Offset for a 16" 47 Chief Wheel

[bobmac]

I've got a repo 16" rim that measures 3.875" wide. According to what I've read the correct offset for the 47 should be 2.3125". So when I divided the width of the rim by two and then subtract the 2.3125" offset I get -.375". Does this mean the hub on the non brake drum side should extend .375" beyond the edge of the rim?

Bob

[indianut]

The best way I have found to do that, with all the variables that are possible, is to bolt the hub up to a front end with all bearings etc. and true the wheel to the CENTER of the Forks! It makes for a Perfect Truing Fixture as well.

[Bill Huth]

Hi Bob, The original Kelsey-Hayes rim was 4" wide. With an original rim and hub, I have set my '46 and up 16"s this way: Take the rim, and lay a metal yard stick on it's narrow edge, bisecting the rim. Set the machined, brake drum mounting surface 1/4" to 5/16" below the edge of the yard stick. This should give you the correct offset. Don't forget to put the valve stem hole of the rim on the opposite side from the brake drum. Since your reproduction wheel is 1/8" narrower than stock, you will have to set the distance from the rim edge to brake mount surface on the hub 1/16" less, so 3/16" to 1/4". I haven't built my own wheels, but have had the same wheel builder do several sets of Chief wheels for me, and he said this is how he sets the offset. He doesn't like the fact that the center offset that you listed goes to the side of the hub that doesn't have a flat surface. It's unclear if that number goes all the way out to the snap ring flange or the curved surface of the spoke flange. I think the bad thing about doing it the way I mentioned, is you will have to take the brake drum off and on a couple times to check it while truing, since half your bearings are in the drum and are needed to spin it for trueing. Here is a pic to show the offset. Regards, BillOffset.jpg

[fillibuster]

I like Indianut's suggestion, especially if this goes on the rear. I found a 20 mph difference in handling due to incorrect offset/frame alignment. Felt like the rear wheel was on black ice at 65.

[Bill Huth]

If you have poor frame alignment, this just bolsters the case for not trueing the wheel to the frame/fork components. The front and rear wheels are interchangeable, and meant to be rotated. If you set your front wheel offset to the front fork and rear wheel offset to the rear plungers, there might be trouble in future wheel rotations if there is a problem with frame/fork alignment. Both wheels should have the same offset. The frame and fork should be straightened to factory specs.

[fillibuster]

If you have poor frame alignment, this just bolsters the case for not trueing the wheel to the frame/fork components. The front and rear wheels are interchangeable, and meant to be rotated. If you set your front wheel offset to the front fork and rear wheel offset to the rear plungers, there might be trouble in future wheel rotations if there is a problem with frame/fork alignment. Both wheels should have the same offset. The frame and fork should be straightened to factory specs.

Absolutely. But what are "factory specs"? Not that you need them, imo, but I am a novice. I trued my frame by establishing a center plane perpendicular to the steel, flat table (4'x12') in my shop, and bringing the fork center, the neck center, the rear center, and (initially) the engine center mounts into that plane. The wheel centers then happened correctly, but I had to move the rear approx 1/4" with spoke adjustment. ... no hands at 80 mph.

[Bill Huth]

The factory blueprint for the frame is available on the virtual indian website in the archives. It is the 40-45 neck, but the rest of the frame numbers are usable for 40-53. Back to the question of wheel offset. I would never recommend to anyone to just make the wheel fit their bike. Each component of the machine should be checked for straightness and corrected, as you did. I don't know what Bob has done in this dept., but I hope he checks everything out first. Can you interchange your wheels with one set 1/4" different from the other? I found out the hard way with a Chief I bought. Front and rear wheel cleared fine, I could drive the bike with no handling problems and it also went straight "no hands". But when I went to rotate the wheels, the rear, now put on the front, dragged against the fender badly, and just would not work. There are a multitude of things Bob could do to set his offset, or just make the wheels work on his bike. I was just offering a suggestion. He can take it or leave it.

[indianut]

The question was about setting the Offset. If you center a wheel in a Fork that is Proper, with all the Proper components, then the wheel will be set correctly for any chassis of that particular wheel type. Assuming the Components are Proper. Frame and Fork has to be True and Correct to specs or nothing else will be right. He didn't ask about straightening his Frame or Fork, just about wheel offset.

[Bill Huth]

I had John Bivens straighten my latest project frame and fork. He commented that in 25 years, he's received 1 frame that was "straight" and has straightened dozens, maybe hundreds of frames. So you are correct, if all the components are straight, you could use the bike as a trueing stand. I'm just worried that Bob doesn't have all straight components to start with. I really don't know one way or the other. So when someone says to just true the wheels to bike, I want to sound off a note of caution. His stuff may be slightly bent and he doesn't realize it. I am trying to point out to view the whole bike as a system. Pointing out that front and rear wheels are intended to have the same offset. That is why I'm bringing up the frame and fork. It is all related to the final product. The things I am bringing up are problems I've personally encountered with a Chief I bought 16 years ago and still own. The previous owner trued the wheels to the bike. One of the rims had the valve stem hole on the brake side, and one had it on the non brake side. The offsets were different for both wheels, so I had to fix all this stuff when I'd put a few thousand miles on the bike and went to rotate the wheels. I'm not denying your advice will work, just trying to point out some details I have encountered. Also, I'm taking the point of view that the question stems from a restoration project. This may not be the case. Maybe Bob's bike is a running bike that just needs a new wheel, and everything I'm saying isn't feasible to check at this time. When I had the trouble with my wheels having different offsets, one piece of advice I received was to just not rotate the wheels. I would just wear out the rear tire sooner, and replace it more often than the front. I was lucky, my wheel builder set the offset to what he told me was the factory offset, and the issue went away. My apologies if it sounds like I'm saying you are giving bad advice. I'm not saying that at all, just trying to provide another suggestion. I'll let Bob, who posed the question make up his own mind. I think he will know the state of his components better than us who are just speculating.

[bobmac]

Thanks for all of the good advise! I had the rims laced by a person who usually does HD wheels and I assumed he just set the offset to the wrong side because both my front and rear wheels are shifted towards the brake side of the bike and not centered in the fender. I'll add a picture next weekend. Thanks Bob