Reversed front wheels on 2910 for wider stance

[hayden]

I went ahead and reversed the front wheels on my 2910 to give it a wider stance and better stability on slopes. I decided the risk of possible early spindle bearing failure (which I think is remote) is a much better choice than the risk of getting smooshed in a tractor roll.

I like it, and can feel the difference. Mowing my very hilly fields was a much less hair raising experience this time. I didn't soil my armor even once.

Sharp turns do seem to chew up the ground more than before. Anyone remember their geometry well enough to explain why?

 

[MJB]

Years ago I worked as a mechanic in an alignment shop. The front wheels will tend to scuff more in turns if they are not in the designed position. An imaginary line extending downward through the king pin of a front axle should contact the ground at a point in the center of the tires contact patch on the ground left to right. In this configuration the tire will pivot on the center of its contact patch as the steering is turned. If the tire is well outside (or inside) of this point the tire must slide as well as piviot when the steering is turned. Hope this helps.

 

[Taz]

I upsized from the B2910 specifically because of stability on slopes. It's one nice machine. Hope it works out for you.

<font color=blue>Anyone remember their geometry well enough to explain why? </font color=blue>

No, but I'll take a shot anyway...
If you turn the wheels and drive the tightest circle possible the inner wheel will create a circle, as an example, let's say with a diameter of 10 feet (and a radius of 5). The circumference of that circle (pi*diameter), is 31.4 feet. The outer wheel is say 4 feet further out on the radius so it wants to drive a circle with a radius of 9 which has a circumference of 56.5 feet. So setting the wheels further apart increases the size of the outer circle which increases the difference in circumferences.

 

[Anonymous Poster]

If the B2910 front end is made with the same type of design as the B2400, then a wider stance or filled tires would not increase stability under most operating conditions.

At least with the B2400, the front axle can float so that one wheel can go up and the other down relative to the tractor. The rear axle is held solidly to the frame. Because of this any additional weight or width in the rear wheels will increase tractor stability. Since the front axle can float, additional stability would not occur until the front axle floated far enough to reach the axle stop. This would occur with certain irregular terrain conditions or if the tractor started to roll and the rear wheel was in the air, but under normal operating conditions the tractor should not feel more stable. I would think the rear would be a better place to add width or weight and increase stability.

Andy

 

[PowerMax]

I'm pretty sure I read somewhere in the owners manual of the 2910, where it said to "absolutely not reverse the front rims." Don't know why, but thought I'd let you know.

Jeff

 

[ronjhall]

Jeff
I checked my manual this morning. It says:

IMPORTANT:
Do not turn front discs to obtain wider tread.
In setting up the front wheels, make sure
that the inflation stem of the tires faces outward.

I don’t know why this would be a problem. /w3tcompact/icons/eyes.gif But you are correct about the manual. /w3tcompact/icons/smile.gif

 

[chim]

We had this discussion a while back about rear wheels. With certain tire / rim combinations, it is possible to exceed the maximum recommended center-to-center width on the tires on tractors like the B7500 with a selection of holes in the rear axle. The tractors are engineered for stresses and loads put on the parts under certain conditions. A 60" brush hog in the "carry" position flopping up and down on the 3PH, for example, causes more stress on the bearings and axles as the wheels are spread farther apart.

Same deal with the front, especially with a loader, front weights, etc. On the front, it also changes the geometry for steering, which was designed with the wheels set a certain distance apart.

Although the reasons behind instructions in the Owner's Manual are not crystal clear, there are generally reasons for the things they tell us to do (or not to do)....................chim

 

[smthng2do]

I think if you look at the hub also, you will see that it is not actually sitting flush on the hub. The little bumps in the hub of the rim actually sit on the wheel hub, so it is not a good thing. Some cases though, I have swapped them at the customers request, but only if it sat flush on the hub.

 

[hayden]

Humm, your logic makes sense, but it really does seem more stable. Maybe I am just imagining it. If I pretent to widen them more, will it get even better?

 

[hayden]

Yes, I'm aware of the warnings, but I chose to ignore them in favor of improved stability.

However, Andy has burst my bubble on that one, so I'll have to rethink it.