35x15x12.5 tire on a 8" wide rim possible??? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

kickinasphalt · 04-26-2004, 07:32 PM

Leaning toward 35x15x12.5 tires and need to know if an 8" rim is enough or do you need a 10"? Is there any advantages/disadvantages of going with an 8"? Thanks.

*1FaastC10* · 04-26-2004, 08:50 PM

8" is fine. you'll be able to air them down more for off road traction without worrying about blowing a bead as much as a wider wheel

Destructo · 04-26-2004, 08:57 PM

I have 33x12.5's on a 8" wheel, works great for off-road, not as great for on-road, I have to keep the rear tires down around 21psi on the road so that they don't wear in the middle too much.

**Stocker** · 04-27-2004, 12:15 AM

I realize guys run 12.5s on 8" rims, but I disagree with it. I think you'll find most tire people recommend 10.5s on 8" and 12.5s on 10". As suggested above, running a wider tire on a narrower rim pulls the beads too close together, which causes excessive center tread wear - the fix is to run lower than normal air pressure. Just my .02..... :p

IoWnZa · 04-27-2004, 03:22 AM

10

Chris_T · 04-27-2004, 11:26 AM

I've run both and I prefer an 8" rim offroad. Because of the bigger sidewall bulge you get less 'crap' wedging between the rim and the tire causing leaks. The tire wear is a non-issue - no matter what size rim it is on you need to find the correct air pressure for YOUR vehicle to get the proper footprint.

ryanroo · 04-27-2004, 01:43 PM

i run a 9.75 wheel on a 15 inch tire width. it works fine. i like the way the wheel tire combo looks with the narrower wheel. just make sure to test and adjust the pressure for the best wear and i think youll be fine with the 8"
Ryan

2wdBlazer · 04-27-2004, 02:35 PM

I run 15.50's on a 10 inch. You will have no problem running your combo.

kickinasphalt · 04-27-2004, 08:59 PM

I'm not really concerened about maximum traction and more concerened about tire wear (since this pickup would see a lot of gravel). It sounds like a 10" rim would be best for me. What is the proper offset for a 10" rim?

Joey-D · 04-28-2004, 01:15 AM

I ran 10" on 12.50" but see a lot of guys running 8". The tire taller of a 8" rim or is that just and optical illusion?

Joey-D · 04-28-2004, 01:22 AM

Hell anything is possible, I am running a 15 inch wide tire on a 14 inch rim, while my roommate has BFGoodrich All Terrians 31x10.50/15 (which actually measures 9.75 inch wide tread) on a pro comp 15x10 rim that measures 10.25 wide. So the Rim is actually 1/2" wider and it works fine, looks a little funny though, but just a little.

**JIMs70GMC** · 04-28-2004, 06:17 AM

A lot of it, from the above responses, has to do with the ratio of tread to side wall. A taller side wall allows for the narrower rim. I'd check out some manufacturers websites and see what they recommend as far as rim width. Also remember the 12.5 and 10.5 are the nominal side wall width not tread width. A 33/12.5R15 BFG all terrain has right at 10" of tread width. I had 325/60R15 BFGs on 15x10" rims and they had a hair over 11" of tread width they looked bigger than the 33s but were under 31" tall.

**JIMs70GMC** · 04-28-2004, 06:23 AM

I forgot and I'll post pics this evening. I have a set of 33s mounted on 4 rims which I thought were all 8.25" wide (these are 16.5" rims) One of the rims is actually a 9.75" rim. The only way I could tell was when they were laying in the back of my truck the tire on the 9.75 rim is taller(wider). Then I looked closer and could tell the rim was slightly different form the other three.

**JIMs70GMC** · 04-28-2004, 08:50 PM

These are 33/12.5r16.5 tires mounted on 8.25" and 9.75" rims. This first one has a 9/16 NF die in the foreground it's about 1/2" thick and will not slide under the straight edge:

**JIMs70GMC** · 04-28-2004, 08:51 PM

2

**JIMs70GMC** · 04-28-2004, 08:52 PM

8.25" rim:

**JIMs70GMC** · 04-28-2004, 08:52 PM

9.75" rim:

**Stocker** · 04-28-2004, 09:23 PM

Quote:

Originally posted by JIMs70GMC
I'd check out some manufacturers websites and see what they recommend as far as rim width.

Great advice - and one more small point. As a rough rule-of-thumb, rim width (inside bead-to-bead) should roughly match the tread width.

Destructo · 04-28-2004, 10:08 PM

Quote:

Originally posted by Joey-D
Hell anything is possible, I am running a 15 inch wide tire on a 14 inch rim, while my roommate has BFGoodrich All Terrians 31x10.50/15 (which actually measures 9.75 inch wide tread) on a pro comp 15x10 rim that measures 10.25 wide. So the Rim is actually 1/2" wider and it works fine, looks a little funny though, but just a little.

Yeah, I used to have 10.5" tires on 10" rims, then I got smart. I blew 2 beads in one day because of that stupid combo, I would not run 10" wheels with 31x10.5" tires, its asking for trouble.

04-26-2004, 07:32 PM	#1
kickinasphalt Registered User Join Date: Jan 2000 Location: North Dakota Posts: 351	35x15x12.5 tire on a 8" wide rim possible??? Leaning toward 35x15x12.5 tires and need to know if an 8" rim is enough or do you need a 10"? Is there any advantages/disadvantages of going with an 8"? Thanks. __________________ 1972 K-10 Longbox,6" lift w/35's/350/SM465/NP205/3.73 1972 C-10 Longbox,350/350 1998 Pontiac Grand Prix GTP FOR SALE: 1971 K-10 Longbox,350/SM465/NP205

04-26-2004, 08:57 PM	#3
Destructo Registered User Join Date: Sep 2003 Location: Lewisville, NC Posts: 1,836	I have 33x12.5's on a 8" wheel, works great for off-road, not as great for on-road, I have to keep the rear tires down around 21psi on the road so that they don't wear in the middle too much. __________________ 1985 Scottsdale Shortbed 4x4 Stout 350 with some "upgrades"-700r4-33x12.5" Mud Tires, Warn 8274-50 winch. 2005 Chevrolet Colorado Regular Cab 2wd 4-banger, 5 speed, Street Pack with 3.73 axle.

04-27-2004, 12:15 AM	#4
Stocker 20' Daredevil (Ret) Join Date: May 2003 Location: Jefferson State Posts: 13,575	I realize guys run 12.5s on 8" rims, but I disagree with it. I think you'll find most tire people recommend 10.5s on 8" and 12.5s on 10". As suggested above, running a wider tire on a narrower rim pulls the beads too close together, which causes excessive center tread wear - the fix is to run lower than normal air pressure. Just my .02..... :p __________________ - Mike - 1972 K20 LWB 350/350/205 RIP El Jay

04-27-2004, 03:22 AM	#5
IoWnZa Big Block Blazer Join Date: Sep 2003 Location: Ellsworth, ME. Posts: 509	10 __________________ [1985 Chevrolet K5 Blazer][454BBC][TH400][NP241][Dana 44][GM 12 Bolt w/ Eaton LSD][Hedman HTC Hedders][Dual 2.5" Stainless Steel Exhaust][Hedman Turbo Muffler's][Dual Spal's 14" Electric Fan's][32x11.50R15 BF Goodrich All Terrain TA KO's on 15x8 Rallys]

04-27-2004, 01:43 PM	#7
ryanroo Senior Member Join Date: Apr 2004 Location: sw colorado Posts: 2,720	i run a 9.75 wheel on a 15 inch tire width. it works fine. i like the way the wheel tire combo looks with the narrower wheel. just make sure to test and adjust the pressure for the best wear and i think youll be fine with the 8" Ryan __________________ 72 K20 12v build 72 K20 "parts truck" A place for your diesel swap questions

04-26-2004, 08:50 PM	#2
1FaastC10 Account Suspended Join Date: Oct 2002 Location: Elkhart, IN Posts: 6,400	8" is fine. you'll be able to air them down more for off road traction without worrying about blowing a bead as much as a wider wheel

04-27-2004, 11:26 AM	#6
Chris_T Registered User Join Date: May 2003 Location: Saskatoon, SK Posts: 44	I've run both and I prefer an 8" rim offroad. Because of the bigger sidewall bulge you get less 'crap' wedging between the rim and the tire causing leaks. The tire wear is a non-issue - no matter what size rim it is on you need to find the correct air pressure for YOUR vehicle to get the proper footprint.

04-27-2004, 02:35 PM	#8
2wdBlazer The Blazer King Join Date: Sep 2000 Location: Valrico, Fl (Tampa) Posts: 1,213	I run 15.50's on a 10 inch. You will have no problem running your combo. __________________ 72 2wd Blazer. Its the superbichinest, megacoolinest, superflowinest.

04-27-2004, 08:59 PM	#9
kickinasphalt Registered User Join Date: Jan 2000 Location: North Dakota Posts: 351	I'm not really concerened about maximum traction and more concerened about tire wear (since this pickup would see a lot of gravel). It sounds like a 10" rim would be best for me. What is the proper offset for a 10" rim? __________________ 1972 K-10 Longbox,6" lift w/35's/350/SM465/NP205/3.73 1972 C-10 Longbox,350/350 1998 Pontiac Grand Prix GTP FOR SALE: 1971 K-10 Longbox,350/SM465/NP205

04-28-2004, 01:15 AM	#10
Joey-D City's Articulation Ramp Join Date: Jan 2004 Location: St. Louis Missouri Posts: 452	I ran 10" on 12.50" but see a lot of guys running 8". The tire taller of a 8" rim or is that just and optical illusion? __________________ 85 K90 SWB Rockwells 46x19.5 on double beadlocks 20" lift 305/sm465/NP208 Toy 00 Silverado 2wd SWB 4.8 auto 3/4 drop slamair bags esclade rims Daily Driver 06 Harley Sporster 883 low 19?? Zamboni, Really I own a Zamboni! "If your gonna be stupid, then you better be tough."

04-28-2004, 01:22 AM	#11
Joey-D City's Articulation Ramp Join Date: Jan 2004 Location: St. Louis Missouri Posts: 452	Hell anything is possible, I am running a 15 inch wide tire on a 14 inch rim, while my roommate has BFGoodrich All Terrians 31x10.50/15 (which actually measures 9.75 inch wide tread) on a pro comp 15x10 rim that measures 10.25 wide. So the Rim is actually 1/2" wider and it works fine, looks a little funny though, but just a little. __________________ 85 K90 SWB Rockwells 46x19.5 on double beadlocks 20" lift 305/sm465/NP208 Toy 00 Silverado 2wd SWB 4.8 auto 3/4 drop slamair bags esclade rims Daily Driver 06 Harley Sporster 883 low 19?? Zamboni, Really I own a Zamboni! "If your gonna be stupid, then you better be tough."

04-28-2004, 06:17 AM	#12
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	A lot of it, from the above responses, has to do with the ratio of tread to side wall. A taller side wall allows for the narrower rim. I'd check out some manufacturers websites and see what they recommend as far as rim width. Also remember the 12.5 and 10.5 are the nominal side wall width not tread width. A 33/12.5R15 BFG all terrain has right at 10" of tread width. I had 325/60R15 BFGs on 15x10" rims and they had a hair over 11" of tread width they looked bigger than the 33s but were under 31" tall. __________________ 1970 K25, 8' stepside bed 350/465/205 44 up front, 60 in the rear 4.10s rolling on 33" Dunlop MTs 1986 K5, 350/465/208 Dana 60/14 bolt from a cucv 36" Super Swampers TSL/SX 1983 K20 w/ CUCV axles, 350/700R4/208 sitting on 37" Goodyears 1986 M1031 6.2 diesel, TH400/NP205 locker in the rear and a LS in the front, all stock for now..... 1986 K30, 350/400/205 dana 60 and 14 bolt. I kept the drivetrain. Body/bad and chassis are gone. 1981 K30, 350/465/205 dana 60 and dually 14 bolt. Has a G80, and a flat bed. Going to replace the flat bed. 1985 K20, 350/400/208 10 bolt and SF 14 bolt. I wonder where I can find some 1 tons. Hmmmmm

04-28-2004, 06:23 AM	#13
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	I forgot and I'll post pics this evening. I have a set of 33s mounted on 4 rims which I thought were all 8.25" wide (these are 16.5" rims) One of the rims is actually a 9.75" rim. The only way I could tell was when they were laying in the back of my truck the tire on the 9.75 rim is taller(wider). Then I looked closer and could tell the rim was slightly different form the other three. __________________ 1970 K25, 8' stepside bed 350/465/205 44 up front, 60 in the rear 4.10s rolling on 33" Dunlop MTs 1986 K5, 350/465/208 Dana 60/14 bolt from a cucv 36" Super Swampers TSL/SX 1983 K20 w/ CUCV axles, 350/700R4/208 sitting on 37" Goodyears 1986 M1031 6.2 diesel, TH400/NP205 locker in the rear and a LS in the front, all stock for now..... 1986 K30, 350/400/205 dana 60 and 14 bolt. I kept the drivetrain. Body/bad and chassis are gone. 1981 K30, 350/465/205 dana 60 and dually 14 bolt. Has a G80, and a flat bed. Going to replace the flat bed. 1985 K20, 350/400/208 10 bolt and SF 14 bolt. I wonder where I can find some 1 tons. Hmmmmm

04-28-2004, 08:50 PM	#14
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	compare pics These are 33/12.5r16.5 tires mounted on 8.25" and 9.75" rims. This first one has a 9/16 NF die in the foreground it's about 1/2" thick and will not slide under the straight edge: __________________ 1970 K25, 8' stepside bed 350/465/205 44 up front, 60 in the rear 4.10s rolling on 33" Dunlop MTs 1986 K5, 350/465/208 Dana 60/14 bolt from a cucv 36" Super Swampers TSL/SX 1983 K20 w/ CUCV axles, 350/700R4/208 sitting on 37" Goodyears 1986 M1031 6.2 diesel, TH400/NP205 locker in the rear and a LS in the front, all stock for now..... 1986 K30, 350/400/205 dana 60 and 14 bolt. I kept the drivetrain. Body/bad and chassis are gone. 1981 K30, 350/465/205 dana 60 and dually 14 bolt. Has a G80, and a flat bed. Going to replace the flat bed. 1985 K20, 350/400/208 10 bolt and SF 14 bolt. I wonder where I can find some 1 tons. Hmmmmm

04-28-2004, 08:51 PM	#15
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	With out die in pic 2 __________________ 1970 K25, 8' stepside bed 350/465/205 44 up front, 60 in the rear 4.10s rolling on 33" Dunlop MTs 1986 K5, 350/465/208 Dana 60/14 bolt from a cucv 36" Super Swampers TSL/SX 1983 K20 w/ CUCV axles, 350/700R4/208 sitting on 37" Goodyears 1986 M1031 6.2 diesel, TH400/NP205 locker in the rear and a LS in the front, all stock for now..... 1986 K30, 350/400/205 dana 60 and 14 bolt. I kept the drivetrain. Body/bad and chassis are gone. 1981 K30, 350/465/205 dana 60 and dually 14 bolt. Has a G80, and a flat bed. Going to replace the flat bed. 1985 K20, 350/400/208 10 bolt and SF 14 bolt. I wonder where I can find some 1 tons. Hmmmmm



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04-28-2004, 08:52 PM	#16
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	bulge 8.25" rim: __________________ 1970 K25, 8' stepside bed 350/465/205 44 up front, 60 in the rear 4.10s rolling on 33" Dunlop MTs 1986 K5, 350/465/208 Dana 60/14 bolt from a cucv 36" Super Swampers TSL/SX 1983 K20 w/ CUCV axles, 350/700R4/208 sitting on 37" Goodyears 1986 M1031 6.2 diesel, TH400/NP205 locker in the rear and a LS in the front, all stock for now..... 1986 K30, 350/400/205 dana 60 and 14 bolt. I kept the drivetrain. Body/bad and chassis are gone. 1981 K30, 350/465/205 dana 60 and dually 14 bolt. Has a G80, and a flat bed. Going to replace the flat bed. 1985 K20, 350/400/208 10 bolt and SF 14 bolt. I wonder where I can find some 1 tons. Hmmmmm

04-28-2004, 08:52 PM	#17
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	bulge 9.75" rim: __________________ 1970 K25, 8' stepside bed 350/465/205 44 up front, 60 in the rear 4.10s rolling on 33" Dunlop MTs 1986 K5, 350/465/208 Dana 60/14 bolt from a cucv 36" Super Swampers TSL/SX 1983 K20 w/ CUCV axles, 350/700R4/208 sitting on 37" Goodyears 1986 M1031 6.2 diesel, TH400/NP205 locker in the rear and a LS in the front, all stock for now..... 1986 K30, 350/400/205 dana 60 and 14 bolt. I kept the drivetrain. Body/bad and chassis are gone. 1981 K30, 350/465/205 dana 60 and dually 14 bolt. Has a G80, and a flat bed. Going to replace the flat bed. 1985 K20, 350/400/208 10 bolt and SF 14 bolt. I wonder where I can find some 1 tons. Hmmmmm

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