Has Anyone Moved The 212 Engine's Clutch To The Flywheel Side?

[CrazyDan]

Is there any way to put a bearing on the outside portion of the shaft to take up some of the load. The flywheel side of the motor tends to be thinner because it doesn't take much load, putting the clutch on the right side might be too much for the single bearing. It's too bad the arc racing billet sidecover with dual bearings is for the left side of the engine, Would have been nice if it was for the right side.

 

[5-7HEAVEN]

Is there any way to put a bearing on the outside portion of the shaft to take up some of the load. The flywheel side of the motor tends to be thinner because it doesn't take much load, putting the clutch on the right side might be too much for the single bearing. It's too bad the arc racing billet sidecover with dual bearings is for the left side of the engine, Would have been nice if it was for the right side.

The flywheel shaft is shorter, but thicker than the clutch shaft.
.
The clutch shaft is 25mm at the bearing, and quickly machined to 3/4".

The flywheel shaft is 25mm at its bearing, and TAPERS to a 3/4" snout.

Good thinking about fabbing an outboard bearing bracket!

I guess a thick steel plate could be welded from the engine's mounting plate.

It's too bad that OEM clutch shafts are so short.

I guess the clutch retaining bolt could be replaced with a longer bolt or stud, to make use of the outboard bearing.

 

[5-7HEAVEN]

The clutch retaining bolt is an 5/16”-size.

It can be replaced with a stud or longer bolt.

The pillow block bearing that would work for my setup is M8-5/16”size.

I'd have to decide if the custom bracket hangs from the top of the engine, or rises up from the
bottom motor plate.

The custom bottom bracket MIGHT be simpler and easier to fabricate.

However, with a fabricated top-mounted bearing support, moving the engine in any direction won't affect the location of the outboard bearing support.

 

[5-7HEAVEN]

Yeah, I'm thinking of fabbing a 7.5" X 6" X 6" right-angle bracket,.

It'd be 3/16" thick steel plate, sandwiched between the engine and motor mount,
and gusseted at the bend for support.

The bracket plate's holes under the engine would not be slotted.
That way, if the engine needed to be shifted front or rear, the outboard bearing would still be in perfect position.

An 8mm x 22mm x 7mm pillow block bearing would support the clutch shaft end.

Seems simple enough.

 

[5-7HEAVEN]

More measurements:

If I use the clutch shaft I cut off the new crank, it'll be short, forcing the need for a longer clutch retaining bolt..

The load might be imposed on the extended M8/5-16" clutch bolt and tiny 8mm x 22mm x 7mm bearing.

If the clutch shaft is extended 1", then I can use a much larger M14/3/4"(12-16") 19mm x 35mm x 12mm outboard bearing.

Instead of welding up a longer clutch shaft, I can use my 1" keyed shaft that is 12" long.

The shaft needs to be drilled and tapped to screw onto the flywheel shaft, then machined down to 3/4" and grooved for the clutch's keyway.

I mocked up the clutch and 120t chainring pulley.

I'm using 3/16" steel plate for the 90-degree angled outboard bearing bracket.

It'll be a triangular plate, designed to work within the confines of the 25mm timing belt, which will run from clutch to chainring pulley.

 

[5-7HEAVEN]

The 23-toothed clutch pulley belts to a 120t chainring pulley.

This 120t bolts to a freewheel, which is connected to the right side pedal arm.

Belt Drive Sprockets :: Sprockets :: Sprockets :: Comet Kart Sales

The 10” long spindle with 3/4” bottom bracket bearings are from Amazon.

CDHPOWER Conversion Kit Crank Set Bottom Bracket for bicycle bike bottom bracket | eBay

A 27t inboard chainring sprocket links to the 25t sprocket on the 8-speed Sturmey Archer hub.

So, First gear is 15.7:1 and Eighth gear is 4.83:1.

Perfect.

 

[5-7HEAVEN]

The 120t chainring pulley is mated to the freewheel with an adaptor plate.
The pulley's diameter is 7.5", slightly smaller then a 48t chainring sprocket.

The pulley has a 6-hole/5.25”(133.35mm) bolt circle diameter (BCD).

The "adaptor plate" will have to be drilled for a 5-hole/2.56"(65.055mm) BCD. It already has a 54mm center hole, which registers with the standard 5-hole freewheel.

This is the "adaptor plate". It’s about 6.2” diameter.

It's actually a 62-tooth pocket bike sprocket:

8mm Sprockets for Electric Scooters, Bikes, and Go-Karts - ElectricScooterParts.com

This is the all-important freewheel, which prevents the engine from spinning the crank pedals:

Front Freewheel - Sick Bike Parts

The big issue is the wide spacing created between the crank arm’s freewheel and both chainring sprockets.

The inboard chainring MUST line up with the rear sprocket.

The outboard chainring MUST align with the clutch pulley.

The outboard pulley is usually bolted to the freewheel, which screws onto the Sick Bike Parts crank arm.

The crank arm MUST be wide enough to clear the engine and outboard bearing bracket.
If the crank arm clears the engine, but the outboard chainring doesn’t line up with the clutch pulley, then an Staton freewheel adaptor must be placed/welded onto the spindle.

3/4” ID x .9" wide 3 Prong, 3/16" keyway, 2 set screws, Freewheel Sprockets Adaptor (staton-inc.com)

 

[5-7HEAVEN]

The freewheel on the outboard chainring bolts to the inboard chainring with five M5 studs.
The distance between the chainrings will determine the studs’ lengths.

If the distance is too great, then a custom cylindrical spacer needs to be fabricated.

The spacer would look like the spinning cylinder of a 5-shot pistol/revolver.

 

[Wrench]

cap the studs with bullet shells

 

[5-7HEAVEN]

Yes, cap the studs.