Wheel motor:wheel size rule of thumb?

   / Wheel motor:wheel size rule of thumb? #1  


Platinum Member
May 4, 2010
Jessup Mill, NC
Rk55HC 4n1 fel/bh, Power-Trac 1850, 425d, Terex pt30, Kubota kx033, bx1880, yanmar 8x8 dumper, Magnatrac mh5000 w/ loader, six way blade & backhoe, Dew-eze ATM72LC Slope Mower, Terramite t6 4wd, DR Power brush mower
I'm curious if there is any guidance available to determine the maximum wheel size that a wheel motor should be matched to for direct drive.

I'm repurposing fairway mower wheel motors that were driving 26" diameter wheels (rim& turf tire). In the new application, they'd ideally be driving 30" wheel (rim & tractor tire) .

The hydraulic system psi is the same from old to new applications and the flow is reduced to keep the available rpm down. This is a low mph (under 10)application and the weight of the the new machine (w/ payload) is 20% less than the old application.

   / Wheel motor:wheel size rule of thumb? #2  
A bigger tire just means a longer lever arm, resulting is less torque. The other concern would be the ability to induce more side loading, but the slow speed and weight decrease should negate that. ISZ
   / Wheel motor:wheel size rule of thumb?
  • Thread Starter
Thanks for the response. I appreciate your thoughts.

I scored a couple of overhung load bearings and considered applying those to mitigate side load.... But seems like overkill....at least for the prototype... I'm sure I'm going to be making changes going ahead.