Over the last couple of weeks I noticed that the fork on my Superdelite seemed to be getting harsher than normal. It just didn't seem to be reacting to small bumps as well as it had previously. On a motorcycle this is usually caused by excessive stiction coming from the seals. Yesterday I thought I might pull the fork apart and see what the problem might be. My bike only has a bit more than 1500 miles on it but servicing it completely fixed it and now it is back to being as plush as before. This is a very simple job as it turns out and took about an hour never having done it before. The hardest part by far was turning the bike upside down even with the batteries out otherwise there's nothing much involved or any special tools required. Here are the basic steps. I also found a YouTube video that details the steps quite nicely. The only difference is that the tech in the video adds a little oil to each fork before buttoning it up. This isn't recommended by the manufacturer nor was there any oil in the fork when I took it apart but having said that, I can't see where a little oil would hurt and might even extend the service interval by a bit.
- Remove the air cap from the top of the left side fork tube and let all the air out of the fork
- Flip bike upside down
- Remove front wheel. You do not have to remove the fender.
- Remove brake caliper and cut the wire tie holding the brake line to the fork
- Carefully pry off the red rebound adjuster from the bottom of the right side fork tube
- With a pointed tool remove the small O-ring that was under the red adjuster
- With a 10 mm socket remove the fitting that the red adjuster was attached to being careful not to lose the washer underneath
- Remove the 5 mm socket head screw located at the bottom of the left side fork tube
- Now you're going to slide the lower fork tube assembly off of the upper tubes along with the fender. Mine was a little hard coming off. Turns out the left side internal piece that the socket head screw screws into was stuck. I just reinstalled the screw a few turns and gave it a tap with a hammer and the lower fork assembly popped right off.
- Clean and inspect the upper tubes. Mine looked perfect.
- At the top of the tubes in the lower assembly you removed are seals and below the seals are felt rings that are used to lubricated the sliding parts. Remove the felt rings. In my case they were pretty dry. Pour a small amount of 80 wt oil in a cup and drop the felt rings in and let them soak for a while.
- Clean and inspect the seals. In my case the seals were fine. Lubricate the seals by packing light grease underneath the seal lip. Slickoleum is very popular in the bike world and reasonably priced. I got mine from Amazon.
- Reinstall the now oil soaked felt rings in the recess below the seals. Make sure they are nice and square.
- Reinstall the lower fork assembly being careful when the the seal hits the upper tube. Don't force it or you can damage the lip of the seal. The tip of upper tube has a beveled white plastic piece installed which facilitates the tube sliding into the seal. A little grease here will help. Slide the lower fork assembly all the way down and reinstall the left side 5 mm screw, right side fitting and washer. Torque for the 5 mm screw and fitting is 10 nm otherwise just snug is all it needs. Reinstall the O-ring and red adjuster.
- Reverse the disassembly, add air with your R&M supplied air pump (I use half my weight in PSI), check and adjust for sag and you're done.
Here is a link to the video I mentioned. It helps to watch it first. If your fork internals were dry like mine were you will find a marked improvement in ride quality besides which you now know how to do the basic fork service yourself