Oversized wheels on a BCS

[MatSu]

Hello Everyone.
I've been lurking on the forum for years but now need to jump in and ask a question.

I purchased a BCS 948 specifically because of the slower transmission with the intent of installing over-sized wheels. I need the higher clearance for hilling potatoes and to straddle vegetable beds. I have been working with the 23" wheels that came with the tractor for the last two seasons and now I have time to prepare for next season. I only plan on using the oversized wheels in combination with a cultivator bar and hilling disks so if I have to stretch out the wheelbase to avoid rubbing against the engine I won't be putting too much stress on the axle and transmission. For all the pto implements I'll continue to use the 23" wheels.

I was thinking of going to the junkyard and getting some tires off a small pickup and then having my local fabricator alter the bolt pattern to fit the BCS hub but I would really like to get the lugs of true agricultural tire. This area of Alaska has silty soils and a little bit of rain (or irrigation) makes the surface very greasy.

While I'm putting out my wish list, narrow tire width is preferred. It keeps the wheels lighter and I can keep the beds closer together. I would love to find a wheel that is a little smaller in diameter than the rear wheels on a Allis Chalmers - G tractor. My target would be 30" to 36" diameter with a 6" width. If anyone has experience with over-sized wheels I would love to hear about it.

I did look at the track kits made for 4-wheelers but I ruled them out for several reasons: The modifications to make them fit my BCS would be too expensive, I would lose too much maneuverability in tight spaces, and the tracks looked wider than would be useful to me.

Video of BCS with tracks at https://www.youtube.com/watch?v=O0YVjLICEBU

Thanks in advance, Jeff

 

[js5020]

Someplace in this forum there is a thread where the poster (oldmech) made a set of steel wheels, they were stock size but one could make whatever diameter, width and offset they wanted,,, however going to tall is going to produce high ground speeds even in low gear and likely require modification of attachments since you have raised the operating height considerably. Steel wheels are aggressive and not for the lawn and generally last a long time.

 

[shallowwatersailor]

It might be difficult in your area but you might get lucky. The original David Bradley tractors used 16" wheels but a five bolt pattern (they actually only used three of the lugs.) I have read that the original WWII Jeep used a similar wheel. Tires with an agricultural tread are still available in 6.00-16 and are 29" in diameter.

 

[Brad_Blazer]

Front tires for ATVs are a little wider than you are looking for but the mud types have lug treads. 30" seems about as big as they get. My other thought was dirt bike knobby tires but I'm not sure if the diameter goes big enough. A 90/100-21 front tire would have a 28" OD. A 130/70-19 rear tire would be about 26".
Mud Tires

 

[mddorange]

:welcome:
To TBN MatSu. I guess you username is for the Matanuska River. I lived in Eagle River from 1984-1988 while stationed at Elmendorf AFB. We liked going to Palmer for the fair.

 

[bcp]

In photos, it looks like a large 4 bolt pattern. Maybe it would match an 8 lug 3/4T truck wheel.

What is the bolt circle diameter?

Bruce

 

[MatSu]

Thanks everyone for those great ideas!

Once you told me about the 6.00-16 size lugged tires that opened a few doors. I have contacted a few Lower-48 tire dealers to see what they can do.

I'll look into the ATV tires. The 28" one has potential.

I'll measure the bolt pattern next time I'm near the machine.

Yep, I live in the MatSu valley, Alaska's main vegetable production region. I'm an agricultural scientist for my day job and I raise specialty crops on the side.

Jeff

 

[BCSSHOP]

Thanks everyone for those great ideas!

Once you told me about the 6.00-16 size lugged tires that opened a few doors. I have contacted a few Lower-48 tire dealers to see what they can do.

I'll look into the ATV tires. The 28" one has potential.

I'll measure the bolt pattern next time I'm near the machine.

Yep, I live in the MatSu valley, Alaska's main vegetable production region. I'm an agricultural scientist for my day job and I raise specialty crops on the side.

Jeff

The bolt pattern is 100mm making a 4" bolt pattern nearly fit. A little elongating of the holes on a wheel with the 4" pattern and it fits fine.

 

[bcp]

There are a LOT of 4x100 wheels out there.

4x100 wheels

Bruce

 

[MatSu]

After a crazy busy summer I'm back with some oversize wheel followup questions and hopeing for some reality checks. Once I got pointed to the rim size website for 4 by 100 mm bolt patterns I found out that (in theory) I can use the 15" by 6" rims from a 91-97 Ford Escort LX or the 16" by 7" rims from a 2002+ Honda Civic SI Hatchback to fit on my 948 BCS.

According to a tire height website:

235-70-15 tires are 28" tall
255-70-15 tires are 29" tall
|
215-75-15 tires are 27.7" tall
225-75-15 tires are 28.3" tall
235-75-15 tires are 28.9" tall
265-75-15 tires are 30.7" tall

285-60-16 tires are 29.5" tall

255-65-16 tires are 29" tall
275-65-16 tires are 30" tall


So, between the 15" rims and the 16" rims I have some options in oversizing my wheels from the current 23" to the desired 28-30 inches. A 28" wheel would give me an additional 2.5 inches clearance between the undercarrige and the raised bed while a 30" wheel would give me 3.5" additional clearance. I'm using axle extensions to avoid engine clearance issues with the oversized wheels.

The speed range specs on various websites indicate that the 853 is about 22% faster than the 948

1st gear 0.6 mph versus 0.7 mph = 16.7 % increase in speed of an 853 over a 948
2nd gear 1.4 mph versus 1.7 mph = 21.4 % increase
3rd gear 2.2 mph versus 2.7 mph = 22.7 % increase
Transport 6.8 mph versus 8.3 mph = 22.1 % increase

Compared to my current 23" wheel which has a 72" circumrerance...
a 27" diameter has a 85" circumf. Which is a 18.4 % increase over the standard 23" wheel
a 28" diameter has a 88" circumf. Which is a 22.8 % increase
a 29" diameter has a 91" circumf. Which is a 27.2 % increase
a 30" diameter has a 94" circumf. Which is a 31.6 % increase

So, it looks to me that if I increased my wheel diammeter from 23' to 28" my 948 would have a similar ground speed as a 853 but with an additional 2.5" of ground clearance. If I go with the 29" or 30" wheels I may have to drop down a gear to get the optimal ground speed. I plan on only using the oversized wheels with a cultivator and a sicklebar mower. I'll switch back to the 23" wheels for the slower implements (tiller, rotary plow etc.).

So, what do you think? Should this work? Or, is my logic flawed and/or I'm missing something important?

Thanks in advance, Jeff