Minimum difference between chainrings on 130 BCD cranks

[[email protected]]

What is the minimum difference between chainrings that will work
acceptably with double chainring front derailleurs? I have an old
crank I want to use on my cross bike and tried using 40 and 42 but the
derailleur did not have enough clearance to shift up to the 42 from the
40.

 

[Nick Payne]

I've used 39-42 chainrings successfully with a Campagnolo Nuovo Record front
derailleur...

<[email protected]> wrote in message
news:[email protected]...
> What is the minimum difference between chainrings that will work
> acceptably with double chainring front derailleurs? I have an old
> crank I want to use on my cross bike and tried using 40 and 42 but the
> derailleur did not have enough clearance to shift up to the 42 from the
> 40.
>

 

[Qui si parla Campagnolo]

[email protected] wrote:
> What is the minimum difference between chainrings that will work
> acceptably with double chainring front derailleurs? I have an old
> crank I want to use on my cross bike and tried using 40 and 42 but the
> derailleur did not have enough clearance to shift up to the 42 from the
> 40.

I'm thinking about 4 teeth...before ya gotta raise the FD to keep it
from hitting the small ring whilst on the big...

 

[[email protected]]

[email protected] wrote:
> What is the minimum difference between chainrings that will work
> acceptably with double chainring front derailleurs? I have an old
> crank I want to use on my cross bike and tried using 40 and 42 but the
> derailleur did not have enough clearance to shift up to the 42 from the
> 40.

I've used bikes with the front derailleur mounted a hlaf inch above the
outer chainring and never noticed any problems. So you can use
chainrings with just 1 tooth difference or even 0 tooth difference and
it will work just fine. My loaded touring bike has half step gearing,
45-42 outer and middle rings. I use a Sora double front derailleur.
Its mounted about 1/4" or so above the outer ring. Works just fine.

I've looked at Peter White's TA page and wondered what it would be like
to put together a TA Zephyr triple crankset with 110/74 bcd with
34-33-32 rings. 34 and 33 being the 110mm bcd and 32 being the 74mm
bcd.

 

[* * Chas]

<[email protected]> wrote in message
news:[email protected]...
> [email protected] wrote:
> > What is the minimum difference between chainrings that will work
> > acceptably with double chainring front derailleurs? I have an old
> > crank I want to use on my cross bike and tried using 40 and 42 but
the
> > derailleur did not have enough clearance to shift up to the 42 from
the
> > 40.
>
> I've used bikes with the front derailleur mounted a hlaf inch above
the
> outer chainring and never noticed any problems. So you can use
> chainrings with just 1 tooth difference or even 0 tooth difference and
> it will work just fine. My loaded touring bike has half step gearing,
> 45-42 outer and middle rings. I use a Sora double front derailleur.
> Its mounted about 1/4" or so above the outer ring. Works just fine.
>
> I've looked at Peter White's TA page and wondered what it would be
like
> to put together a TA Zephyr triple crankset with 110/74 bcd with
> 34-33-32 rings. 34 and 33 being the 110mm bcd and 32 being the 74mm
> bcd.
>

I've run 49/45 1/2 step gearing on a lot of bikes. 4 or 5 teeth
difference seems to work without any problems.

Chas.

 

[John Forrest Tomlinson]

On 7 Nov 2006 09:00:46 -0800, [email protected] wrote:

>I've looked at Peter White's TA page and wondered what it would be like
>to put together a TA Zephyr triple crankset with 110/74 bcd with
>34-33-32 rings. 34 and 33 being the 110mm bcd and 32 being the 74mm
>bcd.

Can you build a ten-speed 11-21 cassette for the back?
--
JT
****************************
Remove "remove" to reply
Visit http://www.jt10000.com
****************************

 

[[email protected]]

John Forrest Tomlinson wrote:
> On 7 Nov 2006 09:00:46 -0800, [email protected] wrote:
>
> >I've looked at Peter White's TA page and wondered what it would be like
> >to put together a TA Zephyr triple crankset with 110/74 bcd with
> >34-33-32 rings. 34 and 33 being the 110mm bcd and 32 being the 74mm
> >bcd.
>
> Can you build a ten-speed 11-21 cassette for the back?

Why build it? Why not just buy a Record 11-21 10 speed ti/steel
cassette and be done with it? Lot simpler. But a 11-21 is not a
straight block. 11-12-13-14-15-16-17-18-19-21. Missing the 20 tooth.

Whereas a Veloce 14-23 10 speed cassette is a true straight block.
14-15-16-17-18-19-20-21-22-23. And a 14-23 seems more appropriate with
a 34-33-32 crankset. Going for the low gears, not the high ones using
an 11 cog.

You cannot build a true 10 cog straight block with Campagnolo beginning
with a 11, 12, or 13 cog. The last cog on Campagnolo 10 speed has to
be bent towards the spokes. Veloce loose last cogs are only available
in 23, 25, 26, and 29. All other groupsets from Campagnolo have the
last cog as part of a 2 or 3 or 4 spider cluster. And none of these
clusters have consecutive cogs as the last two cogs.






> --
> JT
> ****************************
> Remove "remove" to reply
> Visit http://www.jt10000.com
> ****************************