Re: Max tire size in Campag calipers?

[Paul Kopit]

On Tue, 15 Jul 2003 22:33:14 GMT, "Nick Burns"
> wrote:

>What is the maximum tire size for modern Campagnolo (short reach, Record D)
>calipers? I am thinking about commuting by bike and larger tires would help
>out in many ways. The only limiting factor should be the calipers.
>
>TIA
>

It is sometimes tough but possible to get a 28 in. If you get an
inline cable adjuster at the last cable stop, you can get 32s in.
With a Shimano brake with it's integral release and the Ergo lever
release, 32s go in.

[Robin Hubert]

"Nick Burns" > wrote in message
...
> What is the maximum tire size for modern Campagnolo (short reach, Record
D)
> calipers? I am thinking about commuting by bike and larger tires would
help
> out in many ways. The only limiting factor should be the calipers.
>

Best clearance is cantilevers but barring that you could use Shimano
calipers and Campag. Ergo for maximum opening power.



--
Robin Hubert >

[Pete Biggs]

Sheldon Brown wrote:
> Nick Burns wrote:
>
>> What is the maximum tire size for modern Campagnolo (short reach,
>> Record D) calipers? I am thinking about commuting by bike and larger
>> tires would help out in many ways. The only limiting factor should
>> be the calipers.
>
> This question is only useful if you're planning to build a frame. If
> you already _have_ a frame, it is the frame itself that will
> determine this.

But there's a limiting factor before that. You need to be able to remove
the wheels without too much hassle. Campag brakes have the quick release
in the lever, not the calipers, and this doesn't open the brakes very
much, unfortunately. If one likes the pads close to rims, opening q/r
plus turning cable barrel adjuster a few turns provides only just enough
clearance to remove an inflated 25mm tyre, IME. 28's might be ok at a
push. I would not even bother trying to use Campag calipers for anything
wider.

~PB

[Antti Salonen]

Pete Biggs > wrote:

> But there's a limiting factor before that. You need to be able to remove
> the wheels without too much hassle. Campag brakes have the quick release
> in the lever, not the calipers, and this doesn't open the brakes very
> much, unfortunately. If one likes the pads close to rims, opening q/r
> plus turning cable barrel adjuster a few turns provides only just enough
> clearance to remove an inflated 25mm tyre, IME. 28's might be ok at a
> push. I would not even bother trying to use Campag calipers for anything
> wider.

I've used tyres which actually measure about 24 mm, and they rub both
brake pads when you release the brake and remove the wheel. 25 mm is
probably OK, depending on how close to the rim you have set the brake
pads, but 28 mm would almost certainly require deflation.

Of course, for many people this might not be a problem. After all, at
home most people have a good floor pump and at road the tyre is probably
empty if you want to remove the wheel.

-as

[Qui si parla Campagnolo]

Chris-<< What is the maximum tire size for modern Campagnolo (short reach,
Record D)
calipers? I am thinking about commuting by bike and larger tires would help
out in many ways. The only limiting factor should be the calipers. >><BR><BR>

Probably 28c but the problem is the brake bridge and fork crown, not the brakes
generally.

Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"

[Sheldon Brown]

Quoth Pete Biggs:

>>But there's a limiting factor before that. You need to be able to remove
>>the wheels without too much hassle. Campag brakes have the quick release
>>in the lever, not the calipers, and this doesn't open the brakes very
>>much, unfortunately. If one likes the pads close to rims, opening q/r
>>plus turning cable barrel adjuster a few turns provides only just enough
>>clearance to remove an inflated 25mm tyre, IME. 28's might be ok at a
>>push. I would not even bother trying to use Campag calipers for anything
>>wider.

Antti Salonen wrote:

> I've used tyres which actually measure about 24 mm, and they rub both
> brake pads when you release the brake and remove the wheel. 25 mm is
> probably OK, depending on how close to the rim you have set the brake
> pads, but 28 mm would almost certainly require deflation.

It isn't just a matter of the tyre width, but also the width of the rym,
more specifically, the difference betwixt the twain.

This is one of the reasons I like mixing the two systems. If you have
Campagnolo brake levers and Shimano calipers, you have _two_ quick
releases, which, when used together, give you enough quick releasitude
to handle touring tyres on narrow ryms.

> Of course, for many people this might not be a problem. After all, at
> home most people have a good floor pump and at road the tyre is probably
> empty if you want to remove the wheel.

Hard for some folks to realize that quick-release brakes were virtually
unknown until the 1970s, even though most cyclists back then rode rather
wider tyres than are currently fashionable.

Sheldon "Deflation Is Always An Option" Brown
+----------------------------------------------+
| Every person who has mastered a profession |
| is a skeptic concerning it. |
| --George Bernard Shaw |
+----------------------------------------------+
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

[Todd Kuzma]

Qui si parla Campagnolo wrote:
> Chris-<< What is the maximum tire size for modern Campagnolo (short reach,
> Record D)
> calipers? I am thinking about commuting by bike and larger tires would help
> out in many ways. The only limiting factor should be the calipers. >><BR><BR>
>
> Probably 28c but the problem is the brake bridge and fork crown, not the brakes
> generally.

Ditto. We build Herons so the pads are near the bottom of
the adjustment slot. This gives a bit more clearance than
on most frames. We can fit true 700x28s (which measure
28mm, not just labeled 28mm) under Campy dual pivots with
room to spare.

Todd Kuzma
Heron Bicycles
Tullio's Big Dog Cyclery
LaSalle, Il 815-223-1776
http://www.heronbicycles.com
http://www.tullios.com

[Paul Southworth]

In article >,
Nick Burns > wrote:
>What is the maximum tire size for modern Campagnolo (short reach, Record D)
>calipers? I am thinking about commuting by bike and larger tires would help
>out in many ways. The only limiting factor should be the calipers.

My 1999 Chorus calipers can handle a 700x32 Panaracer in back and
a 700x28 Avocet in front. The 700x32 tire won't clear in front.
What will work in your bike I don't know but a 700x28 is probably
possible. Much depends on the frame.

--Paul

[Appkiller]

<snip>
> Probably 28c but the problem is the brake bridge and fork crown, not the brakes
> generally.
>
> Peter Chisholm
<snip>

I recently put some 25c tires on and the fork crown is so tight to the
tire that rocks will get picked up by the tire, squeeze under the
crown and enter the bottom of the steerer tube. They bounce up and
down between the brake fixing bolt and the tire, making an annoying
tinkling noise. And probably slowly chewing up the fixing bolt and
the steerer tube.

A cautionary tale for those who are overly concerned with noises and
considering a wider tire.

App

[David L. Johnson]

On Wed, 16 Jul 2003 19:38:31 +0100, Pete Biggs wrote:

> Sheldon Brown wrote:
>
>> It isn't just a matter of the tyre width, but also the width of the rym,
>> more specifically, the difference betwixt the twain.
>
> That's a good point - one which I hadn't thought of at all. So another
> reason to use wide rims for wide tyres then.
>
Actually, that depends. When you go to really wide tires there would be a
lot of reasons to get wider rims, but going up to a bigger tire for extra
comfort may not be helped by wider rims.

I thought about this a while back. I was wondering whether a wider tire
would still fit, and thought about how the rim width would affect the
clearance. The height of the tire (in cross-section) depends both on rim
width and of course tire width, and that relationship is highly nonlinear.
The graph of the height of the top of the tire as a function of rim width
has a maximum when rim width is about 15% of tire width (from bead to
bead, spread flat). Most tires are far short of that -- or most rims are
wider than that -- so a wider rim will lower the overall height unless you
have a very fat tire. Lower height of course improves clearance, but it
will make the ride harsher.

--

David L. Johnson

__o | Do not worry about your difficulties in mathematics, I can
_`\(,_ | assure you that mine are all greater. -- A. Einstein
(_)/ (_) |

[David L. Johnson]

On Wed, 16 Jul 2003 12:24:34 +0000, Sheldon Brown wrote:

> Hard for some folks to realize that quick-release brakes were virtually
> unknown until the 1970s, even though most cyclists back then rode rather
> wider tyres than are currently fashionable.

Really? My '69 Frejus had/has a QR on the cable hanger for the
center-pull brakes the bike came with. I*don't think such things were
unusual at the time.

--

David L. Johnson

__o | To announce that there must be no criticism of the president, or
_`\(,_ | that we are to stand by the president right or wrong, is not
(_)/ (_) | only unpatriotic and servile, but is morally treasonable to the
American public. --Theodore Roosevelt