Author Topic: Can someone Harley Davidson literate help answer a question?  (Read 772 times)

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Offline Alan F.

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I'm researching for a project and on the subject of 41mm fork tubes it was recommend that I have a look at aftermarket fork tubes for H-Ds as they're available in many lengths over and under stock length. I guess stock is 24-1/4" right?

While bopping around the interwebs I found a forum post that suggested that the 41mm fork tubes on Harley models are actually 1-5/8" or 41.275mm and will not interchange with actual 41mm forks from other bikes.

I've found that the 1-5/8" forks began in the 1940s and were used into the early 1970s when front drum brakes were replaced by disc brakes and on until present day. Was there at some point a change to true 41mm tubes? I can't seem to find confirmation one way or another.

Offline Alan F.

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Re: Can someone Harley Davidson literate help answer a question?
« Reply #1 on: May 20, 2023, 08:49:21 PM »
I guess this pretty much says it:
https://www.jockeyjournal.com/threads/41-mm-fork-tube-differences.28116/

Fork cap threads may differ, 41mm is 41mm, before Showa became a vendor 1-5/8" forks were used, the two are not compatible.

Offline dusterdude

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Re: Can someone Harley Davidson literate help answer a question?
« Reply #2 on: May 21, 2023, 03:40:11 AM »
Harley started using showa front ends around 1973,give or take a year

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Offline Just John

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Re: Can someone Harley Davidson literate help answer a question?
« Reply #3 on: June 08, 2023, 12:23:54 PM »
HD further confused the 41mm fork system by offering different lengths of fork tubes for different models.  Make sure you check the overall length of any potential purchase to make sure they are right for your project.  I just finished rebuilding 3 sets of 41mm forks and none of the three were the same overall length.  They were all from the same year group but different models.
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