A modern double top tube

Rik O'Shea said:

A modern double top tube...
http://tinyurl.com/3ydhhm

I still dont get it...

It keeps the down and top-top-tube from flexing as the head tube bends
downwards, as (we might suppose) under hard front braking.

The stubby head tube used is not optimal for the advantage however.

Even sillier is the Flying Merkel-style style fork bars (-missing the
crown brace, and therefore rather useless).
~

Rik O'Shea said:

A modern double top tube...
http://tinyurl.com/3ydhhm

I still dont get it...

It keeps the down and top-top-tube from flexing as the head tube bends
downwards, as (we might suppose) under hard front braking.

The stubby head tube used is not optimal for the advantage however.

Even sillier is the Flying Merkel-style style fork bars (-missing the
crown brace, and therefore rather useless).
~

DougC said:

Rik O'Shea said:

A modern double top tube...
http://tinyurl.com/3ydhhm

Quoted message said:

I still dont get it...

It keeps the down and top-top-tube from flexing as the head tube bends
downwards, as (we might suppose) under hard front braking.

The stubby head tube used is not optimal for the advantage however.

Even sillier is the Flying Merkel-style style fork bars (-missing the
crown brace, and therefore rather useless).
~

Actually, what happened is that they guy took that bike out for a spin
and the first time he had to brake, he bent the top tube. To prevent
the top tube from bending any further, he brazed it with an extra top
tube. the extra tubes on the front are for aerodynamics.

Andres

DougC said:

Rik O'Shea said:

A modern double top tube...
http://tinyurl.com/3ydhhm

Quoted message said:

I still dont get it...

It keeps the down and top-top-tube from flexing as the head tube bends
downwards, as (we might suppose) under hard front braking.

The stubby head tube used is not optimal for the advantage however.

Even sillier is the Flying Merkel-style style fork bars (-missing the
crown brace, and therefore rather useless).
~

Actually, what happened is that they guy took that bike out for a spin
and the first time he had to brake, he bent the top tube. To prevent
the top tube from bending any further, he brazed it with an extra top
tube. the extra tubes on the front are for aerodynamics.

Andres

Rik O'Shea said:

A modern double top tube...http://tinyurl.com/3ydhhm

I still dont get it...

Ozark's gonna love this one, a 69cm A. Homer Hilsen:

http://preview.tinyurl.com/23jjeg

Rik O'Shea said:

A modern double top tube...http://tinyurl.com/3ydhhm

I still dont get it...

Ozark's gonna love this one, a 69cm A. Homer Hilsen:

http://preview.tinyurl.com/23jjeg

Quoted message said:

DougC said:

Rik O'Shea said:

A modern double top tube...
http://tinyurl.com/3ydhhm

Quoted message said:

I still dont get it...

[...]

Quoted message said:

Quoted message said:

Even sillier is the Flying Merkel-style style fork bars (-missing the
crown brace, and therefore rather useless).

Actually, what happened is that they guy took that bike out for a spin
and the first time he had to brake, he bent the top tube. To prevent
the top tube from bending any further, he brazed it with an extra top
tube. the extra tubes on the front are for aerodynamics.

Actually, the extra tubes make the front end laterally stiff yet
vertically compliant.

Quoted message said:

DougC said:

Rik O'Shea said:

A modern double top tube...
http://tinyurl.com/3ydhhm

Quoted message said:

I still dont get it...

[...]

Quoted message said:

Quoted message said:

Even sillier is the Flying Merkel-style style fork bars (-missing the
crown brace, and therefore rather useless).

Actually, what happened is that they guy took that bike out for a spin
and the first time he had to brake, he bent the top tube. To prevent
the top tube from bending any further, he brazed it with an extra top
tube. the extra tubes on the front are for aerodynamics.

Actually, the extra tubes make the front end laterally stiff yet
vertically compliant.

Hank Wirtz said:

Rik O'Shea said:

A modern double top tube...http://tinyurl.com/3ydhhm

Quoted message said:

I still dont get it...

Ozark's gonna love this one, a 69cm A. Homer Hilsen:

http://preview.tinyurl.com/23jjeg

http://www.coolopticalillusions.com/crazy/images/drunk.jpg

/s

Hank Wirtz said:

Rik O'Shea said:

A modern double top tube...http://tinyurl.com/3ydhhm

Quoted message said:

I still dont get it...

Ozark's gonna love this one, a 69cm A. Homer Hilsen:

http://preview.tinyurl.com/23jjeg

http://www.coolopticalillusions.com/crazy/images/drunk.jpg

/s

Hank Wirtz said:

Rik O'Shea said:

A modern double top tube...http://tinyurl.com/3ydhhm

Quoted message said:

I still dont get it...

Ozark's gonna love this one, a 69cm A. Homer Hilsen:

http://preview.tinyurl.com/23jjeg

I've seen it. Apparently, no 69cm, but a 72cm is available.

As much as I appreciate 'traditional construction', there is a
practical limit. A frame that size needs oversized tubes. Big, fat,
aluminum tubes would probably work well and allow a strong, rationally
priced frame that doesn't look just plain stupid.

I'm sure The Grant will find a few mesmerized suckers to buy that
silly POS, though.

Hank Wirtz said:

Rik O'Shea said:

A modern double top tube...http://tinyurl.com/3ydhhm

Quoted message said:

I still dont get it...

Ozark's gonna love this one, a 69cm A. Homer Hilsen:

http://preview.tinyurl.com/23jjeg

I've seen it. Apparently, no 69cm, but a 72cm is available.

As much as I appreciate 'traditional construction', there is a
practical limit. A frame that size needs oversized tubes. Big, fat,
aluminum tubes would probably work well and allow a strong, rationally
priced frame that doesn't look just plain stupid.

I'm sure The Grant will find a few mesmerized suckers to buy that
silly POS, though.

Ozark Bicycle said:

Hank Wirtz said:

On Nov 6, 3:18 am, Rik O'Shea <[email hidden]> wrote:

Quoted message said:

Quoted message said:

A modern double top tube...http://tinyurl.com/3ydhhm

Quoted message said:

Quoted message said:

I still dont get it...

Quoted message said:

Ozark's gonna love this one, a 69cm A. Homer Hilsen:

Quoted message said:

http://preview.tinyurl.com/23jjeg

I've seen it. Apparently, no 69cm, but a 72cm is available.

As much as I appreciate 'traditional construction', there is a
practical limit. A frame that size needs oversized tubes. Big, fat,
aluminum tubes would probably work well and allow a strong, rationally
priced frame that doesn't look just plain stupid.

Usenet needs an eyewash station. That's just UGLY. I agree, though I'm
a fan of simple tig welded steel frames for the visual simplicity--if
you're an ogre, then use appropriate materials.

Ozark Bicycle said:

Hank Wirtz said:

On Nov 6, 3:18 am, Rik O'Shea <[email hidden]> wrote:

Quoted message said:

Quoted message said:

A modern double top tube...http://tinyurl.com/3ydhhm

Quoted message said:

Quoted message said:

I still dont get it...

Quoted message said:

Ozark's gonna love this one, a 69cm A. Homer Hilsen:

Quoted message said:

http://preview.tinyurl.com/23jjeg

I've seen it. Apparently, no 69cm, but a 72cm is available.

As much as I appreciate 'traditional construction', there is a
practical limit. A frame that size needs oversized tubes. Big, fat,
aluminum tubes would probably work well and allow a strong, rationally
priced frame that doesn't look just plain stupid.

Usenet needs an eyewash station. That's just UGLY. I agree, though I'm
a fan of simple tig welded steel frames for the visual simplicity--if
you're an ogre, then use appropriate materials.

Rik O'Shea said:

A modern double top tube...
http://tinyurl.com/3ydhhm
I still dont get it...

'it's for selling'
btw, Pereira was in the NYTimes yesterday, with photo!
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

Rik O'Shea said:

A modern double top tube...
http://tinyurl.com/3ydhhm
I still dont get it...

'it's for selling'
btw, Pereira was in the NYTimes yesterday, with photo!
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

Ozark Bicycle said:

As much as I appreciate 'traditional construction', there is a
practical limit. A frame that size needs oversized tubes. Big, fat,
aluminum tubes would probably work well and allow a strong, rationally
priced frame that doesn't look just plain stupid.

Big fat aluminum frames in such sizes would be lovely, if anybody made
them. But if you need a size that mainstream manufacturers won't
provide, you have to get one from a framebuilder. And if you get a
frame from a framebuilder, you'll get it in the material he or she
works with.

I was able to get a big fat brazed steel frame (2" downtube, 1.5" top
& seat tubes) from David Bohm of Tucson AZ. It was an ordeal for him
to make it. Several other "custom" builders including Waterford
Precision told me they would not do my project. (I did not specify
that I needed big tubes, only that I wanted the frame length-- top
tube and chainstays-- to scale up with the frame size.)

There are some features, like lugs, that aren't available for
seriously oversized frame tubes. If you want your own special bike to
have those, you'll be using pretty conventional diameters of tubing.
It would make sense to use tubes with walls thick enough to delver the
requisite stiffness, but I think it offends the sensibilities of many
builders to use straight-gauge aircraft chromoly or the equivalent in
order to meet the challenge. Certainly Dave Bohm did not think that
straight gauge tubing of any kind would be a worthy material to use in
my frame.

The kinds of reinforcement that work well for very large frames and
traditionally sized tubing are all on display in tandem frames. The
"single marathon" frame design (large tube from middle of head tube to
middle of seat tube, third set of stays from that point to the
dropouts) works as well for a large single frame as it does for a
tandem, and to my eyes it looks very nice too. Full length mixte-
style stays also do the job, as does a "direct lateral" tube to the BB
shell.

Quoted message said:

From my own experience, and speaking as a rider who is not only very

tall but also very heavy, I can say that frame flex is not nearly as
annoying or debilitating as its reputation would suggest-- that is, so
long as the parts attached to that frame are not themselves twisty and
flexible. I have an old 68.5cm 1970s Nishiki road bike with a 1" top
tube and 1-1/8" down tube, and it provides me a fine ride with which I
have no complaint. But the bike is fitted with a rugged BMX crank
with a solid 22mm spindle, slingshot-type MTB stem holding very thick-
walled motocross handlebars, and stout 48-spoke wheels. The frame's
sway is perceptible, but the overall effect is that of a pretty solid
bike.

I reckon that folks who are bothered by flex on an old or old-
fashioned road bike frame would do well to try one of the new external
bearing cranks with a big steel spindle. That alone would probably
make enough difference to restore a confidence-inspiring feel.

Chalo

Ozark Bicycle said:

As much as I appreciate 'traditional construction', there is a
practical limit. A frame that size needs oversized tubes. Big, fat,
aluminum tubes would probably work well and allow a strong, rationally
priced frame that doesn't look just plain stupid.

Big fat aluminum frames in such sizes would be lovely, if anybody made
them. But if you need a size that mainstream manufacturers won't
provide, you have to get one from a framebuilder. And if you get a
frame from a framebuilder, you'll get it in the material he or she
works with.

I was able to get a big fat brazed steel frame (2" downtube, 1.5" top
& seat tubes) from David Bohm of Tucson AZ. It was an ordeal for him
to make it. Several other "custom" builders including Waterford
Precision told me they would not do my project. (I did not specify
that I needed big tubes, only that I wanted the frame length-- top
tube and chainstays-- to scale up with the frame size.)

There are some features, like lugs, that aren't available for
seriously oversized frame tubes. If you want your own special bike to
have those, you'll be using pretty conventional diameters of tubing.
It would make sense to use tubes with walls thick enough to delver the
requisite stiffness, but I think it offends the sensibilities of many
builders to use straight-gauge aircraft chromoly or the equivalent in
order to meet the challenge. Certainly Dave Bohm did not think that
straight gauge tubing of any kind would be a worthy material to use in
my frame.

The kinds of reinforcement that work well for very large frames and
traditionally sized tubing are all on display in tandem frames. The
"single marathon" frame design (large tube from middle of head tube to
middle of seat tube, third set of stays from that point to the
dropouts) works as well for a large single frame as it does for a
tandem, and to my eyes it looks very nice too. Full length mixte-
style stays also do the job, as does a "direct lateral" tube to the BB
shell.

Quoted message said:

From my own experience, and speaking as a rider who is not only very

tall but also very heavy, I can say that frame flex is not nearly as
annoying or debilitating as its reputation would suggest-- that is, so
long as the parts attached to that frame are not themselves twisty and
flexible. I have an old 68.5cm 1970s Nishiki road bike with a 1" top
tube and 1-1/8" down tube, and it provides me a fine ride with which I
have no complaint. But the bike is fitted with a rugged BMX crank
with a solid 22mm spindle, slingshot-type MTB stem holding very thick-
walled motocross handlebars, and stout 48-spoke wheels. The frame's
sway is perceptible, but the overall effect is that of a pretty solid
bike.

I reckon that folks who are bothered by flex on an old or old-
fashioned road bike frame would do well to try one of the new external
bearing cranks with a big steel spindle. That alone would probably
make enough difference to restore a confidence-inspiring feel.

Chalo

"Rik O'Shea" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

A modern double top tube...
http://tinyurl.com/3ydhhm

I still dont get it...

Rik,
Thanks very much for this posting - I hadn't heard anything about the first
Oregon Handmade Bicycle Show - will definitely go there.
Thanks again,
Kerry