Hi all,
I am just about to re-fit my freshly powder coated swinging arm to my freshly powder coated frame and wondered if anyone can give me a couple of pointers.
I have pressed in new silentbloc bushes into the swinging arm. I did this at work using a hydraulic press and some specially made spacers and collars in order to fit the bushes so that the outside of them is flush with the sides of the swinging arm, leaving the inside diameter of the bushes protruding an equal amount.
I have a new stainless steel hollow spindle, purchased from CPC Engineering in Cornwall and this feels like a perfect fit inside the new bushes. A good, tight sliding fit with no play, as if the bushes had been reamed for it.
I need to make some accurate measurements, using the large vernier calipers in the machine shop at work, but for now I have measured the gap between the two swinging arm 'side cheeks' on the frame with a steel rule as 9" & 3/8".
When I offer the swinging arm in it seems too wide across the outside edges of the bushes and looks like it would take too much force to get it to line up with the holes in the side cheeks. I remember when I took the swinging arm out of the frame it was a good fit but slid out fairly easily.
As far as I know the swinging arm silentbloc bushes should be a good fit inside the frame 'side cheeks' and when the spindle nut is tightened they should be 'trapped', so that when the swinging arm moves normally they do not spin but the rubber flexes. I would assume that, because of this, the swinging arm spindle nut should be fully tightened when the bike is fully assembled with the rider sat on it?
Has anyone had any experience that they could share on this job and what they did to ensure that the swinging arm and silentbloc bushes were a good. correct fit in the frame.
As soon as I have accurate measurements of the inside of the 'side cheeks' and the distance across the swinging arm and bushes I will have a better idea of where I am and I will come back with them.
In the meantime I would appreciate the thought of those who will be more experienced than me with this subject.
Thanke, Kev
Hi Bess,
Unfortunately I made the fundamental error of not measuring anything before I pressed the bushes in.
I assumed that, coming from a reputable supplier (Kidderminster Motorcycles), they would be correct.
In hindsight I should have made all the measurements before I put the bushes in and thus ensured that they would butt up to each other and leave the required dimension between the two outside faces.
It's very unusual for me to fit something without measuring up. I'm usually a bit anal about such things and like to measure and draw things up up in AutoCad so that I have records of everything.
I obviously got carried away with the excitement of all the shiny new bits and wanting to get them all assembled.
Anyway I am where I am and I am now currently in the process of making jigs etc to get the job sorted.
I have the following accurate dimensions now: -
Dimension in between the frame side cheeks = 9.375"
Dimension across the swinging arm tube = 9.268"
Dimension across the outside edges of the inner tube of the bushes with their O.D. flush with the swinging arm tube = 9.537"
I have a difference of 0.162" between the span of the swinging arm bushes and the inside of the frame side cheeks, which if I divide by 2 means I need to get the bushes in at each side by another .081".
I am just checking what gap, if any, there is between the two bushes where they meet in the middle of the swinging arm tube. If, when the bushes are butt to butt, I need to still get more off them I will have to take the necessary steps to take any excessive 'meat' of the ends of the silentbloc bushes.
Oh how I wish I'd have made all these measurements before I pressed them in. It would have saved a bit of work.
You live and learn, even at 64 years old :)
Hi Kev,
Quote from a previous thread:
"Hi Kev Ev,
I have changed my A10 and A65 recently all went well, (part number 42-4362, bizarrely I have a single one left over). Be aware some inner sleeves supplied have been too long, measure and cut before fitting because you won't get them out in one piece if you fit them too long."
Best wishes...
Thanks for the feedback, I thought you were ignoring me :) :)
Good to hear you solved the issue and on the way to completing the bike. I am in the process in face-lifting a A65 build I did a few years back and by the sounds of it a few months ahead of you. Hopefully overcoming some of the issues you are encountering and helping if I can.
Bess...
Hi Bess,
I'm very sorry if I gave you the impression that I was ignoring you.
That certainly wasn't the case and I am very grateful for your comments and advice.
Take care and happy building.
Kev Ev
Hi again Bess,
I've just read back in the previous posts and somehow I must have completely missed your reply when you mention checking the bushes etc. Either that or my memory really is getting bad 😱.
How I also wish, I'd have looked and read more carefully and heeded your excellent advice.
I will try to concentrate more in future.
Kev