I recently swapped all six tires on my Monarch. The front ones were 7 and 9 years old, junk. The rear 4 were replaced in October but were different size than the front. I replaced them all with taller tires all the same size.

As a result I have 4 Samson 255/70 x 22.5 tires with only 5000 miles on them. Date codes are all late 2015. I paid over $300 each. I would like to sell them to someone who can use them and recover some expense. Make me an offer...

I need some new tires since my date code is all 06 on 6 tires now. My coach has been running 235/80 R 22.5 and I wonder what the effects of replacing them with 255/70 R 22.5 tires would be? Small diameter might upset the speedo, etc.

Hi Cantrade,

At some point, one of the previous owners changed Tonka's original 245/75 R22.5 to 255/70 R22.5 Goodyear G670 Rv's.

The diameter difference for our change is only around -1%. I don't know but doubt if they made any changes to anything to compensate for the diameter difference.

My GPS speed and speedometer match very closely.

We've been really happy with the performance and handling of the tires and have since replaced the tires with the same size Goodyear G670 RV tires.


Here's a website with a tire size calculator.

https://www.tacomaworld.com/ti...-80r22.5-255-70r22.5


Thanks,
Wally

I think Wally is exactly correct. If any changes happen they are probably beneficial. A smaller diameter will mean a lower ratio on the rear tires and might help with getting off the dime at stop signs etc. Although, I doubt that it could be detected.

I don't think the 235/80 R22.5 is made anymore also. I have looked on the internet and no luck. Lots of 255/70 tires around but no 235.

Steve can you supply the date code on your tires and the tread depth? I am getting very interested. Also what is your location? Shipping of these guys is a big consideration.

Don, KM5XK

Steve, sorry I see the date code in your first post.

Don

BTW, Steve I think we met up in an RV park a few years ago when on our ways to FL. I think you had just finished the Chevy Engine install then and was fighting a slight oil leak.

Don

Don, we did meet in Florida, I think St. Andrews state park.

I will have to measure the tread depth. Not much wear I'm sure. Installed in late Oct, sat until late Jan. Drove to Texas, around the Gulf, to the Keys and home again. 5,000 miles total.

I think these are about right for the Breakaways, most have tires close to this size. I honestly believe Barth had these left over and put them on my coach in the twilight months of their existence. No other Barth coach over 34 ft had these smaller sized tires, all were bigger. The new tires are over 3.5 inches in diameter larger!

I should have done more research before I bought this size but that was what the coach came with so I assumed it was OK. The old tires were 9 years old and had sidewall cuts and I was anxious to replace them right away. Anyway, hopefully someone can use them.

Should have mentioned they are GL283A tires, just corrected the thread title. Here is a description;

https://www.youtube.com/watch?v=1wArM1ocwC8

They are described there as a steer tire but they are all position.

Steve,

I sent you a P.M.

Don

Here's the latest.

I have decided to replace the Michelin 235/80R22.5 tires with TOYO 245/75R22.5 M154 tires. It turns out that my coach has 22.5 6.75 rims and the Samson 255/70R22.5 require a minimum rim width of 7.5 so those are not a choice. I could probably get by with mounting the Samson on the slightly narrow rim but it is better to stick with the design spec rim width.

The TOYO tires are almost exactly the same dimensions as the original Michelins so there should be no fitting problems like rubbing between the rear tires, etc. Also the TOYO load rating will allow a us to run a lower than maximum tire pressure since the front weight spec is 6,000# and the rear is 14,000#. I will weigh the coach and set the pressures accordingly.

All in all it looks like a good solution for around $2K.

Don

These tires are still available, sitting in the barn in storage. It would be good to get them in service somewhere. Let me know if you can use them.