Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: its toby on April 15, 2016, 03:28:09 pm

Title: Turning radius with larger tires
Post by: its toby on April 15, 2016, 03:28:09 pm
I am preparing to out new tires on our unihome 280 and there is little to no choice on tires in the 275/80 size. I cannot seem to go up a load range locally without going to the 295 tires and then there are lots of brand choices. I am aware that you need to adjust the steering stops and the box to keep the tires from touching the airbag pedestals. My question is for the people who have done this, have you noticed the increase in turning radius and do you really miss that little bit?
Title: Re: Turning radius with larger tires
Post by: Chuck & Jeannie on April 15, 2016, 03:43:46 pm
I'll be interested in whatever answers you get.  We have same model coach, and our tires are approaching the 6-year-old mark...
Title: Re: Turning radius with larger tires
Post by: Mike Leary (RIP) on April 15, 2016, 03:59:16 pm
I would wonder if the larger tires would put extra wear on the wheel bearings?
Title: Re: Turning radius with larger tires
Post by: Chuck & Jeannie on April 15, 2016, 04:17:28 pm
According to Michelin charts, going from 275/80 XZA3 (LRH) to 295/80 XZA2 (LRH), you're adding about 11 pounds per tire.  Some really clever physics major on the Forum should be able to calculate added stress at the bearing.

Don't look at me - I'm a English major...  8)

Tire and Retread Selector | Michelin Truck (http://www.michelintruck.com/tires-and-retreads/selector/#!/info/xza3+-evertread)

Tire and Retread Selector | Michelin Truck (http://www.michelintruck.com/tires-and-retreads/selector/#!/info/xza2-energy)
Title: Re: Turning radius with larger tires
Post by: wolfe10 on April 15, 2016, 04:36:33 pm
Assume (please confirm) that you are considering 295/75R22.5 to replace the 275/80R22.5 and not 295/80R22.5 as replacements.

Without knowing which 295 you are considering, you will get a wide range of comments.
Title: Re: Turning radius with larger tires
Post by: Doug W. on April 15, 2016, 04:42:47 pm
"The diameter difference between brands of the same size will be greater than any diameter difference between 295/75 and 275/80. This means a 0.1" difference is of no consequence. "

I have run both Goodyear and Toyo 
295/75 tires on both coaches with no alterations. I had a small amount of rubbing on front airbag plates on the 89 GV but nothing on the 96 U270.
Title: Re: Turning radius with larger tires
Post by: Mike Leary (RIP) on April 15, 2016, 04:44:16 pm
So, the 40 footers take a larger tire than the 255/80R/ 22.5/ XRV that we with "short" coaches run ?
Title: Re: Turning radius with larger tires
Post by: wolfe10 on April 15, 2016, 04:55:47 pm
Correct, Mike.

The larger/heavier coaches take a larger tire.

BTW, your 255/80R22.5's ARE an upgrade/upsize. OE was 9R22.5 (look on the GVWR plaque)!
Title: Re: Turning radius with larger tires
Post by: Chuck & Jeannie on April 15, 2016, 04:59:13 pm
BTW, your 255/80R22.5's ARE an upgrade/upsize. OE was 9R22.5 (look on the GVWR plaque)!
Or, if you go to Beamalarm and check the "Specifications" for each model, it lists the factory standard tire.
Title: Re: Turning radius with larger tires
Post by: Mike Leary (RIP) on April 15, 2016, 05:43:30 pm
Quote from: wolfe10 link=msg=229552 date=14607537  your 255/80R22.5's ARE an upgrade/upsize. OE was 9R22.5 (look on the GVWR plaque)! [/quote

I've not ever had "fat tires". That being said, why the upsize? No tire dealer I've ever been to has weighed the coach on all fours, so are the "fattys" a money maker for the dealer? Granted, our coach rides perfect, but, I'd think the suspension and the custom shocks we have does the trick, rather than the tires. The only better ride was a Marathon/Prevost I drove a while ago, "Like driving on a cloud". 
Title: Re: Turning radius with larger tires
Post by: its toby on April 15, 2016, 06:21:26 pm
I am currently looking at both 295 sizes as I am still exploring options. Experience either way would be beneficial.
Title: Re: Turning radius with larger tires
Post by: Andy 2 on April 15, 2016, 08:35:53 pm
Toby, I put Firestone 560 295x 75 r on our u300 and have had good luck with them, no rubbing.
Title: Re: Turning radius with larger tires
Post by: red tractor on April 15, 2016, 09:29:18 pm
I think you will have an issue with the 295 80 tires, but not so much with the 295 75 tires