Frequently Asked Questions

Do you have questions about our products or services? Below are some of our most commonly asked question.


Theoretically any combination is available by multiplying single reduction ratios: 6, 8, 11, 13, 15, 17, 21, 25, 29, 35, 43, 51, 59, 71, 87, and 119:1.

In general terms, the speeds are 1750 and 1165 RPM.  The selection tables in our catalog are based on 1750 RPM.  When other input speeds are used, the horsepower and torque ratings will vary.

The standard ratings for Cyclo® BBB4 are based on 10-hour daily service under conditions of uniform loads (equivalent to AGMA service factor 1.0). By following the product selection process outlined in our catalog, you will determine and apply the Service Factors to compensate for the severe operating conditions.

Cyclo® BBB4 Speed Reducers provide 300% momentary intermittent shock load capacity. For applications with shock loads greater than 300%, consult a Sumitomo Application Engineer.

To select the proper reducer for your application, you will need to know:Application: type of driven machine
Hours of operation per day
Motor horsepower (HP) and speed (RPM)
Loading Conditions
Mounting Position 
Ambient environment (altitude, dusty, chemical, explosive, water) 
Ambient temperature and humidity 
You must also note any special environment factors or operation requirements.  This information will be important in determining the your application's service factor. 

In general, reducers and gearmotors are rated for specific conditions and operating requirements of the application by the use of AGMA-defined Service Factors.  There are three AGMA load classifications for reducers: uniform (U), moderate shock (M), and heavy shock (H). Refer to our catalog for a list of AGMA load classifications. These Service Factors are used in the product selection process to adjust for the specific conditions and operating requirements of your application.

Other Questions?

We invite you to contact us with any questions that you might have.