Maneuverability of B-series tractors?

[jrv]

What is bi-speed turning? Is this compatible with 4WD?

 

[Rick Jay]

jrv:

Bi-speed turning is a system Kubota uses on the B2410 (and a few others, I think) to turn the front wheels faster than the rear wheels in very tight turns when 4 wheel drive is engaged. This allows tighter turning and less "scrubbing" of the front wheels during tight maneuvering.

I don't have it on my tractor, and my dealer said he's never sold one with it, so I can't tell you if it's worth the price difference.

Hope this helps.

~Rick

 

[art]

When you have to mow in four wheel drive because of hills it's a great tool. We sell them to some people in our area but not all. The tractor can turn as tight as in two wheel drive with no bucking or axle wrap.

 

[Kelvin]

"Bi-Speed Turn" is an option only for 4wd tractors. According to sales brochures, it is currently available only on the B2410. It was previously available on the B1550/B1750/B2150 and B1700/B2100/B2400 series.

Per the B2410 sales brochure, "Bi-Speed Turn increases the speed of the front wheels by approximately 60% of the rear wheels, giving you smoother, faster and much tighter turns. Even most trees can be mowed around with a single turn. Bi-Speed Turn automatically engages when the turning angle of the front wheels exceeds approximately 35 degrees. The minimum diameter of uncut area is substantially reduced from 83 to 51 inches."

 

[Kelvin]

Bird,
The following is the original post from the previous board. There were a few follow-on posts. Using the "search" feature looking for "Loader and Mower" from this board didn't bring up and posts for the previous board. After reading this post, I asked the local dealer about the problem and he agreed that he had seen the problem before. Basically, the mid-mower & loader combination makes it more difficult to remove & replace the loader, but not impossible.

<blockquote><font size=1>In reply to:</font><hr>

I have the B2150 with the LA350A Loader. I have learned the hard way that you can't drop the loader with the mid-mower mounted. What a hassle to have to drop the mower to drop the loader then have to mount the mower again without the aid of the loader to pick up the front end. Has anyone else come up with a solution. And no....I can't let my wife mow with the loader mounted. She has hit the well casing in the yard with the bucket once, and I can't risk her hitting it again. So I need to drop the bucket when she mows.

Thanks, Tim Pratzer

<hr></blockquote>

Hopefully you'll be able to research this more if desired.
Kelvin


<P ID="edit"><FONT SIZE=-1>Edited by Kelvin on 6/15/00 09:17 PM.</FONT></P>

 

[Bird]

Kelvin, that's interesting. I wish Tim Pratzer had explained why or how it worked that way. I don't think I'd like such an arrangement at all; however, I use 3-point mowers instead of mid-mount so it doesn't affect me. Of course, he was talking about a B2150 and I don't know exactly what's different in it and the LA350A loader.

Bird

 

[jrv]

Rick, this may seem a silly question, but: does the 4WD B-series Kubota have a full set of three differentials so that all four wheels can turn at different speeds, even without bi-speed steering? I'm puzzled about how 4WD works on these tractors without bi-speed steering.

If there isn't a full set of differentials then I would expect it to turn very badly in 4WD over a hard surface and to really tear up a soft surface! /w3tcompact/icons/shocked.gif

I suppose that if the tractor can turn at a sharp enough angle that the path followed by the front wheels is much longer than the path followed by the rear wheels, which means that the front wheels need to turn significantly faster than the rears (even after the tire size difference is allowed for, etc). Perhaps the center differential normally doesn't like so much slip?

 

[Kelvin]

Jrv,
For what it's worth, it is my understanding that 4wd tractors without Bi-Speed Turn operate just like 4wd Pickup trucks...you aren't supposed to operate them on non-slippery surfaces (the newer "All Wheel Drive" vehicles are another matter).

On my B7100 with 4wd engaged, it doesn't take too much of a turn angle to start tearing up grass and causing a slight bucking action as the front and rear differential fight one another. My B2150 (with 4wd engaged) seems to handle a larger turn angle than does the older B7100.

 

[Bird]

jrv, like Kelvin said, it works just like older 4WD pickups. You only have the two differentials; one on each axle, so you don't want to use 4WD on dry hard surfaces, and yes, it can tear up the turf a bit when you're turning, but in the only situations that I've used 4WD, that was not a concern. I don't use 4WD mowing my yard. And unless you're turning pretty sharp and/or pretty fast, it doesn't do a lot of damage to the ground.

Bird

 

[W5FL]

Nope, as Bird stated, no center differential, just front and rear like the pickups. I have a Jeep Cherokee that has 3 differentials, but tractor just has two. I mow a yard rather than a bermuda tiff lawn (use a walking lawnmower for that since the gate is only 3 feet wide) and can see little difference in 2WD or 4WD in terms of scuffing the yard, but a big difference in not sliding sideway on a slope in 4WD.

There are three levers on my tractor intended to improve traction when needed: The 4WD lever, the Rear Differential lock which is used while turning and you need additional traction, and the Front and Rear Differential Lock which is used while going straight and you need more traction.

The 4WD really works fine on soft surfaces and should never be used on paved or concrete hard surfaces. 4WD is not normally necessary for mowing (which takes very little power) but is much better than 2WD when mowing on slopes.

4WD is absolutely essential for loader operation and very effective on ALL ground engaging tasks where lots of traction is essential to proper operation. You never see a manufacturer's brochure showing a loader in operation on a 2WD tractor. They know better.