2 questions about Schrockworks bumpers
- Thread starter Mabuse
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shuly
New member
Mabuse said:
The bumper should not interfere with the airbag operation of the vehicle. The bumper bolts up to the frame of the vehicle so that you can winch from it. So if you hit something and the front end crumples enough that you need the air bags....you can probably start crying right away. :sobbing: No need to worry about running into the unibody cars on the roads though. You will probably annihilate them. :clap: That said I leave plenty of following space in front of me.
As far as weight of the bumper it will depend on what winch you put on. Figure 250-300#. The load ratings of the tire will be on the sides of the tires. Figure the weight of the vehicle divided by 4. If you want to be safe add 500# to that number and then divide by 4 to figure out how much is on each wheel. That is only a rough estimate, but should give you an idea of what load is placed one each tire. Technically the load is never distributed 100% evenly. If you are close to the load rating of the tires you have, why not replace them with something gripier for off-road anyway.
Oh don't take for granted the load ratings of the tires. My tires can each take 3300 lbs. That would be over 12000 lbs for the whole vehicle. Your vehicle's axle has its own limit. However you won't come near that with normal mods.
One more thing...the 4runners front end dropped by about 1/2" after adding the bullbar and the winch. I have a Downey lift kit, so I am not sure how much the front will drop with stock suspension just be aware of it. I would also recommend synthetic winch rope. It will help remove weight from the front end, has a higher pull rating and won't snap back like a steel line will.
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It's great that you responed to this thread, because it's your set-up that I most closely want to copy. My long term plan for the next 18 months to 3 years is to:
1. Upsize the tires to 265/70/17
2. Remove the xreas and get an aftermarket suspension lift
3. Add the Schrockworks bumper
I want the bumper for increased durability and approach angle. My stock bumper is allready missing a lot of paint due to light colisons on the trail and scrapping when the approach angle is greater than the bumper can handle. I'm not too concerned about winching and getting stuck. Of course I always have the option to add the winch if I change my mind.
Anyway, I'm buying the new tires in January, and I realize that the tires I buy now need to be compatible with what I am planning on doing in the future. And I'm realizing that if I'm going to add a Schrockworks (bumper only) in 2 years, I need to buy tires today that will handle the load I add in the future.
So how heavy is the Schrockworks bumper only? Ballpark guess. I think maybe I heard that it's 90 lbs. But it could be 250 lbs for all I know. Whatever the weight is, the question is simply this: If I'm adding XXX weight, is a C tire required? Or will a P suffice?
You've got E's don't you?
1. Upsize the tires to 265/70/17
2. Remove the xreas and get an aftermarket suspension lift
3. Add the Schrockworks bumper
I want the bumper for increased durability and approach angle. My stock bumper is allready missing a lot of paint due to light colisons on the trail and scrapping when the approach angle is greater than the bumper can handle. I'm not too concerned about winching and getting stuck. Of course I always have the option to add the winch if I change my mind.
Anyway, I'm buying the new tires in January, and I realize that the tires I buy now need to be compatible with what I am planning on doing in the future. And I'm realizing that if I'm going to add a Schrockworks (bumper only) in 2 years, I need to buy tires today that will handle the load I add in the future.
So how heavy is the Schrockworks bumper only? Ballpark guess. I think maybe I heard that it's 90 lbs. But it could be 250 lbs for all I know. Whatever the weight is, the question is simply this: If I'm adding XXX weight, is a C tire required? Or will a P suffice?
You've got E's don't you?
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shuly
New member
Wow...I'm honored that want to copy me 
Thanks!
You are definitely lucky in that you already have 17" rims. You have a ton of tire options open to you w/o needing to buy new wheels. Once you have the shrockworks bumper though you will hate your departure angle. Be prepared to start saving up for a new rear bumper... (my next big planned purchase). The approach is WONDERFUL and you can practically drive up to anything!
I didn't have a scale and so I never actually weighed the thing. It does way probably about 100#. Then you add the winch line and steel cable and it can get up to 250-300. I don't think you will have any major issues adding that to your vehicle.
Ok now tires...I have a feeling you are mixing and matching some numbers. The number C or E has to do with a load range and the number of plies. The more plies the higher the load range of the tire. A 'C' tire has 6 plies and an 'E' tire has 10 plies. The more plies the less likely to puncture the tire. Keep an eye also for the number of sidewall plies. The TA KO's have 3ply sidewalls. The more plies the less likely of puncture by rocks on trails. The only downside is that commonly more plies=rougher ride when compared to an equivalent tire. You probably only care about this if you plan on spending 99% of your time on pavement.
The load range is tied to but not dependant on the letter you are speaking of. You need to find out the load range of your tire based on the sidewall. Keep in mind these load ratings are based on a fixed tire pressure. The less the pressure the lower the load rating. They don't typically give you enough data to generate such a curve but I haven't heard of anyone having major issues with airing down to 20-25# and having load rating issues.
The 'P' number means it is a passenger metric tire.
The tires I have on my vehicle are: LT265/65R18/E
http://www.bfgoodrichtires.com/specs/all-terrain-t-a-ko/44.html
See the table in the link for more info about that fixed size. I couldn't put the 285's on because the rims on the stock ltd 18" are 7.5" and you need an 8" or you won't necessarily be able to keep the bead, especially when aired down.
Ok here are a couple of links for you in regards to tire info.
Basic tire definitions to help clear up any confusion:
http://www.discounttire.com/dtcs/infoTireTerm.dos
Tire load rating tables:
http://www.discounttire.com/dtcs/infoLoadIndex.dos
Read your sidewalls
Thanks!You are definitely lucky in that you already have 17" rims. You have a ton of tire options open to you w/o needing to buy new wheels. Once you have the shrockworks bumper though you will hate your departure angle. Be prepared to start saving up for a new rear bumper... (my next big planned purchase). The approach is WONDERFUL and you can practically drive up to anything!
I didn't have a scale and so I never actually weighed the thing. It does way probably about 100#. Then you add the winch line and steel cable and it can get up to 250-300. I don't think you will have any major issues adding that to your vehicle.
Ok now tires...I have a feeling you are mixing and matching some numbers. The number C or E has to do with a load range and the number of plies. The more plies the higher the load range of the tire. A 'C' tire has 6 plies and an 'E' tire has 10 plies. The more plies the less likely to puncture the tire. Keep an eye also for the number of sidewall plies. The TA KO's have 3ply sidewalls. The more plies the less likely of puncture by rocks on trails. The only downside is that commonly more plies=rougher ride when compared to an equivalent tire. You probably only care about this if you plan on spending 99% of your time on pavement.
The load range is tied to but not dependant on the letter you are speaking of. You need to find out the load range of your tire based on the sidewall. Keep in mind these load ratings are based on a fixed tire pressure. The less the pressure the lower the load rating. They don't typically give you enough data to generate such a curve but I haven't heard of anyone having major issues with airing down to 20-25# and having load rating issues.
The 'P' number means it is a passenger metric tire.
The tires I have on my vehicle are: LT265/65R18/E
http://www.bfgoodrichtires.com/specs/all-terrain-t-a-ko/44.html
See the table in the link for more info about that fixed size. I couldn't put the 285's on because the rims on the stock ltd 18" are 7.5" and you need an 8" or you won't necessarily be able to keep the bead, especially when aired down.
Ok here are a couple of links for you in regards to tire info.
Basic tire definitions to help clear up any confusion:
http://www.discounttire.com/dtcs/infoTireTerm.dos
Tire load rating tables:
http://www.discounttire.com/dtcs/infoLoadIndex.dos
Read your sidewalls
Thank you, that is all excellent advice.
I'll be really specific about my tire buying puzzle. I have decided I want Goodyear Wrangler Silent Armor 265/70/17. In that size I have two choices:
1. P metric tire that is a 113T with a max load of 2,535 at 44 PSI
2. C tire that is 112.109 with a max load of 2,470 at 50 PSI
I think I'm beginning to see what you are talking about. The P tire actually has a max load greater than the C tire. The difference is the greater number of plies that the C tire has which make it more durable, puncture resistant tire. But as far as Max Load they are actually nearly the same.
The curb weight of the V6 4WD 4Runner is 4,300 lbs.
The Gross Vehicle Weight Rating is 5,580 lbs.
Am I correct in assuming that by taking the max load numbers of the tires above and multiplying by 4 I will get the max weight that a set of tires can support? 2,535 x 4 = 10,140 That's a HEAVY car!
I guess it doesn't matter which tire I buy, both can support the weight of the bumper (and a lot more). So instead I have to decide how durable a tire I want and if I am willing to trade durability for ride comfort.
Since either tire can handle the weight, it's really the suspension that is going to need to compensate for the added weight. If I throw that bumper on today, with my stock suspension, it would cause the front end to sag. Stiffer (and taller) struts or shocks will have to bare the load. Right?
I'll be really specific about my tire buying puzzle. I have decided I want Goodyear Wrangler Silent Armor 265/70/17. In that size I have two choices:
1. P metric tire that is a 113T with a max load of 2,535 at 44 PSI
2. C tire that is 112.109 with a max load of 2,470 at 50 PSI
I think I'm beginning to see what you are talking about. The P tire actually has a max load greater than the C tire. The difference is the greater number of plies that the C tire has which make it more durable, puncture resistant tire. But as far as Max Load they are actually nearly the same.
The curb weight of the V6 4WD 4Runner is 4,300 lbs.
The Gross Vehicle Weight Rating is 5,580 lbs.
Am I correct in assuming that by taking the max load numbers of the tires above and multiplying by 4 I will get the max weight that a set of tires can support? 2,535 x 4 = 10,140 That's a HEAVY car!
I guess it doesn't matter which tire I buy, both can support the weight of the bumper (and a lot more). So instead I have to decide how durable a tire I want and if I am willing to trade durability for ride comfort.
Since either tire can handle the weight, it's really the suspension that is going to need to compensate for the added weight. If I throw that bumper on today, with my stock suspension, it would cause the front end to sag. Stiffer (and taller) struts or shocks will have to bare the load. Right?
shuly
New member
Mabuse said:
I still think you are still getting a few things confused. The "P" just means P metric (basically passenger tire). The "LT" means light truck tire. The LT tires typically have more plies and/or higher load ratings. I found the link for the specific tire you are looking for. There are actually three in that list that show your size of 265/70R17. Do a search and you will find there are two LT tires one is an "E" grade capable of 3,195# @ 80psi. Don't overlook this tire. Chances are it isn't that much more expensive and should be more puncture resistant.
http://www.goodyeartires.com/goodye...eadwidth=&aspectratio=&rimdiameter=&sidewall=
Mabuse said:
YES!!! @ the rated pressure the tire manufacturer states
If you air down that "E" tire you should be fine to 15-20psi even with the added bull bar. Don't forget though your axles do have a limit. I have no idea what they are but don't try to add weight to get the truck up to 10,000 lbs. The axles will go before the tires will haha. Don't worry though normal added weight of persons and cargo + roof rack is fine.
Mabuse said:
I would upgrade the suspension...throw on a lift kit. It helps with ground clearance in the front and gives more of a truck type ride (which I prefer.) It is still comfortable but you don't feel like your driving a Camry or something anymore
If you are going to spend the money on a bumper go with a coil over suspension. Do it right the first time. Spacers are ok...but if you have the money do it right you will be happier in the end. The bull bar in the front on stock suspension should still be fine. I wouldn't expect any sagging until the suspension has worn after 80k+. By that time it would need replacing anyway. The front end will drop though by 1/2-1" when you add the bull bar. If you replace the front end suspension with coilovers you can level it out once you add the bumper. You can re-level it if you add a winch later.
Be sure to post some before and after pics when you get this stuff done.
I am following you. Thanks for the advice. Now about the E tire...
Don't you think the E is a little excessive? If I aired down the C tires (tires that could support a 10,000 lb truck if fully inflated) they would still support the 4Runner and the bullbar at 15-20psi, wouldn't they? Is there a table somewhere that shows the weight rating at different inflaction levels?
shuly
New member
Mike07SE said:
I love them
I am and have been partial to those tires for many years, primarily because of treadlife. They last forever. Overalll the ride is truck like with both the lift and the tires. It still handles like a 4runner though. I have the best of both worlds IMO, the comfort and handling of a 4runner and the ride of a truck.
