20x10 KMC Rockstars fit?? -25 offset 4.5 backspace

g356gear · 02-14-2007, 12:22 PM

I have been told that the KMC rockstars in a 20x10 are only available in -25 offset with a 4.5" backspacing. I want to run the Nitto Mud Grapplers with the rims in a 33" or 35" if they will clear with a PRG leveling kit and pinch mod. Any feedback on the fitment?? Thanks.

i<3mytitan · 02-14-2007, 12:31 PM

35s most likely won't fit. my friend has the prg 4 inch spindle lift and still needed to do the pinch weld mod to fit 35 muds with 20x10inch rims.

yscty · 02-17-2007, 08:50 PM

That wheel is really gonna have about 4" of backspacing because of the negative offset. Good luck.....

clm003 · 09-21-2009, 01:12 PM

I'm bringing back this thread because it's 100% relevant to me... I bought these identical rims used for a good price. I installed one but it rubs pretty bad after 1 full turn of the steering wheel. It seems that I will need more than just a pinch weld mod to make these work.

Also, they stick out like 2.5 inches. They look pretty badass but would require me to buy fender flares.

What are my options?

I think I'm going to buy some RBP 20" x 9" black/chrome rims (0 offset) and sell the Rockstars. I am going to keep the 33 x 12.5 x 20 Toyo OC MT rubber though.

Please ensure me that a 0 offset will fit with the 33 x 12.5s and a 9" wide instead of 10...

Thank you!

idiotsaray · 09-21-2009, 01:24 PM

i have the same problem with the offset i would look for a narrower rim with a 0 to plus offset but i would try and track down norcal4X4 or message him. he knows all about this stuff

$ickTitan · 09-21-2009, 09:57 PM

I have about 3.5'' of lift and I have 20X10 wheels with a -18mm offset. My tires are only 305/55/20 (33X12.50X20) and they rub at full turn. I gotta do the PWM mod most likely.

NorCal 4x4 · 09-22-2009, 02:34 AM

Quote:

Originally Posted by clm003

I'm bringing back this thread because it's 100% relevant to me... I bought these identical rims used for a good price. I installed one but it rubs pretty bad after 1 full turn of the steering wheel. It seems that I will need more than just a pinch weld mod to make these work.

Also, they stick out like 2.5 inches. They look pretty badass but would require me to buy fender flares.

What are my options?

I think I'm going to buy some RBP 20" x 9" black/chrome rims (0 offset) and sell the Rockstars. I am going to keep the 33 x 12.5 x 20 Toyo OC MT rubber though.

Please ensure me that a 0 offset will fit with the 33 x 12.5s and a 9" wide instead of 10...

Thank you!

Where did you see RBP 20x9's? All I saw were 20x10s and they were crazy expensive.

A 9" width rim with 0 mm of offset will have 5" backspacing. With -12 mm offset it has 4.5" of backspacing, and the tires can rub on on leveled Titan with 33.2" diameter LT295/70R17 Nitto Terra Grappler A/T. This tire has about the same 12-1/4" section width on a 9" width as a Toyo M/T. But they don't have as large of lugs at the shoulder as the Toyo M/T. So even though your 20x9 rims would stick out 1/2" less, they may rub some. With the pinch weld mod you could make it work, but they will stick out about 1-1/2" more than stock SE/LE rims ... 1" wider and 1/2" less backspacing.

Like idiotsaray mentioned, a narrower rim and 0 offset or positive offset is the way to go. That way you have the option of later running taller tires if you decide to. If I were to get a 9, it would have a a +18mm offset and therefore about 5.75" of backspace, and it would still stick out 3/4" more than the stock rims.
Here is an example of one that sort of reminded me of the RBP. Note the "18" for +18 mm offset in the header: "20X9 6-139.7 18B":
Liquid Metal Dyno - Discount Tire Direct

There are a few other 9" width wheels with +18 mm offset on these pages, +12 mm for a 5.5" backspacing would be fine too:
20x9" Wheel Products - Discount Tire Direct

A lot of the 12.5" width tires call for a minimum of an 8.5" width rim. For them I'd look for an offset of +6 mm to +18 mm giving 5" to 5.5" backspacing, respectively:
20x8.5" Wheel Products - Discount Tire Direct

Note: If you have or plan to buy the CST 4" spindles or a CST bracket lift, keep backspacing at 5" or less, for wide tires to avoid tire to spindle rub.

clm003 · 09-22-2009, 07:37 PM

Thank you NorCal, you're the shiz when it comes to this.

Here are my plans...

Near future: Buy 08 springs and bilstein 5100s to raise my front end an additional 2" (4" total lift with leveling kit). Run 2.5" spacer in rear and bilstein 5100 for a total of 3" lift in the rear.

I want to keep the toyo's and run the 94R 20x9 black&machined rim (New rim - they just came out with it). Also, to answer your question, they do sell 20x9... it's just an error on their website. Nick said he was going to get the computer boys at RBP to change that. I think I have attached photos of them (first time...)

If I need to buy UCAs i will...

I want to avoid running fender flares if at all possible. I don't want to chip my paint but I do like the look of the tires sticking out. Nick at RBP said that the rim he would cut for me would be 4.5" backspacing... -12 offset.

I don't think I want a +18 offset and am not sure if RBP will make that for me. I could possibly get them to cut a 0 offset. how much do I stick out over stock with:

+18?
0?
-12?
-25? (what I have now)

Distant future: Possibly go with a 4" spindle lift... I don't really want to run bigger than a 33" tire though so I doubt I will lift 8". If I wanted to lift a truck that high I'd buy a diesel so I can still get some mileage. CUMMINS TITAN!!

Thanks again for the help

NorCal 4x4 · 09-22-2009, 10:41 PM

Quote:

Originally Posted by clm003

Thank you NorCal, you're the shiz when it comes to this.

Here are my plans...

Near future: Buy 08 springs and bilstein 5100s to raise my front end an additional 2" (4" total lift with leveling kit). Run 2.5" spacer in rear and bilstein 5100 for a total of 3" lift in the rear.

I want to keep the toyo's and run the 94R 20x9 black&machined rim (New rim - they just came out with it). Also, to answer your question, they do sell 20x9... it's just an error on their website. Nick said he was going to get the computer boys at RBP to change that. I think I have attached photos of them (first time...)

If I need to buy UCAs i will...

I want to avoid running fender flares if at all possible. I don't want to chip my paint but I do like the look of the tires sticking out. Nick at RBP said that the rim he would cut for me would be 4.5" backspacing... -12 offset.

I don't think I want a +18 offset and am not sure if RBP will make that for me. I could possibly get them to cut a 0 offset. how much do I stick out over stock with:

+18?
0?
-12?
-25? (what I have now)

Distant future: Possibly go with a 4" spindle lift... I don't really want to run bigger than a 33" tire though so I doubt I will lift 8". If I wanted to lift a truck that high I'd buy a diesel so I can still get some mileage. CUMMINS TITAN!!

Thanks again for the help

No problem ... had coffee too late and couldn't sleep.

For the lift you'd be better off getting spindles right away. You can run your stock coilovers, or stock application ones, like the Icons, SAWs, or the 2" body Radflo, or any OEM compatible like the Bilstein HD with them, as well as leveling kits, and still use the stock UCA, unless going above their normal maximums. Sort of like a free 4".

Adding level kits to the coilovers is a bad idea ... check out these posts by PRG:
http://www.titantalk.com/forums/1193958-post36.html
http://www.titantalk.com/forums/1336280-post9.html

As for the offset on a 9" width rim, and how far the rims would stick out compared to stock:

+18? 3/4" more than stock SE/LE rims, (an inch more if you also count the tires' extra width, which stick out about 1/4" more, as far as section width). You'd likely have CST spindle rubbing with wide tires though with 5.75" backspacing.

0? Rims stick out 1.5" more than stock. Might not rub at the pinch weld. 5" backspacing. This would be my pick if I could run spindles.

-12? 2" more than stock ... pinch weld rubbing. 4.5" backspacing. Popular size for thr pinch weld mod, but shouldn't be too bad with 33s. With 35s even my friend's 6" PC stage 1 lifted Titan needed to cut a little with the old version of the 35x12.5R17 BFG M/T.

-25? Rims would stick out 2.5" more than stock, for a 9" width rim, and would have 4" backspacing. Bad idea.
But if you're talking about the 20x10s then 3" more than stock rims, and 4.5" backspacing. In this case, the backspacing accounts for an inch and the 2" wider width accounts for the other two inches.

Btw, nice looking rims ...

clm003 · 09-22-2009, 11:53 PM

I guess here's another question,

The rims I currently have are 20x10 -25 offset 4.5 backspacing. At 1 full turn of the steering wheel they begin to rub. It seems like A LOT of trimming is needed to make them fit. Is it possible to just run the rims I have with the lift I was planning? If I buy the spindle lift will they fit better?

Spindle lift question: Am I correct here?.. I can run a 4" spindle lift, stock UCAs, and keep my 2" leveling kit for a total of 6" of lift?
PROBLEM: Won't 33's look a little small with 6"? In that case, should I just run the 4" spindle and no leveling kit?

I think I screwed up in telling you the offset RBP was going to give me. They are planning on making a 20x9, 0 offset, which is 5" backspacing. I like the idea of a spindle lift now that you cleared things up. I am now leaning towards that route.

Also, I don't know if you are the expert here but I need some extra payload capacity for my truck because I'm always towing or hauling bricks in my box. Can I incorporate a add-a-leaf or a helper spring or new leafs into my lift? What are my options?

Thank you!

EDIT: My truck is 4x4... do they make spindle lifts for 4x4s?

NorCal 4x4 · 09-23-2009, 01:04 AM

Quote:

Originally Posted by clm003

I guess here's another question,

The rims I currently have are 20x10 -25 offset 4.5 backspacing. At 1 full turn of the steering wheel they begin to rub. It seems like A LOT of trimming is needed to make them fit. Is it possible to just run the rims I have with the lift I was planning? If I buy the spindle lift will they fit better?

Spindle lift question: Am I correct here?.. I can run a 4" spindle lift, stock UCAs, and keep my 2" leveling kit for a total of 6" of lift?
PROBLEM: Won't 33's look a little small with 6"? In that case, should I just run the 4" spindle and no leveling kit?

I think I screwed up in telling you the offset RBP was going to give me. They are planning on making a 20x9, 0 offset, which is 5" backspacing. I like the idea of a spindle lift now that you cleared things up. I am now leaning towards that route.

Also, I don't know if you are the expert here but I need some extra payload capacity for my truck because I'm always towing or hauling bricks in my box. Can I incorporate a add-a-leaf or a helper spring or new leafs into my lift? What are my options?

Thank you!

EDIT: My truck is 4x4... do they make spindle lifts for 4x4s?

Sorry, thought you had a 2wd ... No spindles for 4x4s. With the 4x4 bracket lifts, they have spindles but these are bracket lifts such as the ProComp, FabTech, Rancho, and the CST which has the same issue as their 2wd 4" spindle lift.

So your choices are a bracket lift or a 4" maximum coilover lift, and a harsh ride, or 3" like most of us run, so the ride is better.

If you want to run those 20x10's a bracket lift, good adjustable coilovers that are designed for bracket lifts, and some major trimming, because like you said 33s will look small on an 7 or 8 inch lift. I'd ditch the rims and get some that fit with a 3" lift, and your 33s will look fine.

As for the the heavy loading, I'd get some air bags so your suspension isn't affected except when you need them. There are also helper springs available, and threads here on both.

clm003 · 09-23-2009, 10:54 AM

Alright,

So what do I gotta do to get the extra inch that I don't have? Ditch the leveling kit and buy coilovers? If I have to go that route I might as well buy the 08 spring and keep my leveling kit. Will that work?

NorCal 4x4 · 09-23-2009, 10:25 PM

Quote:

Originally Posted by clm003

Alright,

So what do I gotta do to get the extra inch that I don't have? Ditch the leveling kit and buy coilovers? If I have to go that route I might as well buy the 08 spring and keep my leveling kit. Will that work?

With a '04-'07 4x4 you will need an aftermarket UCA to get that extra inch, because 2" maximum with the stock UCA. This can be done with some of the '08+ OEM coilovers, adjustable coilovers, or adjustable coilovers and a custom PRG spacer, (designed for it), but not coilovers and a leveling kit, (as Greg explained in his posts that I linked to, in my previous post #9).

Looks like you will need to add alignment cams too, if you don't already have them on your '05. This post also explains the '08+ coilovers:
http://www.titantalk.com/forums/1533298-post11.html

clm003 · 09-25-2009, 12:32 AM

Ok I don't know if I'm reading this right but if I run UCAs, 08 springs, and Bilstein 5100s (or stock shocks), I can still run my leveling kit? What kind of lift will that give me?

I'm not interested in aftermarket coilovers. I won't own the truck long enough to justify ANOTHER $1000.

NorCal 4x4 · 09-25-2009, 09:13 AM

Quote:

Originally Posted by clm003

Ok I don't know if I'm reading this right but if I run UCAs, 08 springs, and Bilstein 5100s (or stock shocks), I can still run my leveling kit? What kind of lift will that give me?

I'm not interested in aftermarket coilovers. I won't own the truck long enough to justify ANOTHER $1000.

The way I read this is that on an '07- with aftermarket UCA, '08+ Pro4x coils, Bilstein 5100 set on the 0 lift setting, Bilstein HD, or stock struts, you could run a PRG 1.5" spacer, for a full 3" of lift, maybe slightly more with the 5100s since their 0 setting lifts 1/2".

With the stock struts, since they don't lift the 1/2" like the 5100's do on their 0" setting, Maybe you could run your 2" level spacer.

Your best bet is to talk to Greg though. Because in his other post, Greg stated the 5100 and HD are longer, and can have their bottoms crushed when using spacers.

But in either case, you would need longer bump stops, and alignment cams since lifting over 2.5" on a 4x4, and possibly sway bar removal or PRG end links that are longer.

Here is another way to go, but you'd probably want the aftermarket UCA ... http://www.titantalk.com/forums/1533059-post10.html