38 vs 42 tyres on fendt 724

[Charlie]

Didn't read the thread on BFF before it disappeared.
Options down to 710/60 R42 or 710/70 R38. Opinons please, even if already posted on the other site!

 

[mushnt grummmble]

Didn't read the thread on BFF before it disappeared.
Options down to 710/60 R42 or 710/70 R38. Opinons please, even if already posted on the other site!

bigger is always a better boast downt pub

 

[JohnDeere8530]

both will have the same footprint, however one will hold more air, ie the 38. I have several identical, largish tractors on both 38 and 42 tyres, the 38 tyres give a far better ride than 42 tyres and will carry more for a given pressure, therefore I'd go 38s

 

[AlfM]

The number at the end doesn't seem to have much relevance anymore if it ever did. The wide wheels i mention in another thread are 900/60 R32, and they are supposedly the same rc as my current 620/70 R42. So what is the important/relevant number?

 

[Richard Smyth]

I would go with the 38 as should be able to run less pressure and get a slightly bigger footprint.

Richard

 

[Michael S]

Just bought a 724. Have an 820 on 710/60R42s and I'd say they're better suited to a 150hp tractor max. For the 724 we've gone for 710/70R38+600/65R28 Trelleborgs after good experiences on 930/936/939s.

Michael

 

[Clive]

The 710 60 38s will tread much lighter than the 42's(michelins) as they hold a lot more air - it's what mine ill come on if they will fit bit they might be too tall

 

[Richard Smyth]

The 710 60 38s will tread much lighter than the 42's(michelins) as they hold a lot more air - it's what mine ill come on if they will fit bit they might be too tall

I would go 710/70 r38 if I were you. Bit taller.

 

[jh.]

I went 710/60r42 on my fergie . i usually run mounted kit and thought there would be less messing about with pressures. I pretty much stick them at a bar and leave them unless pressing or rolling.

i also wish to keep the set for the next tractor too so possibly 10 years and thought the sidewalls might last longer. had 710/60r38on my last tractor for 6years and the sidewalls had no perishing or cracks

 

[AlfM]

Had a chat with the Trelleborg man this afternoon, put me off 900/60r32, and we got to a choice between 850/55r42 or 850/60r38, both of which have a longer footprint than the 900, so more rubber on ground and narrower transport width. Both 850's exactly same RC, and he said there was nothing in it. Went for the 850/55r42 with 750/50r30.5 on the front. So i guess i'll have less 'air' in my rears than if i bought a 38, but whether i'll ever notice the difference.....

 

[Serup]

I think you all really should consider the gigantic difference in tyres these days!

If i'm not way off, the 710/60R42 is michelins xeobib. Maybe the best tyre today for tractors under 200 hp. (or bigger, if they can't use taller tyres)
710/70R38 is a "normal" wide, big volume radial, made by many.
850/55-42 is a trelleborg twin, wich is a bias tyre - totally different in construction than radials. Was great 10 years ago, when nobody made wide radial tires for smaller tractors.

They are all about the same height - 1,95 meter

Today i believe the xeobib is superior to twin in every aspect (maybe except price, i don't know)

The xeobib tyre is made with what michelin calls "ultraflex" technology, and have a sidewall that is suppose to flex more than normal radials, creating a longer footprint, because it can be run with lower pressure.

We have a tractor with trelleborg twin, and they a better than narrow radials (wich was on before) for both traction when wet, and especially flotation.
But the sidewalls are hard! No matter how low pressure i run them, they bounce when roading. (there is no suspension on it, apart from seat)

The 710/70R38 is a good size for both volume and load capacity.
The xeobib 710/60R42 i believe is a better tire, for what it can do.
The difference is probably in load capacity, and without checking any databooks, i think the 38" can load more, because it can be used at much higher pressure.

If you need the load capacity, and can live with the higher pressure, you need the 38" - if the load capacity of the xeobib is enough, i would prefer them hands down!

On a general note, i think a lot of farmers could get so much greater returns from their expensive tyres if they spend the time to use them at the right pressure every time!

I don't know any farmers who adjust pressure when they stop hauling trailers, and start drilling - they just run it at the pressure that is enough for the most demanding application, and accept more wheelslip and fuel-use when they actually could run a much lower pressure.

When i run my trailer, i use 1,8 bar in the back wheels, when ploughing 0,8 bar, and when i have duals on, and cultivate, i run them at 0,4 bar.

There is many publications that show the difference in fuel-use with different pressures, and the results always show a healthy benefit from the time spend changing pressure.

Just a little input from a farmer who take a big interest in tyres.

Jacob

 

[AlfM]

Price.......correct. Although this morning I did attempt to by a pair of 900/60r32 RADIALS from Trelleborg and they didn't want to take the extra £800 off me over the 900/60r32 414 twins as they said there isn't much difference unless doing a lot of road work. As it goes I've gone 850 anyway now.

 

[Serup]

I really don't understand that tyredealer. I can't get my head around the fact that he doesnt think there is much difference in the field between bias and radial tyres. I believe that statement is only true if the tyres are run at too high pressure. In that case, they are no better than smaller tyres used correct.

I really hope you will enjoy you twin tyres, and that they give you what you need.

They are not bad, i just believe then technology has advanced since they came around.

 

[AlfM]

It wasnt a tyre dealer. It was the man from Trelleborg. He should know what hes on about i hope. I already have some 800's of their radials and yes good tyre. Xeo-bibs on sprayer, good tyre.

 

[Serup]

Well, if the people making the stuff, says it doesnt matter, that is hopefully what they belive to be true.

After 7 years and 5000 hours with twin tyres on one tractor, i don't believe it - but i'm just a farmer. I don't have any advanced tests to prove my point, but i can see how little difference in sidewall flex i get from reducing pressure from 1,6 to 0,8 bar, even if the load calls for minimum 1,2 bar according to trelleborgs databook.

I believe the sidewalls in the twin tyres, because of their bias construction, is too stiff to give the long even footprint of a radial.

When they came out, they where good, because they where wider than anything else you could get, but now radials come in many different width and heights to suit all needs.

You did the only thing you could - trust the people you buy from. If you don't, then you should shop somewhere else.

 

[AlfM]

Well, if the people making the stuff, says it doesnt matter, that is hopefully what they belive to be true.

After 7 years and 5000 hours with twin tyres on one tractor, i don't believe it - but i'm just a farmer. I don't have any advanced tests to prove my point, but i can see how little difference in sidewall flex i get from reducing pressure from 1,6 to 0,8 bar, even if the load calls for minimum 1,2 bar according to trelleborgs databook.

I believe the sidewalls in the twin tyres, because of their bias construction, is too stiff to give the long even footprint of a radial.

When they came out, they where good, because they where wider than anything else you could get, but now radials come in many different width and heights to suit all needs.

You did the only thing you could - trust the people you buy from. If you don't, then you should shop somewhere else.

I think they were also taking my budget (not much), and what im going to be doing with it (light top cultivation for beet/maize, very little road work) into account. If money were no object we'd all have different things.

 

[Serup]

I didnt get the impression the man from trelleborg talked about price/performance ratio, just not big difference in tyre performance.

I believe the performance difference is big, but i have no idea about price gap, as i can't seem to find a list price for the twin tyres anymore.

I also know from experience that all tyres are really expensive nowadays, so a 20% difference is alot off cash
I really don't believe you get a set of 850/55-42's for "not much" no matter how you put it

Maybe this is the best solution for you, for the price - but thats a whole other discussion

 

[Galcam]

What tyre pressure should I have in front and rear Michelin tyres on a JD 6155R carrying a hedgecutter predominantly on road work? It’s on 650/65 38 and 540/28 on front? Just wondering as the tractors are new here in July and the tyres are currently at 21psi in rear and not sure about front. Thanks in advance.

 

[davidroberts30]

What tyre pressure should I have in front and rear Michelin tyres on a JD 6155R carrying a hedgecutter predominantly on road work? It’s on 650/65 38 and 540/28 on front? Just wondering as the tractors are new here in July and the tyres are currently at 21psi in rear and not sure about front. Thanks in advance.

Had to have the michys at 24/25on the hedger on my similar sized mf running same size tyres

 

[Galcam]

Tks David, mine look low especially the one taking the weight of the machine in work.