I have temp access to both R1s and R4s for a Kubota B2650

[Dexterous]

Guys,

I know that there's been a million questions on R1s, R4s, rim sizes, etc and perhaps i can help. Due to a small mixup in shipping, my new B2650 arrived with R4s on it when I ordered R1s. The dealer send me home with the R4s which I have had for about two weeks now. I just got word that the R1s are waiting for me to pick up and that gave me an idea.

Very few people have gotten to experience the B2650 with both R4s and R1s back to back. Are there any comparison tests you guys would like me to perform or perhaps measurements you would like me to gather? Personally, I am interested in the following:

-Rim size measurement difference (since they are reportedly different)
-ROPS height measurement difference (R1s are supposedly taller)
-Ground clearance measurement difference (same as above)
-Track width (R1s are supposedly narrower)

-Grass damage
-Mud traction
-Mud packing and subsequent flinging

I would imagine that I have about 48 hours more with the R4s and then I will have the R1s so let me know if you guys want me to investigate anything. Thanks!

For reference, this is what I have now:
FRONT - 23x8.50-14 R4 Titan Trac Loader
REAR - 12.4-16 R4 Goodyear Sure Grip Lug

This is what I am about to get:
FRONT - 7-12 R1 Bridgestone Farm Service Lug
REAR - 12.4-16 R1 Firestone Traction Field & Road TT



P.S. Here's a pict of one of my rear R1s sitting at the dealer:

 

[RTSmith]

Well, apparently no one took you up on direct requests- but what are your thoughts on both now 2 weeks later?

 

[Dexterous]

Yeah, not one taker but thanks for asking, I actually forgot to report back.

This is my second Kubota with R4s and I spent a LOT of time stuck in the mud with the last one. I didnt push the R4s too hard on the B2650 but I have taken the R1s to near the max in the mud and I havent been stuck yet! For example, I had to clear a muddy area that often floods out and I was extremely worried about getting stuck. However, my fears were unfounded as the R1s never skipped a beat. I was honestly shocked by how well they worked and convinced that I would have been stuck if I would have had R4s on. At this point I am honestly very impressed with the traction and pleased with my choice. I still have that nagging voice in the back of my head that wishes I could have gotten a set of R14s for the B2650 and maybe I could have but my dealer didnt offer these to me when I purchased the tractor.

While the R1s do offer what I can only describe as an incredible amount of traction, its no surprise that they leave more marks on whatever surface they travel on. The big surprise for me was the amount of track marks that they leave in my crushed limestone driveway. They dont destroy it by any means but I can see all the places I have driven recently and this never happened with the R4. It wont come as any shock to hear the the R4s were far superior on the crushed limestone driveway and much smoother on asphalt.

The thing that most people seem to ask about is how well the R1s do on grass. Before we go any further on the subject of grass, I want to provide some background info my grass situation because thats whats shaping my opinion. First off, I dont mow a lawn with my tractor, its small enough that I use a push-mower. However, I live in a very wet area way back in the woods and I have been digging a ton of ditches and putting yard drains in everywhere. This requires me to drive back and forth again and again on the same piece of usually very damp grass.

Without a doubt, the R1s would never work for anyone who wants to mow their lawn under even the best, very dry conditions. I wouldnt say that they destroy the grass when lightly used but they do leave a very pronounced V imprint in the sod when its damp. On the other hand, the R4s on both my old tractor and the current B2650 did a lot of lawn damage when it was REALLY wet. This mostly happened because the wheels started to slip and they began to tear the sod off as they spun. In contrast, the R1s dont slip so in the worst and wettest conditions, they actually appear to cause less damage. After all, nothing destroys a lawn more than a stuck tractor.

As promised, I did take several measurements of the wheels, tires ground clearance and the height of the ROPs to see what changed. As has been well documented, both the front and rear R1s are skinner than the R4s. From a percentage standpoint, the rears are only slightly skinner by a bit over an inch which isnt really noticeable. The fronts are also skinnier by close to an inch and a half which is very noticeable. The ground clearance and ROPs height only changed by a fraction of an inch so theres really noting to report there.

Here are a few pictures that I took of the machine before and after:

R4s right before the swap:

R1s later that night:

R4 tracks in semi-damp ground (no rain in a few days):

R1 tracks in damp ground (rain 36 hours prior and wet to begin with:

HEAVY R1 traffic on very dry grass (near two dozen passes):

 

[MechanicalGuy]

I got r1's because our property is very hilly and we have no grass as of yet. I don't want to slide on damp hills.

 

[rustyanchor]

To echo what Dexterous posted:

I had R4s on a Farmtrac DTC 360 4WD tractor for 12 years, and as has been said before, they are a compromise tire. They are less 'destructive' in finished ground and give decent traction on fairly level dry surfaces. I bought the tractor in Va and used it on fairly flat ground, it worked pretty well. I moved to a hilly area of Ky and had some very exciting rides on damp or wet hills. 4 wheels spinning and sliding sideways. I was not on severe slopes, but once mud, dirt, or even leaf litter fills the spaces between the lugs, I had 4 slick tires. I fluid filled the rears with about 1.5 barrels of fluid (600 lb) in each tire, it helped some but it would still lose traction and off I would go sliding down the hill.

I use my tractor for a little of everything: bush hogging, moving dirt/rock either in the bucket or in a dump trailer, log moving and handling, on ground that runs from level to 'that's pretty sketchy looking'. It was maddening to hook to a fairly small log in the woods on a not very steep slope and have the R4s start slipping and spinning.

I finally put R1s on and fluid filled them with a barrel each. I lost about 400 pounds of ballast on the rear end, but I am getting much better traction in wet or damp ground. The R1s will tear up ground, but they have given much better traction on my hilly areas.
If I didn't have 4WD, I would add more weight to the rear to get even better rear traction. The rear end does get light with a bucket of dirt or rock.

The R1s are 8-16 on the front and 12.4-24 on the rear.
R4s were 27X8.5-15 front and 43X16-20.

The R1s give me better than an inch of additional ground clearance, and with the rear wheels and centers adjusted to their widest setting I get about the same width.

Long post, but if the tractor is being used for tractor type stuff on soft or less than flat ground, R1s are a good choice. If the tractor is used for more skid steer type stuff on good ground, R4s may be OK.

 

[tradosaurus]

I've stated this before but I'm really surprised that new tractors come standard with R4's. When I bought my first tractor this year I asked an old farmer and he told me he's used R1's for 35 yrs and only had 1 flat that he could recall.

The dealer recommended R4 and I can only assume the salesman never operated a tractor on hills or dirt.

 

[Texasmark]

I replaced R4 rears with R1s on the 2400. Big difference in traction and softer ride. Took off 33x12.5x16.5 and installed 8x16 on new wheels.

 

[Texasmark]

Smoother ride on smooth surfaces. Don't leave little zippers in the ground as much. Surely isn't cheaper. My thoughts.