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Bottom bracket spindle length question



 
 
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  #1  
Old February 26th 05, 01:49 AM
Bruce W.1
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Default Bottom bracket spindle length question

I'm in the process of triplizing the front chainrings on my road bike.

I managed, just barely, to make the Willow triplizer fit on my existing
70's era Campy Nuovo Record bottom bracket spindle. Hurray! But my
enthusiasm was sooned crushed when I mounted my new triple front derailleur.

The derailleur doesn't go in far enough to center on the small inner
chairing, not even close. So it looks like the bottom bracket spindle
will need to be longer. Here's a drawing of the measurements that I took:
http://www.keystandard.com/75.jpg

I tried putting on a Shimano sealed cassette bottom bracket, but I
really didn't like the way it looked. I'd much rather just replace the
Campy spindle if I can.

My question is, how much longer does the spindle need to get on the
right side? And how should the derailleur be able to be positioned over
the inner chainring, centered?

And if you really know your Campagnolo, which spindle can I use?

Thanks for your help.



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  #2  
Old February 26th 05, 03:05 AM
Mark Janeba
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Default

Bruce W.1 wrote:
I'm in the process of triplizing the front chainrings on my road bike.

I managed, just barely, to make the Willow triplizer fit on my existing
70's era Campy Nuovo Record bottom bracket spindle. Hurray! But my
enthusiasm was sooned crushed when I mounted my new triple front
derailleur.

The derailleur doesn't go in far enough to center on the small inner
chairing, not even close.


Here's something that might help, perhaps in combination with a longer
spindle, if your front derailleur won't move "in" far enough, even with
limit screw and cable adjustments:

Find what is stopping travel. Some part of the mechanism is coming in
contact with some other part or in contact with the frame. Remove
derailleur from the bike and judge whether some material can be safely
removed. A few seconds with the Dremel or a few minutes with a needle
file will do the trick.

On modern Campy triple front derailleurs, the swing arms hit the frame.
You can (IMHO safely) remove a bit of material and get another
millimeter or so of travel. On older SunTour fronts, the arms hit each
other, again a bit of material removal extends travel.

Probably not enough to get the amount of travel you seem to need, but it
may help if you can get close with a spindle change.

Again, judge for yourself if the material can be safely removed, or
possibly risk injury, death, or some other witty thing I can't come up
with at the moment.

Mark Janeba

  #3  
Old February 26th 05, 03:38 AM
Bruce W.1
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Posts: n/a
Default

Mark Janeba wrote:


Here's something that might help, perhaps in combination with a longer
spindle, if your front derailleur won't move "in" far enough, even with
limit screw and cable adjustments:

Find what is stopping travel. Some part of the mechanism is coming in
contact with some other part or in contact with the frame. Remove
derailleur from the bike and judge whether some material can be safely
removed. A few seconds with the Dremel or a few minutes with a needle
file will do the trick.

On modern Campy triple front derailleurs, the swing arms hit the frame.
You can (IMHO safely) remove a bit of material and get another
millimeter or so of travel. On older SunTour fronts, the arms hit each
other, again a bit of material removal extends travel.

Probably not enough to get the amount of travel you seem to need, but it
may help if you can get close with a spindle change.

Again, judge for yourself if the material can be safely removed, or
possibly risk injury, death, or some other witty thing I can't come up
with at the moment.

Mark Janeba

================================================== ======

Good suggestion. I contemplated that a few hours ago, then told myself
I must be crazy. I could shave a wee bit off the Campy Racing
derailleur. I also considered taking the Dremel tool to my frame and
digging a hole where the derailler arm hits.

I just ran a string from the front chainring to the rear cluster. It
looks like 3 mm would do the job.

I also tried shifting the spindle to the right by putting a washer
behind the right bearing cup. Unfortunately the left cup will only go
in about and additional 1/100th of an inch, which is insufficient. I
can't figure out why it wouln't go in farther, there's nothing blocking
it and the threads in the bottom bracket look like they go an additional
1/4" or so.

One other idea I had was to put some shim plates on the right spindle
end, so the crank arm wouldn't tighten down as far. Anybody here tried
this?
  #4  
Old February 26th 05, 12:20 PM
A Muzi
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Default

Bruce W.1 wrote:
I'm in the process of triplizing the front chainrings on my road bike.

I managed, just barely, to make the Willow triplizer fit on my existing
70's era Campy Nuovo Record bottom bracket spindle. Hurray! But my
enthusiasm was sooned crushed when I mounted my new triple front
derailleur.

The derailleur doesn't go in far enough to center on the small inner
chairing, not even close. So it looks like the bottom bracket spindle
will need to be longer. Here's a drawing of the measurements that I took:
http://www.keystandard.com/75.jpg

I tried putting on a Shimano sealed cassette bottom bracket, but I
really didn't like the way it looked. I'd much rather just replace the
Campy spindle if I can.

My question is, how much longer does the spindle need to get on the
right side? And how should the derailleur be able to be positioned over
the inner chainring, centered?

And if you really know your Campagnolo, which spindle can I use?


Can you put a 2mm spacer under the right cup? Cheaper than a
vintage spindle.

--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971
  #5  
Old February 26th 05, 01:21 PM
dianne_1234
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Default

On Sat, 26 Feb 2005 03:38:44 GMT, "Bruce W.1"
wrote:

One other idea I had was to put some shim plates on the right spindle
end, so the crank arm wouldn't tighten down as far. Anybody here tried
this?


Yes, it's worked for me. I get about 2mm offset for a piece of drink
can wrapped to cover all four sides of the taper. I've done this
several times over the years and never had any trouble.
  #6  
Old February 26th 05, 01:22 PM
dianne_1234
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Posts: n/a
Default

On Sat, 26 Feb 2005 01:49:28 GMT, "Bruce W.1"
wrote:

I'm in the process of triplizing the front chainrings on my road bike.

I managed, just barely, to make the Willow triplizer fit on my existing
70's era Campy Nuovo Record bottom bracket spindle. Hurray! But my
enthusiasm was sooned crushed when I mounted my new triple front derailleur.

The derailleur doesn't go in far enough to center on the small inner
chairing, not even close. So it looks like the bottom bracket spindle
will need to be longer. Here's a drawing of the measurements that I took:
http://www.keystandard.com/75.jpg

I tried putting on a Shimano sealed cassette bottom bracket, but I
really didn't like the way it looked. I'd much rather just replace the
Campy spindle if I can.

My question is, how much longer does the spindle need to get on the
right side? And how should the derailleur be able to be positioned over
the inner chainring, centered?

And if you really know your Campagnolo, which spindle can I use?

Thanks for your help.



  #7  
Old February 26th 05, 10:49 PM
Mark Janeba
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Posts: n/a
Default

Bruce W.1 wrote:
Mark Janeba wrote:

[...]
Find what is stopping travel. Some part of the mechanism is coming in
contact with some other part or in contact with the frame. Remove
derailleur from the bike and judge whether some material can be safely
removed. A few seconds with the Dremel or a few minutes with a needle
file will do the trick.


Good suggestion. I contemplated that a few hours ago, then told myself
I must be crazy. I could shave a wee bit off the Campy Racing
derailleur.


Worked for me, several thousand miles ago. There was a lot of material
there that didn't appear to be adding any structural strength (a bulge,
actually, on the swing arm), so you don't need to be crazy.

I also considered taking the Dremel tool to my frame and
digging a hole where the derailler arm hits.


I wouldn't go there!

Mark Janeba

  #8  
Old February 27th 05, 01:41 AM
Bruce W.1
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Posts: n/a
Default

dianne_1234 wrote:


Yes, it's worked for me. I get about 2mm offset for a piece of drink
can wrapped to cover all four sides of the taper. I've done this
several times over the years and never had any trouble.

================================================== ==

Thanks all for your help. The job is done. Didn't need a new spindle
after all.

I made two shims out of an AOL mailing tin and put them on perpendicular
sides at the end of the spindle. This gave me 2.5 mm. Then I flattened
the ends of the derailleur arm (where the cable connects) with a Dremel
tool cutting wheel. This gave me about 1.5 mm. So I'm in good shape
now. She's ready for the road!
 




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