Author Topic: K5 and F0 fork tubes  (Read 495 times)

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Offline ekpent

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K5 and F0 fork tubes
« on: August 15, 2018, 06:07:41 AM »
   I think I may have a bent fork tube on a K5,not totally sure yet but for some reason the fork spring binds up bad on one side. Hard to pull in and out as it is binding up or snagging on something. Going to pull it off the bike and break it down and check it over well,roll on flat surface etc, make sure other parts are good etc..
  Have extra 1975 F model forks so question is are the tubes the same or are the F longer and or different and not interchangeable.  Be nice to have the parts on hand first for a quick fix if a swap is needed.  Eric

Offline 754

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Re: K5 and F0 fork tubes
« Reply #1 on: August 15, 2018, 08:50:25 AM »
The F tube would be hard chromed all the way up.
 Does your tube look bent, event if t was bent a lot springs should pull out.
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Offline Jerry Rxman Griffin aka MuthaF'er

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Re: K5 and F0 fork tubes
« Reply #2 on: August 15, 2018, 10:13:42 AM »
The 75/76 F tubes are a -392 part number as are the legs if that helps
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Offline seanbarney41

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Re: K5 and F0 fork tubes
« Reply #3 on: August 15, 2018, 01:08:44 PM »
I think the k5 has the short sliders like earlier bikes...just compare to your f0/1's, Eric...
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Offline ekpent

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Re: K5 and F0 fork tubes
« Reply #4 on: August 15, 2018, 04:11:54 PM »
 Well took it apart and the upper fork tube is bent enough for the spring to not fit well anymore and bind up inside the tube- Crap- Looks like someone may have tried straightening  it before with the old pair of two by fours and sledgehammer routine, some dents in the metal. Put 100 miles on it recently and no fork oil leak. Took it to a local cycle guru who said he could probably fix it but because of the previous attempt be best to swap it out.
  As Sean stated and which is true the lower aluminum section of the fork is longer on the F's then the K's.  If no one has a definitive answer as far as the upper fork tube compatibility and or differences I guess I will have to dissect one F model) and see. Hate to ruin a nice matched pair though and my other spare forks are 1972 and older which are different again.

  Anybody got a spare later model straight upper fork tube for sale ? Rust under the fork tubes is normal and acceptable as long as the seal area is good.

Offline seanbarney41

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Re: K5 and F0 fork tubes
« Reply #5 on: August 15, 2018, 04:41:09 PM »
Eric, you have extra set of f forks?  I have extra set of k3 to k6, we can probably work out something, as usual, lol
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Offline ekpent

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Re: K5 and F0 fork tubes
« Reply #6 on: August 15, 2018, 04:55:18 PM »
Eric, you have extra set of f forks?  I have extra set of k3 to k6, we can probably work out something, as usual, lol
Yes for some reason Sean 2 sets of F forks have come into my life over the last few years. May still snoop around a little for a single upper tube but sounds like a good trade also for both of us  ;)

Offline ekpent

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Re: K5 and F0 fork tubes
« Reply #7 on: August 16, 2018, 06:58:19 PM »
  Well I dissected today what I think was an F0/F1 fork to compare the upper fork tube as I thought they may be the same as my K5. Sadly they are different. The length is the same but there is a different location for that machined band as well as a different style and smaller diameterdamper rod where the allen bolt attaches. Shucks but maybe answer someone elses question in the future. Off to the 'wanted' section for a K tube I guess.