Gs850GT air forks conversion to non-air

[Guest]

Hi all I am restoring an American 1980 gs850g but I want to get rid of the air assistance as used on UK models. I have managed to find a set of GL forks which have the leading axle. My question is can I use the internal springs and spacers from the GL as it is my understanding (I stand to be corrected) the air springs are shorter or weaker.
thanks
Ken

 

[Rich82GS750TZ]

Going to a leading axle fork will change the handling/geometry of the bike, not advised. I've seen posts where folks have inserted a small PVC pipe spacer between the top of the spring and the air cap. Use the same cab, just don't put any air in. You may have to experiment w/ how long a piece of pipe you want depending on the pre-load you want.

 

[Guest]

Thanks Rich
I wasn't planning on changing the fork legs just the springs and caps as my air cap is broken and I can't find a replacement. If I'm honest I have also heard that air forks don't work well anyway. I am aware without the air the springs are too soft with too much sag. As you say I could put a pipe in to give preload but the springs on the air springs are shorter and already have a 4 inch spacer so I'm concerned adding more preload may cause the spring to bind on braking or hitting bumps. I have a set of springs from a GL with no air. The springs are two per side main spring and a softer helper spring at the top but appear slightly longer combined than G. I might just have a go and see what happens.

 

[Rich82GS750TZ]

RichDesmond is the resident fork guru, and (former? - I forget) owner of Sonic Springs. If he doesn't chime here with some advice, send him a PM.

 

[Nessism]

I wouldn't bother with the L fork springs. Take your original springs, chop off 4" of coils, and then fashion a PVC spacer to take up the lost length. This will stiffen up the front end a fair bit. A better solution is to change the fork springs to something stiffer all together.

 

[Rob S.]

Sonic or Race Tech STRAIGHT RATE springs. Use your fully geared up weight, not how much you expect to be in Spring after your Winter diet.

 

[salty_monk]

I wouldn't bother with the L fork springs. Take your original springs, chop off 4" of coils, and then fashion a PVC spacer to take up the lost length. This will stiffen up the front end a fair bit. A better solution is to change the fork springs to something stiffer all together.

If you're going to do this Chop it off from the closely wound end & dress the cut edge. Put a metal washer between the spring and the PVC spacer...

 

[emlivings]

I wouldn't bother with the L fork springs. Take your original springs, chop off 4" of coils, and then fashion a PVC spacer to take up the lost length. This will stiffen up the front end a fair bit. A better solution is to change the fork springs to something stiffer all together.

wait im doing something similar here to the OP.


Nessism, you suggest chopping off 4" of stock springs and replace with PVC?

I am planning on just adding a 5" piece of 3/4 diameter PVC without chopping the stock springs.
Any issues with this setup?

 

[Nessism]

wait im doing something similar here to the OP.


Nessism, you suggest chopping off 4" of stock springs and replace with PVC?

I am planning on just adding a 5" piece of 3/4 diameter PVC without chopping the stock springs.
Any issues with this setup?

Chopping off the spring makes it stiffer. Just adding a bigger spacer increases preload, it doesn't increase rate.