Chain rub on inside of Front Derailleur

Hello,

I am leaving on loaded tour next week and won' t have time to
take my bike to the shop before I go to fix this little problem I have.

My bike is MTB w/ 22-32-42 Crankset and seven speed
13-15-17-20-23-26-30
rear cassette. FD is Shimano Nexave and RD is Deore LX. Everything is
fine except

when I am on 32 front and 30 in the back the chain rub against the
left-side inner
surface of the FD cage. Can you explain how I can adjust this?

I think I can get similar/same gear using 22 front + 20(?) on rear and
I guess I can
use that if I need that particular gear, but IF I wanted to get this
fixed on the road, I would at least like to leave w/ some knowledge of
how I can fix this

Thank you. Have a good day.

wrote in message
ups.com...
Hello,

I am leaving on loaded tour next week and won' t have time to
take my bike to the shop before I go to fix this little problem I have.

My bike is MTB w/ 22-32-42 Crankset and seven speed
13-15-17-20-23-26-30
rear cassette. FD is Shimano Nexave and RD is Deore LX. Everything is
fine except

when I am on 32 front and 30 in the back the chain rub against the
left-side inner
surface of the FD cage. Can you explain how I can adjust this?

No.

I think I can get similar/same gear using 22 front + 20(?) on rear and
I guess I can
use that if I need that particular gear, but IF I wanted to get this
fixed on the road, I would at least like to leave w/ some knowledge of
how I can fix this

Thank you. Have a good day.

Assuming you're on a 26 x 1.25 MTB tire with a 170 mm crank length, your
gear inches with the 32 front, 30 rear measure out at 26.1 gear inches.
Your 22 - 20 will be close at 26.9 gear inches.

Sheldon Brown, Bike Genius would prefer we use gain ratios, and in honour of
him I offer the following gain ratio data:
32 front, 30 rear = 2.0
22 front 20 rear = 2.0

So if you go by gain ratios you are right on the money! You can do the
calculations yourself and personalize the data more precisely he
http://sheldonbrown.com/gears/

You're welcome. You too.
--
Snippy the Bobcat

If you're using e click shift front derailleur, your olny option is to
try o adjust cable tension so that you get no rub in any of your cogs.
No tan easy mission. I know.

That's why I went the easier route; I went back to my bar-end shifters
with friction shifting in the front so I could make adjustments for
chain deflection.

- -
Comments and opinions compliments of,
"Your Friendly Neighborhood Wheelman"

My web Site:
http://geocities.com/czcorner

To E-mail me:
ChrisZCorner "at" webtv "dot" net

"Chris Z The Wheelman" wrote in message
...
If you're using e click shift front derailleur, your olny option is to
try o adjust cable tension so that you get no rub in any of your cogs.
No tan easy mission. I know.

That's why I went the easier route; I went back to my bar-end shifters
with friction shifting in the front so I could make adjustments for
chain deflection.

Adjustments are sometimes not possible. If the inner ring is adjusted
not to rub then the outer ring will rub and vice versa. In these cases I
have taken a pair of pliers and effectively widened the cage to
eliminate the rub. It usually only requires a small tweak at the contact
point with the chain.

Phil H

wrote:
My bike is MTB w/ 22-32-42 Crankset and seven speed 13-15-17-20-23-26-30
rear cassette. FD is Shimano Nexave and RD is Deore LX. Everything is fine except
when I am on 32 front and 30 in the back the chain rub against the
left-side inner surface of the FD cage. Can you explain how I can adjust this?

I'm strictly a roadie who rides Campy, so please excuse my ignorance:
Is there no trim function on this MTB set-up? As a rule, do MTBs
shifters not have trim?

Have a great trip, by the way. Where are you headed? Regards, Roy Zipris

Roy Zipris wrote:
wrote:
My bike is MTB w/ 22-32-42 Crankset and seven speed 13-15-17-20-23-26-30
rear cassette. FD is Shimano Nexave and RD is Deore LX. Everything is fine except
when I am on 32 front and 30 in the back the chain rub against the
left-side inner surface of the FD cage. Can you explain how I can adjust this?

I'm strictly a roadie who rides Campy, so please excuse my ignorance:
Is there no trim function on this MTB set-up? As a rule, do MTBs
shifters not have trim?

Triggers from shimano and Sram do not have trim..you must start the FD
close enogh to the chain in small ring, biggest cog, tight, tight
cable, then shift and most times you will still get rub in middle ring
and at the cog ends...most likely not in bog ring, smallest cog but it
is finicky.

Have a great trip, by the way. Where are you headed? Regards, Roy Zipris