B7100 HST-D R14t Options (Check my math?)

[tsp159]

Good morning,

My B7100 HST-D has some very dry rotted turfs that need to go. I am keen on the newer R14t offerings from Titan/Goodyear, since I will be getting my B1630 loader put back together soon and installed on the tractor.

Doing some research, there are no directly compatible sizes that would maintain the 1.4664 ratio with the stock turf wheels, but if I source new wheels in a 12" and 16.5" size, there's a set that might just work perfectly.

Front - 23x8.5R12 R4T3G8GE RC 68.26"
Rear - 12R16.5 R4T3C9GE RC 99.80"

Based on the specifications posted, the rolling ratio works out to 1.4620, or just 0.3% leading from ideal.

Obviously, this is not a cheap option since I need new wheels all around, but it seems like a really good way to get into modern tire sizes and technology.

Edit:

Links to potential wheel upgrades:
Front 12" https://www.gallaghertire.com/12x7-6-4-27-3-543-orange-steel-wheel-w127027.html
Rear 16.5" https://www.gallaghertire.com/16-5x8-25-8-8-6-38-titan-nh-ag-yellow.html

 

[85Hokie]

Brother - it seems you have done the math and AT THAT 0.3% is nothing in the real world.

Please take some before and after pictures of these new shoes!

 

[tsp159]

One last question - anyone know of any issues with mounting a 9.75" width tire on an 8.25" wheel? It doesn't look like anyone, anywhere, offers a 6x6 16.5" wheel. Anything 9.75" wide is an 8 lug setup.

 

[Lencho]

I suggest checking for clearance between the larger front tire and the loader support as well.

 

[85Hokie]

I suggest checking for clearance between the larger front tire and the loader support as well.

WHAT he said ^^^^^^^^^^^^^^^^^^^^ was my thought too

 

[North Idaho Wolfman]

You missed this part, so yes you'll be fine with the width
And you should be fine on front tire height as it would clear the original AG tires.

 

[tsp159]

You missed this part, so yes you'll be fine with the width
And you should be fine on front tire height as it would clear the original AG tires.

View attachment 99523

Oops! I copied the wrong link - the 12-16.5 is recommended for a 9.75" The 10-16.5 is only 90" RC which would cause the ratio to be out of bounds.

I could also go with a 18x8.5-10 front and 27x8.5-15 rear for a 1.507 ratio (-2.8%) and not need new wheels.

 

[85Hokie]

Oops! I copied the wrong link - the 12-16.5 is recommended for a 9.75" The 10-16.5 is only 90" RC which would cause the ratio to be out of bounds.

I could also go with a 18x8.5-10 front and 27x8.5-15 rear for a 1.507 ratio (-2.8%) and not need new wheels.

I looked at ONE of the links JUST to see the tire style - I trusted you with the math....... yeah I know, we all can screw the pooch every now and again.

EVEN at 3% - you should still be fine - just stay off hard surfaces when in 4wd.

EVER wonder WHY the fronts wear out so fast on tractors? While true they are always turning left/right which wears them out, them leading the rears is what grinds them when in 4wd. Typically the fronts pull the rears to make turning easier while in 4wd.

 

[tsp159]

I looked at ONE of the links JUST to see the tire style - I trusted you with the math....... yeah I know, we all can screw the pooch every now and again.

EVEN at 3% - you should still be fine - just stay off hard surfaces when in 4wd.

EVER wonder WHY the fronts wear out so fast on tractors? While true they are always turning left/right which wears them out, them leading the rears is what grinds them when in 4wd. Typically the fronts pull the rears to make turning easier while in 4wd.

Thanks for the sanity check! Definitely not going to spend too much time on hard surfaces or in 4WD!

 

[Vigo]

Any '6 lug 16.5 implement wheel' will work for your idea but i think you already found just about the best price. Just pointing out you get more results using 'implement wheel' as a search term.

As far as putting that tire on the 8.25" wheel, it's functionally fine as long as whoever is mounting the tire can get it done. If they have a machine that helps you push it should be easy, if they're just doing it with an old rim clamp machine and some prybars they might have a fight on their hands. So it may just depend on what employees or what machines are present at the place you ask. I'm 99% sure i could get it on with the machines i use.

The tire 'ratio' does not need to be that precise since you generally only use 4wd on loose surfaces. I've experienced both 'too big rear tires' and 'too big front tires' on the various 6100/7100 ive either owned or worked on and swapped parts around between.

In general i would rather go bigger than smaller with the tires for a couple of reasons. One is that on all the gear drive 6100/7100 i've driven (never driven an hst) I have always been able to spin tires in 4wd, low range, 1st gear. So i've never 'not had a low enough gear'. But i have definitely wished 3rd gear low range was a bit faster. I'm not sure how much HST changes that, but i would personally prefer low range to have slightly taller gearing. I have seen videos of JD 1025Rs just bogging out and stalling the engine in low range without spinning the tires, hopefully the HST 7100 is not like that!! You also get greater ground clearance from the taller tires. And, possibly the best reason.. gaining weight on/in the tires is one of the best ways to gain weight on a tractor because the axles don't carry it. And adding weight to these tiny tractors is almost exactly the same thing as 'adding capability' because they are traction and counterweight limited, both things get better when you add weight.

As far as loader clearance with the front tires, the front axle has adjustable stoppers for both steering and side to side articulation. I just adjusted those on the one i was fixing for my buddy that had a particularly tall set of 6-12s on the front, and found i had to back the factory stops almost all the way out, but it still worked. They are just bolts so if longer bolts are needed, you just do it. Nothing tricky!