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dropoffs?(10 posts)

Aug 23, 2002 11:00 AM
Is it important to have replaceable dropoffs?If so yet,damage easy!
The term is "dropouts," and...brider
Aug 23, 2002 12:27 PM
it's not really the dropout that's replaceable (I've certainly never seen one). It's the rear derailleur hanger that's replaceable on some frames, usually aluminum. The ductility of steel allows it to be bent back into place should it be bent. Aluminum is very succeptible to work-hardening, and bending it back would most likely result in it being snapped off. Ti dropouts are usually so thick that it would take a nuclear explosion to bend one. And this is usually only a concern off-road (though I've bent a couple on road bikes).
Replaceable dropouts are out there...TJeanloz
Aug 23, 2002 1:42 PM
Particularly on carbon bikes, replaceable dropouts do exist. I believe that Look, Aegis and Kestrel all use them; and I have seen some on aluminum bikes- though not very many recently.

A replaceable derailluer hanger is far more common.
Tjeanloz... somewhat related question5ive
Aug 23, 2002 4:52 PM
The rear dropouts on my aluminum+carbon bike (Prince) are not squarely aligned. If I put my wheel in, the spacing between the wheel and the drive side chainstay is much tighter than the non-drive side. To correct the problem, I've been using dropout screws but it's never perfect. Also, the screw will eventually move around so that the wheel will come out of alignment requiring periodical alignment. This has direct negative effect on shifting performance obviously. Is there a better way to correct this problem? I know aluminum frames with carbon stays cannot be bent into shape and I don't think the axel on the rear wheel can be adjusted laterally to correct this problem. Am I screwed? Thank in advance for any help.
Aug 24, 2002 1:44 PM
It sounds like you have two problems. First is that the wheel is either not properly dished or you have the dropout adjusters set unevenly. If the wheel is properly dished, it will be "square" in the frame if you put it in with the cogs on either side. Set the dropout adjusters evenly, and then put the wheel in both ways. If the rim is closer to one side than the other as you reverse the wheel, then it needs to be properly dished. Your second problem seems to be either poor skewers or not having your skewers tight enough. If you've got them clamped tightly and the wheel still moves in the frame, consider roughening the "nut" surface on the QR. If that doesn't do it, you may need to get some stronger QRs (steel!).
Aug 24, 2002 4:44 PM
Thanks for your reply. The dropout screws ARE set unevenly because the dropouts are uneven on my frame. If I set them evenly (or do not use the screws) then the rear wheel is badly out of alignment as I previous described. I don't think it's the dish on the wheel, since I produce same results with 2 other wheels I've own. Also, the QR are too tight if anything, so that's out. My main question was why wouldn't the screws hold their position in the dropouts and if there's a better way to fix my problem.
Bent frame/dropoutsKerry
Aug 25, 2002 3:28 PM
If you need to adjust the dropout screws unevenly to get your wheel to line up (assuming a good wheel) then your frame or dropouts are bent. You could have them aligned by a top notch shop or a frame builder. I do not understand your question about "why wouldn't the screws hold their position in the dropouts". Does this mean the screws change adjustment after the wheel is clamped in the frame? Are you saying that the wheel is shifting in the frame after it is clamped in? You need to be more clear on what the problem is - I simply can't understand it right now.
Bent frame/dropoutsTJeanloz
Aug 26, 2002 4:37 AM
Here's what I understand is happening:

The dropout screws, for whatever reason, are backing themselves out, allowing the wheel to slide back.

Solution #1 (easy): Dab some blue loctite on the screws.

Solution #2 (harder): Assuming the dropouts have some girth, as most aluminum dropouts do, and the distance isn't too far (which it really shouldn't be), take a rat-tail file, and file out the appropriate dropout to pull the wheel into alignment. There's a response down there that says: A #@$@$#@% $2000 frame shouldn't have this problem. And he's right- the bike shop should have caught this problem and fixed it before it reached the consumer. Frames, especially Italian frames, rarely arrive in perfect condition, and almost always require some prep work. Checking and adjusting alignment is part of this process. In the modern bike shop, frame prep seems to be a lost art, but it is still required at times. If you're not comfortable taking a file to your bike, bring it to the shop and have them do it for you.
You got it...5ive
Aug 26, 2002 9:58 AM
The dropout screws ARE backing themselves out. Your solution #2 sounds very interesting. I did wonder if it was possible to file down the dropout to align the wheel and what possible damage I might cause to the frame if I did. I will ask my local shop mechanic to see if he can do this. Thanks for your suggestions.
What the hell53T
Aug 25, 2002 5:18 PM
Excuse the rant but what good are carbon stays on high-dollar (Prince) import frames when they can't even align the GD dropouts. When basic quality isn't there, all the fancy design and materials isn't worth spit. Sell that dog and get a Trek or Serotta or a good custom AL or Steel. At least they will go straight down the road. Is that too much to ask from a $2000+ frame?