MF 6260 tyres

[Jim B]

MF 6260 with 14.9 R28 (equivalent to 380/85 R28) front and 18.4 R38 (equivalent to 460/85 R38) rear.

Does anyone know if 480/70 R28 and 580/70 R38 would fit, and work with inter axle ratio?

Thank you.

 

[Bullring]

Doubt they would, you would have to go 520/70 r38 and 420/70 r28 on current rims or if rims allow which I doubt they will given your current tyres 600/65 r38 and 480/65 r28.

 

[Jim B]

Found a brochure online

380/70 R28 and 480/70 R38 listed as an option. Wonder if 100 mm wider would still work?

But like you said will need wider rims anyway, so it's probably a no go. Just know of some cheap tyres the size in OP, thinking out loud really...

 

[Mf6260]

Found a brochure online

View attachment 252042

380/70 R28 and 480/70 R38 listed as an option. Wonder if 100 mm wider would still work?

But like you said will need wider rims anyway, so it's probably a no go. Just know of some cheap tyres the size in OP, thinking out loud really...

I run 540 65 r38 and 440 65 28 on mine

 

[Serup]

MF 6260 with 14.9 R28 (equivalent to 380/85 R28) front and 18.4 R38 (equivalent to 460/85 R38) rear.

Does anyone know if 480/70 R28 and 580/70 R38 would fit, and work with inter axle ratio?

Thank you.

The inter-axle ratio would be fine. They are both 1 size bigger in circumference than your current tyres. it's a 70 profile version of 16.9R28 (420/85R28) and 20.8R38 (520/85R38)

I have no idea if they can fit under fenders.

How good a fit they will be, depend on your rims.

14.9R28 should be on 13" rims and are allowed on 11" and 12" also (depending on brand of tyres, this is for Trelleborg TM, as Trelleborg state allowed rims on their website) 480/70R28 should be on 15" rims and are allowed on 14" and 16" also.

18.4R38 should be on 16" rims and are allowed on 15" also. 580/70R38 should be on 18" rims and are only allowed on these.

I would not be afraid to put your wanted tyres on 13" and 16" rims, as i have done similar many times.

What you want to do depends on your rims and what you are comfortable doing.

 

[Jim B]

Thank you Serup, sounds as if those tyres on standard rims might be pushing it.

I have the option of some 420/85 R28 and 520/85 R38 available at the right money too, they are more worn but likely to fit width wise better the standard rims, however the higher profile may not fit under the rear fender...

 

[Serup]

If they won't fit, the 70-profile ones will also not. They are roughly the same height.

 

[Jim B]

580 x 70% = 406
520 x 85% = 442

36 mm higher, not much I suppose.

Does it state recommended rim width in a tyre book? In the case of the 420/85 and 520/85 they are Continental.

Also I assume rim width is measured between bead flange? Only way to accurately measure them is with tyre off if not stamped on rim?

 

[Serup]

Data on Trelleborg 70-profile series
http://www.trelleborg.com/en/wheels/products--and--solutions/tractors--tires/tractors/tm700
Data on Trelleborg 85-profile series
http://www.trelleborg.com/en/wheels/products--and--solutions/tractors--tires/tractors/tm600

their 580/70R38 are 1825mm tall
their 520/85R38 are 1849mm tall. So 2,5 cm difference.

You can also see recommended and allowed rims there. Not all manufactures provide this much info, but google continental, or maybe you will find it under mitas now, and see what they say. Usually they all allow the same rim sizes , but not always.

 

[Mf6260]

I reckon they will fit no problem seems to be lots of space under rear mudguards of 6260

 

[Jim B]

520/85 R38 is equivalent of 20.8 R38 and 420/85 R28 is equivalent of 16.9 R28 so it seems?

Given 20.8 R38 and 16.9 R28 is an option on the bigger models, as well as 18.4 R38 and 14.9 R28, then the 520/85 and 420/85 should go on 6260 without a problem ratio wise? I think rear fenders are the same throughout range too, so should fit?

 

[Serup]

520/85 R38 is equivalent of 20.8 R38 and 420/85 R28 is equivalent of 16.9 R28 so it seems?

Yes, it is the same size, just in mm and inches

Given 20.8 R38 and 16.9 R28 is an option on the bigger models, as well as 18.4 R38 and 14.9 R28, then the 520/85 and 420/85 should go on 6260 without a problem ratio wise? I think rear fenders are the same throughout range too, so should fit?

Ration is almost the same, and is a perfectly fine alternative. In USA they use tyre groups to differ tyres. a 520/85R38 would be a group 46 and 420/85R28 would be group 41. Then tractor manufactures just state the difference in groups between axles, and then you are free to fit any tyre combination you like, as long as you keep eg. a 5 group difference between front and rear axle.

I've found an example that explains it a little and has some examples of tyres in the different groups. http://salesmanual.deere.com/sales/.../8r/understanding_basic_tire_information.html

 

[Jim B]

Yes, it is the same size, just in mm and inches



Ration is almost the same, and is a perfectly fine alternative. In USA they use tyre groups to differ tyres. a 520/85R38 would be a group 46 and 420/85R28 would be group 41. Then tractor manufactures just state the difference in groups between axles, and then you are free to fit any tyre combination you like, as long as you keep eg. a 5 group difference between front and rear axle.

I've found an example that explains it a little and has some examples of tyres in the different groups. http://salesmanual.deere.com/sales/.../8r/understanding_basic_tire_information.html

Seems a very straight forward and sensibly way to do things, it'd be far easier if a similar system was forced upon manufacturers here! It was explained to me years ago that it is important to keep ratios correct for the tractor otherwise wind up and diff problems can occur, hence why I'm making sure the tyres I swap work! I forgot 520/85 was 20.8 and 420/85 was 16.9, so sorry for my thinking out loud here and thanks for your help.

 

[Boohoo]

Fitting tyres on to rims that are narrower than recommended can cause tyres to wear unevenly, with the centre of the tyre usually wearing faster. You also don't get all of the traction and comfort benefits that you would get if the larger tyre was on the recommended rim. Larger tyres will alter the gearing, don't be tempted to 'adjust' the engine power to compensate as this will put even more strain on the transmission. It is worth checking that there is enough spare movement in the pick up hitch assembly before fitting larger tyres because a pick up hitch that won't even touch the ground when fully down is of no use to anyone.

 

[Jim B]

Boohoo, thanks for your concern. I will check the rim widths first. But as Serup says 14.9 R28 should be on 13", and the Continental tyre book lists 13" as one of the recommended rims for 420/85 R 28, it will be ok. Also 18.4 R38 should be on 16" rims and this again this is one of the recommended rims for 520/85 R38 in the Continental tyre book, again it will be ok.

As now looking to fit some very good part worn 420/85 R28 (16.9 R28) and 520/85 R38 (20.8 R38), which are only one size up from the existing 14.9 R28 and 18.4 R38, it shouldn't effect the gearing too much. In addition the bigger models in the series with what I can presume the same transmission list these tyres and bigger as an option, there shouldn't be a problem. Same applies to PUH.

 

[Jim B]

Front rims are 12" wide. Rear rims are 15" wide. Damn!