Author Topic: 900F forks on a '78 750  (Read 1985 times)

0 Members and 1 Guest are viewing this topic.

Offline killerdwarf

  • Full Member
  • *
  • Posts: 26
900F forks on a '78 750
« on: October 24, 2010, 08:45:03 PM »
I have a set of forks, and triples from an 82 900F which I want to fit onto my 78 750K. Anyone done this swap? What would I need to do?

Offline voxonda

  • Master
  • *****
  • Posts: 2,231
Re: 900F forks on a '78 750
« Reply #1 on: October 24, 2010, 11:40:31 PM »
I do a lot of these conversions, these are much better forks. Though I use the earlier ones, 'cause want to stick to 35m/m.
There is one small thing and that is the steeringlock stop(?), you have to change one of them. The one on the lower triple or the one on the head stock. These forks also have less trail than the oem forks and are a fair bit longer.

Good luck, Rob
« Last Edit: October 25, 2010, 06:08:25 AM by voxonda »
Better sorry for failing then for the lack of trying.

Offline tweakin

  • tear down
  • Master
  • *****
  • Posts: 1,955
Re: 900F forks on a '78 750
« Reply #2 on: October 25, 2010, 04:16:49 AM »
Check this out to help with the bearing selection for the conversion.

https://www.allballsracing.com/index.php/forkconvertion

Offline killerdwarf

  • Full Member
  • *
  • Posts: 26
Re: 900F forks on a '78 750
« Reply #3 on: October 25, 2010, 05:37:02 AM »
You guys make it sound easy. I already cut the stop off of my frame. I have the bearings, and races from the 900. They don't fit. The bottom race dia. is too big, and the top race is to small. What bearings, and races do I need? The AllBalls site says everything is the same.

Offline voxonda

  • Master
  • *****
  • Posts: 2,231
Re: 900F forks on a '78 750
« Reply #4 on: October 25, 2010, 06:13:54 AM »
The bearings should be the same, period. Done a lot of these conversions, hope you do have a Honda fork. Pic's?
It'll be OK, don't worry. This is just one of those things..........

Cheers, Rob
Better sorry for failing then for the lack of trying.

Offline killerdwarf

  • Full Member
  • *
  • Posts: 26
Re: 900F forks on a '78 750
« Reply #5 on: October 25, 2010, 06:45:42 AM »
yes they are Honda 900F forks. I have the bearings for the forks. I have the tapered bearing races from an '81 900C frame which I just pulled out last night. I removed the old ball bearing races from my 78K steering head,and the bottom tapered bearing race from the 900C is too big for my 78K frame, and the top tapered race is too small.

Offline killerdwarf

  • Full Member
  • *
  • Posts: 26
Re: 900F forks on a '78 750
« Reply #6 on: October 25, 2010, 05:09:44 PM »
tink tink tink....anyone?

Offline Retro Rocket

  • Eggs are hard due too a
  • Really Old Timer ...
  • *******
  • Posts: 19,279
  • ROCK & ROLL
Re: 900F forks on a '78 750
« Reply #7 on: October 25, 2010, 05:12:01 PM »
tink tink tink....anyone?

Check this out to help with the bearing selection for the conversion.

https://www.allballsracing.com/index.php/forkconvertion

Look it up...

Mick
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline killerdwarf

  • Full Member
  • *
  • Posts: 26
Re: 900F forks on a '78 750
« Reply #8 on: October 25, 2010, 05:33:14 PM »
So if I order the bearings indicated on the allballs site, I'll be able to bolt the 900 forks on w/o any other modifications except for the steering stop?

Offline Retro Rocket

  • Eggs are hard due too a
  • Really Old Timer ...
  • *******
  • Posts: 19,279
  • ROCK & ROLL
Re: 900F forks on a '78 750
« Reply #9 on: October 25, 2010, 10:31:54 PM »
What you need is a set of bearings with the 900 inside diameter and the 750 outside diameter....
The only other thing you need to look at is the length of the steering stem. I am using GSXR forks and clamps but to make it all easier and so i could use standard bearings, i had the Honda 750 stem pressed into the GSXR clamps and it all bolted straight up....
You may be able to do that with the Boldor clamps if the 750 steering stem is the same diameter at the base..

Mick
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline voxonda

  • Master
  • *****
  • Posts: 2,231
Re: 900F forks on a '78 750
« Reply #10 on: October 25, 2010, 11:39:33 PM »
Still wondering if it is a Bold'or fork, or oem bearings for that matter. Am building a 900 fork, with triples into a K6 frame at this moment. No need to make fuzz about the bearing. It is a one on one solution.
Even the stem length is correct, just the stop need adjusting.

Rob
Better sorry for failing then for the lack of trying.

Offline killerdwarf

  • Full Member
  • *
  • Posts: 26
Re: 900F forks on a '78 750
« Reply #11 on: October 26, 2010, 05:22:49 AM »
I have the factory bearings, and races. It is not a boldor set of forks.

Offline Tim2005

  • Expert
  • ****
  • Posts: 1,398
Re: 900F forks on a '78 750
« Reply #12 on: October 26, 2010, 10:59:23 AM »
You can look up the bearings for your shaft/headstock sizes here http://www.timken.com/en-us/products/pages/catalogs.aspx

BTW, what diameter are the fork tubes? 900s here in the UK came with 35s,37s or 39s.  Be careful when changing the fork oil- quantities vary a lot between the different forks so make sure you have the correct info.

Offline killerdwarf

  • Full Member
  • *
  • Posts: 26
Re: 900F forks on a '78 750
« Reply #13 on: October 26, 2010, 11:52:04 AM »
that helps ::)