Fork tube swap - Upper stanchions only on a GS750 1976

[Z32650S]

Hi all,

I have a 1976 GS750B which is getting a makeover this winter. While looking over the bike, I noticed my forks would need some serious work. The current fork tubes are pitted with significant rust spots on the surface of the travel area.

While there are many options, such as a complete front end swap, or simply buying better 750 forks, I was wondering if I might be able to pay less and swap in good quality fork tubes from a GS 550. Some happen to be available near me and they are listed as 35mm as well.

This brings me to my research. I found a list on this forum, of all GS's which had 35mm forks.

Could I just breakdown the GS750 forks, and rebuild them with 35mm fork tubes from a non-750 model? Such as the 550 option noted above? Any downside to this? (Tube thinckness, flex differences, etc.)

Thanks for your help!


GS models with 35mm fork tubes:
GS-450 LD (83)
GS-450 LF/LG/LH/LJ (85-88)
GS-550 LX/ LZ (81-82)
GS-550 B/C/EC (77-78)
GS-550 LN/LT (79-80)
GS-550 LG (86)
GS-650 EX/EZ(81-82)
GS-650 GLX/GLZ/GLD(81-83)
GS-750 B/C/EC (77-78)
GS-750 EX/EZ (81-82)
GS-750 LT/LX (80-81)
GS-750 TZ/TD (82-83)

[sschering]

Tube length..

GS550 fork tubes are Outer Diameter: 35 Length: 593mm

GS550L fork tubes Outer Diameter: 35 Length: 632

GS750E tubes are Outer Diameter: 35 Length: 613

GS750L tubes Outer Diameter: 35 Length: 710


Just for fun to put it out there
GS1000E Outer Diameter: 37 Length: 595

Data from the TNK OEM replacement fork tube list

http://www.tnk.it/en/prodotti7.php?mp=TNK%20GROUP%20SRL&cat=FORK%20TUBES&artd=FORK%20TUBES%20LIKE%20ORIGINAL&mm=SUZUKI

[Z32650S]

Thanks for the info and link sschering! This is very helpful.

I'll be sure to cross-reference potential fork tube options for length.