Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

Newb Torque Wrench Question

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.

Newb Torque Wrench Question

Old 03-04-05, 03:24 PM
  #1  
LSPlo
Always Riding
Thread Starter
 
Join Date: Feb 2005
Location: Biketown, USA
Posts: 134
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Newb Torque Wrench Question

http://www.performancebike.com/shop/search_results.cfm

What's the 3/8 drive vs. 1/4 drive. What does that mean? What's the difference?

Yeah yeah yeah....I'm a big n00b.
LSPlo is offline  
Old 03-04-05, 03:28 PM
  #2  
phantomcow2
la vache fantôme
 
phantomcow2's Avatar
 
Join Date: Aug 2004
Location: NH
Posts: 6,266
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
I believe that has to do with the head of the wrench. FOr instance a head with a 1/4 drive fits a socket with a square cut out of 1/4.
__________________
C://dos
C://dos.run
run.dos.run
phantomcow2 is offline  
Old 03-04-05, 04:51 PM
  #3  
Avalanche325
Senior Member
 
Avalanche325's Avatar
 
Join Date: Apr 2003
Location: Pasadena, CA
Posts: 3,162

Bikes: Litespeed Firenze / GT Avalanche

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Phantom is right. That is the size of the square hole on the socket that the wrench fits into.
Avalanche325 is offline  
Old 03-04-05, 04:58 PM
  #4  
Al1943
Senior Member
 
Join Date: Feb 2005
Location: Oklahoma
Posts: 9,438

Bikes: Trek 5500, Colnago C-50

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
This is why I'm sure our country has never been serious about going metric. The back side of all sockets, even the metric ones, have a square drive hole that is in fractional inches.
Al1943 is offline  
Old 03-04-05, 05:27 PM
  #5  
phantomcow2
la vache fantôme
 
phantomcow2's Avatar
 
Join Date: Aug 2004
Location: NH
Posts: 6,266
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
The country has never and likely will not be in our lifetimes.
__________________
C://dos
C://dos.run
run.dos.run
phantomcow2 is offline  
Old 03-04-05, 06:34 PM
  #6  
neil0502
My bike's better than me!
 
neil0502's Avatar
 
Join Date: Feb 2005
Location: Northern Colorado
Posts: 2,041

Bikes: (2) Moots Vamoots, (1) Cannondale T2000 tourer, (1) Diamondback Response Comp mtb

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Originally Posted by phantomcow2
The country has never and likely will not be in our lifetimes.
The trick is whether or not a Metric measurement is something you can "picture" without converting it first.

For example, do you have an idea of how big a 59cm seat tube is? Congratulations
neil0502 is offline  
Old 03-04-05, 06:39 PM
  #7  
Retro Grouch 
Senior Member
 
Retro Grouch's Avatar
 
Join Date: Feb 2004
Location: St Peters, Missouri
Posts: 29,164

Bikes: Catrike 559 I own some others but they don't get ridden very much.

Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 1107 Post(s)
Originally Posted by LSPlo
http://www.performancebike.com/shop/search_results.cfm

What's the 3/8 drive vs. 1/4 drive. What does that mean? What's the difference?

Yeah yeah yeah....I'm a big n00b.
On the surface it refers to the socket drive size, but it has a deeper meaning especially for torque wrenches. Components like crank bolts and bottom brackets usually require around 30 or 35 lb/ft of torque. Imagine a 30 pound weight on the end of a foot long wrench handle. That requires a medium hefty wrench with a 3/8" drive. Components like stems require around 12 lb/in of torque. That usually involves smaller fasteners that work better with a smaller 1/4" drive.

Can you use one torque wrench for both? Kinda, but it's pointless. To get an accurate torque reading, you need to use a torque wrench that includes your desired torque setting near the center of it's range. A 3/8" torque wrench won't be very accurate at 1 lb/ft of torque for installing a stem. It it's not going to be accurate, what's the point?
Retro Grouch is offline  
Old 03-04-05, 06:40 PM
  #8  
luke.harrison
Senior Member
 
Join Date: Jan 2005
Posts: 156
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
if you grow up with its not an issue...
I cant picture what 24" looks like.

Im gonna refrain from making anymore comments about the how the US system makes "sense".
luke.harrison is offline  
Old 03-04-05, 06:43 PM
  #9  
Brian
Senior Member
 
Brian's Avatar
 
Join Date: Nov 2004
Location: Between the mountains and the lake.
Posts: 16,683

Bikes: 8 bikes - one for each day of the week!

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
The metric system is easy, once you get the hang of it. But speed is a big ripoff. To see 120 (Km) on your speedo, and be going so slow. No fun.
Brian is offline  
Old 03-04-05, 06:46 PM
  #10  
Retro Grouch 
Senior Member
 
Retro Grouch's Avatar
 
Join Date: Feb 2004
Location: St Peters, Missouri
Posts: 29,164

Bikes: Catrike 559 I own some others but they don't get ridden very much.

Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 1107 Post(s)
Originally Posted by Al1943
This is why I'm sure our country has never been serious about going metric. The back side of all sockets, even the metric ones, have a square drive hole that is in fractional inches.
So what size engine does your car have? Bought any prescriptions lately? How about a bottle of booze? It's happening.
Retro Grouch is offline  
Old 03-04-05, 06:52 PM
  #11  
Retro Grouch 
Senior Member
 
Retro Grouch's Avatar
 
Join Date: Feb 2004
Location: St Peters, Missouri
Posts: 29,164

Bikes: Catrike 559 I own some others but they don't get ridden very much.

Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 1107 Post(s)
Originally Posted by luke.harrison
if you grow up with its not an issue...
I cant picture what 24" looks like.

Im gonna refrain from making anymore comments about the how the US system makes "sense".
I have a friend who bought some tulip bulbs from Holland. He planted them 24" deep or whatever he thought it said on the package. Seemed awful deep at the time. HELLO! Holland, like everybody but us is a metric country. 24" is 24 millimeters, about 1 inch not a whole foot. Surpriseingly, most of the bulbs eventually came up anyway, but they were late.
Retro Grouch is offline  
Old 03-04-05, 06:54 PM
  #12  
luke.harrison
Senior Member
 
Join Date: Jan 2005
Posts: 156
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
actaully what's funny in canada is everything is metric except the height and weight of a person. So i know how tall 6' is and how much 200 pounds is. But ask me how far a mile is and im screwed.
luke.harrison is offline  
Old 03-04-05, 07:01 PM
  #13  
Retro Grouch 
Senior Member
 
Retro Grouch's Avatar
 
Join Date: Feb 2004
Location: St Peters, Missouri
Posts: 29,164

Bikes: Catrike 559 I own some others but they don't get ridden very much.

Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 1107 Post(s)
Originally Posted by luke.harrison
actaully what's funny in canada is everything is metric except the height and weight of a person. So i know how tall 6' is and how much 200 pounds is. But ask me how far a mile is and im screwed.
200 pounds. That's 10 stone, right?
Retro Grouch is offline  
Old 03-04-05, 07:10 PM
  #14  
Al1943
Senior Member
 
Join Date: Feb 2005
Location: Oklahoma
Posts: 9,438

Bikes: Trek 5500, Colnago C-50

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Bicycles are not truly metric either. Steer tubes are 1 inch or 1 1/8 inch. Chains are one inch per link (1/2 inch pin to pin), and those are worldwide standards.

Al
Al1943 is offline  
Old 03-04-05, 07:18 PM
  #15  
Brian
Senior Member
 
Brian's Avatar
 
Join Date: Nov 2004
Location: Between the mountains and the lake.
Posts: 16,683

Bikes: 8 bikes - one for each day of the week!

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Originally Posted by Retro Grouch
On the surface it refers to the socket drive size, but it has a deeper meaning especially for torque wrenches. Components like crank bolts and bottom brackets usually require around 30 or 35 lb/ft of torque. Imagine a 30 pound weight on the end of a foot long wrench handle. That requires a medium hefty wrench with a 3/8" drive. Components like stems require around 12 lb/in of torque. That usually involves smaller fasteners that work better with a smaller 1/4" drive.

Can you use one torque wrench for both? Kinda, but it's pointless. To get an accurate torque reading, you need to use a torque wrench that includes your desired torque setting near the center of it's range. A 3/8" torque wrench won't be very accurate at 1 lb/ft of torque for installing a stem. It it's not going to be accurate, what's the point?
Most everything I need to torque on my bike is in inch/lbs. The torque wrenches themselves were all roughly the same price, but I went with 3/8 as that size had the widest variety of sockets in stock.
Brian is offline  
Old 03-04-05, 08:17 PM
  #16  
Rev.Chuck
The Red Lantern
 
Rev.Chuck's Avatar
 
Join Date: Apr 2003
Location: Raleigh NC
Posts: 5,965
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Torque wrenches are like peanuts and potato chips, you can't have just one.
__________________
Are you a registered member? Why not? click here to register. Its free, and only takes 27 seconds!
Help out the forums, abide by our community guidelines.

I am in the woods and I have gone crazy.
Rev.Chuck is offline  

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


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.