Switching from nutted to recessed allen brakes.

[Wayne Pein]

I'm refinishing my 83 Trek 600 and may use Ultegra 57mm dual pivot
brakes I've been hoarding to replace my single pivot Dia Comp.

The rear brake bridge is a round tube the same diameter as the
seatstays. There is a 1/4" "tunnel" through it for the brake bolt. The
ends of the "tunnel" have what look like washers brazed on for strength
that the brake and nut bolt seat against. It looks like an "I" through
the brake bridge.

I know about using the front on the rear and the rear on the front.
However.....

To use the rear brake on the rear, it seems that if I drilled this
"tunnel" with an 8mm (5/16 inch) bit to accommodate the allen nut it
would work, but is the added 1/16 inch hole size enough to breach the
sides of the "tunnel," and if it did would that be a problem? Is this
doable with a hand drill?

On the front I could simply drill the back of the fork to accept the
allen nut and then use the front brake there.

Front and rear would look clean without visible nuts.

Wayne

 

[A Muzi]

Wayne Pein wrote:
> I'm refinishing my 83 Trek 600 and may use Ultegra 57mm dual pivot
> brakes I've been hoarding to replace my single pivot Dia Comp.
>
> The rear brake bridge is a round tube the same diameter as the
> seatstays. There is a 1/4" "tunnel" through it for the brake bolt. The
> ends of the "tunnel" have what look like washers brazed on for strength
> that the brake and nut bolt seat against. It looks like an "I" through
> the brake bridge.
>
> I know about using the front on the rear and the rear on the front.
> However.....
>
> To use the rear brake on the rear, it seems that if I drilled this
> "tunnel" with an 8mm (5/16 inch) bit to accommodate the allen nut it
> would work, but is the added 1/16 inch hole size enough to breach the
> sides of the "tunnel," and if it did would that be a problem? Is this
> doable with a hand drill?
>
> On the front I could simply drill the back of the fork to accept the
> allen nut and then use the front brake there.
>
> Front and rear would look clean without visible nuts.

A closer look will show that it's amazingly hard to cut a neat 8mm
relief in the back of a brake bridge. And, unless it's more substantial
than a simple tube, the caliper will shift when you use the brake.

I'd use the 'medium' length bolt both front and rear (nutted rear, allen
front) as that caliper is not offered with a 'long' (nutted front) bolt.

Or braze in a modern allen-type brake bridge.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

 

[Hank]

On Mar 7, 3:03 pm, A Muzi <[email protected]> wrote:
> Wayne Pein wrote:
> > I'm refinishing my 83 Trek 600 and may use Ultegra 57mm dual pivot
> > brakes I've been hoarding to replace my single pivot Dia Comp.
>
> > The rear brake bridge is a round tube the same diameter as the
> > seatstays. There is a 1/4" "tunnel" through it for the brake bolt. The
> > ends of the "tunnel" have what look like washers brazed on for strength
> > that the brake and nut bolt seat against. It looks like an "I" through
> > the brake bridge.
>
> > I know about using the front on the rear and the rear on the front.
> > However.....
>
> > To use the rear brake on the rear, it seems that if I drilled this
> > "tunnel" with an 8mm (5/16 inch) bit to accommodate the allen nut it
> > would work, but is the added 1/16 inch hole size enough to breach the
> > sides of the "tunnel," and if it did would that be a problem? Is this
> > doable with a hand drill?
>
> > On the front I could simply drill the back of the fork to accept the
> > allen nut and then use the front brake there.
>
> > Front and rear would look clean without visible nuts.
>
> A closer look will show that it's amazingly hard to cut a neat 8mm
> relief in the back of a brake bridge.

I know this from experience, on three different bikes. It's well-nigh
impossible to get a hand drill in there, square against the hole,
without the seat tube interfering.


Best luck I've had was with a Dremel with a flex-cable attachment, and
a tapered grinding bit whose maximum diameter matches that of the
allen nut. Half-moon washers are helpful if the bridge doesn't have
the flats the OP described.

If I had it to do over again, I'd go the "Two Fronts" route.

 

[Wayne Pein]

A Muzi wrote:


> A closer look will show that it's amazingly hard to cut a neat 8mm
> relief in the back of a brake bridge. And, unless it's more substantial
> than a simple tube, the caliper will shift when you use the brake.

Of course! I failed to consider that the relief would be on the seat
tube side. Duh!

Wayne

 

[Tom Ace]

On Mar 7, 4:40 pm, Wayne Pein <[email protected]> wrote:

> I failed to consider that the relief would be on the seat tube side.

Only if you mount the brake the way most people do.

I've mounted the rear brake on the front side of the bridge
(i.e, with the nut on the rear)
on all of my bikes where the bridge permitted doing so.

Tom Ace

 

[Robert Perkins]

A Muzi wrote:

>
> A closer look will show that it's amazingly hard to cut a neat 8mm
> relief in the back of a brake bridge. And, unless it's more substantial
> than a simple tube, the caliper will shift when you use the brake.
>

I did exactly this when putting together a bike for a Burmese refugee in
my town. I had a Nishiki Sebring (probably hi-ten stays) and I was
impatient and wanted to fit a brake with a recessed nut.

The caliper did indeed shift when using the brake after fitting it with
the recessed nut. Bad idea. I got it to work ok, but I wouldn't do it
again.

-- Rob

 

[Donald Gillies]

Honestly, you don't need dual pivots on the rear. Your stopping needs
there are much smaller than on the front. Why modify the frame when
you don't have to? So you can "feel good" about having exactly the
same caliper front and rear? It doesn't make sense, imho.

- Don Gillies
San Diego, CA, USA

 

[Ryan Cousineau]

In article <[email protected]>,
[email protected] (Donald Gillies) wrote:

> Honestly, you don't need dual pivots on the rear. Your stopping needs
> there are much smaller than on the front. Why modify the frame when
> you don't have to? So you can "feel good" about having exactly the
> same caliper front and rear? It doesn't make sense, imho.
>
> - Don Gillies
> San Diego, CA, USA

Actually, I have been known to set up Shimano-equipped bikes with
DP-front, SP-rear, for the same reason that Campagnolo supplies such
brake sets as a standard item (because it looks cool).

--
Ryan Cousineau [email protected] http://www.wiredcola.com/
"In other newsgroups, they killfile trolls."
"In rec.bicycles.racing, we coach them."

 

[_]

On 8 Mar 2008 23:01:57 -0800, Donald Gillies wrote:

> Honestly, you don't need dual pivots on the rear. Your stopping needs
> there are much smaller than on the front. Why modify the frame when
> you don't have to? So you can "feel good" about having exactly the
> same caliper front and rear? It doesn't make sense, imho.
>
> - Don Gillies
> San Diego, CA, USA

Aesthetics are a common determinant of equipment choice amongst cyclists.
This is well known to the marketing types, who will do all they can to
encourage the function-follows-form POV, as it allows them to essentially
turn cycling into a fashion show.

 

[Lou Holtman]

_ wrote:
> On 8 Mar 2008 23:01:57 -0800, Donald Gillies wrote:
>
>> Honestly, you don't need dual pivots on the rear. Your stopping needs
>> there are much smaller than on the front. Why modify the frame when
>> you don't have to? So you can "feel good" about having exactly the
>> same caliper front and rear? It doesn't make sense, imho.
>>
>> - Don Gillies
>> San Diego, CA, USA
>
> Aesthetics are a common determinant of equipment choice amongst cyclists.
> This is well known to the marketing types, who will do all they can to
> encourage the function-follows-form POV, as it allows them to essentially
> turn cycling into a fashion show.


What is wrong with that? Everybody has a choice.

Lou

 

[_]

On Sun, 09 Mar 2008 13:40:11 +0100, Lou Holtman wrote:

>>
>> Aesthetics are a common determinant of equipment choice amongst cyclists.
>> This is well known to the marketing types, who will do all they can to
>> encourage the function-follows-form POV, as it allows them to essentially
>> turn cycling into a fashion show.
>
>
> What is wrong with that? Everybody has a choice.
>

Fashion distorts the function of current production, drives up the price,
and reduces the avilability of previous perfectly adequate previous
versions of equipment.

 

[Lou Holtman]

_ wrote:
> On Sun, 09 Mar 2008 13:40:11 +0100, Lou Holtman wrote:
>
>>> Aesthetics are a common determinant of equipment choice amongst cyclists.
>>> This is well known to the marketing types, who will do all they can to
>>> encourage the function-follows-form POV, as it allows them to essentially
>>> turn cycling into a fashion show.
>>
>> What is wrong with that? Everybody has a choice.
>>
>
> Fashion distorts the function of current production, drives up the price,
> and reduces the avilability of previous perfectly adequate previous
> versions of equipment.


My first serious roadbike in the late 80's cost about 3000 Dutch
guilders about 1350 Euro's; steel frame with SL tubes and Shimano 600
parts; 7 speed indexed downtube shifter. When I spend that amount of
money today I can get much, much better bike. So IMHO you are wrong.

Lou

 

[Tom Sherman]

J. Taylor wrote:
> On Sun, 09 Mar 2008 13:40:11 +0100, Lou Holtman wrote:
>
>>> Aesthetics are a common determinant of equipment choice amongst cyclists.
>>> This is well known to the marketing types, who will do all they can to
>>> encourage the function-follows-form POV, as it allows them to essentially
>>> turn cycling into a fashion show.
>>
>> What is wrong with that? Everybody has a choice.
>>
>
> Fashion distorts the function of current production, drives up the price,
> and reduces the avilability of previous perfectly adequate previous
> versions of equipment.

Like 7/8-speed ATB and 7/8/9-speed road drive-trains?

--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful

 

[_]

On Sun, 09 Mar 2008 14:02:55 +0100, Lou Holtman wrote:

> _ wrote:
>> On Sun, 09 Mar 2008 13:40:11 +0100, Lou Holtman wrote:
>>
>>>> Aesthetics are a common determinant of equipment choice amongst cyclists.
>>>> This is well known to the marketing types, who will do all they can to
>>>> encourage the function-follows-form POV, as it allows them to essentially
>>>> turn cycling into a fashion show.
>>>
>>> What is wrong with that? Everybody has a choice.
>>>
>>
>> Fashion distorts the function of current production, drives up the price,
>> and reduces the avilability of previous perfectly adequate previous
>> versions of equipment.
>
>
> My first serious roadbike in the late 80's cost about 3000 Dutch
> guilders about 1350 Euro's; steel frame with SL tubes and Shimano 600
> parts; 7 speed indexed downtube shifter. When I spend that amount of
> money today I can get much, much better bike. So IMHO you are wrong.
>
> Lou

I used to buy roller chains for under $5; they, and the sprockets (also
cheaper) on which they ran, lasted much longer than the chains now in
fashion.

 

[Lou Holtman]

_ wrote:
> On Sun, 09 Mar 2008 14:02:55 +0100, Lou Holtman wrote:
>
>> _ wrote:
>>> On Sun, 09 Mar 2008 13:40:11 +0100, Lou Holtman wrote:
>>>
>>>>> Aesthetics are a common determinant of equipment choice amongst cyclists.
>>>>> This is well known to the marketing types, who will do all they can to
>>>>> encourage the function-follows-form POV, as it allows them to essentially
>>>>> turn cycling into a fashion show.
>>>> What is wrong with that? Everybody has a choice.
>>>>
>>> Fashion distorts the function of current production, drives up the price,
>>> and reduces the avilability of previous perfectly adequate previous
>>> versions of equipment.
>>
>> My first serious roadbike in the late 80's cost about 3000 Dutch
>> guilders about 1350 Euro's; steel frame with SL tubes and Shimano 600
>> parts; 7 speed indexed downtube shifter. When I spend that amount of
>> money today I can get much, much better bike. So IMHO you are wrong.
>>
>> Lou
>
> I used to buy roller chains for under $5; they, and the sprockets (also
> cheaper) on which they ran, lasted much longer than the chains now in
> fashion.


Last longer, that's not my experience. I can still buy good quality 7-8
speed chains for less than 9 euro. Not so bad if you consider the
inflation over all these years or does your boss still pays you the same
wage as 20 years ago?

Lou