# What are the implications of smaller front tyres on a tractor?



## Mikefarm (Oct 27, 2011)

Hi all

What are the implications of a tractor that has smaller front tyres?
The following are all 60 HP tractors which have a MFWD setting and with the same sized rear tyres.

```
Tractor             Front     Rear
Case Maxxfarm 60  11.2/20  14.9/28
Kioti 551C         9.5/20  14.9/28
Massey 1660        9.5/16  14.9/28 <-- smaller front tyres
```
Am I correct in thinking that the only difference would be that for the same torque from their engine applied to the front (i.e. set it into 4WD) the tractor with the smaller diameter tyres would have less pull from the front?

I'm wondering as all these tractors are on my "look at to buy" list and the Massey Ferguson front tyres loo very small in their brochures compared to other tractors.

Mike


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## BelarusBulldog (Feb 19, 2011)

It's all about gear ratios. If you take a rear wheel drive pick-up with say 16" tires on it, and change them over to 15" you will give the pick-up more torque (pulling power) and less speed. If you change it up to a 17", the opposite is true. If everything was equal with the tractors, the one with the smaller diameter front wheel would have more pulling power up front. = lower gear ratio. Now there are other factors too, that cause manufactures to use different size wheels. Ground clearance is one, stability, turning radius, etc.. Bye


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## Country Boy (Mar 18, 2010)

I believe that the measurement you are looking at is the rim size, not the tire size. Depending on what type of tire it has on the front, the tires may just be the same outer diameter, but one has a smaller rim. The larger rims could have lower profile tires, making them the same outside diameter rims/tires. I'd personally go with wider, bigger tires up front for more flotation, especially if you plan to put a loader on it.


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## Mikefarm (Oct 27, 2011)

Hi



Country Boy said:


> I believe that the measurement you are looking at is the rim size, not the tire size. Depending on what type of tire it has on the front, the tires may just be the same outer diameter, but one has a smaller rim. The larger rims could have lower profile tires, making them the same outside diameter rims/tires. I'd personally go with wider, bigger tires up front for more flotation, especially if you plan to put a loader on it.


Yes, I dont have a tractor handy but that 16 inch is probably rim dia. However looking at pics of the tractors I can see that:
- the top of the front tyre on the Massey is about level with the centre of its rear tyre. 
- the top of the front tyre on the Kioti is about level with the top of the rim of the rear tyre. 

Its quite a bit of a difference.


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## Country Boy (Mar 18, 2010)

Having that larger tire will also give you a larger contact patch with the ground, meaning more torque is transferred to the ground to pull the tractor along. It will also allow the tractor to more easily drive through mud and roll over obstacles like rocks and dirt clumps (like in a plowed field). If the Massey is like my friend's it probably has skid steer tires on the front rather than standard ag tires. My friend and his folks bought a Massey (about 40hp) for use fixing up his grandma's farm and it has small front tires as well. Seems to get around fine, but if you plan to work in mud or soft ground, the larger tires will help keep you from sinking, and if you do, they will be better equipped to pull you through.


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## Rudra Singh (Jun 28, 2021)

Ascenso presents front tyre in all size for all brand tractor.


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## LouNY (Dec 15, 2016)

The different tractors having different tire sizes in the front means that will also have a different gear ratio in the front axle driveline.
Notice I said in the driveline as there are several locations that the gearing can change at, starting at the wheel end the planetary gearset or bevel drive ratio's,
then we have the front differential gear ratio, and then the actual 4wd dropbox ratio.


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