Which is better: B or C?

Hi guys,

B seems more universal to me. C will turn in a tighter radius. A 6 ft mower will fit a B or C but a 5 ft on a C aint the best fit.

I have drove both.

Greg,

If you have a bank you wouldn't drive your C on then you shouldn't be driving your B on it.

Okay, I was wrong about wide front ends. I was only thinking that a wide front end would provide more stability. I guessed wrong. Sorry. 

You can't go wrong with any of them, but I agree that the CA's hand clutch puts it at the top of the list in my book.  And the narrow front on any model definitely makes it easier to get closer to obstacles when mowing.

I have been useing a B with a L 306 woods mower for close to 30 years I mow about 2 acres every week . yes a narrow front  C turns shorter but the rear end is wider than the mower have used both like the B best.

The narrow vs. wide front stability issue is pretty simple, really... you just have to look at three very specific things.

First... the center of gravity.  CG on both machines will be pretty darned close to the same... typically, it's about midway down the torque-tube, darned near centered if not ballasted... but the CG moves farther back when tires are ballasted... and if tires are only half filled, the CG will be lower.

Second... the front end roll-center.  This is the point where the machine 'pivots' when the front of the tractor rolls across a plane which is laterally inclined in comparison to what the rear of the tractor is doing.  In a wide-front, it's the axle pivot point.  In a narrow-front, it's where the wheels contact the ground.

Finally... the point where the roll center changes.  In a wide-front, the roll center changes dramatically when the axle hit's it's pivot limit.  In a narrow front, the roll center never changes... always where front wheels touch the ground.

The tractor's stability is best when the center of gravity is LOWER than the roll axis, and since a NF's axis is on the GROUND, it's obviously at a disadvantage to a WF setup.  With the CG being LOWER than the roll-center, it will WANT to stay upright, and even moreso when the axle's articulation limit is reached, because this establishes a 'new' roll-center that is substantially left or right of the CG... at that point, an overturning condition requires the CG to be much, much higher for the roll to be able to continue.

All that being said, Dick's rule-of-thumb is a very good one to live by... and should be especially noted that rollovers more often occur because the footing on which the tractor rolls turns out not to be as good as assumed.  Having a wheel drop into a hole, or sink into soft ground is more often the cause of peril than a simple condition of traversing a steep incline.

If you're bucking steep hills, consider ballasting tires half-way, spreading out the track as much as you can stand, and fabbing up a stout ROPS to give you an opportunity to survive... and remember that most of the time, when a tractor rolls, if you try to jump to safety, you will most likely be flung in the direction the tractor is rolling.

but Steve, when I come down, I am going to bring you the short arm narrow front end so your tractor get's it's parts back......

I just got to get swapping parts around, cause I got a C/B with C front and B rear. And lotsa' rust with hand brakes.....

DaveKamp wrote: Finally... the point where the roll center changes.  In a wide-front, the roll center changes dramatically when the axle hit's it's pivot limit.  In a narrow front, the roll center never changes... always where front wheels touch the ground.

Dave, I was hoping you would see this and jump in.
 Now if I was on a tractor that either had the uphill wheel off the ground or the down hill wheel sank for some reason, I don't think I would be too comfortable knowing that the roll center would change when the axle stopped pivoting. I think I would be wondering why I decide to try and mow the slope to begin with and how I was going to jump to the top side.
 I just see people talking about the wide front being more stable and never believed there was much difference. I thought having the pivot point up at axle level instead of on the ground would add a very minimal amount of stability.

When the wide front axle hits the pivot stop, the tilt pivot gets moved way out, to the bottom of the tire, much further from the center of gravity.

Then when one front wheel of a narrow front finds a hole the whole front of the tractor is generally in that hole, but if one front wheel of a wide front finds a hole the front of the tractor only sinks half as far.

Wide or narrow, there are a few things that will turn 'em over every time. On a slope dropping the down hill rear in a hole, or bouncing the up hill rear over a rock or stump. On the bank of a creek, pond or gully that's undercut when it caves off the tractor is gone, even if a crawler.

Rear wheel weight helps in safety, spreading the rear wheels out as far as possible helps safety, but there are some hill sides and banks that the row crop tractor should not be on going cross wise, maybe not going up, and less often going down. These critters are made for FLAT level ground they aren't mountain goats.

Gerald J.

All things considered, you also have the weight of the mower down at the ground level helping to lower the center of gravity. I mow with a wide front CA and a belly mower or a narrow front CA with a brush hog. The narrow front presses down too much grass and weeds and 2 days later it all pops up again. I'm thinking of putting the belly mower on 1 of the B's. Bob

Lonn, Easy fix for the gophers. Go to the coops or farm store and get a gab of those little blue pellets that you feed the mice and rats. Pour a hand full down each hole.  It will make the gophers nice and fat. They don't get fat until they stop moving and time and heat get to them but fat in any case.

There is on other factor that can make a tractor unstable. When operating on a slope and you feel the up hill tire getting light if you hit the down hill brake versus the up hill, it will make the situation worse. Don't ask how I know.