CB450 K3 Fork Shortening Questions

[manualofman]

Hey guys - so I'm pulling my fork tubes out to send them off to Frank's for shortening. They are in pretty good shape, some slight surface rust and no pitting in the travel areas. These are extended forks, but I'm not sure exactly how extended they are.

First time builder here, long time over-analyzer, so I've got a couple questions for you guys:

Questions:

1. When measuring the fork length, you measure from the bottom of the fork base (center of axle?) up to the bottom of the top fork nut, correct? On the bike, these measured 33", I believe the 1970 Honda CB450 K3 stock spec was 23"

2. Frank's said they'd cut and remachine the bottoms of the fork tubes. The fork tube itself measures 28" disassembled. What's the original stock length of just the tubes? I assume I'll have to adjust the measurement to account for how far down the fork tube sits in the bottoms?

3. If the tubes are being shortened, do the springs and guide rods need to be shortened as well? Should I include them with the tubes when shipping them out?

4. I'm not sure if these fork bottoms are even stock either - I had assumed the PO just shoved some extended fork tubes into the original bottoms. Some pictures of these Cb450 K3's show bottoms roughly this size, and some show ones that look longer. The brakes fit the forks, wheel guard and wheel properly though - so I assume its stock.

Do I even need to be asking these questions, or should I just send the tubes, springs, and rod off to Frank's and say "cut these to stock" and they'll take it from there?

Thanks guys!

and here's what this thing looked with these extended forks on 'em

 

[manualofman]

Well, I figured I'd answer my own question here for anyone future forum searches.. as I've gotten the matter straightened out.

These forks are actually K5 forks, not K3 forks, the PO put these on with the extended tubes. That's why they look different.

The stock length for K5 fork tubes is 22.25". I did not need my damper rod and springs shortened as the PO had just installed a spacer rod that threaded into the top of the damper rod which threaded into the top fork crown bolt.

Mary over at Frank's really knows her stuff. No non-sense kinda lady. She immediately figured out that these weren't K3 forks and called me up to clarify. She had me remeasure my damper rods to make sure cutting my tubes to stock would still fit with them.