SuperRat ES engine and a 26" HD Axle wheel for SINGLE SPEED bikes

Grubee Inc


This add is for a SR 70cc Engine & HD Axle wheel made for 110 to135mm dropout single speed application.. 

  • Includes the following items:

    • Included:  SuperRat 70cc 3 HP 2 cycle pedal and electric drill start engine contractually made by Nantong JaiLi to Gru-Bee specification. 

    • Included:  OCDT is included for hand held electric starting with 20V battery powered 1/2" drill.

    • Included:  A big downtube front mounting U bracket is included. 

    • Included:  SR Engine has built in integral ignition system and 6203 big bearing crankshaft. 

    • Included:  26" HD Axle wheel rim with our HD Axle and pre-laced with 12ga chrome spokes.   Ready for drop in. 

    • Included:  A 6 hole CCW screw on solid steel hub is included for attaching a disc brake rotor.   

    • Not Included:  A 36-1 CCW screw on Freewheel 5 Hole Hub for 4 cycle rope pull start engines is available as a separate purchase item.

    • Not Included:   36T to 56T chain sprockets must be ordered separately;    The more teeth a sprocket has the slower the speed but the higher the torque. 

    •  NOTE:  ITEMS NOT INCLUDED due to so many variations:   Left side Engine Drive Chain Sprocket,  /  Right side single speed 1.375-24 screw on freewheel pedal sprocket  /  Optional 5 hole Freewheel sprocket hub  / Disc Brake rotor  /  Engine installation kit that has > carburetor, tank, chain, muffler, muffler,  clutch lever & throttle and other misc. items.  

   When building a motorized bike the most critical process is true alignment and securement of the drive sprocket on the rear wheel when using the standard rubber donuts clamp to spokes sprocket installation method.    Yes, it is the CHEAPEST WAY BUT FAR FROM THE MOST ACCURATE AND SAFEST WAY TO DO IT.   When developed in the 1950's the Chinese had no money to spend for a better way.    Today is 2020 and things are different. 

We have the solution.       The HD axle saves your time and provides the most secure and accurate way to install a DRIVE SPROCKET on a solid screw on 6 hole hub and also enables having disc brakes.    

The hub axle has dual ball bearings with double row sealed bearings and that means heavy duty long life!  

Nest comes the engine:  The 70cc SuperRat engine is equipped with integral CDI and 6203 size crankshaft bearings instead of the smaller 202 size found in other engines.   

The exclusive ES engine feature is the ability to hand hold a 1/2" 20V battery powered drill and start the engine effortlessly by using our OCDT.     Only found on Gru-Bee engines.