The steering head bearings on the 1977 R100RS are the same as those used on the 1983 R80ST and the procedure to replace them is also the same. Therefore I will reuse materials I created when I replaced the 1977 R100RS steering head bearings in this document.
If the picture does not contain “1983 R80ST” in the caption, then it’s from the 1977 R100RS project.
I obtained the parts from Euro MotoElectrics who generously offered to provide parts for this charity rebuild for free. The bike will be auctioned and all proceeds will go to the Motorcycle Relief Project.
|31 42 1 234 509||RING, Steering Stem Bearing||1|
|31 42 7 663 941||TAPERED ROLLER BEARING – 28X52X16, Steering Stem-Earlier Part 07 11 9 985 070||2|
I use the Cycle Works tools for removing and installing the steering head bearings. See the “Replace Steering Head Bearings” section below for a link that shows the Cycle Works tools are assembled and used.
Here is a video summarizing how I remove and install the steering head bearings in the 1983 R100 RS. It’s the same procedure I used on this 1983 R80ST.
VIDEO: 1983 R80ST Replace Steering Head Bearings
Steering Head Outer Races
You can see all the details of how I replaced the steering head bearings on my 1977 R100RS here: the procedure is the same for the 1983 RS. This document contains information about rebuilding the front forks which you can disregard.
Rather than repeat what I already published in the document link above, I’m just going to summarize what I found with this bike.
The outer races on this bike are not as Brinelled as others I’ve seen. Since this bike has over 83,000 miles, I assume the steering head bearings got replaced at some point.
Here’s the link to the section about how to remove the outer bearing races from the steering head:
Here’s the link to the description of how to use the Cycle Works tool to install the new outer bearing races in the steering head.
Steering Stem Lower Inner Race
This race was very tight against the triple clamp and I used a large blade screw driver to move the race a bit so I could install the Cycle Works race puller under the grease cup beneath the bearing.
The inner steering head lower bearing is installed on the steering stem. It looks like someone used wheel bearing grease on the bearings. It melts at a low temperature and leaked out of the roller bearing.
The bottom of the lower triple clamp attaches to the steering damper.
You can see the grease cap mounted underneath the lower inner race. The Cycle Works bearing puller stand slides in between the grease cap and the face of the triple clamp.
Here’s the link to using the Cycle Works tool to removing the lower inner bearing race from the steering stem.
I had to reposition the puller as I used up all the puller bolt length but hadn’t gotten the inner race completely past the top wide spot.
Here’s the link to how to install the new inner bearing race on the lower part of the steering stem. I cleaned and polished the lower triple clamp as described below before installing the new inner race on the bottom of the steering stem.
I was able to drop the inner race down to the bottom of the steering stem using the same technique of heating the bearing to about 225 F and freezing the steering stem.
Refinish Lower Fork Brace
The aluminum was dirty, but not corroded. I used the parts washer to clean the grunge off. I followed up with AutoSol aluminum cleaner and a toothbrush. Next I used “0000” steel wool with the aluminum cleaner to remove the surface oxidation. I finished up with AutoSol metal polish to bring back the shine from the polished aluminum.
Install Steering Stem In Steering Head
The steering stem is secured inside the steering head with a special slotted top nut. The slots fit a wrench in the bike tool kit that tightens the nut. The nut has two different faces, one that is flat that goes on top and the bottom face has a bevel and narrow flat. The narrow flat exactly fits on the top bearing inner race. Tightening the nut pre-loads the roller bearings and keeps the steering stem in the steering head.
I pack both the lower and upper steering head inner races with red waterproof grease. I put a lot of grease on the rollers and roll the race around to distribute it to the inside of the bearing and repeat until the rollers are packed in grease. I also put a healthy smear of grease on the outer races too. I want a lot of grease to surround the rollers so they won’t Brinell.
I insert the steering stem into the steering head and put the top inner race over the threads on the top of the stem. Then I install the top nut to hold the steering stem in the steering head.
I use the hook wrench from the bike tool kit to tighten the nut to force the top inner bearing all the way down the steering stem and to seat both bearing inner races tight against the outer races.
There is chrome top dust cap the fits on top of the steering head bearing. The slotted nut fits on top of the dust cap.
The top plate fits on top of the slotted nut and the acorn nut fits in a hole in the top plate and is tightened on the steering stem threads to secure the top plate. I plan to install the Toaster Tan top brace and redesigned acorn nut. When I do that work, I’ll install the Toaster Tan top brace and acorn nut.