared ends, this can catch on the dropout rather than guide it in.

    It could also be that the Dura hub is slightly wider or narrower than your other hubs and therefore not as perfect a fit in the frame.

    I've had some hubs that frequently snag, and my commuter always was a pain until I filed "funnels" in the non contact area on the underside of my rear dropout.
    FB
    Chain-L site

    An ounce of diagnosis is worth a pound of cure.

    “Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin

    “One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

    WARNING, I'm from New York. Thin skinned people should maintain safe distance.

  7. #7
    WNG
    WNG is offline
    Spin Forest! Spin! WNG's Avatar
    Join Date
    Sep 2007
    Location
    Arrid Zone-a
    My Bikes
    I used to have many. And I Will again.
    Posts
    5,964
    Mentioned
    36 Post(s)
    Tagged
    0 Thread(s)
    I think you will find it easier to have the chain in the small chainring instead. It's only cross-chaining during installation, but the lessened tension and extra chain slack will help you work the axle and cassette past the RD and onto the dropout.

    I've not heard of any 7800 issues regarding wheel difficulties. I'm assuming both bikes are spaced for 130mm spacing.
    “You meet the nicest people on two wheels!"
    "Learn from yesterday, live for today, hope for tomorrow." ~Albert Einstein

Posting Permissions

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