Max tire size in Campag calipers?

[Nick Burns]

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

 

[Sheldon Brown]

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.

If you are designing a frame around a particular brake caliper and want max clearance, you'll choose
fork blade length and seatstay bridge placement to caue the brake shoes to be at the very bottom of
their adjustment slots with the intended rim.

In practice, most frames are not built this way, so the amount of usable clearance will depend on
how closely they approach this. In the case of many frames, the limit will be chainstay clearance at
the sides of the tire, and this clearance will partly depend on the width of the rim chosen.

An oversimplified answer would be 28 mm, but you can't count on that.

Sheldon "Easy To Ask, Difficult To Answer" Brown +----------------------------------+
| What sane person could live in | this world and not be crazy? | --Ursula K. LeGuin |
+----------------------------------+ 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

 

[Paul Kopit]

On Tue, 15 Jul 2003 22:33:14 GMT, "Nick Burns" <[email protected]> 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" <[email protected]> wrote in message
news:Ji%[email protected]...
> 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 <[email protected]

 

[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

 

[Qui Si Parla Ca]

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"

 

[Antti Salonen]

Pete Biggs <pLime{remove_fruit}@biggs.tc> 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

 

[Paul Southworth]

In article <Ji%[email protected]>, Nick Burns <[email protected]> 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

 

[Pete Biggs]

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.

~PB

 

[A Muzi]

> 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.

"Sheldon Brown" <[email protected]> wrote in message
news:[email protected]...
> 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.

Really? In the sixties, quick-connect Mafac transverse wires were de rigeur for sport bikes. Of
course that give a disconnect, not a slack, so I do see your point.

--
Andrew Muzi www.yellowjersey.org Open every day since 1 April, 1971

 

[David L. Johnso]

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. Johnso]

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