TA Cyclotour questions

Hoping that the owners of the sites I have listed do not lynch me. This
was a very common crank/chainset, all of the parts can still be had.
http://www.classicrendezvous.com/France/ta_cyclotouriste.htm
http://harriscyclery.net/site/itemdetails.cfm?ID=1174&Catalog=39&sort=Price
http://www.blackbirdsf.org/ta/pro5.html

I think you have a TA criterium crank with the 152 bcd inside spider
for the 54T ring, and a regular 40T ring. I just gone one of these
strange beasts with a 52/44 and the 44 seems like the smallest ring
that fits on the insider spider. 44 is definitely the smallest for
151 bcd campagnolo. So I'm guessin that your 40T ring is bolted to
the crank arms, not to the adapter ring.

http://www.blackbirdsf.org/ta/pro5.html ref 175 / 1755 / 3155

If you want to triplize such a crankset, I believe you need middle and
inner rings, or if the adapter doesn't interfere, just an inner ring.
In any case, you need longer bolts for the crank arm/adapter interface
to take an inner ring.

- Don Gillies
San Diego, CA

On 26 Aug 2005 04:38:07 -0700, [email hidden] (Donald Gillies)

Quoted message said:

http://www.blackbirdsf.org/ta/pro5.html ref 175 / 1755 / 3155

If you want to triplize such a crankset, I believe you need middle and
inner rings, or if the adapter doesn't interfere, just an inner ring.
In any case, you need longer bolts for the crank arm/adapter interface
to take an inner ring.

I guess what I have is more interesting... but perhaps the solution is
the same.

Take a look at this page: http://www.blackbirdsf.org/ta/inner.html

Scroll to the very bottom. My crank and chainwheels are like the ref?
set at the very bottom of the page with dual drillings.

Scroll back up a couple lines to the 152bcd chainguard ref?. I have
one of those attached to the outside of the outer bolt circle of
the 54.

Next, scroll back up a couple lines to the ref? shifting guide plate.
I have one of those installed flush on the back side of the 54.

Now scroll back up to the ref 2082. That's my inner 40 chainwheel and
it is attached to the smaller bcd on my ref? crank.

More interesting facts for those that have read this far: the inner 40
sits on a double set of 4mm spacers (total 8m). This puts the inner
edge of the teeth of the inner chainwheel 10mm from the backside of
the teeth of out chainwheel.

I _think_ this means that I have the triple bolts already (with those
double spacers on there but I will have to pull them out and check.
If that's true, then all I need to do is remove the shifting guide
plate and install another chainwheel and maybe replace the 40 with
something smaller to have a nice triple.

Bob

You must have a total of seventeen bolts holding this lot together. If
I understand you correctly then to make a triple you will have to
remove the shift guide plate and fit one set of the spacers from the
80mm bolt circle in its place I have owned some TA equipment but not
the specific setup you have. I assume that the shift guide plate is to
cope with the large step up to the big gear, you will need to consider
it.
My own two cents worth says that the larger rings are not stiff in
use and that the tooth wear is uneven and over 48/50 tooth is
noticeable after little use. It is a lot to ask of a large flat piece
of alloy to stay still. It does sound as though the bolts on the 80mm
BCD are triple bolts, the length is ½" from shoulder to end. .
You should be careful of derailler choice if you make a triple, the
gap between rear of crank and outside of outer chainwheel is small and
a rub from the outer cage plate is a possibility with a large capacity
derailler.

Quoted message said:

My own two cents worth says that the larger rings are not stiff in
use and that the tooth wear is uneven and over 48/50 tooth is
noticeable after little use. It is a lot to ask of a large flat piece
of alloy to stay still. It does sound as though the bolts on the 80mm
BCD are triple bolts, the length is ½" from shoulder to end. .

Hmmm...
It seems like that if I use a 47 ring - which I think I need
to get the "step" to work and to make it a more rideable combination
that I would need to use a "criterium" approach and bolt the outer
and middle at the 152BCD.

http://www.blackbirdsf.org/ta/pro5.html ref 2205.

Then the inner wheel would be the only one on the flex prone 80mm BCD.
In fact, if I used another "outer" ring for the middle ring and got
creative with the bolts and spacers, I would be able to bolt both
the 80mm BCD and the 152BCD together. This would make the middle
and outer rings stiffer and might be a good solution.

Any reasons this would not work ?

Bob

Quoted message said:

"Any reasons this would not work ?"

It should work Bob. I filled every available hole with bolts on the
setups I had in use. If you have enough bolts and spacers you will find
a way to achieve your setup. Do tell how you get on when you have
completed the job.

I seem to have run into an issue: The 40/54 seems to be a little too
much of a size difference for the Nuovo front derailleur. If I get the
derailleur up high enough to dismount the chain from the large wheel
it seems to be too high for the small wheel - the chain is scraping
on the roller at the bottom of the cage.

Does this seem like "par for the course" as in "the big wheel is just
too big? I am probably putting in a few mm extra clearance because of
the outer chain guard that is on there right now. Do you think it
would work with that removed ?

By all means try removing the chain guard if you can live without it.
You may get the roller to clear the chain when on the 40t but the
Campagnolo NR front derailler is very shallow.
I do not have the spec to hand and its a long time since I owned
one though a 12t overall capacity seems familiar. As I mentioned
previously the TA crank has a narrow gap to the outer chainring. You
may get the roller to clear but the next problem may be having to
overshift by quite a margin to get onto the big ring which could cause
a rub on the crank inner face. I would try a couple of turns of gaffer
tape on the crank while road trialling the setup.
Are you stuck on the Nuovo Record or is it what you have to hand?
If you do not mind using another derailler then you will need to look
for one with a narrowish cage. I ended up using a Suntour Mountech unit
after narrowing the cage gap, that crank to chainwheel clearance issue
on the TA viz is tricky. Good luck and do tell how you get on.

05 Sep 2005 14:08:48 GMT Bob said:

I seem to have run into an issue: The 40/54 seems to be a little too
much of a size difference for the Nuovo front derailleur.

I have a circa '70 Record front running on a 52/39 with no problems at
all. I don't think it's at all close, but I really haven't looked at
it in years (I just ride it.) I believe the chain guide on the Nuovo
Record and its preceeding Record F der are the same.

-
-----------------------------------------------
Jim Adney [email hidden]
Madison, WI 53711 USA
-----------------------------------------------

On Mon, 05 Sep 2005 17:33:21 -0500, Jim Adney <[email hidden]>

Quoted message said:

05 Sep 2005 14:08:48 GMT Bob said:

I seem to have run into an issue: The 40/54 seems to be a little too
much of a size difference for the Nuovo front derailleur.

I have a circa '70 Record front running on a 52/39 with no problems at
all. I don't think it's at all close, but I really haven't looked at
it in years (I just ride it.) I believe the chain guide on the Nuovo
Record and its preceeding Record F der are the same.

I'm only one tooth more than that so maybe I can make it. I will have
to try removing that chain guard and see how it does. With the stepper
ring in between, this really needs a triple axle to put the inner
wheel out where it belongs so I will have to do that too and see where
I end up.

Do you have any issues getting from the 39 to the 52 ?

06 Sep 2005 12:55:41 GMT Bob said:

On Mon, 05 Sep 2005 17:33:21 -0500, Jim Adney <[email hidden]>

Quoted message said:

05 Sep 2005 14:08:48 GMT Bob said:

I seem to have run into an issue: The 40/54 seems to be a little too
much of a size difference for the Nuovo front derailleur.

I have a circa '70 Record front running on a 52/39 with no problems at
all. I don't think it's at all close, but I really haven't looked at
it in years (I just ride it.) I believe the chain guide on the Nuovo
Record and its preceeding Record F der are the same.

I'm only one tooth more than that so maybe I can make it. I will have
to try removing that chain guard and see how it does. With the stepper
ring in between, this really needs a triple axle to put the inner
wheel out where it belongs so I will have to do that too and see where
I end up.

Do you have any issues getting from the 39 to the 52 ?

I just looked, and I'd say that there's room for it to go as low as a
37, which would be a 15T difference. There are no issues with it at
all. That shift is so easy that it's the one I most commonly make.

-
-----------------------------------------------
Jim Adney [email hidden]
Madison, WI 53711 USA
-----------------------------------------------