1957 FLH Rebuild

[WillPhelps52]

I'm over Covid now and trying to build up some strength and endurance (for my age) again. I managed to get back in the garage and finish up all the spacers and business for the front end.

I hope to start working on the rear axle spacers this week.

[WillPhelps52]

I got my speedometer back from John Bordas. Looks awesome!

[WillPhelps52]

Before I jump to a wrong course of action to fix this problem, let show what I'm up against. There may be a simpler solution than what I'm thinking.

Rear Wheel Spacers

The first thing I did was to be sure the axle was straight. I did this by measuring the hex part of the axle on the right and the outer ring on the left. They were different dimensions, so that meant the axle adjusters needed to be different lengths.




So I adjusted the LEFT side axle adjuster to be .500 from the start of the slot and the RIGHT side axle adjuster to be about .450.

I put the wheel on with NO spacers and clamped a piece of angle aluminum to the sprocket. When lined up with the trans sprocket, there was about .250 gap between the wheel bearing and the main axle bushing. I had a .250 spacer, so I installed that and retried aligning the sprockets.



It's hard to see, but the sprockets are almost perfect. There's a very small gap between the angle aluminum and the trans sprocket. It looks like if I took a little off the .250 spacer, it would be perfect.

BUT

The rear wheel is not in the center of the frame. It's slightly too far left. My thought would be to put a spacer between the sprocket and the wheel, but I don't now if that's even possible with these wheels, or where I would get one.

Does anybody have a simple solution? Thanks.






The gap between the bearing and the main bushing on the sprocket side was about

[DoomBuggy]

How does the sprocket line up with the motor?

[WillPhelps52]

How does the sprocket line up with the motor?

The Engine and Trans are stock '57 in a stock '57 frame. There's not much I can do about their placement. It's the rear wheel that's not '57. It's an aftermarket FX style 16" wheel with a sprocket on one side and disk brake on the other.

I tried again to remove all spacers and use that angle aluminum to line up the sprocket, then check the gap. I measured the wheel thickness between the bearings, the main spacer.... everything I can think of. Now I'm going to run the calculations every way possible to make sure I end up with the same number for the first spacer.

[WillPhelps52]

I entered all my measurements into a spreadsheet and came out to .255 spacer thickness

I used FreeCad to enter all my lines, using constraints and the spacer came out to .254.

So with the sprocket all lined up with the transmission, I need a .250 spacer to go between the main spacer and the wheel bearing.

The problem still exists that tire is not centered in the frame. It looks like it's about 1/8" too far to the left. That would mean an 1/8" spacer between the sprocket and the wheel hub. Do they sell those kinds of adapters or do I need a 1/8" spacer behind each bolt?

[WillPhelps52]

I finished the rear wheel axle spacers and got everything set up. I actually made a YouTube video on how I did it.

I got a couple of steel beaded washing machine hoses to use as the spacer. I'm not sure they are thick enough. They are .625 in diameter while the chain is only .570. I had an issue with the chopper the first time I went highway speeds. The tire grew and rubbed the fender causing some bubbles in the paint. I forget what I used as a spacer on the chopper. It might have been a piece of clear tubing I had laying around, so I can't be sure about the diameter.

So now I'm onto the rear fender. First thing I did was put a thin wire across the fender approximately where the fender mounts will go. Then I cut it right at the bottom lip of the fender and folded it in half to find the middle of the wire. (Marked it with a marker). I will need to do the painstaking task of finding the exact location for the bungs.

Before that, though, I need to finalize the length. A buddy of mine thinks I should shorten the fender up about an inch. Here's what it looks like now.

[DoomBuggy]

Really nice work so far, my only regret with this build is that I pulled the plug on the springer, should have listened to my inner voice instead of my wallet.

[confab]

The problem still exists that tire is not centered in the frame. It looks like it's about 1/8" too far to the left.

I am sure you know this and I probably missed it somewhere in the thread, so forgive me for jumping in here half cocked and sounding stupid.. (It's something I do now and then just to stay in practice.)

But you DO KNOW you can place disk brake spacers behind the chain sprocket to align it with the trans, right?

Meaning, if you're too far to the left side of the bike you can center the wheel and then space the sprocket back where you want it to be.

[SteveJ]

Properly made frames are slightly wider on the drive side.
Drop a weighted string line down the neck tube , lay this down the backbone , this is your centerline , use it to line up the center of the wheel.
You can barely see the string taped down the back bone:

This frame is 2" wider on the drive side to accomodate the side/side rotor/sprocket.
Measuring the way you are wont line the wheel up centered and is why you cant figure out the problem.
ALL FRAMES ARE WIDER ON THE DRIVE SIDE.

[WillPhelps52]

Properly made frames are slightly wider on the drive side.

This is a stock 1957 frame. I tried to do my measuring as high up on the tail section as possible. I will try the string as well, though. I did end up buying a spacer for behind the sprocket and it brought me to within .020 of center. I'll check again with the string, but looking by eye from behind the bike, it looks like the center of the tire is in line with the center tube of the frame.

Thanks for your input.