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Bigger steer tire - sbtrucking - 09-05-2016
Hey fellas,
Does any one run bigger steer rim and tire?
With the roads being a mess lattely beating up our trucks and comfort I
want try new combo on steers and maybe on drives, plus driving team and sleeping mostly wile rolling hopping I can smooth things out a little.
I just got 22.5 x 9" alcoa steers and have on the way Yokohama 104ZR spec2
20 ply 315/80/22.5 tires, hope to run them at 80-85 psi
Also on the rears I want swap lo pros with 11r 22.5 16ply so I can drop the pressure few psi and smooth the rear end also.
What are your thoughts on this?
RE: Bigger steer tire - Nilao - 09-05-2016
I'd be Leary of any heavy truck tire pressure that low. Lower pressures have more sidewalk flex which will generate more heat. I would think it would weaken the sidewall. Just my thought on lower pressures.
RE: Bigger steer tire - Waterloo - 09-05-2016
Well, I know the consensus here is to run high pressures to dissipate heat, which I do... But then we have the tire manufacturers saying to run a lower pressure for better, more even wear, around your 85 psi. That was from one of the big tire manufacturers too, like Continental or Goodyear, I read that a year or two ago in one of those industry emails I get... There was never any mention of heat build up though in regards to lower pressures, but they are selling tires...
I doubt it will make a hill of beans of a difference, I would say slow down, and change out your shocks for fresh ones. If you haul heavy, I would make that a yearly purchase. Then we have your weight, how much do you routinely haul? If you are heavy is there a way to better even out the load by loading the trailer differently? Smooth out the ride? And going to those larger steers with lower pressures, won't that slow you down anyways? Also, will your front axle safely handle a wider rim and heavier tire? The trucks running those sized rims and tires up here in Michigan normally have 20,000 lb front ends.
I'm up here in Michigan, and it is said we have the worst roads in the country... What I have done, partially due to the terrible roads and traffic, is to actually change my area of operation. I moved out of the Detroit area and headed over to the center of the state and now camp out in Lansing MI, the state capitol. The roads are much better up this way and with less traffic. Is there a way you can do like I did and just work a different area? Or are you OTR? I'm in a different situation than many here, but had to ask.
Seriously, I think slowing down is your best option, there are roads here that are posted at 55 mph, which I routinely drive at 35 mph or slower, with the four ways on. That is about the only way I can keep my truck in one piece, slow down and take my time. Speed is not in my vocabulary, on a good stretch of road I might crank her up to about 63 mph... And everyone knows how unreliable my truck is, only a few more parts left to replace...
RE: Bigger steer tire - Hammerhead - 09-05-2016
(09-05-2016 )sbtrucking Wrote: Hey fellas,
Does any one run bigger steer rim and tire?
With the roads being a mess lattely beating up our trucks and comfort I
want try new combo on steers and maybe on drives, plus driving team and sleeping mostly wile rolling hopping I can smooth things out a little.
I just got 22.5 x 9" alcoa steers and have on the way Yokohama 104ZR spec2
20 ply 315/80/22.5 tires, hope to run them at 80-85 psi
Also on the rears I want swap lo pros with 11r 22.5 16ply so I can drop the pressure few psi and smooth the rear end also.
What are your thoughts on this?
Steering tires:
I run big (385's) steer tires, for work not comfort. I'm a heavy haul application.
Go to a tire shop and actually look at the info on the sidewalls, 385's REQUIRE 125psi! With wide base tires having such large tread faces, they need high pressure to support the center of the tread face because the sidewall is much further away.
I have friends that run northern Canada that do exactly what your thinking. They run 385's on 12k axles with 90psi on the pavement and drop to 80 for the gravel road. If you want to run them for comfort, you have to understand that there will be a price to pay;
First: they are more expensive because there's more tire.
Second: running lower pressures means you will get less tire life. I highly recommend using "Tire Life" in them, it's a liquid that cools the tire and rim, and actively balances the tire. Tire Life is a brand name and I use three bags in each tire.
Third: change your front hub oils to a high quality synthetic oil, and plan to change this regularly. A standard 12k front axle will support these tires, IF you don't increase the weight load factor, but there is incredibly more drag with a wider tire and lower pressures and your bearings and oils will pay the price, particularly in the temps you operate in TX. Consider spec'ing a 14,600 front axle with a 16,000 steering pump and cooler on future trucks to help with longevity.
Fourth: a 315 really isn't big enough to notice a big difference, they've tried that and they now run 385's. With tires this wide you will need the rubber fender extenders to keep tire spray down.
Now here's where the math gets tricky, because these big tires with lower pressures ride softer their tires costs have gone up, but other maintenance costs went down. In their application and road conditions fuel economy isn't really reliable (1000's of miles on gravel roads that when wet throw any calculations out the window) but yours will be, and I'd like to know what you find.
The overlooked drive suspension
There is actually big improvements to be made here. Depending on your suspension. If you have OEM suspension you might be limited with what I'm about to tell you, but if you have Other suspension (ie: Neway, Hendrickson) you have more possibilities. Most suspensions have several different ratings, pay attention to that. If you have the KW 8 bag 40k axles and suspension, the 46k air bags USED to (in the 90's) fit into the 40k, check the measurements closely!
But what difference is that Hammer? They don't just rate suspensions higher for shits-n-giggles because of the axles, they make them stronger. And to support more weight, without overpressurizing the air bags they use a larger diameter bag. Larger diameter means more surface area. Larger surface area with equal pressure means more support, or INVERSE larger surface area for equal load means LESS pressure for equal support. In other words less pressure in your bags means they are softer and they ride nicer! This means you may have to do some homework, I spent about an hour looking through the parts book before I found a "suitable replacement" for my old '90 Pete with Air Trac, but I found one that was 1 1/2" larger in diameter that fit and bolted in, what an amazing difference! That's why I run 52,000lb suspension with 46k axles in my heavy haul application, to get good ride, because I'm routinely loaded to 40,000 or more on my drives. 40k for me is 57psi, I'd bet your higher than that at your legal 34k.
Not all suspensions have alternatives, remember that when your spec'ing your next truck...
Good luck, and ride SOFTLY
RE: Bigger steer tire - sbtrucking - 09-05-2016
We haul doubles for fedex and they run all their trailers and dollies at 85 psi, also because of doubles my fifth wheel is back so I am ligh on steers, how ever we roll fast my trucks are governed at 70-72 mph, we run team drivers, wild not dedicated runs so when we make it to the yard we get on the list for the next run.
Some of the bigger contractors they have their trucks at 75 mph so they make it sooner on the list and get up to 6-7k miles a week, soon as they get couple hundred k miles on their trucks they trade them in.
You are right speed beats the trucks, I have 11 mns old volvo 780 governed at 72mph and front end is already loose and shaky it has little over 200k miles.
Thats y I am hopping bigger softer tire can help.
RE: Bigger steer tire - Rawze - 09-05-2016
The lower your tire pressure,,.. the more heat and bearing wear you suffer. The more tire wear from drag, lower fuel mileage, etc.. and on and on it goes.
Also, the more "cold air pressure" you put in your tires, the less "hot air" and friction they get in them.
I got a better idea --- PLAN YOUR TRIPS BETTER AND SLOW THE HELL DOWN!.
AND IF YOU CAN'T SEEM TO MANAGE THAT -- govern the truck! -- I guarantee you will figure out real quick how to still make your deliveries on time.
All that BS about high tire pressure and extra wear is just that BULLSH#IT!. I run 120 PSI in ALL MY TIRES -- and guess what --- I got 457,000+ miles out of my last set of drivers,..and I get roughly 160,000 out of my steers. -- ALL my tires always look good.
Lastly,--- If you want to stop beating up your truck and be able to sleep with another driver behind the wheel---- MAKE THE OTHER GUY SLOW THE HELL DOWN!!! Drive 60 or less, keep boost under 20 PSI, keep the damn door shut and keep moving. --- AND YOU WILL SLEEP LIKE A BABY knowing the other driver is driving for safety and fuel economy.
Tires are NOT going to make a smoother ride by any measurable stretch compared to slowing down and making sure your shock, etc.. are in good shape.
RE: Bigger steer tire - Brock - 09-05-2016
I am going to be switching to a wider rim and tire combo shortly. I'm maxed out at 5500kg on my steer and want to put a bambi basher on the front. they'll allow 6000kg if I have a 1" wider rim and tire.
Bad groves in the road up here and I've heard of guys wearing the edges of the wide tires from riding the edges of the ruts.
RE: Bigger steer tire - Hammerhead - 09-05-2016
(09-05-2016 )Brock Wrote: I am going to be switching to a wider rim and tire combo shortly. I'm maxed out at 5500kg on my steer and want to put a bambi basher on the front. they'll allow 6000kg if I have a 1" wider rim and tire.
Bad groves in the road up here and I've heard of guys wearing the edges of the wide tires from riding the edges of the ruts.
That's just the way wide base tires wear. That's why they require 125psi, to support the center. With lower pressures the tread face depresses into the void of the center of the tire and the sidewall supported edges wear more than the centers
RE: Bigger steer tire - hhow55 - 09-05-2016
Here's a good article on tires
http://www.overdriveonline.com/going-low/