Topic: 550 and 750 fork tubes

[Chris Liston]

What is the difference between 550 and 750 fork tubes.  are they interchangeable with the lowers, etc..  I know they are alittle longer.  Any info would be great.  I have a bent tube that needs replacing..

Thanks

[mkramer1121]

If you can wait 'til this weekend I'll tear apart the ugly pair of 750 forks I have and the nasty 550 forks I have...Or you could also just check a parts fiche and compare the drawings/components.

[mkramer1121]

Actually, this deserves 2 posts, just to make sure you didn't miss this one:
Did some research by comparing parts fiche's between a '74 750k4 and a '74 550.  The lower outer tubes are the same.  The springs are different part numbers, presumably for different strengths.  All small parts int heir are the same (mounting bolts, oil seals, fork seals, etc).  Also, seems that the fork cap is the same.  So, differences are spring strength and upper tube length.  Hope this helps.

[chippyfive50]

I have a 74' 750 and a 71' 500, and the bottoms are the same( I have 750 bottoms on my 500) .
HOWEVER, the 71 bottoms do not have the mount holes on the right side for a brake mount(DUAL DISKABLE)
 I do not know when thy started making them on both..
I THINK 75-76 is when the sizes changed...