cutting deeper slots in horizontal dropouts



hello--
would someone please explain how to cut deeper slots in horizontal
dropouts. the dropouts are on a bmx bicycle. i want to bring the
rear wheel a little closer to the frame. thanks
 
J

John Thompson

Guest
On 2007-10-03, [email protected] <[email protected]> wrote:

> would someone please explain how to cut deeper slots in horizontal
> dropouts. the dropouts are on a bmx bicycle. i want to bring the
> rear wheel a little closer to the frame. thanks


Take a round file of appropriate diameter to fit inside the slot and
have at 'er.

--

John ([email protected])
 
L

Leo Lichtman

Guest
<[email protected]> wrote: (clip) would someone please explain how to
cut deeper slots in horizontal dropouts. (clip)
^^^^^^^^^^^^^^^^
Q-1) What is the frame made of? And Q-2) How much do you need to move the
axle forward?

If it's aluminum, you can probably get the job done with a rat tail file.
If it's steel, I recommend a tool-room grinder, diameter to fit the width of
the slot. It will take a little time, but it will work. A Dremel COULD
work if you have a lot of patience.

It goes without saying that it is up to you to limit the change so you don't
make it weak.
 
J

!Jones

Guest
On Wed, 03 Oct 2007 15:50:04 -0700, in rec.bicycles.tech
[email protected] wrote:

>hello--
>would someone please explain how to cut deeper slots in horizontal
>dropouts. the dropouts are on a bmx bicycle. i want to bring the
>rear wheel a little closer to the frame. thanks


If you do not have a mill (and, if you did, you wouldn't ask), then
take it to a machine shop. Alternatively, you might take it to your
local community college who probably teaches aspiring machinists.

It's a fairly simple job where most of the work is clamping the frame
square and solidly... or squarely and solid... or straight (wink,
wink, nudge, nudge), and cranking a 3/8 end mill down the slot. A job
shop will probably do it for a hundred bucks or so.

Jones
 
C

Chalo

Guest
[email protected] wrote:
>
> would someone please explain how to cut deeper slots in horizontal
> dropouts. the dropouts are on a bmx bicycle. i want to bring the
> rear wheel a little closer to the frame. thanks


How come? Most BMX bikes are already really short in the rear end.

Chalo
 
J

John Thompson

Guest
On 2007-10-04, !Jones <****@off.com> wrote:

> On Wed, 03 Oct 2007 15:50:04 -0700, in rec.bicycles.tech
> [email protected] wrote:
>
>>would someone please explain how to cut deeper slots in horizontal
>>dropouts. the dropouts are on a bmx bicycle. i want to bring the
>>rear wheel a little closer to the frame. thanks


> If you do not have a mill (and, if you did, you wouldn't ask), then
> take it to a machine shop. Alternatively, you might take it to your
> local community college who probably teaches aspiring machinists.


Oof! That's major overkill. Most steel dropouts -- even the brand-name
forged ones -- are mild steel and can easily be modified with a simple
hand file. On a BMX bike I'd be especially surpised to find anything
harder than mild steel dropouts.

--

John ([email protected])
 
L

Leo Lichtman

Guest
"!Jones" wrote: (clip) A job
> shop will probably do it for a hundred bucks or so.

^^^^^^^^^^^^^^^^^

The bill would look like this:
Clamping bike frame $95.00
Milling slot 5.00
TOTAL PER SIDE $100.00

Full price 200.00
 
On Oct 3, 5:46 pm, "Leo Lichtman" <[email protected]> wrote:
> <[email protected]> wrote: (clip) would someone please explain how to
>
> cut deeper slots in horizontal dropouts. (clip)
> ^^^^^^^^^^^^^^^^
> Q-1) What is the frame made of? And Q-2) How much do you need to move the
> axle forward?
>
> If it's aluminum, you can probably get the job done with a rat tail file.
> If it's steel, I recommend a tool-room grinder, diameter to fit the width of
> the slot. It will take a little time, but it will work. A Dremel COULD
> work if you have a lot of patience.
>
> It goes without saying that it is up to you to limit the change so you don't
> make it weak.


it's made of aluminum. thanks for the advice
 
On Oct 3, 11:28 pm, Chalo <[email protected]> wrote:
> [email protected] wrote:
>
> > would someone please explain how to cut deeper slots in horizontal
> > dropouts.

>
> How come? Most BMX bikes are already really short in the rear end.
>
> Chalo


^^^ changing gear combination and want to keep chain length pretty
close in length so manualing is easier.

All: thanks for the input. may be able to accomplish what i'm after
with a half link.
 
C

Chalo

Guest
[email protected] wrote:
>
> Chalo wrote:
>
> > [email protected] wrote:

>
> > > would someone please explain how to cut deeper slots in horizontal
> > > dropouts.

>
> > How come? Most BMX bikes are already really short in the rear end.


> ^^^ changing gear combination and want to keep chain length pretty
> close in length so manualing is easier.


That makes sense. And in that case, I'm in agreement with John
Thompson that you should be able to buy the extra slot depth with a
hand file. Be careful not to widen the slot in the process.

> All: thanks for the input. may be able to accomplish what i'm after
> with a half link.


If a half link will work for you, it would surely be easier than
reworking the dropout. Good luck.

Chalo
 
J

!Jones

Guest
On Thu, 4 Oct 2007 22:00:12 -0500, in rec.bicycles.tech John Thompson
<[email protected]> wrote:

>Oof! That's major overkill. Most steel dropouts -- even the brand-name
>forged ones -- are mild steel and can easily be modified with a simple
>hand file. On a BMX bike I'd be especially surpised to find anything
>harder than mild steel dropouts.


If you say so, then it must be thus. Most of them I've cut (which
amounts to exactly one) were a pretty tough alloy. Besides, they're
about 5/32" thick.

But, then, that guy in the "Shashank Redemption" dug a tunnel with a
rock hammer... and Clint dug one with a nail file in "Escape from
Alcatraz", so I know it *can* be done.

Jones... who far prefers a mill to a file!
 
J

John Thompson

Guest
On 2007-10-08, !Jones <****@off.com> wrote:

> On Thu, 4 Oct 2007 22:00:12 -0500, in rec.bicycles.tech John Thompson
><[email protected]> wrote:
>
>>Oof! That's major overkill. Most steel dropouts -- even the brand-name
>>forged ones -- are mild steel and can easily be modified with a simple
>>hand file. On a BMX bike I'd be especially surpised to find anything
>>harder than mild steel dropouts.


> If you say so, then it must be thus. Most of them I've cut (which
> amounts to exactly one) were a pretty tough alloy.


Was this a socketed dropout, or one with tabs that fit into slots on the
stays? Socketed dropouts are cast, and tend to be much harder to
manipulate than forged dropouts. But dropouts in general are better when
made from a soft steel, as they take a lot of abuse and may have to be
realigned more than a couple times over the life of the frame. The
harder cast dropouts tend to break rather than bend when abused, and
fixing a broken dropout is more of a problem than fixing a bent dropout.

--

John ([email protected])
 
On Oct 8, 3:21 pm, John Thompson <[email protected]> wrote:
> On 2007-10-08, !Jones <[email protected]> wrote:
>
> > On Thu, 4 Oct 2007 22:00:12 -0500, in rec.bicycles.tech John Thompson
> ><[email protected]> wrote:

>
> >>Oof! That's major overkill. Most steel dropouts -- even the brand-name
> >>forged ones -- are mild steel and can easily be modified with a simple
> >>hand file. On a BMX bike I'd be especially surpised to find anything
> >>harder than mild steel dropouts.

> > If you say so, then it must be thus. Most of them I've cut (which
> > amounts to exactly one) were a pretty tough alloy.

>
> Was this a socketed dropout, or one with tabs that fit into slots on the
> stays? Socketed dropouts are cast, and tend to be much harder to
> manipulate than forged dropouts. But dropouts in general are better when
> made from a soft steel, as they take a lot of abuse and may have to be
> realigned more than a couple times over the life of the frame. The
> harder cast dropouts tend to break rather than bend when abused, and
> fixing a broken dropout is more of a problem than fixing a bent dropout.
>
> --
>
> John ([email protected])


(( it's a socketed one based on your definition. i ended up using a
half link to obtain the length needed. thanks.