Rear wheel spacers for B2710: Kubota Review  -- Kubota Tractors Discussion Forum and Review Rear wheel spacers for B2710: Kubota Review -- Kubota Tractors Discussion Forum

  parts   |   manuals   |   discussion   |   photos   |   podcast   |   reviews   |   specs   |   dealers   |   classifieds   |   contact   |   faq   |   myProfile   |   home          Login Now | Sign Up


FAQ:   What is a tractor?

Forum Index

Kubota Tractors
  Kubota News
  Kubota Price
  Kubota Review
John Deere Tractors
  John Deere News
  John Deere Price
  John Deere Review
New Holland Tractors
  New Holland Tractor Price
  New Holland Tractor Revie
Other Tractor Brands
  Articulated Tractors
  Belarus
  Bobcat Tractors
  Case
  Cub Cadet
  Hinomoto
  Kioti Tractor
  Long
  Massey Ferguson
  Mitsubishi
  Other Tractor Brands
  Other Tractor News
  Shibaura
  Yanmar Tractors
Lawn and Garden Tractors
  Craftsman
  Cub Cadet Garden
  John Deere Garden
  Kubota Lawn Garden
  Other Garden Tractors
  Simplicity
  Toro Wheelhorse
  Ventrac Lawn Tractors
Antique Tractors
  Allis Chalmers
  Case David Brown
  Farmall IHC
  Ford
  Ford 9N 2N 8N
  Fordson
  Harry Ferguson
  John Deere Older
  Massey-Harris Ferguson
  Minneapolis Moline
  Oliver Cletrac Cockshutt
  Restoration
  Tractor Pulling
Tractor Attachments Implements 3ph
  Back Hoe
  Field Mowers Brush Cutter
  Grooming Mowers Finish Mo
  Loaders
  Snowblowers / Snow Plows
  Tillers and Ploughs
  Tractor Implements
  Trenchers
  Wood Chippers 3PH
Tractor Maintenance
  Diesel Fuel Lubrication E
  Tractor Engine Repair Reb
  Tractor Tires
Utility ATV
  All Terrain Vehicles
  John Deere Gator
  Mule Utility Vehicles
General Tractor
  Farming Ranching Agricult
  Photo Contest
  Size Tractor Needed
  Tractor Projects
  Tractor Safety
  Welding
Chinese Tractors
  Jinma Farmpro Agracat
  NorTrac Tractors
  Other Chinese Tractors
Cars
  All Brands
  Audi VW
  BMW
  Car Tires and Maintenance
  Chrysler
  Exotic, Sports, Racing
  Ford Cars
  General Motors
  Honda
  Hyundai
  Mercedes
  News
  Nissan
  Subaru
  SUV and Trucks
  Toyota Cars
Trucks Trailers
  Chevy Pickup Trucks
  Dodge Pickup Trucks
  Ford Pickup Trucks
  Toyota Pickup Trucks
  Chevy Pickup Trucks
  Dodge Pickup Trucks
  Ford Pickup Trucks
  Toyota Pickup Trucks
Home Building
  Alternate Electric Energy
  Barns Pole Barns
  Buying Ranch Farm Acreage
  Carpentry
  Contractors
  Electric
  Excavation
  Moldings Finish Trim
  Other Home Building
  Pellet Stoves
  Plumbing
  Wood Stoves
Tools
  Electirc Power Tools
  Gas Power Tools
  Generators
  Shop Tools
  Techniques Howto
Landscape
  Flowers Shrubs Garden
  Golf Course Maintenance
  Irrigation Systems
  Landscape Design
  Landscape Lighting
  Landscape Maintenance
  Lawn, Turf, and Grass
  Vegetable Gardening
Construction
  Caterpillar
  Komatsu
  Wheel Loaders
Current Events Health Happiness
  Current Events
  Dogs and other Pets
  Electronics And Computers
  Food
  Health
  Just For Fun Off Topic
  Movies Music Games
  Personal Finance Investme
  Sports Outdoors
Tractorpoint Site
  Member Photos
  Site Members
  Website Operations Howto


New As Posted | Active Subjects



Click to Post a New Message!

Discussion Boards > Active Subjects > Messages as Posted > Kubota Review Forum

Page [ 1 ] | 2 | | Next >>
Reply | Pop Up Window Reply | Add PhotoAdd Photo
 10-24-2004, 02:11 Post: 99142
mangoland



Join Date: Oct 2004
Location: Maui, HI
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster
Posts: 18

6
Filter by User
 Rear wheel spacers for B2710

Does anyone know if it is possible to widen the rear wheels an inch or so on each side by putting in a spacer? What are these usually made of - a thick disk of steel? Or aluminum? I was given this suggestion today and would like to try it. But I am also a bit paranoid about those cantilevered wheel axles sticking out so far already. Has anyone seen a bent rear axle before?

Here is a discussion that I found:






Link:   Wheel spacer discussion 

Reply to PostReply | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo




Bookmarks: Digg It | Del.icio.us |
 10-25-2004, 11:47 Post: 99229
mangoland



Join Date: Oct 2004
Location: Maui, HI
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster
Posts: 18

6
Filter by User
 Rear wheel spacers for B2710

No one seems to be weighing in on the matter, so I got out a pencil and made a few guesses.

Let's say that a tractor has its center of gravity (CG) up off the ground at 3', and centered between the wheels. And the rear wheels are each 2' out from the midline. This would give a tipping angle (where the CG is over the wheel's contact point) of 33.4 degrees (inverse tangent of 2/3). There are many variables here, but I just want to make a comparison.

So let's put a 4" spacer in, to increase the wheels to 2.33'. This now gives a tipping angle of 37.9 degrees, or 4 degrees better. Just by coincidence, it turns out in this case that an inch of spacer results in a degree of improvement, as a rough rule of thumb.

How does that affect the stress on the axle and bearings? On the B2710, it looks like the two axle bearings are 6" apart, and that the axle cantilevers out 1' from the end bearing. This would mean that, if the tire had 1000lbs of load on it, the inner bearing would have twice that, 2000lbs, and the end bearing would then have the sum of those, or 3000lbs. With that 4" spacer in there, the inner bearing would now have 2666lbs, and the outer 3666lbs, or a 22.2% increase.

Is the small improvement in tipping angle worth the increase in stress for this type of design? Death or broken bearings, which is worse?






Reply to PostReply | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo




Bookmarks: Digg It | Del.icio.us |
 10-25-2004, 12:17 Post: 99230
beagle

TP Contributor

View my Photos

View my Photos  Pics
Join Date: Jan 2004
Location: Michigan
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster
Posts: 1333

8
Filter by User
 Rear wheel spacers for B2710

I would agree with mango. You would be better to add rear wheel weights than add spacers. Rear wheel weights will not add to additonal stress on the bearings or bending stresses in the axle.

If fact, mango if you have the time, run the numbers and see how much weight would have to be added to a wheel to accomplish the same tipping angle. It isn't much.






Reply to PostReply | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo




Bookmarks: Digg It | Del.icio.us |
 10-26-2004, 11:16 Post: 99285
mangoland



Join Date: Oct 2004
Location: Maui, HI
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster
Posts: 18

6
Filter by User
 Rear wheel spacers for B2710

OK, good idea. Carrying on with the hypothetical example of a CG 3' off the ground (which on the B2710 looks like it would be the case with the bucket up a ways, for ex.) on wheels 2' out from center. In order for the tipping angle to be improved by a little over 4 degrees, the same as provided by the 4" wheel spacer, the tractor's CG would need to be lowered by about 5".

The axles are about 18" off the ground. To get the 5" lowering of CG, given the tractor weighs 2400 lbs, you would need 923 lbs of weight if they were added concentric to the wheels. That is a fair chunk of mass.

The rear tire measures about 20 gallons of volume. If partially filled with water, so as to obtain the greatest lowering of CG, I estimate that the tires would hold about 100 lbs each (~2/3 full). This would place the water's CG down lower than the axle, say at 12" off the ground. This only gives a lowering of the tractor's overall CG of just less than 2", not so much. It is a little complicated calculation to determine the CG of a partially filled tire, so I am guessing a bit here, but you may not get the maximum lowering of overall CG by filling the tires all the way full, since some of the weight ends up so high.

So it looks like perhaps a smaller spacer, and some wheel weight in combination might be a good comprimise. The 3PH is rated for 1700 lb. If I never carry anything that heavy, I should be within safe limits for bearing load.

Hope someone can check my back-of-envelope, early morning math...






Reply to PostReply | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo




Bookmarks: Digg It | Del.icio.us |
 10-26-2004, 11:53 Post: 99286
shortmagnum

TP Contributor

View my Photos

View my Photos  Pics
Join Date: Nov 2003
Location: Wisconsin
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster
Posts: 848
 Rear wheel spacers for B2710

Mango, your calculations seem reasonable. I don't think a full integral analysis would give much higher accuracy. But here's something to think about. Widening the track would help in a rollover situation such as mowing along a sidehill. There the forces are sideways. But my worst sphincter puckering has happened when I have a loaded bucket and one front wheel falls into a depression. The rear end comes up and if the rear wheels are off the ground, it doesn't matter how wide they are, tipping could occur. Counter weight is necessary. I think your thoughts of a combination of widening and weight are right on.
Dave






Reply to PostReply | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo




Bookmarks: Digg It | Del.icio.us |
 10-26-2004, 12:22 Post: 99290
beagle

TP Contributor

View my Photos

View my Photos  Pics
Join Date: Jan 2004
Location: Michigan
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster
Posts: 1333

8
Filter by User
 Rear wheel spacers for B2710

Mango, I don't think you took into account the couterweight effect of the wheel weights. It seems that the lowering of the center of gravity calculation is reasonable, but I don't think the couterweight effect is in your calculations. The wheel weights would be about 2'0 from the x-axis center of gravity, offering significant couterweight effect. In doing a tipping calculation, the entire spread of the rear wheels with the wieghts would be used. Assuming a rear wheel weight of 250lbs, and a rear wheel spread of 4', taking a moment about the downhill wheel would lead to a couterbalancing moment if 1000ft-lbs. The y-axis contributing moment would be 375ft-lbs.

Plug this moment into the overall stability calculation, and you will see that it effects the overtuning moment significantly. When taking moments for stability, assume the rear wheel weight as a secondary load, not part of the tractors mass. Use your same assumptions as before for the center of gravity for the tractor mass, and couter-act it with the secondary load induced moment. Compare that to the 4" increase in the moment arm (since it is from the CG to the tipping point) from the wheel spacers. I know these are all approximates, but it will give orders of magnitude.






Reply to PostReply | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo




Bookmarks: Digg It | Del.icio.us |
 10-26-2004, 15:29 Post: 99308
mangoland



Join Date: Oct 2004
Location: Maui, HI
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster
Posts: 18

6
Filter by User
 Rear wheel spacers for B2710

I'd agree that the *initial* resistance to rolling would be increased by the moment of wheel weights, and that the dynamics would also be improved by the increase in rotational inertia, leading perhaps to a lessened sphincter response when dropping a front wheel into a hole, as mentioned. If it feels better, it probably is better.

But the all critical tipping angle is just that point when the moment is gone, and the combined CG is above the pivot. If my aging synapses have got this point correctly, in rigid body analysis, you can subsume all the distributed masses into one overall point mass for all intents and purposes. So those two 250lb wheel weights, one on each side, would then be equivalent in CG to 500lb, centered at the middle of the axle. That then combines with the CG of the tractor.

Is that counterintuitive? It's different from a sailboat, for instance, where as you heal over, your pivot point (center of bouyancy) moves out to the side away from the the CG. So ballast effects increase with heal angle. with the tractor, ballast effect decrease with tipping angle, which is why you want to give a good safety margin to allow for those holes. Again, resistance to shock rolling by increase of rotational inertia (weights far from center) is a Good Thing (tm).






Reply to PostReply | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo




Bookmarks: Digg It | Del.icio.us |
 10-26-2004, 16:04 Post: 99312
beagle

TP Contributor

View my Photos

View my Photos  Pics
Join Date: Jan 2004
Location: Michigan
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster
Posts: 1333

8
Filter by User
 Rear wheel spacers for B2710

All the same, agreed. The reason why I was using a rotational moment approach was because the y-axis CG point is unknown. Therefore, treat the difference betweeen spreading the wheels and adding wheel weights as a seperate issue, eliminating the unknown y-dimension of the CG, and look at the differences in rotational moment from these two influences only.

The Center of Gravity is by definition what you suggest, the center of all rotational moments of the mass. For the entire system, this would determine the tipping point of the tractor. It is just a little difficult to calculate where it is for the y-axis. But I would disagree that counter-rotational moments are effective only in dynamic loading conditions. The static equilibrium point is justified as is the dynamic.






Reply to PostReply | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo




Bookmarks: Digg It | Del.icio.us |
 10-26-2004, 16:17 Post: 99313
Murf

TP Contributor

View my Photos

View my Photos  Pics
Join Date: Dec 1999
Location: Toronto Area, Ontario, Canada
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster
Posts: 7041
 Rear wheel spacers for B2710

All the physics and dynamics aside. The big problem with a tractor's stability arises from the pivoting front axle. When you are carrying a load on the FEL it becomes even worse.

If you happen to be close to the critical point and a front wheel drops into a hole or something then the sudden weight transfer may be more than enough momentum to throw all those calc.'s out the window.

Best of luck.






Reply to PostReply | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo




Bookmarks: Digg It | Del.icio.us |
 10-26-2004, 19:03 Post: 99320
BrendonN



Join Date: May 2004
Location: Central Kansas
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster
Posts: 89
 Rear wheel spacers for B2710

This is an interesting thread. I need to upgrade my membership so I can read all the postings. When I was a senior in engineering school, my design project (and also paying job working for my advisor) was to develop a "Stability Index" for tractors. The models I came up with took into effect CG height, track width, front axle pivot height, turning rate, slope, and vehicle speed. Surprisingly, the weight of the tractor reduces out to not being a factor. The final number to represent stability was a number from 0 (lifting a rear tire) to 100 (motionless on level ground). I rigged a Ford 800 with sensors and a datalogger, drove around turning on hills, then analyzed the data. If I remember, the lowest "Stability Index" I recorded was around 45 when operating on a 10 degree slope. Of course, I didn't really want to roll Colorado State's tractor over so I didn't get too carried away!






Reply to PostReply | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo




Bookmarks: Digg It | Del.icio.us |
Reply | Pop Up Window Reply | Add PhotoAdd Photo


Page [ 1 ] | 2 | | Next >>

Discussion Boards > Active Subjects > Messages as Posted > Kubota Review Forum

Thread 99142 Filter by Poster:
beagle 8 | BrendonN 1 | jarndt 1 | mangoland 6 | Murf 1 | shortmagnum 1 |

 (advanced search)

Picture of the Day
Coachlarry

Tractor Engine Repair Rebuild - Yanmar Fuel pump or primer bulb
Yanmar Fuel pump or primer bulb


Unanswered Questions

Belarus 825 - needs a new clut
Drain Cock
Need more hydraulic flow for s
HINOMOTO HB 501
Belarus 420A - Problems bleed

Active Subjects

460 Long hyd leak
460 axle
Key will not start engine
6x4 engine rebuild vsHarbor Fr
Things we say and what do they
The Plus and Minus of Ignoring
Looking to buy a New Pickup Tr
Need more hydraulic flow for s


Hot Topics

Tractor Category 1 2 3 Hitch s
Duerr hp 678 Chipper replaceme
Gator 620i gas in engine oil
KUBOTA Tractor Trouble Free Qu
Gator 6x4 Overheating problem
Duerr hp 678 Chipper Manual
Adjusting 7308 Pressure Relief
Long 460 hydraulic problem


Featured Suppliers

Mountain Creek Labradoodles
      MountainCreekLabradoodles.com





New Forums on Gun Sport Shooting and Hunting -- BarrelPoint.com  New Forums on Horses ManePoint.com
Talk Horses at ManePoint
Hunting + Gun Sports at BarrelPoint



Most Viewed

+ Kubota AT70s Rear Tine Tiller
+ Kubota HST GST Shuttle or Gear Transmission
+ Best Boom Mower for Kubota B2710 Tractor
+ Definition of Tractor Loader Breakout force
+ Kubota B3200 vs JD 2720
+ New Kubota L3240 First Look Review
+ Kubota Transmission Fluid SUDT
+ Kubota BX2230 VS kIOTI CK20HST
+ KUBOTA Tractor Trouble Free Quality
+ kubota bx25 vs john deere 2720

Most Discussion

+ How to match Truck to Trailer
+ New Kubota L3240 First Look Re
+ Kubota Number 1 in Compact Tra
+ KUBOTA Tractor Trouble Free Qu
+ Source for after market produc
+ 3-Point Quick Hitch
+ B 7100 ST - Making the Leap
+ Kubota Transmission Fluid SUDT
+ Kubota vs John Deere Compact T
+ L3130HST vs JD4310Hydro HELP

Newest Topics

+ Kubota B2301 vs Deere 2025R vs Mahindra Max24
+ 5040 shear on my PTO shaft
+ Kubota B7100 HST Flipped Will Not Move
+ Kubota b7100-hst
+ B2601 vs bx1800
+ 2000 B2710 I need a loader dealer wants over 4K an
+ Upgrading the Factory 145amp Alternator to 40 Amp
+ Kubota BX2750 Snowblower Fan Shear Pin Alignment
+ Size Kubota for Homeowner Use
+ I need some OEM Quality decals for a B7500 DT-TLB
















Turbochargers for Tractors and Industrial Machines
Cab Glass for Tractors and Industrial Machines

Alternators for Tractors and Industrial Machines
Radiators for Tractors and Industrial Machines

Driveline Components for Tractors and Industrial Machines
Starter Motors for Tractors and Industrial Machines