Timken Tapered Neck Bearing conversion for Harley J models

I have been asked by several people to expand in more detail the work required to convert a J model Harley roller bearing neck to the tapered Timken bearings we installed on my Cannonball Motorcycle. I would be more than happy to share the details we experienced while machining these cups. Plus, I will include some detail photos of the project.

As you will see, the factory cups for the fork neck on early J model Harleys (1911 - 1921) held 40 - 1/4 inch (.250) roller balls. 20 balls in the upper cup and 20 balls in the lower cup. These balls get wear and develop flat spots on the rollers, which cause a sloppy front end, speed wobble and just stiff turning. For the Cannonball project bike, we decided to install Timken tapered roller bearing in the neck of this 1919 Harley. This conversion is quite common on motorcycles with the ball bearing necks, but no one we found offered the proper cups to fit an early J Harley.

After knocking out the original cups with a brass punch and hammer, inspect the neck and clean all edges.

The factory measurement for the neck height is 5 1/4 or 5.258. At this point, we also decided to install a complete VL I-beam front-end on this bike. All components will exchange. This also allows me to install a front drum factory VL brake setup without any modifications.

Here are some detail shots of the actual bearing cups we machined to hold the races and tapered timken bearings

Timken Race Part # 15520 - sug retail $8.43

Timken Tapered cone bearing Part # 15590 - sug retail $16.28

Here are the measurements for the race holders - Top and bottom cups are exactly the same.

Use a threaded rod with large washers to squeeze the cups into the neck.

Here is the VL fork installed in the J Harley neck with tapered neck bearings.

Hope this is helpful. I have not ridden the bike with this frontend yet, but plan to have it back together in the next few weeks, so we can start to test and adjust it as we continue to press forward on the Coast to Coast Run in 2014 - Thanks

Moving Forward and Completing Phase #1

We actually got to escape to our river cabin up in the Arkansas Ozark Mountains on the Little Red River for the 4th of July holiday. Those trips usually turn out to be tons of work every time we go there, but it is so relaxing and enjoyable, even though its hard work! Got to Trout fish a few days, and even went fishing one early morning with one of my river neighbors, Jason.

 

After we returned home, the collection of boxes delivered to the shop seemed like Christmas morning! After opening all the boxes, sorting all the different parts according to its portion of the project, it seems I may now have all the parts needed to complete phase 1 in my action plan to ride in this 2014 Cannonball Run.

 

 

 

 

Phase 1 consisted of several key achievements:

 

(1) Getting the original motor #10154 back together with the new .020 cylinders, Venolia pistons, off-set rocker arms, over sized push-rods and new valves. This motor is the engine that will run the complete event. (hopefully)

 

(2) Acquire all the missing parts to complete "back-up motor" #13728 - This was quite a parts chase, but now I have everything needed to assemble the spare engine. Many people in the antique motorcycle world have helped me chase down all the special parts needed to complete this step.

 

(3) Roundup all needed parts to complete the 30's VL front end - I already had most of the hard parts here, but finally got all the hardware and pieces needed to install a complete VL front end on the motorcycle. We machined frame neck cups to add Timken tapered bearings, and put sealed bearings in the rear JD hub with stock VL brakes.

 

(4) Build new complete wheels and a spare set. This was a costly expense. New rims, spokes, tires, tubes and rim bands! Times 4!! They are ready to be laced. 2 VL 19inch wheels and 2 19inch JD rear wheels.

 

 

Setting up the JD rear hub in the lathe to cut the

roller ball surface out to install sealed bearings

 

How about that "China" word on my bearing?

Hope that doesn't come back to haunt me!!!

 

All my new wheel sets ready to be laced!

 

 

The 30's VL I-beam front end with Timken tapered roller bearings. Also parkerized all the springs and hardware. About to have the complete rolling chassis ready for a 3500 mile trip!!

 

 

******************************************************************

Now, for some Trivial Fun!!

 

My 1919 Harley Davidson serial number is 19A10154

and my perfect set of spare cases are L19A13728

 

There are many different resources claiming Harley Davidson motorcycle productions per year – It really depends on which book your are reading, but I found a couple of sources that stated very similar numbers. One of those sources was the numbered Harley Davidson museum limited edition book and I have another book about Harley’s that stated the same numbers for 1919.

 

W model (opposed) – 753 units

F model (magneto) – 5064 units

J model (electric) – 9941 units

FS model (US Gov Mil & Side car) – 7521 units

Total production units = 23,279

 

I also confirmed the total number of 23,290 with other references –without the actual different model breakdowns

So check this out:

Engine #1 – 19A10154

Engine #2 – L19A13728

These 2 engines are 3,574 digits apart –

 

 

 

If you divide 23,279 into 365 days, you get 64 engines per day

(this probably didn’t happen working 365 days per year)

5 working days per week =260 days in a year seems more realistic.

So, 23,279 units divided by 260 working days = 90 engines per day

 

90 engines per day, would put my 2 Harley Engines about 40 days apart –

Remember, this happen 94 years ago 

FYI – Just another note: 

1918 total production was 27,250 units & 1920 total production was 28,189 units