Rear axle fitment

jamesp · Jun 12, 2023

Need some help/suggestions on getting my rear axle spacer to fit between the speedo drive and the fork ear. I am coming up almost a 1/4” short of space. I have tried two sets of cush rubbers, one set made shorter to try to get drum closer to hub. Didn’t seem to make much difference. Speedo drive is tapped onto the hub. I have converted to one piece axle assembly with adapter installed. Adapter is right up against bearing on the inside of hub. Distance between rear fork ears is 8”, spacer is a hair over 1-1/4”. I have thought about narrowing spacer or trying to widen distance between fork ears if they are too narrow. They are powder coated, but I don’t think that is it. Any advice is appreciated. Thanks.

L.A.B. · Jun 12, 2023

jamesp said:
Distance between rear fork ears is 8”

Approximately 1/8" less than normal.

Frame dimensions?

I have always had a difficult time getting my rear wheel back into the swing arm. Currently my swing arm is removed and I see that gussets have been added at the front. It may be that the welding has pulled the arms towards each other. I know there is a diagram somewhere with all of the frame...

www.accessnorton.com

jamesp · Jun 12, 2023

L.A.B. said:
Approximately 1/8" less than normal.

Frame dimensions?

I have always had a difficult time getting my rear wheel back into the swing arm. Currently my swing arm is removed and I see that gussets have been added at the front. It may be that the welding has pulled the arms towards each other. I know there is a diagram somewhere with all of the frame...

www.accessnorton.com

Thank you for the info. and the link. I am afraid of cracking a weld or something if I use a bottle jack. The swing arm is already installed with new parts. Would it cause any alignment problems if I went with a shorter spacer? Thanks.

L.A.B. · Jun 12, 2023

jamesp said:
Would it cause any alignment problems if I went with a shorter spacer?

It depends on where the problem lies.

Reducing the spacer (by 1/4"?) is going to offset the wheel/drum sprocket assembly to the right, however, it depends on whether the swingarm plates (arms) are equally narrowed or if only one arm is pulled in and the other is not.

The distance across the outer faces of the axle plates should be (approximately) equal to the distance between the outer faces of the inner frame shock mounting plates or the (pre-Mk3) shocks won't be parallel assuming the upper and lower shock mounts are the same width.

robs ss · Jun 12, 2023

...just a note as a related issue.
Don Pender's single piece axle makes rear wheel fitment sooo much easier as everything is assembled on the one axle inserted from the LHS.
It also eliminates a potential source of failure.

bluto · Jun 12, 2023

robs ss said:
...just a note as a related issue.
Don Pender's single piece axle makes rear wheel fitment sooo much easier as everything is assembled on the one axle inserted from the LHS.
It also eliminates a potential source of failure.

Inserting the axle from the left could be a problem if a wheel bearing seizes and spins as that will try to loosen rather than tighten the axle...so I use the stock axle from the left to hold things together then install the Pender one piece axle from the right side (and push the stock axle out in the process) , works well for me and only a little bit more work.

(FWIW my Sportster is also MUCH easier to deal with when the axle goes in from the left but I go from the right at seized/spun wheel bearings are not unheard of on Harleys. I wish HD had used a left hand thread on the axle nut...)

robs ss · Jun 12, 2023

bluto said:
Inserting the axle from the left could be a problem if a wheel bearing seizes and spins as that will try to loosen rather than tighten the axle...so I use the stock axle from the left to hold things together then install the Pender one piece axle from the right side (and push the stock axle out in the process) , works well for me and only a little bit more work.

(FWIW my Sportster is also MUCH easier to deal with when the axle goes in from the left but I go from the right at seized/spun wheel bearings are not unheard of on Harleys. I wish HD had used a left hand thread on the axle nut...)

If you use modern double sealed bearings then you'd better keep your eyes out for the 747 about to crash down on you.

texasSlick · Jun 12, 2023

I had a similar issue with my Atlas. It turned out the left swing arm had a bow in it. Laying a straight edge along side the swing arm, brought the problem to light.

After removing the swing arm, a hydraulic press ram applied to the arm, with suitably placed braces, took out the bow, and the proper distance between the ears resulted.

Hope this helps,

Slick

Jdub · Jun 12, 2023

Have you made sure the flats in the dummy axle are correctly nestled into the left side slot? Had to ask...

jamesp · Jun 12, 2023

Jdub said:
Have you made sure the flats in the dummy axle are correctly nestled into the left side slot? Had to ask...

I am using the Don Pender one piece axle.

jamesp · Jun 12, 2023

L.A.B. said:
It depends on where the problem lies.

Reducing the spacer (by 1/4"?) is going to offset the wheel/drum sprocket assembly to the right, however, it depends on whether the swingarm plates (arms) are equally narrowed or if only one arm is pulled in and the other is not.

The distance across the outer faces of the axle plates should be (approximately) equal to the distance between the outer faces of the inner frame shock mounting plates or the (pre-Mk3) shocks won't be parallel assuming the upper and lower shock mounts are the same width.

I went back and re-measured the inner distance and it is closer to 8 1/16”. The distance between the outer shock mounting faces and the outer axle mounting faces is consistent at 8.74”. I am thinking that maybe the powder coating is too thick after all.

L.A.B. · Jun 13, 2023

jamesp said:
I went back and re-measured the inner distance and it is closer to 8 1/16”. The distance between the outer shock mounting faces and the outer axle mounting faces is consistent at 8.74”. I am thinking that maybe the powder coating is too thick after all.

Those measurements are close to what I'd expect so if the wheel assembly is almost a 1/4" too wide then the problem could be elsewhere. Sprocket/chain alignment is important so that needs to be checked before reducing the length of the spacer.
Before attempting any straightening of the swingarm it should be noted that it is not completely symmetrical. The axle plates should be equidistant from the frame centre line but the pivot end is offset approximately 1/8" to the left of centre because the cradle is also built with a 1/8" offset to the left. Rim offset from the frame centre should also be checked before reducing the length of the spacer.

YING · Jun 13, 2023

jamesp said:
I went back and re-measured the inner distance and it is closer to 8 1/16”. The distance between the outer shock mounting faces and the outer axle mounting faces is consistent at 8.74”. I am thinking that maybe the powder coating is too thick after all.

James,
I would definitely start with the powder coating.That coating is real nice but can cause a variety of headaches.
Mike

marshg246 · Jun 13, 2023

jamesp said:
Need some help/suggestions on getting my rear axle spacer to fit between the speedo drive and the fork ear. I am coming up almost a 1/4” short of space. I have tried two sets of cush rubbers, one set made shorter to try to get drum closer to hub. Didn’t seem to make much difference. Speedo drive is tapped onto the hub. I have converted to one piece axle assembly with adapter installed. Adapter is right up against bearing on the inside of hub. Distance between rear fork ears is 8”, spacer is a hair over 1-1/4”. I have thought about narrowing spacer or trying to widen distance between fork ears if they are too narrow. They are powder coated, but I don’t think that is it. Any advice is appreciated. Thanks.

Shortening the cush rubbers will do nothing to fix that. They should be flush with the hub when installed. The hub and rubbers should be clean and dry when inserted. Then push them all the way in the hub and spread them as far as possible in the hub. Then apply some rubber grease to the fingers and push them together.

It is possible that one or both of the ends of your forks are bent - easy to fix. If I remember right, there should be 8-1/8" between them (someone will correct me if I'm wrong - I'm not where I can measure right now). If not, determine which is bent. I use an old axel and old fork tube to fix. Put the axel in the slot from the outside in with the threaded part going in first. Position the nut end close to where the round and flat parts of the swingarm meet. Put the fork tube over the other end of the axel and pull - best to have a helper steady the bike but I do it alone. That flat-part metal is malleable so it will move pretty easily.

If the swingarm is OK or you fix it and it still won't go - use wooden handle hammer to force the wheel over enough to get the spacer in.

Saber · Jun 13, 2023

Make sure your cush rubbers are oriented properly. I believe the rounded edges go to the outside of the pocket.

jamesp · Jun 13, 2023

marshg246 said:
Shortening the cush rubbers will do nothing to fix that. They should be flush with the hub when installed. The hub and rubbers should be clean and dry when inserted. Then push them all the way in the hub and spread them as far as possible in the hub. Then apply some rubber grease to the fingers and push them together.

It is possible that one or both of the ends of your forks are bent - easy to fix. If I remember right, there should be 8-1/8" between them (someone will correct me if I'm wrong - I'm not where I can measure right now). If not, determine which is bent. I use an old axel and old fork tube to fix. Put the axel in the slot from the outside in with the threaded part going in first. Position the nut end close to where the round and flat parts of the swingarm meet. Put the fork tube over the other end of the axel and pull - best to have a helper steady the bike but I do it alone. That flat-part metal is malleable so it will move pretty easily.

If the swingarm is OK or you fix it and it still won't go - use wooden handle hammer to force the wheel over enough to get the spacer in.

“Shortening the cush rubbers will do nothing to fix that. They should be flush with the hub when installed.”

The cush rubbers I have extend beyond their space in the hub by about 1/8-3/16”, so I trimmed them to be flush with the hub. However, that doesn’t make any difference as the drum does not fit flush to the hub anyway. I have checked the measurements and I don’t think anything is bent. The frame and swingarm were checked and straightened by Richard at WASCO. So far everything seems as it should be, in that regard.

concours · Jun 13, 2023

jamesp said:
“Shortening the cush rubbers will do nothing to fix that. They should be flush with the hub when installed.”

The cush rubbers I have extend beyond their space in the hub by about 1/8-3/16”, so I trimmed them to be flush with the hub. However, that doesn’t make any difference as the drum does not fit flush to the hub anyway. I have checked the measurements and I don’t think anything is bent. The frame and swingarm were checked and straightened by Richard at WASCO. So far everything seems as it should be, in that regard.

So, did you assemble it WITHOUT the hard plastic (rubbers) mentioned above to prove/disprove the theory they are the problem?

jamesp · Jun 13, 2023

concours said:
So, did you assemble it WITHOUT the hard plastic (rubbers) mentioned above to prove/disprove the theory they are the problem?

I did not try to install it without the rubbers, but I did put the drum on the hub and could see that the rubbers would not interfere when drum is fully seated. In fact, I think the extra length may be necessary to keep the drum from wobbling when in motion.

concours · Jun 13, 2023

jamesp said:
I did not try to install it without the rubbers, but I did put the drum on the hub and could see that the rubbers would not interfere when drum is fully seated. In fact, I think the extra length may be necessary to keep the drum from wobbling when in motion.

The bearings hold the drum from wobbling.

marshg246 · Jun 13, 2023

jamesp said:
“Shortening the cush rubbers will do nothing to fix that. They should be flush with the hub when installed.”

The cush rubbers I have extend beyond their space in the hub by about 1/8-3/16”, so I trimmed them to be flush with the hub. However, that doesn’t make any difference as the drum does not fit flush to the hub anyway. I have checked the measurements and I don’t think anything is bent. The frame and swingarm were checked and straightened by Richard at WASCO. So far everything seems as it should be, in that regard.

That sounds like very incorrect cush rubbers. Maybe they are too thick as well. They are not what prevents the hub from hitting the brake drum. There will be no wobble and they would not prevent it if there were. As concours mentioned, remove them and put it all together. If it won't go then either you have it assembled wrong, have the wrong parts, or the swingarm is bent. If it does assemble without them, you should be able hold the brake drum still and rotate the wheel back and forth until the fingers stop it, and the wheel must not wobble.

When one side it bent it's easy to tell - measure the distance of the flat parts and see if they are parallel. When both are bent - it's harder and what L.A.B. said above is very important. I had one that was bent about 1/8" on the drive size and 3/16" on the timing side both towards the drive side. Fortunately, I had good swingarms to compare with so I could be sure I was straightening it correctly.

Rear axle fitment

jamesp

L.A.B.

Moderator

Frame dimensions?

jamesp

Frame dimensions?

L.A.B.

Moderator

robs ss

bluto

robs ss

texasSlick

Jdub

jamesp

jamesp

L.A.B.

Moderator

YING

Pittsboro,NC

marshg246

Saber

jamesp

concours

jamesp

concours

marshg246

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