Front Fork "Insides" Question

[Guest]

Hi,

I have a 1981 GS1100E that I am doing a bit of fork work on. The back story would be a few years back I took it on a trip from MN to NC and a fork seal blew out on the way. I had a buddy send me down another fork and replaced the fork in a hotel parking lot. Well, ever since then the bike hasn't been quite as stable in the front end. I am guessing maybe I didn't torque things down evenly or put in equal amounts of fork oil. So that brings us to now, where I am putting new fork oil in and torquing things down to spec.

My question pertains to the 'insides' of my forks. It appears they have a couple extra pieces of PVC and an extra washer when compared to the schematic. I don't know a whole lot about suspension so I wanted to ask the experts if I should pull these pieces out when I reassemble or if putting them back in would be the way to go.

I've posted a picture of the 'insides' of the front forks.

Thanks in advance for any help.

fork insides.jpg

[Steve]

Apparently someone took the time to do some "fine-tuning" on the front suspension. For that, you should be thankful.

If it were my bike, I would at least get a new piece of PVC that was the same length as the two pieces that are in there now. Of course, that is assuming that it is the proper length.

What springs are in there? If you still have the stock springs, you might want to consider upgrading to Progressive, Sonic or RaceTech springs. New springs of the proper rate will do a LOT to improve your comfort and handling, but you will then need to determine your own proper-length spacer. It's not a quick process, but you only have to do it once, so it's worth it.

.

[mike_of_bbg]

GS stock suspensions were generally considered "soft" when new - and time usually hasn't done them any favors! Many of us replace our stock front springs with Progressive, Sonic, or other aftermarket alternatives. Though, these are pretty generic and might not match the original springs in length. So the PVC is either there to:

1) Make up the length difference between stock and aftermarket springs.
2) Add pre-load to stiffen the springs.

The washers will be there to prevent the springs from eating into the PVC. As to whether or not you should add them back in, that's purely a matter of personal preference. If you were happy with the "cushiness" of your springs you can put them back in. If you want your suspension softer, remove them. If you'd like it even stiffer you can put longer pieces of PVC in there as spacers. If putting in longer PVC, try cutting slightly shorter amounts at a time. You don't want to use spacers so long they interfere with the travel.

You have a single post, so you're either new or returning from a long absence. If you haven't seen it already, BassCliff has a lot of great information archived on his site, including a Progressive springs installation guide which IIRC includes installing spacers.

http://members.dslextreme.com/users/bikecliff/

Good luck!

[SuperiorGS]

Thanks for much for the help.

I have enjoyed the ride, so I will cut some new PVC to size and put it back in.

[Steve]

Before you cut your new piece, put the forks back together with the current pieces. With the bike on the centerstand, measure the distance from the top of a lower fork leg to the bottom of the lower triple. Now, with some assistance of a helper, take the bike off the stand, and sit on it. Put as much of your weight on it as you can, you want to simulate as much seight as there will be while riding. Have your helper measure the distance from the same two points. Ideally, the amount of "sag" is 20-25% of total travel. Most of our bikes only have about 4 inches of fork travel, so you are looking for 3/4" - 1" of "sag". If it drops more than that, increase the length of your spacers by that extra amount. For example: if you have a 2" difference, add 1" to your spacer (you only want 1" of sag). Now you can cut your PVC to the proper length.

If you ever decide to upgrade to better springs, you will have to do the same "measure the sag" procedure to make sure the ride height and travel are correct.

.

[RichDesmond]

Steve, 3/4"-1" of total sag isn't enough. It's about right for bike sag, without the rider. Total sag should be nearer to 35mm.