Harley motor sprocket shaft taper

80cui · Jul 3, 2018

Hi guys
I usually just read n learn . Ive done a search but gotta post.

Q : Does anyone here know the taper angle of the Harley big twin motor sprocket shaft on the sprocket side ? ? ?

its readily available info to quote 6 degrees which is the angle for the flywheel side of the shaft , then there was a change to 8 1/2 degrees .
there is no reference to the sprocket side .

#24001-30 this is VL , knuckle ,pan up to 1954 when splines came along .

#24000-29 this is DL RL WL 1929 to 1973

#352-25 this is the JD shaft to 1929, WL sprocket fits

#33-2001 this is S&S equivalent to HD big twin ....
I emailed to ask the taper angle of their product ...
their response = "1.000" taper" ..... which is meaningless to anyone

reason Im asking is there are chinese sprockets that V Twin etc sell that are the wrong taper so I started asking around and no one seems to know ....

cheers

Dan from Oakland · Jul 3, 2018

Why don't you just take the shaft end and measure the taper??

tdmidget · Jul 3, 2018

Sounds like 1" per foot or 1 in 12, however you like to call it.

80cui · Jul 3, 2018

I dont have a shaft , I was reading on different forums of guys buying sprockets that simply dont fit .I got curious to find out the correct taper .
one guy bought a dud , the supplier sent another one , that was also a dud . he then went to another supplier ... another dud sprocket .

Ive read of sprockets that dont fit JD HD which are pre 1930 , also 45" flatties and knucklehead and pan head up to 1954 .
the usual response is to buy genuine NOS which is true but that still doesnt fix the problem , typically taiwan tedds V twin parts .

I have Indian stuff , all the tapers are 6 degrees just differet length on diff shafts .
I just thought someone on here might already have gone over the motor shaft or dealt with the problem before . HD topic pops up now and then

1" per foot is 4.76 degree , dont sound right , if included angle thats 9.52

Mud · Jul 3, 2018

I measured a good condition OE Knuckle/Pan sprocket a while back by measuring over precision balls, just looked it up, I have it at almost exactly 15° included (theoretical calculation was 14.978955, the taper is too short to measure it that exactly) Also measured some domestic made belt drive parts, Brand P was 15.1° and Brand B was 14.69°. I think it's safe to say it's 15°.

Oldwrench · Jul 3, 2018

Mud said:
...Brand P was 15.1° and Brand B was 14.69°. I think it's safe to say it's 15°.

Ahhh, yes, the "aftermarket..."
:rolleyes5:

80cui · Jul 3, 2018

Mud ! you champion you , you know it.

I knew this place was it .

I asked S&S , I asked brand P , brand B and brand "Karate" , only heard back from S&S which was pointless.

LOL ,I knew itd be too much for some on this forum ... not to try figure the taper .

the taper tech ended in 1954 ,its obsolete altho used on the 4 sp trans main shaft up to 1980s, Im guessing companies are protecting their present product even tho after market ..... I dunno

anyhoo heres a bike built by Paul Bigsby the guitar guy who designed bikes with Al Crocker . 1936 crocker hemi head with a VL trans , the primary chain is 428-2 = 1/2 pitch .
the crocker sprocket is #35-4 = 4 row 3/8 pitch .

Obviously motor sprocket is swapped out for compatable 1/2 pitch.
both HD and crocker have a 1" dia shaft .

history says Al Crocker made shafts and bits for Indian under contract , all Indian shafts I measure have a 6 degree taper (6,01') .
I was kinda hoping the answer was going to be "6 degrees" and maybe Al used same tooling set up for his shafts on his brand as Indian .
note the VL trans is a crash box , not a knucklehead constant esh or a crocker c-mesh trans

cheers , now I can sleep at night ....

Newman109 · Jul 3, 2018

6 degrees taper for Harley lower end shafts does sound familiar for the Harley sprocket shafts, but it all depends on what year you are talking about. Early HD's were 6 degrees and in the '50's they went to 8-1/2 degrees, then later, in the 80's changed yet again. I found a description of the changes on a page of the Jim's catalog. I'd try to spell it out but it's so small I can't make it out. LOL.

Jim's data should be authoritative, since they have been a vendor to Harley-Davidson for many years on custom parts.

Jims Catalogue

Tapers have been known to let go. I once started my 1982 Harley Shovelhead to go for a ride and the engine started and ran OK. I put it in low gear to take off and....and.....nothing. It wouldn't move. I shut off the engine and then tried to restart it. noting happened. The starter just engaged and whined.

After stripping the engine, I discovered that the nut holding the engine drive shaft into the left flywheel had loosened and the shaft had pulled loose.

I had tor replace the entire flywheel assembly since finding a good left flywheel was not possible at the time.

Oh well.

80cui · Jul 4, 2018

truett and osborne seem to be the guys everyone goes to .
the info in Jims catalog used to be widely available on different sites.

the 6 and 8 1/2 degree is on the flywheel end of motor shaft .
Ive got 76 shovelhead , cant seem to let go of it , its S&S flywheels etc probaly worth less than stock ....

moonlight machine · Jul 4, 2018

So where the hell are all the Shovel Heads? There used to be millions of them. I don't remember the last time I saw one on the road or for sale. They must be in barns and garages everywhere....

Mud · Jul 4, 2018

They got shipped to Japan and Europe by the containerload, along with older models.

Zahnrad Kopf · Jul 4, 2018

moonlight machine said:
So where the hell are all the Shovel Heads? There used to be millions of them. I don't remember the last time I saw one on the road or for sale. They must be in barns and garages everywhere....

Japan. Not kidding. Still have some I won’t let go of. :cool:

Newman109 · Jul 4, 2018

moonlight machine said:
So where the hell are all the Shovel Heads? There used to be millions of them. I don't remember the last time I saw one on the road or for sale. They must be in barns and garages everywhere....

H-D built them from '65 to '84 but those were not good years for Harley and sales and production were down. Then the Chopper craze came along and the Shovelheads literally got chopped to pieces.

They just wouldn't leave them alone. Every bike had to have high bars, custom paint, chopped and re-welded fork heads to change the rake and ruin the trail so that they were hard to ride. Also, they added longer fork tubes, and on and on and on.

They also fooled with the engines to bump compression so that they would run hot enough to make the valve seats fall out. LOL.

Newman109 · Jul 4, 2018

Zahnrad Kopf said:
Japan. Not kidding. Still have some I won’t let go of.

Lots of them and their parts were shipped to Japan and also Australia. I used to hang out at an aftermarket dealer who regularly shipped crates of Harley parts to Australia. Both countries love Harleys.

jim rozen · Jul 4, 2018

Why would you want a chain.

MetalCarnage · Jul 4, 2018

moonlight machine said:
So where the hell are all the Shovel Heads? There used to be millions of them. I don't remember the last time I saw one on the road or for sale. They must be in barns and garages everywhere....

One is in my office

...

and the other is spread out through my garage waiting to get the frame back from the shop. I'm having it hard tailed.

I don't remember the last time I saw one riding around town though.

-Ron

10 fingers · Jul 5, 2018

Over the years I've worked with firms distributing aftermarket, HD product. It's a whore's market I want no part of. Very few firms have a professional engineering dept, or subscribe to any recognized QC program. Certified gages are non existent. Those that do bring well engineered, popular parts to market risk having them instantly knocked off. So bad I wouldn't ride a HD if you gave it to me. Can't distance myself far enough from that mindset.

Danny VanVoorn · Jul 5, 2018

I have a '76 Superglide (mostly stock) I ride occasionally, the yuppies I see at the beer bashes these days look at it like it's foreign made.
I have to agree with the comments in regard to after market parts distributors. I bought a cam bearing recently for one of my projects and the package proudly said made in china, the original was a torrington product. I found some on ebay NOS I suppose, am going to order one and hope for the best.
Dan

awander · Jul 5, 2018

You guys and your modern bikes..... :rolleyes5:

Newman109 · Jul 5, 2018

10 fingers said:
Over the years I've worked with firms distributing aftermarket, HD product. It's a whore's market I want no part of. Very few firms have a professional engineering dept, or subscribe to any recognized QC program. Certified gages are non existent. Those that do bring well engineered, popular parts to market risk having them instantly knocked off. So bad I wouldn't ride a HD if you gave it to me. Can't distance myself far enough from that mindset.

I rode Harleys for many years until age caught up with me. They are just a motorcycle. The mindset is in the minds of some who ride them. It doesn't have to be adopted by the Harley owner.

I was always a motorcyclist but never a biker. I wanted to be considered as a civilian as opposed to the hard core bikers and the 1%ers.

I'm not sure what you mean about aftermarket parts. There are some very good vendors out there - Jims. S&S, Custom Chrome, V-Twin, S&S, Chrome Specialties, to name a few. Sure, lots of parts are made offshore but they fill a void. Try finding an original speedometer or a speedometer cable inner and outer for a 1955 Harley Panhead sometime and you will see what I mean.

Anyway, they are just motorcycles, nothing more nothing less.

Harley motor sprocket shaft taper

Plastic

Titanium

Diamond

Plastic

Diamond

Titanium

Plastic

Attachments

Diamond

Plastic

Diamond

Diamond

Diamond

Diamond

Diamond

Diamond

Stainless

Hot Rolled

Titanium

Stainless

Diamond

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