How to measure backspacing - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Hotrodding Basics
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 06-14-2006, 09:16 AM
Registered User
 
Last photo:
Join Date: Jan 2004
Location: Houston, TX
Age: 31
Posts: 126
Wiki Edits: 0

Thanks: 10
Thanked 0 Times in 0 Posts
How to measure backspacing

Let's use this image as an example:



Lets just say that this rim is 7" wide, and has 3" of backspacing.

I want to go to a 8" rim, and I need more backspacing for my car.... so if this rim were 8" wide with 3" backspacing - there would just be an extra inch sticking out on the front compared to a 7" rim, correct? Or it will have a "deeper dish"?

Just don't want to order the wrong stuff

Thanks,
Sean

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 06-14-2006, 09:22 AM
Registered User
 
Last photo:
Join Date: Nov 2004
Location: Cali
Posts: 994
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Backspacing is backspacing, no matter what the width of the rim. 3" of backspacing on an 8" rim would have your A dimension at 3", same as a 7" rim. If you want to move the inner edge of the rim inboard 1", get 4" of backspacing.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 06-14-2006, 01:09 PM
steve392's Avatar
just passin' thru
 
Last wiki edit: How to title a hot rod
Last journal entry: Willys - Body and Paint
Last photo:
Join Date: Feb 2005
Location: NJ
Posts: 272
Wiki Edits: 2

Thanks: 0
Thanked 6 Times in 6 Posts
stratt,

Quote:
so if this rim were 8" wide with 3" backspacing - there would just be an extra inch sticking out on the front compared to a 7" rim, correct? Or it will have a "deeper dish"?
Its like '67 says, the distance from the rim mounting surface to the inside edge of rim will still be the same regardless of overall rim width. You will just have "an extra inch sticking out on the front" and it will have a deeper dish when viewed from the outside of the rim.
Don't confuse backspace with wheel offset . Offset is the difference in distance between the centerline of the wheel and the mounting surface. For more info, go here:
http://www.rsracing.com/tech-wheel.html

hope this helps,
Steve
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 06-17-2006, 01:16 PM
Registered User
 
Last photo:
Join Date: Jan 2004
Location: Houston, TX
Age: 31
Posts: 126
Wiki Edits: 0

Thanks: 10
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by steve392
Don't confuse backspace with wheel offset . Offset is the difference in distance between the centerline of the wheel and the mounting surface.
I shouldn't have to worry about offset with my application, right? I think I found the rims I need at Jegs & Summit. The specs for the rims don't mention offset on either website....
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 06-19-2006, 07:40 AM
steve392's Avatar
just passin' thru
 
Last wiki edit: How to title a hot rod
Last journal entry: Willys - Body and Paint
Last photo:
Join Date: Feb 2005
Location: NJ
Posts: 272
Wiki Edits: 2

Thanks: 0
Thanked 6 Times in 6 Posts
No, you shouldn't have to worry about offset. It's just another term used for wheel dimensions. When ordering wheels, the backspace dimension is the one usually used. You should be fine.

Steve
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 06-21-2006, 02:47 AM
lust4speed's Avatar
Member
 
Last photo:
Join Date: Oct 2003
Location: Inland Empire, SOCAL
Posts: 424
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
And a 7" rim will be 8" wide, and an 8" rim will be a total of 9" wide since both aluminum and steel wheels average almost exactly 1/2" width from the inside bead area to the outside of the rim. Therefore an 8" rim with 3" of back spacing will have 6" from the mounting flange to the outside of the wheel (9" with 3" to the inside and 6" to the outside). So it doesn't hurt to take a straight edge from the mounting area and measure out both ways to insure that there is sufficient clearance for the planned wheel.
Reply With Quote Quick reply to this message

Recent Hotrodding Basics posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may 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
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
M-II, Dropped Spindles and Backspacing? GS Guy Suspension - Brakes - Steering 1 03-26-2005 06:46 PM
Wheels and backspacing Loup Suspension - Brakes - Steering 1 04-03-2004 03:30 AM
Corvette Ralley wheel backspacing edubois General Rodding Tech 3 03-14-2003 08:59 PM
measuring for backspacing christopher406 Suspension - Brakes - Steering 3 02-19-2003 10:54 PM
Wheel Backspacing Bill Ford Suspension - Brakes - Steering 2 11-09-2002 02:27 PM


All times are GMT -6. The time now is 01:51 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.