Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 07-29-05, 09:38 AM   #1
Doug Campbell
Senior Member
Thread Starter
 
Doug Campbell's Avatar
 
Join Date: Aug 2004
Location: Tucson, AZ
Bikes:
Posts: 110
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I have just swapped the 105 crank on my Trek 520 for an LX crank (44/32/22). The 105 derailler works OK, but I suspect that an LX or XT derailler which is sized for the smaller chainrings would work better. When I checked out deraillers, I saw that Shimano makes LX/XT front deraillers in "top swing" and "bottom swing". What's the difference? Which do I need> Thanks.

OOPS SORRY! FOUND ANSWER IN FORUM AFTER DOING A SEARCH.

Last edited by Doug Campbell; 07-29-05 at 09:46 AM. Reason: found answer
Doug Campbell is offline   Reply With Quote
Old 07-29-05, 09:53 AM   #2
Mentor58
'Mizer Cats are INSANE
 
Mentor58's Avatar
 
Join Date: May 2005
Location: Clarksville, TN
Bikes: C-dale T800
Posts: 808
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Doug Campbell
I have just swapped the 105 crank on my Trek 520 for an LX crank (44/32/22). The 105 derailler works OK, but I suspect that an LX or XT derailler which is sized for the smaller chainrings would work better. When I checked out deraillers, I saw that Shimano makes LX/XT front deraillers in "top swing" and "bottom swing". What's the difference? Which do I need> Thanks.

OOPS SORRY! FOUND ANSWER IN FORUM AFTER DOING A SEARCH.
Ah, but be advised, as I learned, that you can't toss in a MTB front derailler and expect it to work with your indexed shifter. Has to do with the different amounts of cable pull between road and mt. FD's. (Thanks Sydney). Rivendell has a good little piece on setting up a 105 FD for use with MTB cranks, here's the link
Setting up 105 FD

I hope this helps.


Steve W.
Mentor58 is offline   Reply With Quote
Old 07-29-05, 12:53 PM   #3
sydney
Senior Member
 
sydney's Avatar
 
Join Date: Jan 2004
Bikes:
Posts: 9,428
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Mentor58
Ah, but be advised, as I learned, that you can't toss in a MTB front derailler and expect it to work with your indexed shifter. Has to do with the different amounts of cable pull between road and mt. FD's. (Thanks Sydney).
But there is no issue with an mtb FD if his 520 has barends or downtube shifters.
sydney is offline   Reply With Quote
Old 07-29-05, 05:25 PM   #4
Doug Campbell
Senior Member
Thread Starter
 
Doug Campbell's Avatar
 
Join Date: Aug 2004
Location: Tucson, AZ
Bikes:
Posts: 110
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
THANKS FOR THE INPUT! For the record, I have bar-end shifters. So indexing will not be a problem.
Doug Campbell is offline   Reply With Quote
Old 07-29-05, 09:28 PM   #5
Michel Gagnon
Year-round cyclist
 
Join Date: Apr 2002
Location: Montréal (Québec)
Bikes:
Posts: 3,023
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
In theory, the MTB derailleur would work better, but I'd suggest you save your dollars and keep your 105. If your chain falls off the small ring sometimes, just lower it a bit and turn it sideways (a bit) so that the bottom part sticks out a bit more than the top part.

For your information, I'm using 44-34-22 with the original 105 derailleur and bar-end shifters. After some 15 000-20 000 km, no problems to report. The only slow shift is when I upshift from the granny to the middle ring.
Michel Gagnon is offline   Reply With Quote
Old 07-30-05, 09:02 PM   #6
rmfnla
Senior Member
 
rmfnla's Avatar
 
Join Date: May 2005
Location: La La Land (We love it!)
Bikes: Gilmour road, Curtlo road; both steel (of course)
Posts: 6,049
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 156 Post(s)
Quote:
Originally Posted by sydney
But there is no issue with an mtb FD if his 520 has barends or downtube shifters.
Are you sure about this? Barends and DT shifters are regulated the same as "brifters"; for road FDs, and that is not the same as an MTB FD.
__________________
Today, I believe my jurisdiction ends here...
rmfnla is offline   Reply With Quote
Old 07-31-05, 07:04 AM   #7
sydney
Senior Member
 
sydney's Avatar
 
Join Date: Jan 2004
Bikes:
Posts: 9,428
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by rmfnla
Are you sure about this? Barends and DT shifters are regulated the same as "brifters"; for road FDs, and that is not the same as an MTB FD.
Yeah, sydney is sure,and wasn't smoking carpet when composing that blurb. Barends and downtube front shifters are friction ! They don't know the difference in arm length, type or brand of the FD. There was one exception I ever saw and that was a set of 6 speed shimano downtubes that did have a friction and INDEX mode for the front lever. Obviously , in the friction mode, it would make no difference if the FD was road or mtb or even some other brand.
sydney is offline   Reply With Quote
Old 07-31-05, 08:14 AM   #8
Doug Campbell
Senior Member
Thread Starter
 
Doug Campbell's Avatar
 
Join Date: Aug 2004
Location: Tucson, AZ
Bikes:
Posts: 110
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Yes, Sidney. Front shifter is friction and rear shifter is either friction or indexed. However, have managed to get the 105 derailler working perfectly. Thanks.
Doug Campbell is offline   Reply With Quote
Old 08-01-05, 08:25 AM   #9
rmfnla
Senior Member
 
rmfnla's Avatar
 
Join Date: May 2005
Location: La La Land (We love it!)
Bikes: Gilmour road, Curtlo road; both steel (of course)
Posts: 6,049
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 156 Post(s)
Quote:
Originally Posted by sydney
Yeah, sydney is sure,and wasn't smoking carpet when composing that blurb. Barends and downtube front shifters are friction ! They don't know the difference in arm length, type or brand of the FD. There was one exception I ever saw and that was a set of 6 speed shimano downtubes that did have a friction and INDEX mode for the front lever. Obviously , in the friction mode, it would make no difference if the FD was road or mtb or even some other brand.
Ohmighod, I can't believe I missed that; of course thay are friction , and of course it makes no difference.
__________________
Today, I believe my jurisdiction ends here...
rmfnla is offline   Reply With Quote
Old 08-01-05, 08:33 AM   #10
sydney
Senior Member
 
sydney's Avatar
 
Join Date: Jan 2004
Bikes:
Posts: 9,428
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by rmfnla
Ohmighod, I can't believe I missed that; of course thay are friction , and of course it makes no difference.
Ya gotta lay off the carpet dude,otherwise you are doomed to becoming just another nose picking muppet.
sydney is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 09:02 AM.