Posted 2016-02-06 9:14 AM (#166026) Subject: Trailer tire up-sizing
Regular
Posts: 67 Location: Everton, Arkansas
My trailer came with Chinese tires, ST 235/80R16 which have a diameter of 30.8 inches. I am wanting to upgrade my tires to a Michelin XPS RIB. I am looking at 3 options; a LT 235/85R16 which has a diameter of 31.7 inches, a LT 245/75R16 which has a diameter of 30.5 inches or a LT 215/85R16 with a diameter of 30.4 inches. This gives me the option of an overall diameter size difference of +0.9 inches or as short as -0.4 inches. Currently I have about 2.75 inches gap between the two axles/tires. Upsizing would give me about 1.65 inch gap between axles/tires. My concern is: is this a sufficient gap between the rotating masses? Or would I be better off downsizing to a LT 245/75R16 or the LT 215/85R16 which has a diameter of 30.5 and 30.4 inches respectable?
Posted 2016-02-06 11:40 AM (#166028 - in reply to #166026) Subject: RE: Trailer tire up-sizing
Regular
Posts: 56 Location: Belchertown MA
I had the same dilemma on my Lakota when switching tires. I ended up going with the 245/75/16's because of the clearance inside top of fender in the rear, I had a 235/85 from another trailer and put it on and loaded horses and backed onto incline that loaded rear axle and tire came pretty close, so I went with the 245's which had basically the same clearance as what it came with and a little wider tread. Did a 2,000 mile trip last summer plus many shorter trips with no problems with them. I also remember reading somewhere about a couple people having problems with hitting fender on Lakota's with the 235/85's. Not sure what kind you have but that is what i did.
Posted 2016-02-06 8:29 PM (#166033 - in reply to #166026) Subject: RE: Trailer tire up-sizing
Veteran
Posts: 233 Location: Pataskala, Ohio
My Lakota is very close in the fenders but has never rubbed the LT235/85/16. I upped the size for greater load carring capacity and that 1/2 inch of additional ground clearance to safeguard my tanks.
Posted 2016-02-06 10:14 PM (#166036 - in reply to #166026) Subject: RE: Trailer tire up-sizing
Expert
Posts: 3853 Location: Vermont
The minimum safe distance between tires on the same side of a tandem axle trailer should be 4 inches. Technically speaking, you will need a minimum of 1 inch between the tires with the suspension in full flex which is when the tires will be the closest together.
Trailer tire up-sizing
