Cradle and Swing Arm Question

Years ago this bike got sidelined when the cradle cracked. We could not separate the cradle from the swing arm and when we sent the assembly to a guy in a machine shop to do the job he couldn't get them apart either and instead, he cut a part out of the replacement cradle and welded it into the cracked cradle attached to the swing arm. Here is a picture:



My first question is, does this seem like a reasonable repair or should I start with an intact cradle that was never welded?

I'm also going to try to remove the swing arm from the cradle again (so I can clean it up and send both off for powercoating). Once I find a 1/2" x 20 bolt I'm planning to try this method http://oldbritts.com/sa_spind.html using a long bolt and a short piece of 1 inch pipe instead of socket head. Given that we couldn't get them apart before I'm not optimistic that I'm going to have any success 30 years later...we shall see. I'd love any suggestions!

My other question is to see if these marks shown in the below photo on the bottom of the cradle are a problem. I'm thinking they are just from where the center stand rubbed on the cradle and that they shouldn't be an issue...is that correct?

Need to be signed in to google to see those pics ?
Is there a public link that can be used to make them display.

Its always fun getting that rusty and worn pin out of there,
but it is do-able. What year is this for ?

Thanks for letting me know the photos were not visible. I moved them to Flickr - not sure why they didn't show up on Google Photos.

The bike is a 1971.

I can't comment o the welding of the cradle, obviously the factory welds the pieces to make the cradle so give the capability of the previous welder it should be workable,

as for getting the swingarm off the cradle; if it can't be budged loose, the shaft and very likely badly corroded and not reuseable anyway, get a big@ss drill and drill shaft centre hole till it collapses. I would go this way if all else fails.

i'm sure others will also provide some method to pull the shaft...

Perhaps also consider drilling the cradle to take the later oil filter assembly?

https://www.oldbritts.com/13_064283.html
http://www.norvilmotorcycle.co.uk/techtalk13.htm

When I have been involved with shafts seized in sleeves, the best results have been achieved with lots of heat and rotation back and forth. When you hear the first crack and if it moves even a mill you can almost guarantee that it will come out, but you need serious determination and a couple of mates to assist you otherwise it's not fun at all . However when you get it out it a great sense of accomplishment and well worth a cool one!

Jg

wrecks said:

Once I find a 1/2" x 20 bolt I'm planning to try this method http://oldbritts.com/sa_spind.html using a long bolt and a short piece of 1 inch pipe instead of socket head.

Click to expand...

If this works but the spindle remains stuck part way out, you could try using a suitable length of "allthread" - known as Brooker rod here in Oz - in conjunction with a longer piece of pipe, to extract the spindle all the way.

Heat and brute force.

A hydraulic press should do it. I would support it on the timing side and push it out. Best way to do it without breaking any parts. While you're there at the machine shop have them drill out/bush the center stand bolt holes back to stock size.

mikeinidaho said:

A hydraulic press should do it. I would support it on the timing side and push it out. Best way to do it without breaking any parts. While you're there at the machine shop have them drill out/bush the center stand bolt holes back to stock size.

Click to expand...

Spoke to Ronnie Guidi about this and he said he thought it would be easy . He said it didn't work and he was no choir boy.

Torontonian said:

Heat and brute force.

Click to expand...

This man has been there , done that , got the Tshirt . Couldn't agree more!

Rust is pretty strong stuff , see what it does to concrete. It can lift a building

Thanks for all the tips. I was looking at it with my 16 year old son this morning and he said, "I bet we can press that out in my team's robotics lab with our 20 ton press." He was correct, it still took a bit of heat, penetrating spray, and some force but we got the spindle out.



The spindle itself isn't in the best of shape but I'm assuming I can polish it up and re-use it...is there any reason to replace this part? Also, should I replace the bushings?



We buggered up the outside lip of the swing arm a little bit in the process.

wrecks said:

The spindle itself isn't in the best of shape but I'm assuming I can polish it up and re-use it...is there any reason to replace this part? Also, should I replace the bushings?

Click to expand...

The bushes/bushings are reasonably cheap, so a false economy not to replace them, in my opinion.
I'd also say that spindle needs to be replaced.

We can all get seized things out or moving , the trick is not to damage it in the process . Plenty parts wasted or damaged with screwdrivers , pry bars , fins broken through thoughtless hammering . I have a shelf of shame in my workshop and it will get filled with more bits I'm sure. Change the spindle, I would .

Jg

I have to laugh at the "shelf of shame". I also keep the parts that relate to the mistakes I make...

.... but I wanted to add another suggestion here to the crux of this thread. The bike's cradle is an early model. It doesn't have the improved swingarm tube with the two "wedge bolts" that the later model swingarms have. My bike's handling suffered greatly from a sloppy swingarm tube. I changed every part related to handling and it never improved until I discovered the "Kegler Modification" which fixed my bike's handling. IF you have an early cradle and it's already out of the bike, either replace it with a late model cradle or do the kegler modification to your existing cradle's swingarm tube.

I made my own kegler clamps, by flatening one side on a grinder, then drilling and threading each clamp. I bought them from Mcmaster-Carr in plain steel. They come in stainless and aluminum too
http://www.mcmaster.com/#6436k19/=10hgkld

The clamps look like this when mounted on the swingarm tube.


The Kegler modification removes the play that developed in the early swingarm tubes. The norton factory changed their later swingarm tubes (which is pictured below) to fix the issue. They tighten a wedge in a vertical tube to lock the swingarm shaft solidly in the tube.



You need to make 2 flat spots on your new spindle to recieve the pressure from the kegler clamp set screws in the location where you mount the clamps. It will look something like this picture below.


Good luck with your project

*If you don't want to make your kegler clamps, I think NYCnorton will sell you a set of clamps already set up to mount on your tube.