L2800 vs. B7800 Frame construction - durability

[paulgwin]

Hi perhaps you can help me better understand the frame styles between the B and L series tractors.

I'm contemplating buying a nice new orange tractor but have to come to grips with the differences in frame style between the L and B series.

From a durability perspective wrt to 20 to 30 yrs down the road, do the L series have an advantage over the B series?

My comparison is my old 1948 Ford 8N, that uses the conventional engine, transmission, and differential case as the tractor chassis and of course this is bullet proof - 60 yrs old and it will be here in another 60 yrs from now - very durable.

That is what I like about the L-series Kubota - they have the same chassis as the old school tractors.

The B series frame seems to be two steel plates in parallel with perhaps the foot platform (sheetmetal) attached to it. I don't think this would have near the torsional ridgidity or durability as the L series has (ok I'm a mechanical engineer). Also I would think it likely that the frame would loosen up over the years due to torsional loads (bolts working loose).

Perhps I've got it all wrong and the new way it just as good - but not having owned one I can only go off of design principals. Can anyone shed some light on the durability differences between the two tractors. Maybe it's a non-issue. I like the size of the B7800 for my current property but really like the L series bullet proof chassis style.

I also read somewhere that the B series have a lot of alluminum castings rather than cast iron - which to me doesn't seem as good either.

So why don't I just buy an L series? Well because the B7800 is shade smaller than the L2800 and a little bit more nimble I suspect. But if the L series is a machine that is much more durable I would rather sacrifice 15% mobility for the durability.

Thanks for your help.

Paul

 

[JOHNTHOMAS]

I'm not a mechanical engineer. I have purchased 6 Kubotas in the past 4 years and never considered the structrial rigidity of the frame in my decision making. I considered ground clearance when I traded my BX2200 to a B7800. I then considered a better ride and quick attach bucket and 0% interest for 42 months when 3 years later I traded my B7800 to a L3240HST. I failed to consider the HP being about the same for the B7800 and L3240 but the weight was about twice as much. I should have kept my B7800 or traded it to a B3030 since I have rather steep hills and the B7800 seemed to perform better for me than the L is doing. I don't know if a motor moving twice as much weight for 40 years would last as well as one of the same HP moving about half the weight for the same amount of time but I suspect it would not. I believe fuel consumption would also be different. I believe the L frame is heavier than the B and will probably be more durable that the B but I believe there are other more important factors to consider. Could be the difference between one frame lasting 99 years over one lasting 145 years. I know, it's that mechanical engineer thing. Ha! How about motor life between the two?

 

[N1ST]

I went through the same thought process and now have a B7800. I move between 5' gates and around fences a lot and mine is the largest I think I'd want to be using. The 30 hp seems like a good match for the size and weight. It also works good in the dirt and I don't have the rear tires filled. Sometimes it does slip if I'm in deep ruts, but I think that's expected.

 

[pax_tractor]

I went through the same thought process and now have a B7800. I move between 5' gates and around fences a lot and mine is the largest I think I'd want to be using. The 30 hp seems like a good match for the size and weight. It also works good in the dirt and I don't have the rear tires filled. Sometimes it does slip if I'm in deep ruts, but I think that's expected.

I went through the same decision process. I chose an HST L2800 with a FEL. The tractor is bigger and the frame style different as you described. For me, I wanted more heft to handle the FEL. I'm pleased with the tractor and glad I went that way. It's still pretty small overall. If I were to do it again, I would have gotten the L3400. Same size just a bit more hp.

 

[teg]

I think the only time the frame will come into play is if the tractors were worked really hard, actually putting stress on the frame. I don't think that over 30 years either would give out. I think you should look at your end use and decide which is right. I got the bigger tractor since I did not have to worry about tight spaces and I move a lot of dirt and rocks. I would concentrate on what your main uses for the tractor will be...

If I were to do it again, I would NOT buy the 3400 for the extra ponies... I have not had a problem with any "lack" of HP with the 2800... (pto is another story)

 

[la200o]

I went from a 60 year old 8N to an L2800 HST. No regrets--much more powerful seeming and it STARTS.

Bill

 

[paulgwin]

Thanks All. Very good things to consider and good perspectives.

La2000 - How does the L2800 compare in maneuverability to the 8N? You probably are the best reference for me since the 8N is my comparison. I do need more agility than the 8N which I'm sure the both of these surpass (especiall since the 8N front wheels slide and right/left braking is marginal on my 8N. How did your like the seat height difference between the 8N and L2800 (the L2800 seemed higher to me but I didn't have the N there to compare).


Can anyone state how much more maneverable the B7800 is compared to the L2800, or is it? Specification wise the L2800 looks like it should be as maneuverable as the L2800.
Specs:
L2800: wheel base = 63.3, width = 51.4 length = 106.5
B7800: wheel base = 65.6, width = 53.8, length = 99.2
The L2800 seat height does seem a bit higher than the B7800

Thanks again.

Paul

 

[lawn_king]

The big difference i noticed jumping from the B series to the GL series is a much smoother ride, the big frame machines dont jerk you around as much. I tend to be in my tractor all day making my living, so comfort is a big deal to me.

 

[la200o]

Paul,

I have the HST model. The tractor seems far more maneuverable than the 8N(shorter turning radius, power steering, ability to inch back or forward). The seat height is fine and more comfortable. The thing is just in all ways a better tractor (though whether or not it'll last 60 years is open to question!). It is very easy on fuel--seems to burn no more diesel that the 8N burned gas, or maybe even less. I can do the same mowing jobs in about 2/3 the time it used to take me.

Bill

 

[LBrown59]

I'm not a mechanical engineer. I have purchased 6 Kubotas in the past 4 years and never considered the structrial rigidity of the frame in my decision making. I considered ground clearance when I traded my BX2200 to a B7800. I then considered a better ride and quick attach bucket and 0% interest for 42 months when 3 years later I traded my B7800 to a L3240HST. I failed to consider the HP being about the same for the B7800 and L3240 but the weight was about twice as much. I should have kept my B7800 or traded it to a B3030 since I have rather steep hills and the B7800 seemed to perform better for me than the L is doing. I don't know if a motor moving twice as much weight for 40 years would last as well as one of the same HP moving about half the weight for the same amount of time but I suspect it would not. I believe fuel consumption would also be different. I believe the L frame is heavier than the B and will probably be more durable that the B but I believe there are other more important factors to consider. Could be the difference between one frame lasting 99 years over one lasting 145 years. I know, it's that mechanical engineer thing. Ha! How about motor life between the two?

Looks like I have some catching up to do.
I have only bought 3 Kubotas in 4 years.