Trek Rig rear wheel falling out: diagnosis and solution- Mtbr.com
Results 1 to 8 of 8
  1. #1
    mtbr member
    Reputation: itsdoable's Avatar
    Join Date
    Jan 2004
    Posts
    1,902

    Trek Rig rear wheel falling out: diagnosis and solution

    (X-posted in the Trek Forum for obvious reasons...)

    One of our riders bought a Rig in the summer (2011 model), and we've had a number of issues with it, but this particular one was perplexing. The rear wheel would come out under load, usually accompanied by lateral forces on the wheel (rocks & roots). The first time it happened, we assumed user stupidity. After the 3rd time, we got suspicious, then down right suspicious the 4th time. We also noticed that this was happening to other people:

    I read it first in the SS forum (https://forums.mtbr.com/singlespeed/...ig-748922.html). But since noticed the same post in the Trek Forum (https://forums.mtbr.com/trek/2011-20...ig-748924.html) and another rant here: (https://forums.mtbr.com/trek/2012-tr...me-754111.html). There are probably others.

    Anyways, this is what we've discovered on this particular bike after a few months(!).

    The non-drive-side swinging dropout does not extend far enough beyond the frame, interfering with QR head. As a result the axle does not sit all the way in the dropout, and is askew, causing the dropout to flex when the QR is closed, not allowing the QR to clamp fully. The causes disc mount to flex when the QR is tightened, making it hard to align the caliper. In fact, I was facing the caliper mount to address this issue when we discovered this.



    This is what it looks like with the stock skewer. Normally the skewer is already mounted and the QR head bottoms on the frame instead of the axle bottoming out in the dropout.



    The solution was to file down the head of the skewer for clearance, we used a Shimano version because we wanted better clamping force.


    We only filed it enough for the axle to bottom in the dropout.

    ...and for the first time we notices axle marks (marks made by the threaded axle) in the bottom of the dropout. This also solved our caliper alignment issue, increasing the QR clamping force does not change the caliper alignment any more.

    The drive side has lots of clearance.


    I don't recommend filing the frame.

    We think the ejection issue occurred when lateral forces flexed the rear triangle such that the dropout re-aligned with the (miss-aligned) axle, resulting in less clamping force, so the wheel got pulled out under hard effort.

    As for the sliders slipping and set screws bending, we can minimize it so it's manageable - better hardware would help (ie: M6 screws), but such is life with a light weight frame.


    Hopefully this info will help a few people.

  2. #2
    one chain loop
    Reputation: fishcreek's Avatar
    Join Date
    Apr 2007
    Posts
    2,360
    its a shame to file a nice skewer over a bad dropout design just to make it work. are they going to send in a redesigned dropouts to replace a recall part?
    everything sucks but my vacuum cleaner.

  3. #3
    nothing to see here
    Reputation: Stevob's Avatar
    Join Date
    Feb 2009
    Posts
    3,271
    Did you try fitting the skewer with the clamp on the drive side?

    edit...I see that the top pic shows it was indeed fitted with the clamp on the drive side...carry on.
    I see hills.

    I want to climb them.

  4. #4
    mtbr member
    Reputation: itsdoable's Avatar
    Join Date
    Jan 2004
    Posts
    1,902
    Quote Originally Posted by fishcreek View Post
    its a shame to file a nice skewer over a bad dropout design just to make it work. are they going to send in a redesigned dropouts to replace a recall part?
    Yea, almost makes you want to file the frame... fortunately Shimano skewers are not expensive, easy to find, and work better than stock. I've heard people talk about a replacement kit, but the lbs has not mentioned anything. This fix works fine, so we're good.

    We tried several different skewers looking for one with a smaller head, but they all interfered with the frame.

  5. #5
    Sweep the leg!
    Reputation: Caffeine Powered's Avatar
    Join Date
    Mar 2005
    Posts
    3,803
    Good job solving the problem. Did you pass this information on to Trek?
    Authorities speculate that speed may have been a factor. They are also holding gravity and inertia for questioning.

  6. #6
    On wuss patrol
    Reputation: Glide the Clyde's Avatar
    Join Date
    Nov 2009
    Posts
    4,953
    Nice work finding a fix but that bikes been ridden hard and put away wet.
    Sometimes, you need to go fast enough that the trail is a blur to find clarity. -- Wild Bill

  7. #7
    mtbr member
    Reputation:
    Join Date
    Oct 2011
    Posts
    135
    this was just a poorly designed frame. I cracked the frame at the rear drop out on the driveside, it only took 7months. This is the 4th rig ive owned, my favorite was the rootbeer coloured one. cheers

  8. #8
    mtbr member
    Reputation: itsdoable's Avatar
    Join Date
    Jan 2004
    Posts
    1,902
    Quote Originally Posted by Caffeine Powered
    Good job solving the problem. Did you pass this information on to Trek?
    No, but this did get cross-posted to the Trek forum.


    Quote Originally Posted by Malibu412
    Nice work finding a fix but that bikes been ridden hard and put away wet.
    All bikes get put away wet this time of the year (up here).


    Quote Originally Posted by angryx
    this was just a poorly designed frame. I cracked the frame at the rear drop out on the driveside, it only took 7months...
    We'll see how long this one lasts, but taking the stress out of the dropout/rear triangle should help.

Similar Threads

  1. trek 69er rear wheel
    By dbikeco in forum 27.5
    Replies: 12
    Last Post: 01-04-2016, 03:18 PM
  2. Replies: 53
    Last Post: 04-27-2013, 08:14 PM
  3. Rear wheel trek fuel ex8 2011
    By stangbang in forum Trek
    Replies: 6
    Last Post: 11-12-2011, 10:33 AM
  4. quick wheel problem diagnosis?
    By gcavy1 in forum Wheels and Tires
    Replies: 5
    Last Post: 04-07-2010, 06:31 PM
  5. Using 24" rear wheel on Trek Session 77
    By stevet101 in forum Downhill - Freeride
    Replies: 6
    Last Post: 07-22-2007, 06:32 PM

Members who have read this thread: 0

Posting Permissions

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

THE SITE

ABOUT MTBR

VISIT US AT

© Copyright 2019 VerticalScope Inc. All rights reserved.