Filing a brake caliper that's just too short?

Hey everyone,

I just bought a front brake caliper that's *just* too short for the
Peugeot frame that it'll be one. Seriously, I only need another 1 mm of
reach...maybe 2 mm tops.

Does anyone see an danger to me filing a flat spot in the bolt like this:

http://sheldonbrown.com/images/sovos_flat_axle.gif ???
only it'd be on the brake pad's bolt...not my axle...you get the picture.

I've also thought about filing the caliper itself down just a hair since
there is a significant amount of material below the lowest point at
which the pads can sit. Does anyone see dangers to doing this? Keep in
mind I need only a little --||--- more room and the brakes are
/perfect/. Additionally, I'd like to avoid buying a new brake caliper as
I bought this one second hand and can't really return/exchange it (it's
also nice).

Thanks so much!
\\paul
--
Paul M. Hobson
Georgia Institute of Technology
http://www.underthecouch.org
..:you may want to fix my email
address before you send anything:.

On Thu, 28 Jul 2005 22:22:27 -0400, Paul Hobson wrote:

I've also thought about filing the caliper itself down just a hair since
there is a significant amount of material below the lowest point at
which the pads can sit.

I'd go with filing the caliper brake shoe mounting slot with a teeny round
file.

Seems to me that you'd have no problem with safety even if you filed it so
far down as to make a tuning fork. I'd loctite the brake shoe nut if I did
that though. :P

Seems imminently safer than constructing a jerry rigged drop bolt for such
a short distance.

Good and simple idea.

In article ,
maxo wrote:

On Thu, 28 Jul 2005 22:22:27 -0400, Paul Hobson wrote:

I've also thought about filing the caliper itself down just a hair since
there is a significant amount of material below the lowest point at
which the pads can sit.

I'd go with filing the caliper brake shoe mounting slot with a teeny round
file.

Seems to me that you'd have no problem with safety even if you filed it so
far down as to make a tuning fork. I'd loctite the brake shoe nut if I did
that though. :P

Seems imminently safer than constructing a jerry rigged drop bolt for such
a short distance.

Good and simple idea.

I have had some success in a similar case with using pads like these
Kool-Stop Thinlines:

http://www.koolstop.com/brakes/index...chor-Also-6785

The spherical "V-brake" washers allow you to cheat the pad down a bit
lower than the lowest setting of the brakes.

Sheldon would surely recommend the similar BMX pads:

http://sheldonbrown.com/harris/brakeshoes.html#bmx

Or possibly the Supra 2s.

I found setting things up like this on a marginal dual-pivot setup a bit
fussy, and I eventually put a longer-reach caliper in there.

Nashbar long-reach, which seem to be private-label Tektros, have served
me well, and are probably the best value in new brakes around.

Sheldon has the most extensive collection of long-reach brake solutions
around:

http://sheldonbrown.com/harris/brakes.html#calipers

--
Ryan Cousineau http://www.wiredcola.com/
"I don't want kids who are thinking about going into mathematics
to think that they have to take drugs to succeed." -Paul Erdos

On Thu, 28 Jul 2005 22:22:27 -0400, Paul Hobson wrote:

Hey everyone,

I just bought a front brake caliper that's *just* too short for the
Peugeot frame that it'll be one. Seriously, I only need another 1 mm of
reach...maybe 2 mm tops.

Does anyone see an danger to me filing a flat spot in the bolt like this:

http://sheldonbrown.com/images/sovos_flat_axle.gif ???
only it'd be on the brake pad's bolt...not my axle...you get the picture.


I have a better solution. File a thick-ish washer so that it is a wedge,
then put it between brake and frame. It'll push the brake arms down just
enough to fit.

--

David L. Johnson

__o | It is a scientifically proven fact that a mid life crisis can
_`\(,_ | only be cured by something racy and Italian. Bianchis and
(_)/ (_) | Colnagos are a lot cheaper than Maserattis and Ferraris. --
Glenn Davies

Paul Hobson wrote:
Hey everyone,

I just bought a front brake caliper that's *just* too short for the
Peugeot frame that it'll be one. Seriously, I only need another 1 mm of
reach...maybe 2 mm tops.

Does anyone see an danger to me filing a flat spot in the bolt like this:

http://sheldonbrown.com/images/sovos_flat_axle.gif ???
only it'd be on the brake pad's bolt...not my axle...you get the picture.

I've also thought about filing the caliper itself down just a hair since
there is a significant amount of material below the lowest point at
which the pads can sit. Does anyone see dangers to doing this? Keep in
mind I need only a little --||--- more room and the brakes are
/perfect/. Additionally, I'd like to avoid buying a new brake caliper as
I bought this one second hand and can't really return/exchange it (it's
also nice).

I assume the problem is the brake pad or shoe is contacting your tire?

I'd first consider extending the slot by 1 mm, as someone else
suggested.

Another possibility may be to shave 1 mm of rubber off the top of the
brake pad. That's five minutes work with a utility knife. The only
downside is microscopically faster pad wear.

- Frank Krygowski

wrote:
Paul Hobson wrote:
Hey everyone,

snip

I've also thought about filing the caliper itself down just a hair since
there is a significant amount of material below the lowest point at
which the pads can sit. Does anyone see dangers to doing this? Keep in
mind I need only a little --||--- more room and the brakes are
/perfect/. Additionally, I'd like to avoid buying a new brake caliper as
I bought this one second hand and can't really return/exchange it (it's
also nice).

I assume the problem is the brake pad or shoe is contacting your tire?
snip

Another possibility may be to shave 1 mm of rubber off the top of the
brake pad. That's five minutes work with a utility knife. The only
downside is microscopically faster pad wear.

- Frank Krygowski

Frank, thanks for the additional suggestion. I thought about that, but
I figured y'all would think it's silly. But now I'll definitely
reconsider it if it turns out I have to file more than I planned.

Thanks again
\\paul

Maxo,

Thanks for the tip. I don't think I'll be needing any loctitie though

master mechanic over at schwinn now specialized spotted my too short
caliper problem-the centerpulls are mounted on the wrong side for a
rack/cable clearance increase

Paul Hobson wrote:

I just bought a front brake caliper that's *just* too short for the
Peugeot frame that it'll be one. Seriously, I only need another 1 mm of
reach...maybe 2 mm tops.

Does anyone see an danger to me filing a flat spot in the bolt like this:

http://sheldonbrown.com/images/sovos_flat_axle.gif ???
only it'd be on the brake pad's bolt...not my axle...you get the picture.

I don't think that would be a good idea, because you would presumably
also be filing active threading that should be used to secure the shoe
to the caliper.

In the example shown, the threads removed are threads that serve no
actual purpose.

I've also thought about filing the caliper itself down just a hair since
there is a significant amount of material below the lowest point at
which the pads can sit. Does anyone see dangers to doing this? Keep in
mind I need only a little --||--- more room and the brakes are
/perfect/.

I've done this on occasion on my own bikes, never had a problem with it.

I'd be reluctant to do it on a customers' bike though.

Sheldon "Different Standards" Brown
+-----------------------------------------+
| Well, the truth is usually just |
| an excuse for a lack of imagination... |
| --Garak, DS-9 |
+-----------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

Bob wrote:
On Fri, 29 Jul 2005 11:50:29 -0400, Sheldon Brown
wrote:


I don't think that would be a good idea, because you would presumably
also be filing active threading that should be used to secure the shoe
to the caliper.


How about back to the root of the problem: what model Peugeot, what
set of brakes/reach ? If this is an older bike you can probably get
the "correct" brakes for some very short money.

Well, I've already spent short money on the low-end Tektro caliper
(side-pull). But I've also spent some not-so-short money on other parts
for the bike. I already have a file, so widdling down 2 mm is worth it
to me.

But to answer your question: the Peugeot is from the mid to early 70's,
it's the model below the PX-10, and the calipers seem to have a reach
equal to the calipers that come stock on most bikes. I'm almost done
converting it to a fixie. I just need a brake cable/housing, a cog, and
some wheels (haha..."almost").

I luckily scored an alloy 26.4 mm seatpost on eBay (the bike didn't have
a seatpost at all). So I was pretty happy about that. I got some
decent cranks and a set of drop bars from the spare parts bin at REI for
5 bucks. I got this brake and lever from a friend of a friend, so I
can't really just go back and return it. It's nice, although it doesn't
have the quick-release knob on it.

\\paul

--
Paul M. Hobson
Georgia Institute of Technology
http://www.underthecouch.org
..:you may want to fix my email
address before you send anything:.