Worn dropout question

GaryM said:

I have a Cannondale F3000SL. I was replacing the disk brakes recently
and found that I could not prevent the new pads from rubbing. Upon
further inspection I notice that the dropout was worn and the axle had
started to eat into the frame. This means that the wheel is slightly
askew and no amount of shims can stop the rubbling. I was wondering if
there is a solution, aside from trashing the frame. I believe
Specialized use a steel dropout to prevent this kind of thing.

Firstly, if the axle is eating in to the frame then you didn't do up your
quick releases tight enough, and the whole axle was rotating.

Secondly, are you sure that it's the worn dropouts causing the issue? How
deep is hole in the dropout? There are plenty of reasons why discs might
be rubbing - make sure you have diagnosed the problem correctly.

Thirdly, many alu frames have a steel /mech hanger/ in case it gets bent.
Not the dropouts. Wearing dropouts in the fashion you describe should
never happen.

If it's as bad as you say it is, then I'd say you're a bit screwed and
you've probably made that area weaker. Maybe a washer or thin nut on the
inside of the dropout for the shimming(?)

--
a.m-b FAQ: http://www.j-harris.net/bike/ambfaq.htm

a.bmx FAQ: http://www.t-online.de/~jharris/bmx_faq.htm

"bomba" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

GaryM said:

I have a Cannondale F3000SL. I was replacing the disk brakes recently
and found that I could not prevent the new pads from rubbing. Upon
further inspection I notice that the dropout was worn and the axle had
started to eat into the frame. This means that the wheel is slightly
askew and no amount of shims can stop the rubbling. I was wondering if
there is a solution, aside from trashing the frame. I believe
Specialized use a steel dropout to prevent this kind of thing.

Firstly, if the axle is eating in to the frame then you didn't do up your
quick releases tight enough, and the whole axle was rotating.

Secondly, are you sure that it's the worn dropouts causing the issue? How
deep is hole in the dropout? There are plenty of reasons why discs might
be rubbing - make sure you have diagnosed the problem correctly.

Thirdly, many alu frames have a steel /mech hanger/ in case it gets bent.
Not the dropouts. Wearing dropouts in the fashion you describe should
never happen.

If it's as bad as you say it is, then I'd say you're a bit screwed and
you've probably made that area weaker. Maybe a washer or thin nut on the
inside of the dropout for the shimming(?)

I've seen this happen, especially w/Shimano axles - repeated removal and
re-fitting, and the knurled nut can bite away bits of metal over time. My
suggestion would also be the (steel) washer thing.

Shaun aRe

GaryM said:

I have a Cannondale F3000SL. I was replacing the disk brakes recently
and found that I could not prevent the new pads from rubbing. Upon
further inspection I notice that the dropout was worn and the axle had
started to eat into the frame. This means that the wheel is slightly
askew and no amount of shims can stop the rubbling. I was wondering if
there is a solution, aside from trashing the frame. I believe
Specialized use a steel dropout to prevent this kind of thing.

Warranty?

Bill "or get used to turning" S.

bomba <[email hidden]> wrote in
news:[email hidden]:

Quoted message said:

Secondly, are you sure that it's the worn dropouts causing the
issue? How deep is hole in the dropout? There are plenty of
reasons why discs might be rubbing - make sure you have diagnosed
the problem correctly.

I can see thread marks on the frame which leads me to believe it was
rotating as you mentioned. As to how deep, impossible for me measure,
but very smail, perhaps 1mm.

Quoted message said:

If it's as bad as you say it is, then I'd say you're a bit screwed
and you've probably made that area weaker. Maybe a washer or thin
nut on the inside of the dropout for the shimming(?)

Obviously would prefer not be screwed, but also would love a good
reason to get a new frame 😉. As I am non-mechanical, how would the
washer work? Won't the axle tend to slip into the groove, so to
speak, or does the washer hold it in place?

Thanks for the reply.

GaryM said:

Quoted message said:

Secondly, are you sure that it's the worn dropouts causing the
issue? How deep is hole in the dropout? There are plenty of
reasons why discs might be rubbing - make sure you have diagnosed
the problem correctly.

I can see thread marks on the frame which leads me to believe it was
rotating as you mentioned.

Are you sure these thread marks aren't just indentations from the nut?
Something like this: http://www.carbuffs.com/1963dropout.jpg

Quoted message said:

As to how deep, impossible for me measure,
but very smail, perhaps 1mm.

If it's only 1mm, how come you can't shim the caliper? The washers that
came with my discs give me about 10mm to play with.

Quoted message said:

Quoted message said:

If it's as bad as you say it is, then I'd say you're a bit screwed
and you've probably made that area weaker. Maybe a washer or thin
nut on the inside of the dropout for the shimming(?)

Obviously would prefer not be screwed, but also would love a good
reason to get a new frame 😉. As I am non-mechanical, how would the
washer work? Won't the axle tend to slip into the groove, so to
speak, or does the washer hold it in place?

The washer should go on the axle, between the groove and the hub. As long
as the wheel is held in tight and the washer is larger than the groove, it
should keep everything in place.

GaryM said:

Quoted message said:

Are you sure these thread marks aren't just indentations from the
nut? Something like this: http://www.carbuffs.com/1963dropout.jpg

No the thread marks are at the top of the groove. Is that a valid email
address? I can use dropload.com to pass you a few images. I don't have
a public web site available to me unfortunately.

Yep, just reactivated it after Hotmail kindly shut it down. Send me the
pics and I'll host them for everyone to have a look at. Alternatively, you
could have a look at http://www.fotopic.net

--
a.m-b FAQ: http://www.j-harris.net/bike/ambfaq.htm

a.bmx FAQ: http://www.t-online.de/~jharris/bmx_faq.htm

bomba said:

GaryM said:

I have a Cannondale F3000SL. I was replacing the disk brakes recently
and found that I could not prevent the new pads from rubbing. Upon
further inspection I notice that the dropout was worn and the axle
had started to eat into the frame. This means that the wheel is
slightly askew and no amount of shims can stop the rubbling. I was
wondering if there is a solution, aside from trashing the frame. I
believe Specialized use a steel dropout to prevent this kind of
thing.

Firstly, if the axle is eating in to the frame then you didn't do up
your quick releases tight enough, and the whole axle was rotating.

It's possible that the QR was tightened, but the miniscule amount of
movement of the axle in the dropout caused it to hit the dropout over and
over. bomba, I think that you're thinking laterally instead of
longitudinally (left and right instead of the top and bottom directions).
I've seen axle threads completely flattened from use. The QR was EXTREMELY
tight on it... i.e. need leverage from a screwdriver to get it loose. Rider
was 150 lbs, steel frame, XT M756 hub.

--
Phil, Squid-in-Training