Why 31.8?



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M

Mark A. Clark

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I've noticed more and more handlebars being sold in 31.8 clamp diameter. Is there any real advantage
to this (other than marketing?)
 
W

Waldo Hinshaw

Guest
Mark A. Clark wrote

> I've noticed more and more handlebars being sold in 31.8 clamp diameter.
Is
> there any real advantage to this (other than marketing?)

And why 31.8 mm instead of, say 32 mm? Why pick 1 1/4 inches and specify it in millimeters. Seems
strange enough that there must be some history behind
it.
 
A

A Muzi

Guest
"Mark A. Clark" <[email protected]> wrote in message news:3e[email protected]...
> I've noticed more and more handlebars being sold in 31.8 clamp diameter.
Is
> there any real advantage to this (other than marketing?)

Confusion, duplication of inventory, waste, frustration and just plain orneriness. All with hallowed
histories in this industry.

--
Andrew Muzi http://www.yellowjersey.org Open every day since 1 April 1971
 
Q

Qui Si Parla Ca

Guest
mark-<< I've noticed more and more handlebars being sold in 31.8 clamp diameter. Is there any real
advantage to this (other than marketing?)

None-zero, zipp, nada...

I wish they would make the MTB bar 26mm...and find a standard among bikes-a long shot, I know.

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

Sheldon Brown

Guest
Pietro Chisolmo scritta:

> I wish they would make the MTB bar 26mm...and find a standard among bikes-a long shot, I know.

Long shot? That's an understatement! Just when things are close to settling on the internationally
accepted ISO standards, you propose creating a new size!

Historically, the old-fashioned national and proprietary sizing systems have been being replaced by
the international ISO dimensions, to the great benefit of the bicycle industry and cyclists. The old
French sizes, once so common, are gone, as are the Raleigh proprietary sizes and the Swiss sizes.

The single remaining atavistic national size system still breathing is the quirky Italian system. It
is only the excellence of many Italian framebuilders that keeps this ludicrous size system limping
along, with it's ******* thread dimensions, wrong-way bottom bracket threading and all.

The international ISO handlebar clamp diameter is 25.4 mm, and well over 90 percent of all bikes
sold use this size. Dispite what many think, most drop handlebars and corresponding stems are also
this size, except for very expensive high-end and aftermarket models.

The 26.0 size is overdue to join the French 25 mm and 23.5 mm sizes, the Cinelli 26.4 size, The
Titan 27 mm size, the English 15/16 size and the BMX 7/8" size in the dustbin of history.

For those who feel they need a fatter, thicker handlebar size to cope with their extraordinarly
studliness, 31.8 makes more sense, since it is larger by a meaningful amount, so there's some gain
in strength to be had in exchange for the lack of interchangeability.

Sheldon "ISO" Brown +-------------------------------------------------+
| To stay young requires unceasing cultivation | of the ability to unlearn old falsehoods. |
| --Robert A. Heinlein |
+-------------------------------------------------+ 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
 
P

Pete Biggs

Guest
Sheldon Brown wrote:
>
> The single remaining atavistic national size system still breathing is the quirky Italian system.
> It is only the excellence of many Italian framebuilders that keeps this ludicrous size system
> limping along, with it's ******* thread dimensions, wrong-way bottom bracket threading and all.
>
> The international ISO handlebar clamp diameter is 25.4 mm, and well over 90 percent of all bikes
> sold use this size. Dispite what many think, most drop handlebars and corresponding stems are also
> this size, except for very expensive high-end and aftermarket models.

That's not how it seems to me over here in Europe. Many reasonably-priced and even cheap drop bars
and stems - both those supplied with bikes and on the aftermarket - are 26.0 or 25.8 now. The likes
of ITM and 3T don't just make fancy stuff, and these brands are hugely popular; plus, some
non-Italian brands also use 26.0. I preduct that these sizes will almost completely take over,
globally, for drop bars within the next three years - that's if the oversized jobs don't become the
norm first!

> For those who feel they need a fatter, thicker handlebar size to cope with their extraordinarly
> studliness, 31.8 makes more sense, since it is larger by a meaningful amount, so there's some gain
> in strength to be had in exchange for the lack of interchangeability.

A larger diameter bar is also more comfortable - as I have discovered by using extra layer(s) of
tape. (I'm assuming it's not just the bulge/collar in the centre that's oversized?)

~PB
 
M

M-Gineering Imp

Guest
Pete Biggs wrote:

>
> A larger diameter bar is also more comfortable (I'm assuming it's not just the bulge/collar in the
> centre that's oversized?)
>
Wrong, just think what fun you would have trying to get the brakeleverclamp on if the rest of the
bar would be oversize. Enough trouble with aerobars as it is.

--
Marten
 
P

Pete Biggs

Guest
M-Gineering import & framebouw wrote:
> Pete Biggs wrote:
>> A larger diameter bar is also more comfortable (I'm assuming it's not just the bulge/collar in
>> the centre that's oversized?)
>>
> Wrong, just think what fun you would have trying to get the brakeleverclamp on if the rest of the
> bar would be oversize. Enough trouble with aerobars as it is.

Oh right, of course. Thanks for the correction.

I agree that they're a bad idea then!

~PB
 
B

Bluto

Guest
[email protected] (Qui si parla Campagnolo) wrote:

> I wish they would make the MTB bar 26mm...and find a standard among bikes-a long shot, I know.

That's a terrible idea! 25.4mm is a much better size to standardize on. Have you ever seen a piece
of 26mm tubing? Didn't think so.

25.4mm means being able to make components, both bars and stems, with normal materials, tools, and
processes. It means tinkering and adapting parts do not necessarily require a machine lathe-- let
alone hydroforming or cold drawing equipment!

It also means Harley-Davidson handlebars will fit. :-D

I understand the motivation to go metric, but let's face it, 26mm is a ******* size even in the
metric world! Better 25mm, or 30mm, or even
25i. And none of those sizes are as ubiquitous in metric industry as
26.00" is in the inch-speaking world.

Chalo Colina

Italian engineering standards should have died with Il Duce
 
M

Marten Gerritse

Guest
Bluto wrote:

>
>
> That's a terrible idea! 25.4mm is a much better size to standardize on. Have you ever seen a piece
> of 26mm tubing? Didn't think so.
>
>

got it. And much easier to find than 25.8, 26.4 etc!

/Marten
 
B

Bluto

Guest
[email protected] (Qui si parla Campagnolo) wrote:

> Like I said to Sheldon, I'm not in love with 26mm...just would be nice to have stems...not road
> stems and MTB stems...

That *would* be nice, wouldn't it?

It would also be nice to have one handlebar grip diameter, so that brake levers and shifters would
be interchangeable between different types of bars.

Chalo Colina
 
P

Peter Cole

Guest
"Bluto" <[email protected]> wrote in message
news:[email protected]...
> [email protected] (Qui si parla Campagnolo) wrote:
>
> > Like I said to Sheldon, I'm not in love with 26mm...just would be nice to have stems...not road
> > stems and MTB stems...
>
> That *would* be nice, wouldn't it?
>
> It would also be nice to have one handlebar grip diameter, so that brake levers and shifters would
> be interchangeable between different types of bars.

And a standard cable pull for both.
 
S

Sheldon Brown

Guest
Peter Cole wrote:
> "Bluto" <[email protected]> wrote in message
> news:[email protected]...

Pietro Chisolmo scritta:

>>>Like I said to Sheldon, I'm not in love with 26mm...just would be nice to have stems...not road
>>>stems and MTB stems...

That's how it is for us, since we mostly sell ISO standard bars and stems, whether drop or upright.
The only thing standing in the way of this is the fact that some manufacturers persist in using the
old Italian national 26 mm size instead of the international ISO standard of
25.4 mm.

Chalo C wrote.

>>That *would* be nice, wouldn't it?
>>
>>It would also be nice to have one handlebar grip diameter, so that brake levers and shifters would
>>be interchangeable between different types of bars.

Not gonna happen, 'cause the levers need to curve toward the bars for drops, away from the bars for
straight bars.

Also, at present there's a laudable degree of standardization in handlbar diameter, and
introducing a new fatter MTB standard would benefit nobody, while a skinnier drop bar is an idea
whose time has gone.

Not everybody realizes it, but the prevailing 7/8" vs 15/16" sizing didn't originate as one size for
upright bars and t'other for drops. Rather, the 7/8" was for many years the standard size for steel
bars, and the 15/16" size was for aluminum bars.

You used to be able to buy both sizes of clamp bands for drop bar levers, and for the better quality
upright bar levers as well (Weinmann, Mafac...)

Steel drop bars went extinct in the 1980s, and 15/16" upright bars rather earlier than that (though
I still have a nice pair of 15/16" GB All Rounders that I like a lot.

> And a standard cable pull for both.

Also not gonna happen, unless you can de-invent "v-type" brakes. The long cable travel these use is
necessary because of the constraints of standard canti-boss placement and tire/fender clearance
requirements.

"V-type" brakes are so clearly superior to the old centerpull cantis that this is not going
to happen.

(Note, "v-type" brakes are superior only when used with straight-bar levers designed for them. I
strongly recommend against using them with drop bars. While there are ways to make them work, these
ways remove most of the advantages of the design, and performance is not so hot.)

Sheldon "To Everything There Is A Season" Brown +--------------------------------------------+
| In order to understand recursion, | first, you have to understand recursion. |
+--------------------------------------------+ 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
 
B

Bluto

Guest
Sheldon Brown <[email protected]> wrote:

> Chalo C wrote.
>
> >>It would also be nice to have one handlebar grip diameter, so that brake levers and shifters
> >>would be interchangeable between different types of bars.
>
> Not gonna happen, 'cause the levers need to curve toward the bars for drops, away from the bars
> for straight bars.

Flat bar levers are nicely used on the flats or the drops of drop bars that are versatile enough to
accomodate them. Dummy hoods and pivot bodies can always be robbed from those old drop bar levers
that never seem to work as well as their flat bar counterparts.

The bend, which is the least-used, least comfortable position on a drop bar, is the only position
where full braking power is available with drop bar levers. Back'ards, for sure. Witness the sudden
proliferation of flat-bar-like supplementary levers for cyclocross racers, some of the only drop-bar
riders who demand affirmative braking and steering control. Like flared drops, those levers are a
functional improvement over traditional road bike paraphernalia.

> Also, at present there's a laudable degree of standardization in handlbar diameter, and
> introducing a new fatter MTB standard would benefit nobody, while a skinnier drop bar is an idea
> whose time has gone.

My last, failed attempt to accustom myself to drop bars involved the use of 22.2mm steel drops.
Though I couldn't really get used to them, they proved superior to similarly-shaped aluminum drops
in every way, from accepting thumbshifters on the bar tops to refusing to wag around limply like
aluminum bars.

My Suzuki motorcycle and all Harley-Davidson motorcycles use 1" handlebars, rather than the more
common 7/8" kind. I think the larger size helps-- offering both a stiffer steering interface and a
more comfortable grip diameter.

Now that faceplate stems have taken the market, it seems like a good opportunity to offer bars that
are 1" from end to end. The tube wall can be tapered or sleeved internally, and bars can thereby be
made stronger, lighter and/or stiffer-- actually supplying what 31.8 bars promise but don't
deliver. 1" flat bar levers for freestyle already exist, and road levers would be easily
retrofitted with new bands.

Such a diameter would not give back what the double grooving of drop bars has taken away, but it
would help.

Chalo Colina
 
S

Steve Palincsar

Guest
On Wed, 05 Mar 2003 10:52:16 -0500, Sheldon Brown wrote:

> The international ISO handlebar clamp diameter is 25.4 mm, and well over 90 percent of all bikes
> sold use this size. Dispite what many think, most drop handlebars and corresponding stems are also
> this size, except for very expensive high-end and aftermarket models.

If true, it's only true because the vast majority of bikes sold are mountain bikes.

I hate to disagree with you, Sheldon, but I have two road bikes (a Santana tandem and a Bruce Gordon
Rock 'n Road Tour) that take a 25.4 drop bar, and I've had to replace the bars on the Bruce Gordon
twice. It's been a major hassle. I think you may be the only bike shop on the planet that has a 25.4
drop bar in a traditional Maes bend and a shallow drop. Both times, the only bars I could find for
the Gordon were early 90s Santana Nitto takeoffs.
 
S

Sheldon Brown

Guest
Steve Palincsar wrote:

I wrote:

>>The international ISO handlebar clamp diameter is 25.4 mm, and well over 90 percent of all bikes
>>sold use this size. Dispite [sic] what many think, most drop handlebars and corresponding stems
>>are also this size, except for very expensive high-end and aftermarket models.

Steve Palincsar wrote:

> If true, it's only true because the vast majority of bikes sold are mountain bikes.

No, it's not that.

> I hate to disagree with you, Sheldon, but I have two road bikes (a Santana tandem and a Bruce
> Gordon Rock 'n Road Tour) that take a 25.4 drop bar, and I've had to replace the bars on the Bruce
> Gordon twice. It's been a major hassle. I think you may be the only bike shop on the planet that
> has a 25.4 drop bar in a traditional Maes bend and a shallow drop. Both times, the only bars I
> could find for the Gordon were early 90s Santana Nitto takeoffs.

I get my Nitto bars from Quality Bicycle Products, and so can any bike shop in the country.

"Drop bars in a traditional Maes bend and a shallow drop" are no easier to find in 26.0, in fact
they're _harder_ to find. Most drop bars these days have the silly cable grooves and the
"anatomical" bumps and angles, whatever their clamp diameters may be.

I will agree that the majority of high-end _aftermarket_ drop bars you'll see for sale in shops are
Italian 26 mm size.

However, most O.E.M. drop bars on mass-produced road bikes are ISO standard 25.4 mm, as well they
should be.

Sheldon "I Own A Dial Caliper" Brown +-------------------------------------------------+
| Search the Quality Bicycle Products Catalog | and order on line: |
| http://sheldonbrown.com/quality |
+-------------------------------------------------+ 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
 
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