Cycling and bicycle racing discussion forums.   View New Forum Topics
Today's Forum Topics

Set as homepage


Go Back   Cycling Forums > Mountain Bikes > Tech Corner - Mountain Bike
User Name
Password
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read


Welcome to CyclingForums.com

You are currently viewing our website as a guest which gives you limited access to view most discussions. You will have to register before you can post to this thread.

By joining our free online community you will have access to post new topics, communicate privately with other cyclingforums.com members (PM), respond to polls, upload photos and access other special features like product reviews and classifieds.


48t crankset on mtb

Reply
 
Thread Tools Search this Thread Display Modes
Old 04-10.-2006, 10:51 PM   #1
cateye333
Registered User
 
Join Date: Sep 2006
Posts: 7
Question 48t crankset on mtb

I remembered shimano XT used to have 48t on the crankset for mtb, why did they stop making them? And i do find comfort or trekking mtb with 48t (which, in theory, are faster than an XTR )

i was thinking of switching the 44t crankset with a 48t to speed things up since i always find that there is no resistance left on a 44t-11t when i am cycling on the road/downhill. Any real advantage in speed or complications? Shd i or shdnt i? Any other options to speed up my mtb??

I dont usually do dirtjumps or stunts, just cross-country and occassional trails/bushes for fun. I do find 44t-32t pretty useful when going up almost any hill while xc; so if i change to a 48t i gonna lose that gear ratio...


Another matter, how do i know if i fit a 170,172 or 175mm on the crankset?


cheers

Last edited by cateye333 : 04-10.-2006 at 11:42 PM.
cateye333 is offline  
Reply With Quote
Old 04-10.-2006, 11:40 PM   #2
Scotty_Dog
Registered User
 
Scotty_Dog's Avatar
 
Join Date: Jul 2004
Posts: 742
Default Re: 48t crankset on mtb

For the same cadence, your speed should increase by 9.1% (48/44=1.091).

As far as complications, you might need a new front derailleur (or a grinding wheel if you're savvy).

Also check out this thread from forum member gclark8:
http://www.cyclingforums.com/showthread.php?t=363004
__________________
"There is alot of blather here that does not float the hooey barge." boudreaux 11/22/2005
Scotty_Dog is offline  
Reply With Quote
Old 05-10.-2006, 12:38 AM   #3
gclark8
Registered User
 
Join Date: Apr 2004
Location: Perth (Basso), West Australia
Posts: 3,508
Default Re: 48t crankset on mtb

It would help to know what brand and model the bike is, and what crankset is currently fitted. Shimano make many Triple cranksets with 48t big ring for MTB, I will try to find one that will fit your existing Bottom Bracket.

As for crank arm length how tall are you? However, not many to choose from with 48t, mainly 170mm and a few 175mm, again depending on BB type.
__________________
Cheers,
George.
gclark8 is offline  
Reply With Quote
Old 05-10.-2006, 02:57 PM   #4
cateye333
Registered User
 
Join Date: Sep 2006
Posts: 7
Default Re: 48t crankset on mtb

Quote:
Originally Posted by gclark8
It would help to know what brand and model the bike is, and what crankset is currently fitted. Shimano make many Triple cranksets with 48t big ring for MTB, I will try to find one that will fit your existing Bottom Bracket.

As for crank arm length how tall are you? However, not many to choose from with 48t, mainly 170mm and a few 175mm, again depending on BB type.


I've got a GT Zaskar Pro 2003 in Medium, and it has a XT hollow II in it ( i think its a 44,32,22). And i am 178cm; but my legs are kinda long...


Is 48t the largest for mtb? And i thought i coulkd just re-adjust the front derailleur slightly higher to accommodate the larger teeth
cateye333 is offline  
Reply With Quote
Old 05-10.-2006, 05:15 PM   #5
gclark8
Registered User
 
Join Date: Apr 2004
Location: Perth (Basso), West Australia
Posts: 3,508
Default Re: 48t crankset on mtb

For Deore XT Hollowtech II, 26/36/48 tooth a 170mm, 175mm or 180mm crankset is available. Ask for part number FC-M761 # the length of your choice.

See how you go with adjusting the height of the FD, however, if you have trouble getting up to the 48t smoothly, the angle between the chain stay and seat tube will need to be checked before ordering a new Front Derailleur:
for 63-66 degree use FD-M761-3
for 66-69 degree use FD-M761-6
(from the pix, it looks like 69 deg)

(See Page 178 of the 2005 Shimano Manual)

Print this out and take to your LBS.
__________________
Cheers,
George.

Last edited by gclark8 : 05-10.-2006 at 05:50 PM.
gclark8 is offline  
Reply With Quote

Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump



All times are GMT +10. The time now is 05:19 PM.


Powered by: vBulletin Copyright © 2000 - 2008, Jelsoft Enterprises Ltd.
Copyright © 2001 - 2006 cyclingforums.com

Links to websites we like:
Pezcyclingnews | Cyclingnews.com | Wine Zone | iinet