Whe is a Tractor Tire Worn Out?

Would like to get some thoughts from people on when a tractor tire starts to lose field traction (from new) as the lugs wear down. I'm talking tires with a standard R-1 type tread, bias ply type, if any of that makes a difference. I'm hoping to get a number, such as "if the lugs are less than X inches deep, they've lost performance." The Firestone 16.9-34 tires on my 826 are a bit under 50 percent of new by my estimate and somewhat unevenly worn and cupped. Sometimes I slip when I don't think I should be and think a deeper tread may help. Any and all commentary welcome and appreciated!

Second question: Can I put 18.4-34 tires in place of 16.9-34s? I think I may already be able to answer "yes" to that based on what I see in an old Tire and Rim Association manual I have. I can get a smokin' deal on a set of like new, R-2 tread Firestones in that size.

I dont have a surefire answer, but I would say when you think they are not doing the job you want, and you have the money to replace them.

Someone using an old tractor to check fences and haul in a little firewood is going to have a different set of critera than someone using it for rowcrop work. Or someone showing it at tractor shows.

Personally I wish people would replace them sooner as I would like to find a good used set.

gene

Ours usually dry-rot and crack open before the lugs are worn beyond 35% remaining.

When the tire goes flat or spins out excessively, it's time for a replacement.

Yea when they get past that 40% mark they become dual status and if ya want to go to a 18.4 34 myself i would get two new -used 16 inch wide rimes as the 16.9x34's used a 14 inch rim . You can put the 18's on the 14 inch rim but it pulls the side walls in to much and humps the center . And a 826 really needs the 18's as it will set the tractor up and give better performance .

Jim: There are a lot of answers to your questions, but the most important one is does the current traction suit you. There will also be a lot of opinions.

A tractor as heavy as the 826 with remaining you have will probably pull as much as it ever did on hard road, be marginally less in haying operations and depending on moisture will be between substancially less and useless in tillage operations.

I used to find keeping tractors off black top and hard gravel roads as much as possible greatly extended the life of tractor tires. When I was farming governments treated us much better in lisencing of farm trucks. I used to get my truck lisence 1/6 of commercial, insurance about the same. I rarely hauled a load behind my tractors on the road, often I'd load the tractors on lowboy for a 5 mile move. I had a loboy that I could run 1066 and folding wing disk or cultivator on quickly without unhitching. I think we have to tell our governments, if they want those damn tractors off the road, lets get back to sensible truck licencing, taxes and insurance.

About you tire and rim size, every tire is labled for ideal rim size. Ideal will give you optimum traction. I know being off an inch does affect traction. I had a neighbor go from 18.4x38 to 20.8x38 on a 986, said he gained very little until he changed the rim size. Personally I never changed a big tractor, however I saw the same results with 30-50 hp tractors.

Tractor tires that slip wast a bit of energy. Thactor tires that slip more than about 10 % of ground speed waste too much. Thactor tire systems and weight that are built to be so heavy and tractive that they do not slip will usually break transmission and drive train components if used in very low gears. Tires that do not slip also --Can--- promote the lugging of engines.
The best is a small amount of slippage 2 to 5% with a confident and aware driver. Weight (beet juice and wheel weights. can keep 1/2 worn tires in action without grief. It is usually a judgement call. I hope this helps. JimN

I read in an old farming book that 8% slippage was optimum. I think the book was from the 50's. It said that less slippage indicated there was too much weight or not enough load on the drawbar. More slippage was a waste of fuel. It may have been referring to tillage only. I'm sorry that I can't remember more details for you.

gene, what size tires are you lookin for??? we got two auctions coming up, one feb 7th and one the last week of feb. i picked up a set of 18.4-34 duals on rims with clamps, 50% tire for 55 dollars. november i got of set of 13.6-38 on peterson dual rims for my m for 10 dollars. i can keep my eye open for ya!!

Jim, if you want a new tractor out of your 826 go to the junk yard buy you a set of 38" rims. Either trade your 34" wheel centers for 38's or buy spacers to put on 34" centers. I have been where your going an let me tell you it made my 756 german diesel a different tractor. Let everyone know where your from an maybe we can help you find something reasonable. Good luck ,Gene

gene, i'll look for a set of duals for ya in good shape cheap. its real funny around here at auction, if there is a loose pair of decent tires, they go high. put em on a set of clamp on dual rims, nobody wants em. unless of course they are yellow and go on a green tractor. dang funny that way. must be an auction mindset, geez i dont need duals but hey there is a loose pair i can use, wow bid em up!!!!

there was an article in the farm journal a few years back that did a tire test on various tread wear. just like at a tractor pull the seventy percent worn out tire pulled the best in the field under regular field conditions. i would imagine that under muddy conditions like rice farming the deep trread would be needed.

Jim: I didn't consider the possibility of someone suggesting 38" tires as Gene has. It will probably be costly, however might be worth a look. One just never knows what he might stumble onto. You wouldn't believe your 826 is the same tractor with 38" tires compared to the 34" you now have.

Thanks all, for the comments so far.

The tractor is strictly used for tillage using mounted equipment for the hardest of the work (9 shank chisel). I don't have wheel weights or liquid ballast. I plan of getting a coupla hundred pound of iron for each wheel for the versatility. I mostly need that weight pulling my 15' cultimulcher with the chisels in deep.

I just found out what the original tread depth was for my tires new, so tomorrow I'll be comparing the current measurement against the new figure.

My manual says I have W15L, 15 inch wide rims but I have not verified that. The tire manual says 15 or 16 inch rims for 18.4-34s. Rim width versus tire section width I understand very well, so I won't be putting 18.4s on it unless my rims fit into the tire's approved rim width range for the tire. I believe I saw markings on the rim but I also have a big set of calipers that might work.

Randy Hall: I have heard about that article but haven't been able to find it. I did find a test that compared R-1 tread against R-2 (and R-1W) and it said that the R-1s are the best in dry to moderately dry conditions. The main difference between the two tires tested was the tread depth, with the R-2s being considerable deep tread tires.

I definitely won't be upgrading to 38s. Everybody wants 'em so they would cost. Ditto for used 38 inch tires. 34s always seem cheaper and I doubt the performance difference compares favorably with the price difference. I ran across some 16 inch wide 34 inch rims at an auction last year, and they went for next to nothing, but I couldn't find out what they fit. I had only minutes to make a WAG, so backed out (got enough scrap iron around here as it is).

An update: The tires I have (Firestone Traction Field and Road R-1, 16.9-34) are indeed mounted on a 15 inch wide rim. They have 1-1/8-inch of tread depth left and with the original depth being 1.57 inches, that means I have 57 percent left. If I can score the 18.4-34s, I will, but I'll run these another season or few and take some time to try to score a set of 16-34 rims on the cheap.

yes alittle sorry to everyone about the mutiple posts

i know when they are worn -out ,,when the wife can not use them in the flower bed ! LOL