How to determine backset?
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sargentrs
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How to determine backset?
1970 F100 Sport Custom. When I got my truck it had 235/75-15's on it, stock wheels. I got a set of 265/75-15's on some Dodge 4wd wheels later on, what I have on it now. I really like the way the 265's look on it. I'll be putting some new mags and tires on it when I get through with the build and I was looking at wheel options online. How do you measure backset? Is it from the inside of the wheel mounting surface to the bead surface on the back side? And what was the "standard" factory wheel backset? I'm leaning toward a 265/60-17 tire and want to make sure I've got enough clearance when I pick out wheels. Thanks!
Randy
1970 F100 Sport Custom Limited LWB, 302cid, 3 on the tree. NO A/C, NO P/S, NO P/B. Currently in 1000 pcs while rebuilding. Project thread: http://www.fordification.com/forum/view ... 22&t=59995 Plan: 351w, C4, LSD, pwr front disc, p/s, a/c, bucket seats, new interior and paint.
1987 F-150 XLT Lariat, 5.0/C6 auto.
1970 F100 Sport Custom Limited LWB, 302cid, 3 on the tree. NO A/C, NO P/S, NO P/B. Currently in 1000 pcs while rebuilding. Project thread: http://www.fordification.com/forum/view ... 22&t=59995 Plan: 351w, C4, LSD, pwr front disc, p/s, a/c, bucket seats, new interior and paint.
1987 F-150 XLT Lariat, 5.0/C6 auto.
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forrestbump
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Re: How to determine backset?
Randy,
I start by placing the tire only (unmounted) in the wheel well to get a visual. With the truck on jack stands, I mark in chalk the tires footprint on the ground where I want it centered.
I than C clamp a yard stick vertically to the brake drum with the bottom of the yard stick touching the ground inside the chalk mark I previously drew. Measure from the edge of the yard stick to the edge of the chalk mark should give you a pretty good idea of back spacing.
It gives me a ball park idea, at best, knowing that my desired back spacing will have to be compromised by what wheels are available and their back spacing. Close is usually good enough.
I start by placing the tire only (unmounted) in the wheel well to get a visual. With the truck on jack stands, I mark in chalk the tires footprint on the ground where I want it centered.
I than C clamp a yard stick vertically to the brake drum with the bottom of the yard stick touching the ground inside the chalk mark I previously drew. Measure from the edge of the yard stick to the edge of the chalk mark should give you a pretty good idea of back spacing.
It gives me a ball park idea, at best, knowing that my desired back spacing will have to be compromised by what wheels are available and their back spacing. Close is usually good enough.
1970, 2WD, F-250, C/S, Dual Tanks, 390 FE (of course), C6, Power Steering, Power Disc Brakes, Dana 60 3.73, Sky View Blue, Ranger XLT
1970, 2WD, F-250, C/S, A/C, Dual Tanks, 390 FE (again, of course), C6, Power Steering, Power Disc Brakes, Dana 60 3.73, Wimbledon White & Sky View Blue, Ranger (almost twin brothers!)
"One of the greatest discoveries a man makes, one of his great surprises, is to find he can do what he was afraid he couldn't do" - Henry Ford
Larry
1970, 2WD, F-250, C/S, A/C, Dual Tanks, 390 FE (again, of course), C6, Power Steering, Power Disc Brakes, Dana 60 3.73, Wimbledon White & Sky View Blue, Ranger (almost twin brothers!)
"One of the greatest discoveries a man makes, one of his great surprises, is to find he can do what he was afraid he couldn't do" - Henry Ford
Larry
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fordman
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Re: How to determine backset?
i have read on this site. that you measure the back set by measurring from the face of the brake drum to the nearest object that would rub the tire. probably the wheel well of the bed. and that will give you the back set of the tire. when fully inflated mounted on the rim.
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sargentrs
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Re: How to determine backset?
Both good tips. Thanks guys!
Randy
1970 F100 Sport Custom Limited LWB, 302cid, 3 on the tree. NO A/C, NO P/S, NO P/B. Currently in 1000 pcs while rebuilding. Project thread: http://www.fordification.com/forum/view ... 22&t=59995 Plan: 351w, C4, LSD, pwr front disc, p/s, a/c, bucket seats, new interior and paint.
1987 F-150 XLT Lariat, 5.0/C6 auto.
1970 F100 Sport Custom Limited LWB, 302cid, 3 on the tree. NO A/C, NO P/S, NO P/B. Currently in 1000 pcs while rebuilding. Project thread: http://www.fordification.com/forum/view ... 22&t=59995 Plan: 351w, C4, LSD, pwr front disc, p/s, a/c, bucket seats, new interior and paint.
1987 F-150 XLT Lariat, 5.0/C6 auto.
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BobbyFord
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Re: How to determine backset?
You can easily go 5" of backspacing on the rear if you don't get too wild with the tire tread width. I have 325mm of tread width on 10" rims with 5" of backspacing and it cleared the left side but not the right due to rear housing offset. The left side missed clearing by about 3/4"-1".
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sargentrs
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Re: How to determine backset?
Thanks Bobby. What are you running on the front?
Randy
1970 F100 Sport Custom Limited LWB, 302cid, 3 on the tree. NO A/C, NO P/S, NO P/B. Currently in 1000 pcs while rebuilding. Project thread: http://www.fordification.com/forum/view ... 22&t=59995 Plan: 351w, C4, LSD, pwr front disc, p/s, a/c, bucket seats, new interior and paint.
1987 F-150 XLT Lariat, 5.0/C6 auto.
1970 F100 Sport Custom Limited LWB, 302cid, 3 on the tree. NO A/C, NO P/S, NO P/B. Currently in 1000 pcs while rebuilding. Project thread: http://www.fordification.com/forum/view ... 22&t=59995 Plan: 351w, C4, LSD, pwr front disc, p/s, a/c, bucket seats, new interior and paint.
1987 F-150 XLT Lariat, 5.0/C6 auto.
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BobbyFord
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Re: How to determine backset?
I think they're 4" backspace, 15X8, but I'm changing to 15X7, with 3 3/4" backspace.sargentrs wrote:Thanks Bobby. What are you running on the front?
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sargentrs
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Re: How to determine backset?
That sounds sharp. Thanks, that gives me a ballpark to work with.
Randy
1970 F100 Sport Custom Limited LWB, 302cid, 3 on the tree. NO A/C, NO P/S, NO P/B. Currently in 1000 pcs while rebuilding. Project thread: http://www.fordification.com/forum/view ... 22&t=59995 Plan: 351w, C4, LSD, pwr front disc, p/s, a/c, bucket seats, new interior and paint.
1987 F-150 XLT Lariat, 5.0/C6 auto.
1970 F100 Sport Custom Limited LWB, 302cid, 3 on the tree. NO A/C, NO P/S, NO P/B. Currently in 1000 pcs while rebuilding. Project thread: http://www.fordification.com/forum/view ... 22&t=59995 Plan: 351w, C4, LSD, pwr front disc, p/s, a/c, bucket seats, new interior and paint.
1987 F-150 XLT Lariat, 5.0/C6 auto.
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sargentrs
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Re: How to determine backset?
Found this..... http://www.ehow.com/how_6814385_measure ... ckset.html
Randy
1970 F100 Sport Custom Limited LWB, 302cid, 3 on the tree. NO A/C, NO P/S, NO P/B. Currently in 1000 pcs while rebuilding. Project thread: http://www.fordification.com/forum/view ... 22&t=59995 Plan: 351w, C4, LSD, pwr front disc, p/s, a/c, bucket seats, new interior and paint.
1987 F-150 XLT Lariat, 5.0/C6 auto.
1970 F100 Sport Custom Limited LWB, 302cid, 3 on the tree. NO A/C, NO P/S, NO P/B. Currently in 1000 pcs while rebuilding. Project thread: http://www.fordification.com/forum/view ... 22&t=59995 Plan: 351w, C4, LSD, pwr front disc, p/s, a/c, bucket seats, new interior and paint.
1987 F-150 XLT Lariat, 5.0/C6 auto.
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sargentrs
- 100% FORDified!
- Posts: 9866
- Joined: Fri Jun 22, 2007 9:30 am
- Location: Georgia, Jasper
Re: How to determine backset?
Good, detailed explanation of wheel terminology a friend found for me. I hate it when a chebbie guy has to explain something to me and says, "I don't know about Ford but on a GM product......." http://www.chevellestuff.com/tech/wheel_offset.htm
Randy
1970 F100 Sport Custom Limited LWB, 302cid, 3 on the tree. NO A/C, NO P/S, NO P/B. Currently in 1000 pcs while rebuilding. Project thread: http://www.fordification.com/forum/view ... 22&t=59995 Plan: 351w, C4, LSD, pwr front disc, p/s, a/c, bucket seats, new interior and paint.
1987 F-150 XLT Lariat, 5.0/C6 auto.
1970 F100 Sport Custom Limited LWB, 302cid, 3 on the tree. NO A/C, NO P/S, NO P/B. Currently in 1000 pcs while rebuilding. Project thread: http://www.fordification.com/forum/view ... 22&t=59995 Plan: 351w, C4, LSD, pwr front disc, p/s, a/c, bucket seats, new interior and paint.
1987 F-150 XLT Lariat, 5.0/C6 auto.