Rebuilding on the cheap...

Or...

Purchase a 110 BCD 50t big ring???

I guess the real tech question is - will a twelve-tooth difference in
the big/middle ring allow the use of the LX FD I have?

Thanks again,

E.P.

Quoted message said:

I have a MTB project I'm doing in which I am trying to use what spares
are in my parts box, existing bike parts and trying to do everything as
simply and cheaply as possible.

With that background, here we go:

I have an old LX triple Biopace crankset, 48-38-28. I have a newer
FD-M580 LX front derailleur. Now, the learned among you will know what
my problem is immediately, but to you others, I have a problem that
needs solving. Seems that a ten-tooth spacing is no good with this FD,
as the inner cage hangs on the middle chainring when the thing is
mounted the proper distance away from the big ring's tallest teeth
(Biopace, the added complication)

Supposedly, I need twelve-tooth spacing from big-to-middle. My idea
was to spend some small amount of money and purchase a Sugino 36-tooth
middle ring. Please, you gurus out there - will this be the easy
fix-it I'm praying for?

I would try raising the front changer enough to clear first.
If you are unhappy with the shift response then try a new
ring.

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

A Muzi said:

Quoted message said:

I have a MTB project I'm doing in which I am trying to use what spares
are in my parts box, existing bike parts and trying to do everything as
simply and cheaply as possible.

With that background, here we go:

I have an old LX triple Biopace crankset, 48-38-28. I have a newer
FD-M580 LX front derailleur. Now, the learned among you will know what
my problem is immediately, but to you others, I have a problem that
needs solving. Seems that a ten-tooth spacing is no good with this FD,
as the inner cage hangs on the middle chainring when the thing is
mounted the proper distance away from the big ring's tallest teeth
(Biopace, the added complication)

Supposedly, I need twelve-tooth spacing from big-to-middle. My idea
was to spend some small amount of money and purchase a Sugino 36-tooth
middle ring. Please, you gurus out there - will this be the easy
fix-it I'm praying for?

I would try raising the front changer enough to clear first.
If you are unhappy with the shift response then try a new
ring.

Yeah, I did that. Shifted like "poo". Worse than poo, really.
Shifting to the larger from smaller rings sucked pretty bad, but
shifting from bigger to smaller sucked really, really bad. And yes,
those are precise, technical terms. 😉

Thanks for the tip - I'm kinda sorry it wasn't that easy.

E.P.

A Muzi said:

Quoted message said:

I have a MTB project I'm doing in which I am trying to use what spares
are in my parts box, existing bike parts and trying to do everything as
simply and cheaply as possible.

With that background, here we go:

I have an old LX triple Biopace crankset, 48-38-28. I have a newer
FD-M580 LX front derailleur. Now, the learned among you will know what
my problem is immediately, but to you others, I have a problem that
needs solving. Seems that a ten-tooth spacing is no good with this FD,
as the inner cage hangs on the middle chainring when the thing is
mounted the proper distance away from the big ring's tallest teeth
(Biopace, the added complication)

Supposedly, I need twelve-tooth spacing from big-to-middle. My idea
was to spend some small amount of money and purchase a Sugino 36-tooth
middle ring. Please, you gurus out there - will this be the easy
fix-it I'm praying for?

I would try raising the front changer enough to clear first.
If you are unhappy with the shift response then try a new
ring.

Yeah, I did that. Shifted like "poo". Worse than poo, really.
Shifting to the larger from smaller rings sucked pretty bad, but
shifting from bigger to smaller sucked really, really bad. And yes,
those are precise, technical terms. 😉

Thanks for the tip - I'm kinda sorry it wasn't that easy.

E.P.

A Muzi said:

Quoted message said:

I have a MTB project I'm doing in which I am trying to use what spares
are in my parts box, existing bike parts and trying to do everything as
simply and cheaply as possible.

With that background, here we go:

I have an old LX triple Biopace crankset, 48-38-28. I have a newer
FD-M580 LX front derailleur. Now, the learned among you will know what
my problem is immediately, but to you others, I have a problem that
needs solving. Seems that a ten-tooth spacing is no good with this FD,
as the inner cage hangs on the middle chainring when the thing is
mounted the proper distance away from the big ring's tallest teeth
(Biopace, the added complication)

Supposedly, I need twelve-tooth spacing from big-to-middle. My idea
was to spend some small amount of money and purchase a Sugino 36-tooth
middle ring. Please, you gurus out there - will this be the easy
fix-it I'm praying for?

I would try raising the front changer enough to clear first.
If you are unhappy with the shift response then try a new
ring.

Yeah, I did that. Shifted like "poo". Worse than poo, really.
Shifting to the larger from smaller rings sucked pretty bad, but
shifting from bigger to smaller sucked really, really bad. And yes,
those are precise, technical terms. 😉

Thanks for the tip - I'm kinda sorry it wasn't that easy.

E.P.

A Muzi said:

Quoted message said:

I have a MTB project I'm doing in which I am trying to use what spares
are in my parts box, existing bike parts and trying to do everything as
simply and cheaply as possible.

With that background, here we go:

I have an old LX triple Biopace crankset, 48-38-28. I have a newer
FD-M580 LX front derailleur. Now, the learned among you will know what
my problem is immediately, but to you others, I have a problem that
needs solving. Seems that a ten-tooth spacing is no good with this FD,
as the inner cage hangs on the middle chainring when the thing is
mounted the proper distance away from the big ring's tallest teeth
(Biopace, the added complication)

Supposedly, I need twelve-tooth spacing from big-to-middle. My idea
was to spend some small amount of money and purchase a Sugino 36-tooth
middle ring. Please, you gurus out there - will this be the easy
fix-it I'm praying for?

I would try raising the front changer enough to clear first.
If you are unhappy with the shift response then try a new
ring.

Yeah, I did that. Shifted like "poo". Worse than poo, really.
Shifting to the larger from smaller rings sucked pretty bad, but
shifting from bigger to smaller sucked really, really bad. And yes,
those are precise, technical terms. 😉

Thanks for the tip - I'm kinda sorry it wasn't that easy.

E.P.