Compensating sprocket and springs

[belmont]

Anyone have some input on what all of this is? See the photos.
I was exploring in boxes and found these. One of the springs was tagged with part number 40302-52. That is for a K model according to my 57 Sportster and K Model parts book. The spring shown in my K Model parts books doesn't show the tabs that make this a torsion spring. The compensating sprockets are dual row 21 tooth and fit a tapered sprocket shaft with a key, like the 1954 back to 1938 big twin style shaft. These compensating sprockets do not look anything like the diagram in my 1956 Big Twin parts book. I see that Harley introduced a compensating sprocket for the 1938 to 54 big bikes in 1954 accessory catalog. That compensating sprocket isn't listed in my 1961 parts book, so I think it was discontinued by then most likely from lack of sales.

Thanks for any insight you can give me on these. belmont

[kitabel]

Dual row is 428-2, only used 1930-* big twin and 45 Daytona etc. racer (but the 45 wouldn't have a compensator).

[belmont]

Thanks kitabel, I checked my 1939 parts book and the cushioned sprockets offered used rubber blocks for both the 45" and big twin.
Nothing like these other than using a 2 row chain. I checked the threads on the nut on the NOS one and it measures at 11/16 x 18 tpi. An unusual thread size for sure.

belmont

[sswaney]

They are aftermarket Compensating sprocket setups. I can't make out if they are triple row or double row? They made one for Indian Chief and HD Big Twins with the tapered motor shaft.
Power Flow by Southern Products

[PRG]

Howdy chaps,

The PowerFlow is a transformational piece of kit for a Chief, though somewhat fragile if abused. Beyond the elimination of torque pulses your final drive chain and trans gears will last far longer. Unlike cam/ramp designs it dampens on accel only, not decel, the ears on the springs were prone to breaking off, Kevin Flannagan sold heavier duty versions at one time. Also, Ed Glasgow once sold a version out of Denmark(?) based on the HD FXB design using rubber rollers and a stator on the crank. You can view the components of the PowerFlow at one of my sites below.

https://petergz.smugmug.com/Motorcyc...-346/i-6Ng6MMn

[RichO]

Peter, Not to highjack this thread, but what road runs are you doing in '23? Pa. and Mass. on this end.

[sswaney]

I've got installation instructions in pdf files. The file is too large to post here.
If anyone would like a copy PM me your email address and I will send what I have

[PRG]

Well howdy sir!

Pa and Mass on this end? You didn’t move back to Pa from SMF did you? At this point we’re planning to do Black Hills, Pa and Ma with that after ride in Maine. After following your beautimus FXB in Monterrey for 3 days if your doing any of the of the east coast’s then I’ll bring mine.

[RichO]

Still out here but traveling by train back to Vermont to ride to PA. and Mass. rides on borrowed bikes. Our paths will cross. Merry Xmas to you two. Lenny just passed Wednesday. Legs hanging in my shop.

[PRG]

And kind sir, speaking of your cross country travel, can’t forget this one, not by train but the confines of a Suburban after these two argued incessantly about the proper tying down of this machine. As the bickering continued, you were grateful to have fortified yourself for that 30 plus hour journey back to LA from Elkhart Lake WI with two full cases of Yuengling. Merry Christmas to you and yours and see u back east.

[belmont]

Been occupied elsewhere for the last few weeks, the wife had hip replacement and needs my full attention.

sswaney, thanks for the info.These are dual row. I will PM you to get the PDF file on installation.

PRG, the pics on your site narrow it down on these to most likely being for Harley, dual row primary. I wonder if they were made to fit inside the original pre 55 tin cover.

belmont

[PRG]

Howdy sir,

The premise under which they were offered (for Indians at least) was with this device you didn’t have to replace anything else. You will note that the shoulder protruding outward beyond the face of the sprocket teeth approximates the lateral space occupied by the chain links and protruding pins. Obviously the whole mounted device does not protrude outward further or primary chain alignment would be compromised.

My concern would not be fitment rather the potency of the powerplant to which it was attached in conjunction with the heavy weight of the machine. Both of which on a big twin Pan would not only challenge spring longevity but the sheer weight with that torque would keep this device pinned to its stop therefore rendering it solid like the sprocket it just replaced.

[belmont]

Valid points. sswaney sent me PDFs of instruction sheets and I should be able to try fitting one of these on my 53 FL while it is on the lift for the winter. I won't know how it works while riding until May, when the snow is gone around here.

Thanks for the help, Karel

[sswaney]

"The premise under which they were offered (for Indians at least) was with this device you didn’t have to replace anything else."
PGR, I'm wondering how they sealed the motor bearing as they have no provision for the cork seal on the back side of the sprocket.
My Indian riding buddy is talking about adding a modern seal in the bearing race by narrowing the bearing spacer between the roller cages?

[PRG]

Howdy sir,

I’d formerly separated the primary from the trans with a lip seal in both the 346 and 348 to enable using thinner primary and heavier trans lube. The cork seals are really not all that effective for they were designed to do. At the time when I pulled this 50 plus year old cork out it had turned to hard carbon black while I didn’t accumulate a noticeable amount of fluid rise in the then shared primary/trans which admittedly is a large reservoir to accommodate any blow by.