Replacing my deteriorated 1971 Rupp Roadster 2 swingarm bushing

#1
Well it turns out my bike is a 1971 since the rear swingarm was red. I gently sanded through the yellow an the frame was 20190709_221210.jpg red.
 
#2
Rubber deteriorates (dry rots) and on a 48-year-old bike one side of my red swingarm bushing, the rubber sleeve which is sandwiched between the 2 metal parts was completely missing. I burnt it out with my propane torch. The hardest part was removing the metal bushing ring that was on the inside of the swingarm tube. The rubber compounds had totally broken down over the 48 years the bike has been around and I highly recommend that people rebuilding a Rupp Roadster 2 get the new nylon swingarm bushing. Old dry rotted rubber bushings are sloppy and will fail which will lead to the rear swingarm moving all over the place and disrupting the bike's handling. Thank you to form member delray for pointing this out. I have pictures to prove these rubber bushings fail.

20190709_210609_resized.jpg 20190709_222815_resized(1).jpg
 
#4
I just did this to a purple roadster i'm working on. I pressed it out. had to make a couple small tools to do that. i'll post pictures later...
Did you buy the nylon and steel replacement bushing from Blackwidowmotorsports? In my picture you can see how there was several mm of movement which ended up leaving a ridge in the steel swingarm. Delray said that he made a tight aluminum bushing on his metal lathe and pressed it in to the swingarm and that the bike now handles so much better. He said with the dryrotted rubber and thin steel tube bushing the rear swingarm was all sloppy and all over the place and he races it which is way harder on that swingarm bushing than the average recreational rider would be. Actually modern automobiles now use urethane and steel bushings and they are darn near impervious to the elements unlike the old rubber bushings that crack and dryrot away. Plus the stiffness of the bushings can be made different depending on the urethane compound used. Basically any original Rupp Roadster metal and rubber swingarm bushing is at least 45 years old and 45 year old rubber is most likely pretty comprised.
 
#5
I just did this to a purple roadster i'm working on. I pressed it out. had to make a couple small tools to do that. i'll post pictures later...
I used a punch and I first heated the outside up with a propane torch. Once I got one side out I used a bolt with a head which was bigger than the bushing insert which just fit inside of the swingarm opening and pushed the other bushing insert out by tapping it with a hammer.
 
#9
I just used my propane torch and I burned out the remaining rubber and then used a punch to remove the metal sleeve. Once I removed one side I used a 6 sided head long bolt which fit inside the swingarm tube and tapped out the other sleeve. On one side the rubber totally was gone and you can see that the swingarm was pivoting and it left a wear ridge in the steel. Do you work in a machine shop? I only have my garage tools. My wife sort of hates it when I work on projects like this but she sure enjoys riding the minibikes.
 
#14
I just learned that recently. I wonder if the dimples were on my swingarms when I struggled to get those out. Lol.
Mine has the dimples too and yes it was pretty difficult to remove the bushing inner sleeve. I burnt mine out with a propane torch and one side the rubber bushing was almost completely gone and it allowed the swingarm to rock a bit side to side as shown in the photo with the wear ridge. After burning it out I used a long punch and a hammer to pop out one sleeve then I used a 6 sided head long bolt and tapped out the other sleeve.

Do you just press in the new bushing? Or should you coat it with an adhesive of some sort or epoxy? I was going to wait until I paint my Green Rupp Roadster 2 frame the correct color of green.
 
#18
In case anyone would like to make one. here's the blackwidow version for comparison. I think the plastic portion is Delrin. it's a well constructed and thought out product from black widow. well worth the $25.

I agree. The part is well made and the nylon outer bushing is extremely durable and most likely would never wear out no matter how much you ride your bike. Plus the original rubber and steel bushing from the factory is over 45 years old so it is going to literally be brittle and dryrotted and as seen in my picture one side the bushing the inner rubber which is sandwiched between the metal parts was almost completely missing and the swingarm was able to rock from side to side and left a wear mark on the metal swingarm.
 
#19
I use a press to get out the swing arm bushing. Frankly it's a bear to do it. The one below refused to come out, had to use a press and heat. Used a allen head bolt as a tool to press it out. Last pictures shows the allen head bolt, and the hot mess that came out of the swing arm.





The bushing you pressed out appeared to be in way better condition than the one in my Rupp Roadster 2. Since I do not have a press like you do. I found that burning the rubber out is the easiest way to remove the bushing. After that beat one of the bushing insert out with a punch then a bolt head just large enough to fit in the hole makes it easy to remove the other bushing insert.
 
#20
The bushing you pressed out appeared to be in way better condition than the one in my Rupp Roadster 2. Since I do not have a press like you do. I found that burning the rubber out is the easiest way to remove the bushing. After that beat one of the bushing insert out with a punch then a bolt head just large enough to fit in the hole makes it easy to remove the other bushing insert.
I think that is how I got mine out. Some place on the forum there is a picture of me doing that job.
 

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