GS850 Front Forks - Are All Years Universal?

[caselat]

What's up all, I tried searching for this and came up short. I'm sure someone has a simple answer.

The inner tubes of my 1980 GS850 have pits that are ruining my front forks seal. I can't find an OEM to replace except a $225 each version.

I'd like to get a used set off of Ebay. Just wondering before I pull the trigger if 1979-83 are using the same forks? Really hard to find something that won't do the same thing so it'd be nice to open up my options to other years.

Cheers!

 

[Steve]

No, there are four separate model numbers involved. Not sure what the differences are but here they are:

'79-'81 850G and 1000G
'82-'83 850G and 1000G
'79 1000L and '80 850GL and '80 1000GL
'81-'83 850GL and '81 1000GL and '82-'83 1100GL

The obvious difference will be the L forks, which will be longer. Not sure about the others.

.

 

[Dogma]

Starting in '82 (I think) the G models at least have the air balance port that requires some extra parts to make the pneumatic connection between them. Check the parts diagrams at an online retailer. I don't recommend trying to maintain air pressure in the forks (just make correct length preload spacers), but you do need the extra parts in order to close the forks and keep oil in and contamination out. Keep that in mind when buying used fork sets. Steve usually also points out that the L model forks have an offset angle requiring different triple clamps. Not sure why he didn't mention it this time.

Don't forget that used forks off of eBay may have pits too small to see in pics (look for good pics, or pass on it), and they may be slightly bent. Once you get them disassembled for rebuilding, roll the chrome tubes against each other to see if there are gaps between them or places where they don't roll consistently. If there is a bend, and it's small enough to tolerate, mark the tube so you know which way the bend is. When installing on the bike, align the tubes to make sure you get smooth motion of the wheel assembly without sticking.

 

[Steve]

Steve usually also points out that the L model forks have an offset angle requiring different triple clamps. Not sure why he didn't mention it this time.

Because he was only asking about the inner tubes. Those don't affect the offset, just the lower (outer) tubes, which offset the axle. The different triples are necessary to bring the fork tubes back a bit, keeping the axle in pretty much the same place, but at the expense of hitting the fuel tank when turned. That is one reason the L models have smaller tanks.

.

 

[Dogma]

Oh, that's why. I don't think I've never seen just the chrome tubes on eBay, so I assumed the opposite.