Help With GT Aero Frame: Funky Seatpost!

spincircles said:

Description of what I have to work with here:

*** Any second now a bunch of meanie poopoo heads
are going to yell at you to take it to rec.bicycles.tech.

---
k e i t h a l e x a n d e r
http://www.nootrope.net
http://www.keithalexander.com/blog
http://www.modernamerican.com

- - e n d t r a n s m i s s i o n - -

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

Quoted message said:

Description of what I have to work with here:
I own what It believe is a pre-curser to the GT Vengeance, or perhaps
is GT vengeance frame. Looks a bit like the Olympic superbikes that
(IIRC) were used to rough out the positions on our olympic athletes
before the full-tilt superbikes were made for them. All aluminum. It
has a teardrop down and seat tube. The rear wheel fits into a cutout
in the curved seat tube. The faired seat tube actually extends below
the bottom bracket, kind of like a little hook to allow the wheel
remian faired below the BB. the top tube is round. The rear triangle
is all bladed alluminum. Rear drops face rear (like a track bike). It
has a rear der hanger that is not replaceable. The rear drops and fork
ends accept standard road hubs with standard width axles.

It came (used) without a seatpost, which was (from what I've gathered)
orignally a funky looking post with a built on fairing. It originally
had a small bar that fit into the leading edge through which two bolts
extended to somehow either secure a fairing or a seatpost, or both (If
the fairing was an integral part of he seatpost. The two holes in the
front, leading edge of the seat tube are present. They are not tapped
of reniforced in any way.

The tube inside the faired-out seat tube is very skinny (I'd guess
around 25.0) and this seat tube has the end of the top tube crudely
poking into it at the junction in such a way as to prevent a seat post
from dropping below the seat / top tube junction. That is, the bottom
of a seatpost slides down the tube to rest on top of the top tube
intrusion.

There is no pinch bolt to secure a seatpost.

The Questions:
I bought it with the assumption that I could fabricate what I needed to
get a faired seatpost to be fitted. Now that I've looked at it for a
while, I'm not sure how to proceed.

Should the seatpost be inserted until it bottoms out on the intruding
top tube, then somehow secured with two horizontal bolts?

What should I NOT do, so as to avoid damage to the frame?

How can get a seat post to work in this frame?

Sources for origial parts?

Pat, I don't think that there's much of a chance to find out anything like
that here.

I also believe that you'll have to find some frame builder to make up
something special for you. It isn't as if bicycles are that difficult to
work on, just that there isn't that many people around that want to work for
a living any more.

Tom Kunich said:

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

Quoted message said:

Description of what I have to work with here:
I own what It believe is a pre-curser to the GT Vengeance, or perhaps
is GT vengeance frame. Looks a bit like the Olympic superbikes that
(IIRC) were used to rough out the positions on our olympic athletes
before the full-tilt superbikes were made for them. All aluminum. It
has a teardrop down and seat tube. The rear wheel fits into a cutout
in the curved seat tube. The faired seat tube actually extends below
the bottom bracket, kind of like a little hook to allow the wheel
remian faired below the BB. the top tube is round. The rear triangle
is all bladed alluminum. Rear drops face rear (like a track bike). It
has a rear der hanger that is not replaceable. The rear drops and fork
ends accept standard road hubs with standard width axles.

It came (used) without a seatpost, which was (from what I've gathered)
orignally a funky looking post with a built on fairing. It originally
had a small bar that fit into the leading edge through which two bolts
extended to somehow either secure a fairing or a seatpost, or both (If
the fairing was an integral part of he seatpost. The two holes in the
front, leading edge of the seat tube are present. They are not tapped
of reniforced in any way.

The tube inside the faired-out seat tube is very skinny (I'd guess
around 25.0) and this seat tube has the end of the top tube crudely
poking into it at the junction in such a way as to prevent a seat post
from dropping below the seat / top tube junction. That is, the bottom
of a seatpost slides down the tube to rest on top of the top tube
intrusion.

There is no pinch bolt to secure a seatpost.

The Questions:
I bought it with the assumption that I could fabricate what I needed to
get a faired seatpost to be fitted. Now that I've looked at it for a
while, I'm not sure how to proceed.

Should the seatpost be inserted until it bottoms out on the intruding
top tube, then somehow secured with two horizontal bolts?

What should I NOT do, so as to avoid damage to the frame?

How can get a seat post to work in this frame?

Sources for origial parts?

Pat, I don't think that there's much of a chance to find out anything like
that here.

I also believe that you'll have to find some frame builder to make up
something special for you. It isn't as if bicycles are that difficult to
work on, just that there isn't that many people around that want to work for
a living any more.

Hey Tom
Richie could build anything you want and make it a totally functional,
reliable, piece of art. I agree with you that the concept of
independent craftsmanship is dying here in America. It's about hype and
hard sales, not about craftsmanship and tradition.
At least in the motorcycle world there's a bit of a renaisance for
true artists and craftsmen, but compared to Britten they are all hacks.
I love classic motorcycles and have dedicated myself to them, but the
cutting edge is cool too. I love all the new tech that makes Pro
bicycles what they are, and really appreciate it, but that makes a
difference for maybe 100 people in the US.
The Suzuki GSXRs are cutting edge, and maybe 1 person in 10,000 can
actually ride the bikes to their limits. A lot of the rest just
increase our insurance rates by stuffing it.
I agree though that American craftsmanship and innovation is pretty
much dead.
Bill C

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

Quoted message said:

Tom Kunich said:

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

Quoted message said:

Description of what I have to work with here:
I own what It believe is a pre-curser to the GT Vengeance, or perhaps
is GT vengeance frame. Looks a bit like the Olympic superbikes that
(IIRC) were used to rough out the positions on our olympic athletes
before the full-tilt superbikes were made for them. All aluminum. It
has a teardrop down and seat tube. The rear wheel fits into a cutout
in the curved seat tube. The faired seat tube actually extends below
the bottom bracket, kind of like a little hook to allow the wheel
remian faired below the BB. the top tube is round. The rear triangle
is all bladed alluminum. Rear drops face rear (like a track bike).

It

Quoted message said:

Quoted message said:

Quoted message said:

has a rear der hanger that is not replaceable. The rear drops and

fork

Quoted message said:

Quoted message said:

Quoted message said:

ends accept standard road hubs with standard width axles.

It came (used) without a seatpost, which was (from what I've

gathered)

Quoted message said:

Quoted message said:

Quoted message said:

orignally a funky looking post with a built on fairing. It originally
had a small bar that fit into the leading edge through which two bolts
extended to somehow either secure a fairing or a seatpost, or both (If
the fairing was an integral part of he seatpost. The two holes in the
front, leading edge of the seat tube are present. They are not tapped
of reniforced in any way.

The tube inside the faired-out seat tube is very skinny (I'd guess
around 25.0) and this seat tube has the end of the top tube crudely
poking into it at the junction in such a way as to prevent a seat post
from dropping below the seat / top tube junction. That is, the bottom
of a seatpost slides down the tube to rest on top of the top tube
intrusion.

There is no pinch bolt to secure a seatpost.

The Questions:
I bought it with the assumption that I could fabricate what I needed

to

Quoted message said:

Quoted message said:

Quoted message said:

get a faired seatpost to be fitted. Now that I've looked at it for a
while, I'm not sure how to proceed.

Should the seatpost be inserted until it bottoms out on the intruding
top tube, then somehow secured with two horizontal bolts?

What should I NOT do, so as to avoid damage to the frame?

How can get a seat post to work in this frame?

Sources for origial parts?

Pat, I don't think that there's much of a chance to find out anything

like

Quoted message said:

Quoted message said:

that here.

I also believe that you'll have to find some frame builder to make up
something special for you. It isn't as if bicycles are that difficult to
work on, just that there isn't that many people around that want to work

for

Quoted message said:

Quoted message said:

a living any more.

Hey Tom
Richie could build anything you want and make it a totally functional,
reliable, piece of art. I agree with you that the concept of
independent craftsmanship is dying here in America. It's about hype and
hard sales, not about craftsmanship and tradition.
At least in the motorcycle world there's a bit of a renaisance for
true artists and craftsmen, but compared to Britten they are all hacks.
I love classic motorcycles and have dedicated myself to them, but the
cutting edge is cool too. I love all the new tech that makes Pro
bicycles what they are, and really appreciate it, but that makes a
difference for maybe 100 people in the US.
The Suzuki GSXRs are cutting edge, and maybe 1 person in 10,000 can
actually ride the bikes to their limits. A lot of the rest just
increase our insurance rates by stuffing it.
I agree though that American craftsmanship and innovation is pretty
much dead.
Bill C

Oh, an OCC guy....

Actually, if I recall correctly ( from memory of an old cycling magazine
review of the bike ), the seat post was a stubby, and was mounted into a
holder that fitted into the frame; allen screws went through the 2 holes you
see and tightening would secure the seat-post.
I think your best bet would be to locate an authorized gt dealer, who might
have an illustration of the part you need ( maybe have one on hand !!!),
they could also contact GT for the part or perhaps to provide a technical
drawing for you ( unlikely, but it would be worth asking ).. A machine shop
could then fabricate your part.

Your frame is aluminum, so really be careful no mater what; A mistaken
assumption might ruin it.
Best of luck

Laz

In article <[email hidden]>,

Bill C said:

Richie could build anything you want and make it a totally functional,
reliable, piece of art. I agree with you that the concept of
independent craftsmanship is dying here in America. It's about hype and
hard sales, not about craftsmanship and tradition.

I don't think it's dying, but you do have to look a bit harder
sometimes. People do have to make a living, and the bottom line stuf can
get in the way when the public is willing to settle for stuff that isn't
quite as craftsmanlike. It's like the difference between a custom framed
bike versus a (for example) Trek. I think most people see the difference in
price between the two and decide that they can live with the Trek (which,
it must be said, is going to be a pretty damn good bike).

Quoted message said:

The Suzuki GSXRs are cutting edge, and maybe 1 person in 10,000 can
actually ride the bikes to their limits.

That's kind of the same thing with bicycles: the technology and
components have moved along far enough that a production bike is quite
close to the spec level (a least) of a full custom bike from a few years
ago.

I'd still rather put my own bike together, of course.

--
tanx,
Howard

Butter is love.

remove YOUR SHOES to reply, ok?

You should try to contact Dave Tiemyer (tiemyercycles.com???). He was
the one who built all those bikes and may have parts lying around, or
maybe he can make one for you.

Or you can just run a 25.0 seatpost.

There was originally an a threaded aluminum sleeve that slid down in
front of the seat post, and it normally had three hex bolts that
secured that aero post. The hex bolts in the front of the seat tube
will hold it fine. That is how the original setup worked. It doesn't
need to bottom out. But you do need the threaded aluminum sleeve. It
was round in the early bikes sortof moon shaped later.

Good luck.