Tires for Big Class C
Hi, Folks, I have a 2011 Itasca Impulse 31N, a 32' class C. This motor home is big and heavy compared to my last one (1999 Coachmen Catalina Sport 220-RK) and is close to the max load range of its...
Forum Discussion
Thank you all for your replies. My responses:
To MikeRP:
By “checking” I mean cracking. There are cracks, lots of them, in the rubber of the sidewalls as well as along the shoulder of the tire where the tread meets the sidewall.
Thank you for the Rickson suggestion. I searched for Rickson wheels, and read good things and bad. I’m not ready to spend $5k - $6k for new 19.5" wheels and tires, plus new shocks (as recommended by Dan Richter, president of Rickson Truck Wheels, in an interview he did for “Truck Camper” magazine). Also, due to the larger diameter of the tires wouldn’t I also need larger brakes? If I remember my physics, the larger diameter tires have a longer lever arm (distance from hub to road) than smaller diameter tires, meaning that the tire diameter to brake rotor diameter ratio is greater, reducing the effectiveness of the stock brakes, because the larger tires will require greater effort to bring them to a stop. What do you think? This now sounds like I’m rebuilding my motor home, and I’m no automotive engineer, so I think this is something I’m better off not doing.
To Handbasket:
I investigated the Michelin XPS Rib, and I’m considering them. You’re right; they are made in sizes suitable for my chassis. The only doubt I have is that I read they are not designed to be driven in near-freezing temperatures. We’re planning on going to NY and New England, and not leaving for home until mid-October, possibly after the first-frost date. I understand that at colder temps the rubber hardens and the tires become less flexible and stopping distances increase. I’ll not drive in snow, so that’s not an issue. The big questions I have are at what temperature does the rubber harden, at what rate, and how much are stopping distances increased? Are the tires already stiff at 45 degrees, 40, 35? I don’t know, and I don’t know how to find out. Do you know anyone who has installed the Ribs, and what his/her experience with them is?
To Pianotuna:
I would welcome a 1.25" increase in my road-to-motor home distance, especially at the end of my 11' rear overhang. And you’re right in that the increased tire load rating doesn’t change the chassis load rating. You mention a slight increase in gas mileage. I’m guessing that comes from the larger diameter tires. If so, do you notice lengthened stopping distances?
Thank you all for your interest in my dilemma. I appreciate the feedback.
Hiker Rob
To MikeRP:
By “checking” I mean cracking. There are cracks, lots of them, in the rubber of the sidewalls as well as along the shoulder of the tire where the tread meets the sidewall.
Thank you for the Rickson suggestion. I searched for Rickson wheels, and read good things and bad. I’m not ready to spend $5k - $6k for new 19.5" wheels and tires, plus new shocks (as recommended by Dan Richter, president of Rickson Truck Wheels, in an interview he did for “Truck Camper” magazine). Also, due to the larger diameter of the tires wouldn’t I also need larger brakes? If I remember my physics, the larger diameter tires have a longer lever arm (distance from hub to road) than smaller diameter tires, meaning that the tire diameter to brake rotor diameter ratio is greater, reducing the effectiveness of the stock brakes, because the larger tires will require greater effort to bring them to a stop. What do you think? This now sounds like I’m rebuilding my motor home, and I’m no automotive engineer, so I think this is something I’m better off not doing.
To Handbasket:
I investigated the Michelin XPS Rib, and I’m considering them. You’re right; they are made in sizes suitable for my chassis. The only doubt I have is that I read they are not designed to be driven in near-freezing temperatures. We’re planning on going to NY and New England, and not leaving for home until mid-October, possibly after the first-frost date. I understand that at colder temps the rubber hardens and the tires become less flexible and stopping distances increase. I’ll not drive in snow, so that’s not an issue. The big questions I have are at what temperature does the rubber harden, at what rate, and how much are stopping distances increased? Are the tires already stiff at 45 degrees, 40, 35? I don’t know, and I don’t know how to find out. Do you know anyone who has installed the Ribs, and what his/her experience with them is?
To Pianotuna:
I would welcome a 1.25" increase in my road-to-motor home distance, especially at the end of my 11' rear overhang. And you’re right in that the increased tire load rating doesn’t change the chassis load rating. You mention a slight increase in gas mileage. I’m guessing that comes from the larger diameter tires. If so, do you notice lengthened stopping distances?
Thank you all for your interest in my dilemma. I appreciate the feedback.
Hiker Rob
