1" versus 1 1/8" Headset???

(Ryan Bates) said:

hi, wondering what the performance differences are between a 1" and a 1 1/8" headtube? seems to me
like the larger diameter would weigh more and create a greater frontal area? thanks

You're right - they DO weigh more (as does the frame's head tube and the stem). There are those who
insist that the 1-1/8" steer tube yields a "stiffer fork", though I have yet to have any problems
with steer tubes flexing regardless of the diameter, and the majority of flex is going to be in the
fork's legs, which will be identical in both 1" and 1-1/8" formats. Others will claim a greater
amount of strength, but that assumes that fork manufacturers would have two different specs for what
they'll ship (something I find very unlikely).

In the end, you have to console yourself with the fact that somewhere manufacturers are saving
some money.

Mark Hickey Habanero Cycles habcycles.comhabcycles.comOpen ↗ Home of the $695 ti frame

It depends on your weight. Bike designers decided that the weight you mention could not be removed
safely without using the O.S. steerer. This is the case with Profile design's AC fork. Reynolds'
Ouzo pro adds extra steerer material and does weigh more in 1 1/8. Some sub 140# riders notice more
ride compliance on 1". Over 190# IMO use 1 1/8. Eventually obsolesence will make things clearer;
some of my favorite OEM forks are 1 1/8 only. Tom

--
Bruni Bicycles "Where art meets science" brunibicycles.com
410.426.3420 Ryan Bates <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

hi, wondering what the performance differences are between a 1" and a 1 1/8" headtube? seems to me
like the larger diameter would weigh more and create a greater frontal area? thanks

Or you could just use a 1 1/8" fork in a 1" headtube.

(Ryan Bates) may have said:

hi, wondering what the performance differences are between a 1" and a 1 1/8" headtube? seems to me
like the larger diameter would weigh more and create a greater frontal area? thanks

1 1/8" is significantly stronger and stiffer. The weight and frontal area difference is trivial.

That said, for the average rider who does not engage in mtb/atb trail riding of an aggressive
nature, 1" is more than strong enough. Among bikes commonly sold, 1" steerer tubes are generally
used threaded, and 1 1/8" steerers are generally threadless, though both can be had either way.
Which one is preferred is a matter of opinion; both have their adherents. I personally like threaded
steerers, but plenty of people like the threadless setups.

--
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don't respond to something, it's also possible that I'm busy. Words processed in a facility that
contains nuts.

Ryan Bates said:

hi, wondering what the performance differences are between a 1" and a 1 1/8" headtube? seems to me
like the larger diameter would weigh more and create a greater frontal area? thanks

You can fit more bearings in and it gives a decent surface area to weld/braze oversize tubes to. A
Cannondale MTB with a 1" headset would be tricky to weld as the downtube would be about twice as
wide as the head tube!

Someone who wisely concealed his or her identity said:

Or you could just use a 1 1/8" fork in a 1" headtube.

Since he or she didn't quote the post being replied to, I don't know the context, but this is wrong
in any case.

You can't put a bigger fork into a smaller head tube.

You can put a _smaller_ fork into a larger head tube, with suitable adaptors.

Sheldon "Won't Fit" Brown +-----------------------------------------------+
| Many workmen | Built a huge ball of masonry | Upon a mountaintop. | Then they went to the
| valley below, | And turned to behold their work. | "It is grand," they said; | They loved
| the thing. |
| |
| Of a sudden, it moved: | It came upon them swiftly; | It crushed them all to blood. | But
| some had opportunity to squeal. | --Stephen Crane |
+-----------------------------------------------+ Harris Cyclery, West Newton, Massachusetts Phone
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Sheldon Brown said:

Someone who wisely concealed his or her identity said:

Or you could just use a 1 1/8" fork in a 1" headtube.

Since he or she didn't quote the post being replied to, I don't know the context, but this is
wrong in any case.

You can't put a bigger fork into a smaller head tube.

You can put a _smaller_ fork into a larger head tube, with suitable adaptors.

I just assumed it was a weak attempt at a troll.

[QUOTE]Originally posted by Sheldon Brown

BSomeone who wisely concealed his or her identity said:

Or you could just use a 1 1/8" fork in a 1" headtube.

Oops. I meant to say that...
The 1 1/8" steerer of a fork will easily fit into a 1" head tube (not fork)! It's just basic math.

"Bruni" <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

It depends on your weight. Bike designers decided that the weight you mention could not be removed
safely without using the O.S. steerer. This is the case with Profile design's AC fork. Reynolds'
Ouzo pro adds extra steerer material and does weigh more in 1 1/8. Some sub 140# riders notice
more ride compliance on 1". Over 190# IMO use 1 1/8. Eventually obsolesence will make things
clearer; some of my favorite OEM forks are 1 1/8 only. Tom

--
Bruni Bicycles "Where art meets science" brunibicycles.com
410.426.3420 Ryan Bates <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

hi, wondering what the performance differences are between a 1" and a 1 1/8" headtube? seems to
me like the larger diameter would weigh more and create a greater frontal area? thanks

A 1 1/8" can be made lighter than a 1" by using a thinner stearing tube and a thinner stem the
stearer tube is 2.3mm thick more than twice as thick as any other tube without a loss of strenght.

BaCardi said:

Sheldon "Won't Fit" Brown is wrong!!!!! WRONG!

Calm down :-) You're not right either.

Quoted message said:

You can put a 1 1/8" fork into a 1" head tube. A 1" head tube is actually 1 1/4" (aka
31.8mm) in diameter.

The internal diameter of a road bike head tube I've measured is 29.6mm. Over 1 1/8" but not a lot of
room to spare. I suspect IDs vary according to material and design.

Quoted message said:

It is called a 1" head tube because head tubes of that size were made to fit the 1" steerer tubes
of forks. This was before mountain bikes started using 1/18" steerer tubes. So, a 1" head tube
has, in reality a diamter of 1 1/4"!

The 1 1/8" steerer of a fork will easily fit into a 1" fork!

There's got to be a good reason 1 1/8" forks aren't rutinely used in "1 inch" frames (otherwise I'll
have one if ever I upgrade to a full carbon job). It'll be interesting to read the other replies to
your post. I'm wondering about the headset and its bearings. Would you need a 1 1/8" headset with
adaptor? Could that work with 1 1/8" forks?

~PB

Quoted post said:

Originally posted by Pete Biggs
Calm down :-) You're not right either.

The internal diameter of a road bike head tube I've measured is 29.6mm. Over 1 1/8" but not a lot of
room to spare. I suspect IDs vary according to material and design.

There's got to be a good reason 1 1/8" forks aren't rutinely used in "1 inch" frames (otherwise I'll
have one if ever I upgrade to a full carbon job). It'll be interesting to read the other replies to
your post. I'm wondering about the headset and its bearings. Would you need a 1 1/8" headset with
adaptor? Could that work with 1 1/8" forks?

~PB

-----------------------------------------------------------------------
Oh yes I am right! Looks like you are wrong! Not me buddy!

AGAIN... A 1" Head Tube actually has an outside diameter of 1 1/4" (aka 31.8mm). It has traditionally been called a 1" head tube because it fits a 1" (25.4mm) steerer tube. A 1/8" (28.6mm) steerer tube will fit into a 1" head tube. Remember, since a 1" Head Tube is actually 1 1/4" (31.8mm) outside diameter and the inside diameter of the head tube is approximately between 30.6 - 31.0mm, that means a 1 1/8" steerer tube will fit inside the 1" head tube.

Summary:
* 1" head tube is actually 1 1/4" diameter. Only called 1" because traditionally it fit the 1" steerer tubes of forks.
* This 1" head tube is actually 31.8mm outside diameter
* 1" = 25.4mm
* 1 1/8" = 28.6mm
* 1 1/4" = 31.8mm
* A 1 1/8" steerer is 28.6mm outside diameter. A 1" head tube (see above) has a inside diameter of between 30.6 - 31.0mm. Do the math. 28.6mm steerer will fit inside a space of 30.6mm -31.0mm.

A 1/8" fork steerer will fit inside a so-called 1" head tube

Ryan Bates said:

hi, wondering what the performance differences are between a 1" and a 1 1/8" headtube? seems to me
like the larger diameter would weigh more and create a greater frontal area? thanks

"performance differences'????? Geez, the marketing guys have won, it seems. . .

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

I said:

You can't put a bigger fork into a smaller head tube.

You can put a _smaller_ fork into a larger head tube, with suitable adaptors.

Sheldon "Won't Fit" Brown +----------------------

Someone who is afraid to reveal his or her secret identity retorted:

Quoted message said:

Sheldon "Won't Fit" Brown is wrong!!!!! WRONG! You can put a 1 1/8" fork into a 1" head tube. A 1"
head tube is actually 1 1/4" (aka 31.8mm) in diameter. It is called a 1" head tube because head
tubes of that size were made to fit the 1" steerer tubes of forks. This was before mountain bikes
started using 1/18" steerer tubes. So, a 1" head tube has, in reality a diamter of 1 1/4"!

The 1 1/8" steerer of a fork will easily fit into a 1" fork!

Yes, but what are you going to do for a headset?

If you'll check the handy chart I've posted at

sheldonbrown.comgloss h.htmlOpen ↗

you'll see that the outside diameter of a 1 1/8" _headset_, where it fits into the head tube, is 34
mm, while the inside diameter of a standard 1" size head tube is 30.2 mm. No go!

Putting the steerer through the head tube without a headset is not particularly useful. I guess you
could theoretically make a headset where the wall thickness of the cup mounting cylinders was less
than 0.8 mm, (a skosh over 3/100 inch) but such a headset would be rather fragile.

Sheldon "Theory vs. Practice" Brown +----------------------------------------------------+
| A little inaccuracy sometimes saves tons of |
| explanation. --H.H.Munro ("Saki"😉(1870-1916) |
+----------------------------------------------------+ Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041 harriscyclery.comharriscyclery.comOpen ↗ Hard-to-find parts shipped Worldwide
captainbike.comcaptainbike.comOpen ↗ sheldonbrown.comsheldonbrown.comOpen ↗

Someone who wisely concealed his or

Quoted message said:

her identity said:

Or you could just use a 1 1/8" fork in a 1" headtube.

(S Brown)> Since he or she didn't quote the post being replied to, I don't know the

Quoted message said:

context, but this is wrong in any case.

You can't put a bigger fork into a smaller head tube.

You can put a _smaller_ fork into a larger head tube, with suitable adaptors.

-snip- BaCardi said:

The 1 1/8" steerer of a fork will easily fit into a 1" fork!

Semantically speaking you may slip an O/S fork through a standard 1-1/4" head tube but so what?
There's not enough clearance for a bearing assembly so it becomes an art object but not a
rideable bicycle.

Sheldon's right for all practical purposes of bicycle assembly.

Did you have some point?
--
Andrew Muzi www.yellowjersey.org Open every day since 1 April, 1971

On Wed, 10 Dec 2003 01:49:24 -0000, "Pete Biggs"

may have said:

BaCardi said:

Sheldon "Won't Fit" Brown is wrong!!!!! WRONG!

Calm down :-) You're not right either.

Quoted message said:

You can put a 1 1/8" fork into a 1" head tube. A 1" head tube is actually 1 1/4" (aka
31.8mm) in diameter.

The internal diameter of a road bike head tube I've measured is 29.6mm. Over 1 1/8" but not a lot
of room to spare. I suspect IDs vary according to material and design.

Quoted message said:

It is called a 1" head tube because head tubes of that size were made to fit the 1" steerer tubes
of forks. This was before mountain bikes started using 1/18" steerer tubes. So, a 1" head tube
has, in reality a diamter of 1 1/4"!

The 1 1/8" steerer of a fork will easily fit into a 1" fork!

There's got to be a good reason 1 1/8" forks aren't rutinely used in "1 inch" frames (otherwise
I'll have one if ever I upgrade to a full carbon job). It'll be interesting to read the other
replies to your post. I'm wondering about the headset and its bearings. Would you need a 1 1/8"
headset with adaptor? Could that work with 1 1/8" forks?

Look at the bearing dimensions. The shoulder of a 1 1/8" headset can't fit into the ID of the 1"
head tube. Some 1" head tubes might have enough space inside for the 1 1/8" steerer tube to be
passed through without the bearing cups installed, but that's irrelevant. The bearings are
necessary, and the 1" headset bearing assemblies most certainly will not fit on a 1 1/8" steerer.

The 1 1/8" steerer, at the lower end, is 29mm in OD. (Yes, at the upper end, it's 28.6, but that's
only one of the two places where the dimension must be considered, and the lower end is the one
where the problem arises.) The 1" bearing cup's shoulder is 30.2mm in OD. This leaves 1.2mm of
difference in diameter. About 0.5mm of clearance is needed to allow for deflection under load; that
leaves just 0.7mm of diameter for the shoulder, or a shoulder thickness of .35mm, which is about
0.014"; fourteen thousandths of an inch is probably not enough material to keep that shoulder from
shearing off under the compression load of the interference fit, let alone the stresses of riding.

No, there is a reason why no one sells an adapter bearing set to fit a 1 1/8" steerer into a 1" head
tube. It's because it really won't work for very long. Yes, with a lathe, the inclination, and the
time, I could make a bearing set that would allow this miscegenation to be accomplished. I wouldn't
make it, though. It would break.

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My email address is antispammed; pull WEEDS if replying via e-mail.
Yes, I have a killfile. If I don't respond to something,
it's also possible that I'm busy.
Words processed in a facility that contains nuts.

The question we are all debating isn't whether or not you can fit a 1 1/8" fork AND headset into a 1" head tube. The question is whether you can fit a 1 1/8" fork into a 1" head tube. Thus, you guys totally missed the point of the question.

YOU CAN FIT A 1 1/8" FORK STEERER INTO A 1" HEAD TUBE! Now, who's wrong?!

BaCardi said:

-----------------------------------------------------------------------
Oh yes I am right! Looks like you are wrong! Not me buddy!

AGAIN... A 1" Head Tube actually has an outside diameter of 1 1/4" (aka
31.8mm). It has traditionally been called a 1" head tube because it fits a 1" (25.4mm) steerer
tube. A 1/8" (28.6mm) steerer tube will fit into a 1" head tube. Remember, since a 1" Head Tube
is actually 1
1/4" (31.8mm) outside diameter and the inside diameter of the head tube is approximately between
30.6 - 31.0mm, that means a 1 1/8" steerer tube will fit inside the 1" head tube.

Summary:
* 1" head tube is actually 1 1/4" diameter. Only called 1" because traditionally it fit the 1"
steerer tubes of forks.
* This 1" head tube is actually 31.8mm outside diameter
* 1" = 25.4mm
* 1 1/8" = 28.6mm
* 1 1/4" = 31.8mm
* A 1 1/8" steerer is 28.6mm outside diameter. A 1" head tube (see above) has a inside diameter of
between 30.6 - 31.0mm. Do the math.
28.6mm steerer will fit inside a space of 30.6mm -31.0mm.

A 1/8" fork steerer will fit inside a so-called 1" head tube

We all agree that you are right about a perfectly useless fact, unless you're interested in
measurments for the sake of measurements. The point still remains, you can't ride a bike with a 1"
head tube and a 1 1/8" fork.

Rob Strickland

"BaCardi" <[email hidden]> wrote: <snip>

Quoted message said:

Oh yes I am right! Looks like you are wrong! Not me buddy!

<snip>

OKay, sure ... go for it. No, really (c:

My friend SK Grimes (Sheldon knew him well) used to say that to me at his machine shop when the same
type of situation arose ... of course, it didn't take long to figure out he was right once I broke
out the calipers and started to try to make things actually work.

Go back up and read the posts about those things called headsets.

C.Q.C.