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Rear Axle License Plate Holder

5.4K views 19 replies 6 participants last post by  LaGrasta  
#1 ·
Hi everyone.

I'm new here on the forum and hope there is someone who can help me.

I have a Honda CX500 from 1980, where I would like to mount a license plate holder like this one.
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But it is for a 20 mm axle.

It has been done on the Honda CX500 “Betty” by M8 Design.
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But unfortunately I do not know how.
Hope there are others who also have done it who can tell me how.
 
#3 ·
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#4 ·
Hello.

Thanks for your reply.

But it must be as in the picture as I have already bought the holder in the picture.
It is a highway hawk license plate holder. But it is for a 20 mm. axle.
The axle on a CX500 is not 20 mm. but it can obviously be done.

The problem is that there is not much room to put anything in between where the axle and bolt are.
I don't know if they have had a spacial nut made with a larger diameter, or how they have done it.

But thanks for your suggestion.
 
#5 ·
I'd use a flanged collar, 14mm ID, 20mm OD. Cut down the shank to be shorter than thickness of the plate of your holder, so the flange can pinch the plate. This will center the holder on the axle, adding minimal thickness under the axle nut.
 
#6 ·
Make sure that the axle nut still has full thread engagement after modifying the holder.
 
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#8 ·
Can you suggest a donor bike for a longer 14mm axle with the correct head?
 
#10 ·
If the flange adds too much thickness, you can use a shallow, unflanged spacer, but it might be more difficult to install.
 
#11 ·
Randall-in-Mpls I'm not 100% sure what you mean and what kind of part you would recommend.
But I assume it is something like this.

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I don't know if you can buy something like this.
But i think I can get someone to make it on a lathe.
And then I hope the new castellated nut is not too wide.

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Can you possibly link to one like you mean, so I'm sure i understood you right.

Thank you very much for your help.
 
#12 ·
I think I'd weld the hole in and re-drill it to the correct size. I wouldn't want to make the axle nut have any less threads than absolutely necessary.
 
#13 ·
It's also a really good idea
If you can weld and have a welder, it also requires that you powder coat it again.
I wold also prefer that I didn't have to use a nut with less threads but then i can't get the safety pin in the hole.
But I'm not so worried about it, as it can't fall off when there is a safety pin in it.

But thanks for the suggestion.
 
#14 ·
Your drawing is exactly right. I doubt you'll find one the correct length (no more than a couple mm, I imagine), so you'll need to cut down a longer one. Or turn one from rod stock, if you have access to a lathe.
The flange should be as thin as is practical. It's only there to hold the spacer in place during assembly.
 
#15 ·
The flange should be as thin as is practical. It's only there to hold the spacer in place during assembly.
No real need for the flange on the collar. Axle in place, slide the collar onto the axle, then place the license holder over the collar and install the axle nut.
 
#16 ·
I suggested that in post #10, but I believe the flange would make it easier to work with.
I think Bob's suggestion is the best option, if you have access to a welder.
 
#17 ·
Thank you for all your help.
I have now tried what Randall-in-Mpls suggested.
To test it, in the first instance, I 3D printed the washer on the picture, it must of course be made of metal.

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The new nut is perfect, it gives exactly the space I needed, and it is stronger than the original so I am not nervous about the threads.

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Thanks.