Swing Arm Bushings Question

[KJDonovan]

I have a question on swing arm  bushings. I am hoping that someone can answer.  I am in the process of re-assembling my project bike (72 Jackpiner) and was putting the swing arm back together.  The tube that houses the bushings also has a piece of metal tube that fits inside between the bushing at each end.  Well after reassembling it the bushing each protrude about 3/16" from the swing arm on each side.  I never had the original bushings so I don't know if these should be sticking out on each end or not.  Can anyone shed any light on this?

I also have a question on how to remove steering head bearing races the ones pressed into the frame.  Unfortunately, I just noticed how chewed up these are on my bike, after getting the frame back from powder coat.  Anyone have any ideas on getting these out short of heat?

Thanks,

KD


Kevin J. Donovan
Foster, Rhode Island

[john durrill]

KD,
 The book we have says 72 175 used the same bush's that 100/125's did. Its a 3 piece bush.
 I think the assembly is called an Isolastic (sp) bushing.
 The inner sleeve or tube does extend out past the swing arm on both sides. The bush is made up of an inner sleeve and an outer sleeve  bonded together by the rubber you see. The assembly presses into the swing arm and does not rotate. The rubber part twists as the swing arm travels up and down. If the swing arm bolt is tight, the inner tube from each bush and the spacer ( metal tube inside between the bushes) is locked in place and will not rotate either.
 We use a long punch to remove the steering head races from the frame.
 Pass the punch through the top and catch the edge of the bottom race with the punch. Tapping it with a hammer and moveing the punch 90 degrees every tap will walk the race out usually. Then go through the bottom to remove the top race. 3/8 inch drill rod from the hardware store should work for a punch  if you dont have one that long.
 Did this help any?
John D.

[imported_n/a]

KD, funny you should ask! I just came in from the garage after putting the swingarm back on the frame for my 74 Six Day. You are correct, the inner sleeves were both sticking out 3/16th" on the inside edges keeping me from inserting the engine mount bracket. With a folded rag so as to not damage my new powder coat, I used an extra large set of channel locks to gentle squeeze the edge of the inner sleeve back inside of the bushing toward the side that joins the frame. Being somehow fused to the rubber they would quickly begin slide back out but I had just enough time to insert the motor mount before they expanded back out. I had to carefully hold the swing arm and motor mount in alignment, then slip it all into the frame, and slide the 12mm bolt back in. Found there's plenty of room between the outside of the swingarm and the frame when it's all together. As John D. said above, no need to try and tighten the swingarm bolt (axle?) too tight or none of it will rotate. In fact, the frame would have to bend to get it that tight anyway! The smaller 8mm allen holds the 12mm allen in place from loosening. Hope this also helps.

critter

[john durrill]

Critter,
 Keep the swing arm bolt as tight as specs say. The small inner sleeve does not rotate if the swing arm is working right. The inside sleeve sticks out to give clearance on the frame gussets for the swing arm to rotate. The swingarm would wear a circle in the gussets if it did not. Torque from my 73 125 riders hand book is 75 ft lbs for the swing arm bolt.
 Can some one else comfirm this torque spec? I have several books but the swing arm bolt torque spec is listed in only one place.
Thanks,
John D.

[KJDonovan]

Guys,

I just want to make sure I understand, based on what you have said when this is all together the centers of the bushings should or should not be protruding slightly from the sides of swingarm?

Kevin J. Donovan
Foster, Rhode Island

[imported_n/a]

KD, yes, they should be protruding. Keeps everything spaced evenly and away from each other as the swingarm pivots. If the spacers were flush inside the swingarm, when the whole thing was tightened down the swingarm would rub against the engine mount on the inside and the frame on the outside causing friction/damage. John D., thanks for the torque spec.!

critter

[OUCWBOY]

KD,
Critter is referencing the swingarm of the 100 / 125 which is a bit different than the Jackpiner. The Jackpiner, as you know does not have the rear engine mount through the swing arm. So, yes they should prodrude to keep the swingarm from rubbing against the frame.

Donny Smith

[KJDonovan]

Thanks for the feedback guys! My bike was a literal basket case when I got it so I did not take a lot of it apart hence I just like to make sure before putting things back together.

Thanks Again,

KD

Kevin J. Donovan
Foster, Rhode Island