Results 1 to 12 of 12
  1. #1
    Crash Test Dummy
    Reputation:
    Join Date
    Feb 2012
    Posts
    181

    repairing a 1991 Specialized Allez Epic

    A buddy of mine was out for a ride on his CF Allez when the chain dropped off the rear, derailleur jammed in the wheel, and the aluminum derailleur hanger bent. What are the chances of straightening the derailleur hanger?

  2. #2
    RoadBikeReview Member
    Reputation: SOME_1_ELSE_1999's Avatar
    Join Date
    Apr 2011
    Posts
    227
    pics would help....
    Do not argue with an idiot. He will drag you down to his
    level and beat you with experience.
    http://surlybikes.com/blog/2514/

  3. #3
    Crash Test Dummy
    Reputation:
    Join Date
    Feb 2012
    Posts
    181

  4. #4
    LC
    LC is offline
    RoadBikeReview Member
    Reputation:
    Join Date
    Jan 2004
    Posts
    718
    Looks like the bend is past the wheel axle so it is not structural or effects the alignment. Good chance to straighten that one if you have the right tools. I have an old frame with that same dropout and they are really strong so it is going to take some serious effort to bend it back.

  5. #5
    RoadBikeReview Member
    Reputation:
    Join Date
    Dec 2006
    Posts
    3,944
    Aluminum gets weak very quickly as it's bent. Also, due to the age of the frame, it's unlikely you'd be able to get a replacement dropout for a firm that repairs carbon frames to install, if they could.

    The dropout COULD be straightened be you should keep an eye on it, long term, for cracks to form. An aluminum dropout will certainly be weaker after the accident and subsequent realignment; they're is no telling how long it will last. The trick to doing the job easily is to flip the wheel around so the cogs are on the left side of the bike. You WANT the wheel in the dropouts during alignment to keep the dropouts parallel; it's really only the hanger that's bent.

    Next, you install a derailleur hanger alignment tool in place of the rear derailleur. The tool is both an alignment gauge and a leverage tool to straighten the hanger. Most cyclists don't own this tool but bike shops will. It's necessary to get the hanger in correct alignment for good rear shifting. You want to bend the dropout into alignment with as few steps as possible, because aluminum doesn't like the repeated bending.

    Tip for using the tool: The idea is to have the same gap between the tool and the rim. You should reference the same part of the wheel as you rotate the tool i.e., indicate off the rim sidewall adjacent to the valve. This is so because your wheel might be out of true. Tip #2: It's a pain to check alignment using the tool if you have to check a spot between the seat and chainstays i.e., behind the seat tube. The good thing is YOU DON'T HAVE TO. The idea is to have the derailleur hanger and the wheel in the same plane. If you remember your geometry, 3 points in space represent a plane. So, you can check your alignment at the very bottom of the wheel, at the very top, and at the very rearmost, and you're all set.

    If you choose to bring it to a bike shop, expect some to refuse to do the work for fear of cracking the ALUMINUM dropout. It's a real possibility. If you can persuade them you'll absolve them of any responsibility, perhaps they'll give it a go. Otherwise, it would be cheaper to buy the hanger tool yourself to try the alignment, before tossing the frame into the garbage. The hanger tool is handy for any bike with an aluminum or steel dropout, with the earlier reservations on aluminum dropouts still applying. Titanium dropouts are extremely tough to align, and you can't align carbon dropouts at all.

    Episodes such as yours illustrate why it's a good reason to consider how a frame's dropouts are constructed when buying a new bike or frame. Even a bike with a replaceable derailleur hanger would have saved your friend, but his frame likely pre-dates that feature.
    Last edited by Peter P.; 05-18-2012 at 06:44 PM.

  6. #6
    Crash Test Dummy
    Reputation:
    Join Date
    Feb 2012
    Posts
    181
    nevermind

  7. #7
    RoadBikeReview Member
    Reputation:
    Join Date
    Dec 2018
    Posts
    1
    Quote Originally Posted by Peter P. View Post
    Aluminum gets weak very quickly as it's bent. Also, due to the age of the frame, it's unlikely you'd be able to get a replacement dropout for a firm that repairs carbon frames to install, if they could.

    The dropout COULD be straightened be you should keep an eye on it, long term, for cracks to form. An aluminum dropout will certainly be weaker after the accident and subsequent realignment; they're is no telling how long it will last. The trick to doing the job easily is to flip the wheel around so the cogs are on the left side of the bike. You WANT the wheel in the dropouts during alignment to keep the dropouts parallel; it's really only the hanger that's bent.

    Next, you install a derailleur hanger alignment tool in place of the rear derailleur. The tool is both an alignment gauge and a leverage tool to straighten the hanger. Most cyclists don't own this tool but bike shops will. It's necessary to get the hanger in correct alignment for good rear shifting. You want to bend the dropout into alignment with as few steps as possible, because aluminum doesn't like the repeated bending.

    Tip for using the tool: The idea is to have the same gap between the tool and the rim. You should reference the same part of the wheel as you rotate the tool i.e., indicate off the rim sidewall adjacent to the valve. This is so because your wheel might be out of true. Tip #2: It's a pain to check alignment using the tool if you have to check a spot between the seat and chainstays i.e., behind the seat tube. The good thing is YOU DON'T HAVE TO. The idea is to have the derailleur hanger and the wheel in the same plane. If you remember your geometry, 3 points in space represent a plane. So, you can check your alignment at the very bottom of the wheel, at the very top, and at the very rearmost, and you're all set.

    If you choose to bring it to a bike shop, expect some to refuse to do the work for fear of cracking the ALUMINUM dropout. It's a real possibility. If you can persuade them you'll absolve them of any responsibility, perhaps they'll give it a go. Otherwise, it would be cheaper to buy the hanger tool yourself to try the alignment, before tossing the frame into the garbage. The hanger tool is handy for any bike with an aluminum or steel dropout, with the earlier reservations on aluminum dropouts still applying. Titanium dropouts are extremely tough to align, and you can't align carbon dropouts at all.

    Episodes such as yours illustrate why it's a good reason to consider how a frame's dropouts are constructed when buying a new bike or frame. Even a bike with a replaceable derailleur hanger would have saved your friend, but his frame likely pre-dates that feature.

    In case someone ever has same problem, dropout on these bikes is NOT ALUMINUM lol it is steel and it is very easy to repair, just leave your bike at any shop, they have right tool to fix it, Same thing happenned to me, costed me 5 bux and is better than it ever was, perfectly straight.

  8. #8
    RoadBikeReview Member
    Reputation:
    Join Date
    May 2016
    Posts
    67
    Put a new hanger on...they are cheap

  9. #9
    RoadBikeReview Member
    Reputation: Oxtox's Avatar
    Join Date
    Aug 2006
    Posts
    10,156
    Quote Originally Posted by smokersteve View Post
    Put a new hanger on...they are cheap
    feel free to explain how to do it on this particular bike.
    Ancient Astronaut theorists say, 'YES!'

  10. #10
    'brifter' is a lame word.
    Reputation: cxwrench's Avatar
    Join Date
    Nov 2004
    Posts
    13,566
    Quote Originally Posted by smokersteve View Post
    Put a new hanger on...they are cheap
    This was at least 10 years before replaceable hangers became a thing.
    I work for some bike racers
    I've got some bikes, some guns,
    and a bunch of skateboards

  11. #11
    RoadBikeReview Member
    Reputation:
    Join Date
    May 2016
    Posts
    67
    Quote Originally Posted by Oxtox View Post
    feel free to explain how to do it on this particular bike.
    My bad. Didn't see the year of the bike

  12. #12
    a real member's member
    Reputation: blackfrancois's Avatar
    Join Date
    Jul 2016
    Posts
    3,758
    old thread, i know, but ...

    the youtube hack, rj the bike guy (or whatever his name is), has made a helpful video to build your own hanger alignment tool with a couple bolts, nuts, and washers. i did this and have used it a number of times on old bikes. works great.
    Yossarian: don't worry. nothing's going to happen to you that won't happen to the rest of us.

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 ROADBIKEREVIEW

VISIT US AT

© Copyright 2019 VerticalScope Inc. All rights reserved.