new tires?

The life span of an RV tire is approximately 7 years so you are getting close to replacement age. They rarely run out of tread life but rather, as you have discovered, sidewall aging. No, "small" cracks are not too bad unless there are a whole lot of them but a highly noticeable crack can be the sign that it's time to replace. There is no fixed answer but if I was you I would rather be safe than sorry especially when it comes to the front tires. Look at the video posted recently on this site showing an RV blow out on the highway.

19.5 are commercial size and those usually have 10 years life span.
My experience with multi-layer commercial tires is that even big cracks on the outside layer still leaves you several layers of reinforced rubber under.
Would you start seeing fabric, that is another story.
You can do 2 things IMHO.
1 check the tire manufacturer site for recommendations and even email them pictures with question
2 go to commercial tire shop for inspection. Don't talk to yesterday's burger flippers who change tires today at "American Tire" or "Costco"

William, I had sidewall cracks that your describing on my last set of Michelin Tires and the tires were 10 years old. I went to Michelin Tire Care website and what they described about sidewall cracks told me that the sidewall cracks were not dangerous. I drove 1,500 miles home constantly checking the sidewall cracks and had no problems. Sorry, I can't remember perimeters of the cracks you will have to go to there website. When I got home, I had a new set of Michelin tires installed on my RV and I used the FMCA, Michelin Fleet Tire Program to purchase my new tires.

The only place you'll get an unbiased eval is at the manufacturer's web site. IMO. Some of them will have a description of cracks and how deep they can be (usually in mm's) and still be ok. Others, you have to contact them.

Williamh wrote:
I have a 2004 Southwind with 19.5 Michelin tires. I think they are about 6 years old. I can see small cracks in the sidewall of the front tire. I am wondering if these small cracks are considered dangerous and in need of replacement. I also wonder if they are weather related. Any info will be helpful. Thanks in advance.

William

Michelin claim 10 year tire life on a RV.Go see a tire expert and have them judge the weather cracks, Michelin are famous for them

We had B F Goodrich and an experienced tire guy in TX who worked on Prevost told us that 7 years would be his recommendation. We replaced them at 6.5 years and they did have some cracking. We bought Michelins. The tire shop where we bought the Michelins said that we could probably get another year out of the Goodrich tires. They had photos of different degrees of cracks that he showed us for examples. We were heading out on a long trip out west, DH had heart surgery 6 months prior and we didn't want to risk a blow out. So the answer is "it depends". I would go see a Michelin tire shop that sells heavy duty tires and let them check against their example.

usersmanual wrote:

Williamh wrote:
I have a 2004 Southwind with 19.5 Michelin tires. I think they are about 6 years old. I can see small cracks in the sidewall of the front tire. I am wondering if these small cracks are considered dangerous and in need of replacement. I also wonder if they are weather related. Any info will be helpful. Thanks in advance.

William

Michelin claim 10 year tire life on a RV.Go see a tire expert and have them judge the weather cracks, Michelin are famous for them

Not quite true.

Go to: http://www.michelinrvtires.com/reference-materials/tire-guide-warranties-and-bulletins/

Click on "RV Tire Guide".

On page 3: Tires that have been in use for 5 years or more should continue to be inspected by a specialist at least annually.

And further down the same page: While most tires will need replacement before they achieve 10 years, it is recommended that any tires in service 10 years or more from the date of manufacture, including spare tires, be replaced with new tires as a simple precaution even if such tires appear serviceable and even if they have not reached the legal wear limit.

wolfe10 wrote:

usersmanual wrote:

Williamh wrote:
I have a 2004 Southwind with 19.5 Michelin tires. I think they are about 6 years old. I can see small cracks in the sidewall of the front tire. I am wondering if these small cracks are considered dangerous and in need of replacement. I also wonder if they are weather related. Any info will be helpful. Thanks in advance.

William

Michelin claim 10 year tire life on a RV.Go see a tire expert and have them judge the weather cracks, Michelin are famous for them

Not quite true.

Go to: http://www.michelinrvtires.com/reference-materials/tire-guide-warranties-and-bulletins/

Click on "RV Tire Guide".

On page 3: Tires that have been in use for 5 years or more should continue to be inspected by a specialist at least annually.

And further down the same page: While most tires will need replacement before they achieve 10 years, it is recommended that any tires in service 10 years or more from the date of manufacture, including spare tires, be replaced with new tires as a simple precaution even if such tires appear serviceable and even if they have not reached the legal wear limit.

X-2, I read the same thing.