Swing arm bearing again

[dirtbike]

Hi!
I read the messages but It's unclear wether he replaced the stock rubber bushing with a needle bearing. Anyway that's what I want to do. Does anybody know about that? I was thinking about using two bearings with a few mm space in between. Drill a hole and install a nipple for applying grease which then, I assume would come out on each side keeping it clean and ever lasting.

By the way, I'm painting the frame now. The swingarm is ready and the rear KONI dampers are restored completely and looks brand new.
The housing is gold finish and the spring is painted red. Not the original color,but nice aftermarket shock finish anyway.

//Bengt

 

[john durrill]

bengt,
which engine do you have?
 a KTM or a sachs? and which year?
 if it used the rubber bushings and is a KTM frame, you could do needle bearings. you  might need another swing arm to do that i'm not sure, the inner shaft / bearing surface is hard to find right now. we had a lot of trouble finding one for our 75 175. the bearings you can get from a bearings house still . the two nuts for the load adjustment on the needle bearings would have to be found also.
 If its a 100/125, Dom is making up replacement bearings now out of some hi tec plastic. he has used this already on huskys and knows it will work.
 the way i understand it the swing arm on a Sachs engine Penton does not pivot on the swing arm bolt.to move through its travel the swing arm twists the rubber that is bonded to the outer and inner shell of the rubber bushing. when the swing arm bolt is tighted down it locks the inner steel sleeve of the bushing against the frame on the outer side and the engine mount on the inner side. the  bushing is a press in interferance fit and does not turn in the swing arm. what happens is the rubber twists and allows the swing arm to move. no dirt can enter to ruin a bearing and water will not bother it. when the rubber gives out you have to replace the bushing.
 Dom is making up a bearing we can slip in and has two o rings to seal out water and dirt on each end. it should not pivit on the bolt but on the inner sleeve of the new bearing.
 if someone else has more or better info on how the swing arm works please jump in here and let us know.
 Because of the age of NOS rubber parts i'm a bit leary putting in NOS bearings. they are no fun to remove and install. an NOS bearing might not last very long due to the age of the material.
 I have seen a picture of the setup Dom made for the rubber bushed 175 engine frames and it looks like it will do the trick , just has to be redesigned a bit for the difference in the Sachs engine frame and swing arm.
 Its made from some kind of Polly material. i know that lots of cars use this type of material for suspension componets that have the same loads as our swing arms on them. they work fine.
 drop Dom an e-mail and ask him what he is making. see if it wont do the job for you.
 we are waiting on two sets as soon as he can deliver them.
 John & Peter



Edited by - john durrill on 03/13/2003  08:39:13 AM