Scrub line ? Help please...

[Flywheel]

OK ON MY TRUCK STRAIGHT AXLE...
1. AXLE TO GROUND IS 6 3/4
2. WHEEL TO GROUND IS 4 1/4

SUBTRACT 2 FROM 1 =2 1/2

SO IF I WANT TO USE A 4" DROP I END UP WITH A NEG. # . ?[S

I NEED TO USE A BIGGER RIM /WHEEL ? TO GAIN SOME SCRUB ?
OR JUST USE LESS DROP ?[S
OR AM I MISSING SOMETHING ?
I AM
I WANTED TO GO WITH A 4" DROP FRONT AXLE TO PUT IT IN THE WEEDS !
MY FRONT BUMPER IS 16" OFF THE GROUND RIGHT NOW ! I KNOW ITS A TRUCK BUT IT IS NOT A 4X4 LOL

 

[ruggs]

Flywheel.
Thanks for the consideration of Scrub Line. You'll live longer. I will post something for you when I can that will give you a better understanding of the principals. You can still put it in the weeds and be safe..........ruggs

 

[donsrods]

Essentially it just refers to what would touch the ground if any of the four tires got a flat. Ideally, nothing should touch the ground in that situation.

With the low cars we sometimes build it is very hard to achieve that clearance. I've been guilty a few times myself of sinning in this regard.

Don

 

[EnglishBob]

 

[ruggs]

You boys are fast, I only left for a minute. If no tires were on the wheels, would anything touch the pavement?....ruggs

 

[Flywheel]

Drop axle

RIGHT NOW WITH THE SET UP IN IT NO. NOTHING WOULD TOUCH THE GROUND IF BOTH FRONT TIRES WHERE FLAT. I WOULD HAVE LIKE 2 IN. CLEARANCE.

BUT IF I PUT IN A 4: DROP AXLE ? THAT IS WHAT I WAS TRYING TO FIGURE OUT AND GOT ALL LOL

 

[Sam_Fear]

Lets stay with reality. How often have you had or even heard of someone having 2 flats at once??? - not including slashed tires from ex's.

So go with the pictures above allowing for 1 blown tire. Also consider front to back opposite corners - that can also grind a bumper into the ground on some vehicles.

If you only have a 4-1/4" sidewall, you have fairly short tires and that truck is gonna be harder to turn without power.

If you want to know what your axle clearance is with one flat, go flatten one tire and measure the lowest point on the axle.

What size tires are you running?

 

[Flywheel]

P 205-70-15

lets stay with reality. How often have you had or even heard of someone having 2 flats at once??? - not including slashed tires from ex's.

So go with the pictures above allowing for 1 blown tire. Also consider front to back opposite corners - that can also grind a bumper into the ground on some vehicles.

If you only have a 4-1/4" sidewall, you have fairly short tires and that truck is gonna be harder to turn without power.

If you want to know what your axle clearance is with one flat, go flatten one tire and measure the lowest point on the axle.

What size tires are you running?

p 205-70-15 is what is on it now...

 

[Sam_Fear]

p 205-70-15 is what is on it now...

For some reason I was thinking bias tires.....

Still, the taller the tire, the easier it will be to turn.

 

[Flywheel]

Tires

For some reason I was thinking bias tires.....

Still, the taller the tire, the easier it will be to turn.

TIRE SIZE ! Isn `t going to change my scrub line if it is measured when tire is flat it is the rim or wheel size that will make a diff .. or am i lost?

 

[Flywheel]

or

i could just pull 3 leafs out and run the stock straight axle !
or go with a mono spring ?
and a 3" drop axle and hope tire dosn`t come off the rim lol

i am right back to where i started [cl[S

 

[EnglishBob]

Unles it will affect your inspection or titling I'd do what you want.
If you want to be negative imagine how many cars on 'air' would be so wrong if the bags all collapsed at the same time.
here's mine.

 

[Flywheel]

my truck

i am talking about the front axle

 

[Flywheel]

Unles it will affect your inspection or titling I'd do what you want.
If you want to be negative imagine how many cars on 'air' would be so wrong if the bags all collapsed at the same time.
here's mine.

yeah !!thats what i am talking about. is the axle lower than the rim or wheel?
if it goes flat it will still be 1 in if rubber between the wheel and the road ...right
[cl sweet
i like the revers eye springs ! what are you puting that under?

 

[Sam_Fear]

EnglishBob - do you violate the scrub line (one flat) with that? It looks close, but not over the line.

Your right, tire size won't change scrub line by much. I got sidetracked on tire size - I run short tires on my F100 and it is a bear to turn at low speed.

Odds are, a 3" drop axle will be above scrub.

Remove 3 leafs and you'll likely be hitting the rubber stop constantly. You could mount the axle over the spring, but again you'll run into bump stop issues.

Do you like the big rim look? 17" rims, low pro tires, and the 4" drop axle would do it.

 

[Flywheel]

sam

not big on the big rim and low pro tires !
i would like to use the wheels i have ,may change the front runners?

i was looking at the axle flip but would cause oil pan issues... and some other prob.
so i have come to the conclusion .
3" drop with a mono spring or pull couple of the stockers out and play around till
i get it right .
the stock springs are very stiff ,so i could pull couple out and soften it up a little .
the mono spring and 3" drop would get me 4 or more i think .
the stock leaf pack has 6 leafs in it and measures 1 1/4 in. thick
the mono leaf, may give me oil pan issues also ?
i know what i want just have to figure out how to get it there..HA HA
HEY AT LEAST I AM TRYING !
I ALREADY HAVE DENT IN HEADER TUBE, FROM DRAG LINK ROD, Have to do some more figuring .

 

[EnglishBob]

EnglishBob - do you violate the scrub line (one flat) with that? It looks close, but not over the line.

Your right, tire size won't change scrub line by much. I got sidetracked on tire size - I run short tires on my F100 and it is a bear to turn at low speed.

Odds are, a 3" drop axle will be above scrub.

Remove 3 leafs and you'll likely be hitting the rubber stop constantly. You could mount the axle over the spring, but again you'll run into bump stop issues.

Do you like the big rim look? 17" rims, low pro tires, and the 4" drop axle would do it.

That was with 15" rims and without tyres it was too close for comfort so I changed to 16" rims but won't have them till Monday but will gladly take pics with the rims sans tyres.

 

[HOT40ROD]

TIRE SIZE ! Isn `t going to change my scrub line if it is measured when tire is flat it is the rim or wheel size that will make a diff .. or am i lost?

The NSRA inspector go by, if all four tires are flat. Nothing can be below the bottom edge of the rims except the exhaust.

 

[Flywheel]

Scrub

I WILL HAVE TO GIVE NOSTALGIA SID`s A CALL ...!
or go with a Gasser Theem....!

 

[Blue Eyed Devil]

I WILL HAVE TO GIVE NOSTALGIA SID`s A CALL ...!

That is a good idea. Sid is VERY informed on these matters and can give you just about any info you need on dropped axle setups. He's a really good guy to deal with, and is giving you info from experience - not just what he heard that his cousin's buddy's friend who might have been drunk said one time a few years ago...