Replacement 11-1/4 Inch Rear Brake Rotor

#91031039

Replacement 11-1/4 Inch Rear Brake Rotor

Name: Replacement 11-1/4 Inch Rear Brake Rotor
Brand: Speedway Motors
SKU: 91031039
Price: 77.99 USD
Availability: InStock
Rating: 5 (22 reviews)

22 Reviews

9 Questions

Premium cast iron vented rotor design reduces brake fade and extends service life
These 11-1/4" rotors feature dual wheel bolt patterns to fit 5 on 4-1/2" and 5 on 4-3/4" axles
These are compatible with axle flange diameters of 6-1/4" or smaller

$77.99

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Product Summary

Universal Fit, Rear Position, Round Rotor Shape, Plain

Premium cast iron vented rotor design reduces brake fade and extends service life
These 11-1/4" rotors feature dual wheel bolt patterns to fit 5 on 4-1/2" and 5 on 4-3/4" axles
These are compatible with axle flange diameters of 6-1/4" or smaller
Center hole size is 2.78" ID but you can machine it larger to suit your needs
2.30" backspace works well with several bolt on rear brake brackets

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Key Specs

Rotor Diameter	11.25 Inch
Rotor Style	Plain Face
Rotor Material Type	Cast Iron
Rotor Thickness	1"
Bolt Pattern	5 on 4.5" \| 4.75"

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Installation Details

Installation Tips

Installation note:

The inside diameter of this rotor will accept an axle flange that has a diameter of 6-1/4" or smaller. If your axle flange exceeds 6-1/4" in diameter, you will need machine your axle flange to decrease your axle flange diameter to fit this rotor as necessary.

When utilizing an aftermarket axle with disc brake conversion kits, it may be necessary to reduce the diameter of the axle flange to a diameter necessary to adequately fit inside the required Clearance I.D. that the brake hat/brake rotor will require. (see above diagram for illustration)

This rotor has been designed for use with axles that have a 2.790" pilot. Aftermarket axles such as Currie have a 2.795" pilot and require the center hole of this rotor to be machined larger in order to fit. If you are using aftermarket axles with a 2.795" pilot, we offer Part # 91631039 with a 2.80" Center Hole Diameter that is better suited to these applications.

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Speedway Motors 91031039 Details

These 11-1/4" one-piece, vented iron disc brake rotors are for rear disc brake applications. Features dual bolt patterns for 5 x 4.5" (Ford/Mopar) and 5 x 4.75" (Chevy/GM) wheels.

Center Hole: 2.78"
Backspace: 2.30"
Maximum Axle Flange Diameter: 6-1/4"
Thickness: 1"
Thickness @ Center of Rotor: 0.236"

CA Prop 65

Speedway Motors 91031039 Specifications

KEY SPECS
MFG. Part #	91031039
Brand	Speedway Motors
Rotor Diameter	11.25 Inch
Rotor Style	Plain Face
Rotor Material Type	Cast Iron
Rotor Thickness	1"
Bolt Pattern	5 on 4.5" \| 4.75"

GENERAL
Position	Rear
Rotor Shape	Round
Rotor Type	Vented
Rotor Finish	Plain
Backspace	2.3"
Inside Diameter	2.78"
Flange Diameter	6.25"
Sold in Quantity	Each
Notes	Thickness at Center of Rotor: 0.236"

Ratings & Reviews

22 Reviews

Overall Assessment

Customers underscore the product's broad applicability, noting its compatibility with various models like the '69 El Camino, Ford 9", and G Body, amongst others. They laud its fitting perfection and ease of installation, with even higher-duty axles requiring only center hole diameter enlargement. The product's quality and manufacturing earn positive remarks, with users noticing its tight tolerances and great fit, improving safety with enhanced stopping power. Praiseworthy attributes also include the product's pricing, perceived to offer high value for money. The product's performance often leads customers not only to purchase again but also to recommend it for universal applications.

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22 reviews

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Nice parts

5.0

6 months ago

C fal

Ohio

Verified

85 g body. 9" tear works great with speedway brackets

Would Recommend

Heavy duty rotors

5.0

8 months ago

Ghost

Ohio

Verified

Brake conversion on g body. Nice rotors

Would Recommend

I would buy this again

5.0

11 months ago

Litnin

Phoenix

Verified

Rotors fit well on my S10 , don't forget to install longer wheel studs !

Would Recommend

brakes worked great

5.0

a year ago

gatlingun45

vero beach fl

Verified

The rotor worked great for my application

They will work.

5.0

4 years ago

Bob

Maywood, Ca.

Verified

Put on the rear of my 69 el camino. Fitted to ford 9".

Would Recommend

I would buy again

5.0

4 years ago

David

Port angeles wa

Verified

Great prices great product

Would Recommend

Yes

5.0

4 years ago

Bill

Wilmington,ohio

Verified

Perfect for universal applications

Would Recommend

I would buy this product again and again!

5.0

5 years ago

Tomcat

Dawsonville, Ga.

Verified

Well manufactured

Would Recommend

Would purchase again.

5.0

6 years ago

Art Butler

Lake City Fl.

Verified

Used them on a narrowed 9'' ford rear end with disk conversion that used 1979-1985 Cadillac rear calipers. Rotor offset, diameter and thickness were perfect fit. However, outside axle hole had to be enlarged a small amount and enlarged wheel stud holes to 39/64 to accept .615 Knurl 1/2''x 20 wheel studs. All and all this is Hot Rodding!

Would Recommend

If needed I would purchase again

5.0

7 years ago

Jim

Fritch Tx

Verified

Everything was great. Employees very professional

Would Recommend

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Showing 10 of 22 reviews

Questions & Answers

9 Questions • 9 Answers

Sort Questions

Can you tell me the measurement of the rotor sitting flat on the ground to the top of the hat. So the overall thickness?

by Kim

• 7 years ago

1 answer

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i have a 96 ss stock rear end with axles drilled to 5x 4.75 will thes directly bolt up

by martell

• 8 years ago

1 answer

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i am doing a weld on GM metric caliper bracket on my ford 9" i built for my G-body. my bolt pattern is 4 3/4 on 5. what are the stud hole sizes on this rotor? they need to be 1/2" for my application. and i can place the mount and caliper to fit this rotor.

by Blake

• 9 years ago

1 answer

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Will these rotors fit Currie axles, and if so, do the center holes have to be enlarged? What is the best way to enlarge register hole?

by Charles

• 9 years ago

1 answer

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Will these rotors work on a ford 9" with the "new" "big" style bearings? I know many work with the small bearing rear, but not many with the big. Looking at specifically clearance over the axle flange and then over the center snout of the axle thats typically used for centering the rotor (even though I am sure this universal rotor centers via the lug holes)

by RickT

• 11 years ago

1 answer

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are thees rotors available sloted

by groucho

• 12 years ago

1 answer

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do these rotors have provisions for internal emergency brakes? I'm trying to use these with explorer rear discs. thank you for your time.

by Tinker

• 14 years ago

1 answer

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ARE THESE A STOCK ROTOR & WHAT DO THEY FIT

by SMITTY

• 14 years ago

1 answer

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What size bolt holes are drilled?

by Rhino

• 15 years ago

1 answer

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9 of 9 questions shown