Just Forking Around

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swooshdave

swooshdave

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Gearbox is on hold. Brake caliper is on hold. Powdercoating has been canceled as powdercoating funds went to fix the furnace (probably just going to sandblast and rattle can some of the bigger parts. Smaller ones I can powdercoat myself). So what to turn my attention to next?

How about the forks?

Just Forking Around

New tubes, bushings, etc. Yes, many parts missing. :(

Problem Number One:
Just Forking Around


This is as far as it fits. Perhaps a little heat on the leg and it would go in, assuming the hole is bigger down below...
 
Nope.

"Not all fork bushings are created equal" or something like that.

Send 'em back and request another set. (ask them to check the dimensions and make sure the set they send you is smaller)

Once the fork leg cools down (if you manage to get that sucker in there while it's hot), you'll destroy it tring to get the stanchion to budge after that.
 
Is that RUST on your new tubes? Where did you buy them? I'd take a wire wheel and finish buff with a strip of emery to that rust or whatever that is and also do the same to the stantion tube ends. These parts aren't machined too finely but oil does pass over the surfaces under pressure so why not provide a smooth surface to avoid unnecessary turbulence and aeration.
 
RennieK said:
Is that RUST on your new tubes? Where did you buy them? I'd take a wire wheel and finish buff with a strip of emery to that rust or whatever that is and also do the same to the stantion tube ends. These parts aren't machined too finely but oil does pass over the surfaces under pressure so why not provide a smooth surface to avoid unnecessary turbulence and aeration.
Click to expand...

Well, they are "new" but they've been sitting around for many years. Can't blame the vendor for that. Yes, they'll get touched up a little.
 
grandpaul said:
Nope.

"Not all fork bushings are created equal" or something like that.

Send 'em back and request another set. (ask them to check the dimensions and make sure the set they send you is smaller)

Once the fork leg cools down (if you manage to get that sucker in there while it's hot), you'll destroy it tring to get the stanchion to budge after that.
Click to expand...

There was another discussion a while ago here that the parts might come a little bigger to compensate for the wear of the old fork legs. And that it might be a "make to fit" scenario.

Anyone have the "correct dimensions"? I'll get a measurement on these in a little bit. *Update* 1.503 which is exactly the same as the bronze bushings

As mentioned above these parts were purchased a while ago. If new ones are required that's what it will take.
 
I got my stanchions and bushings from Mike at Walridge. The lower new steel bushings were a bit tight on the new stanchions, so I used some emory and took a bit off the stanchions until they rotated freely. I coated everything with WD40 and carefully pushed the stanchions with the bushings into the fork tubes and then pressed by hand the new upper brass bushings into the top of the fork tubes. Everything went together just hunk/dory and they all slid up and down just fine. No beating or swearing. I have to say that one of the upper brass bushings was out of round, so Mike sent me a new one, but that was the only problem. I don't think you should have to heat or freeze any parts to get the forks together. Personal opinion and experience. Your mileage may vary.

My parts were also purchased about 2-3 years ago.

Dave
69S
 
DogT said:
I got my stanchions and bushings from Mike at Walridge. The lower new steel bushings were a bit tight on the new stanchions, so I used some emory and took a bit off the stanchions until they rotated freely. I coated everything with WD40 and carefully pushed the stanchions with the bushings into the fork tubes and then pressed by hand the new upper brass bushings into the top of the fork tubes. Everything went together just hunk/dory and they all slid up and down just fine. No beating or swearing. I have to say that one of the upper brass bushings was out of round, so Mike sent me a new one, but that was the only problem. I don't think you should have to heat or freeze any parts to get the forks together. Personal opinion and experience. Your mileage may vary.

My parts were also purchased about 2-3 years ago.

Dave
69S
Click to expand...

Just Forking Around

I took a little (somewhere around .003) off the bushing and it worked. It will fall under it's own weight. Went at the second one but ran out of time. Hopefully tomorrow nite.

I also took the liberty of painting the triple clamps. First a couple coats of primer and then some aluminum-ish paint I've used on my Bultacos. They look really nice.

Just Forking Around

Just Forking Around
 
New bottom bushes, 38.0/38.05mm (1.496+.002").
Lower leg 38.1 (1.500"), do not know the limits on this, but I measured mine with bore mic' & they were 38.1, with one leg slightly worn up to 38.14.
Hope this sounds professional 8)
 
Flo said:
New bottom bushes, 38.0/38.05mm (1.496+.002").
Lower leg 38.1 (1.500"), do not know the limits on this, but I measured mine with bore mic' & they were 38.1, with one leg slightly worn up to 38.14.
Hope this sounds professional 8)
Click to expand...

I don't have a bore mic, all I know is that the one is just fits. I hope that with oil in it it still moves.
 
If it "falls under it's own weight", it might be too loose...

I like a smooth sliding fit with light oil (10/30)
 
grandpaul said:
If it "falls under it's own weight", it might be too loose...

I like a smooth sliding fit with light oil (10/30)
Click to expand...

It's definitely not too loose. When I mean fall I don't mean drop. I mean it slowly lowers.

Now you're going to make me post a video to prove it. :mrgreen:
 
What a farce I've just had with a similar thing. I got one of John's most excellent Lansdowne damping kits and decided my old bike needed a full front end overhaul. So renewed everything and on Friday I finished, all exited to see how the front end would feel, bloody stiffer than a 12 week old corpse!!
So left it over the weekend to take solace in whisky before attacking it again today. My fault of course thinking that the new parts would actually fit, why I'm not sure, had a Commando most of my life so should know by now. The forks did move but were very stiff and notchy, a day spent with fine emery and a nice easy sliding fit now, all rebuilt and actually working like suspension should nowadays rather than how it worked (or didn't) 50 years ago.
Main issue seemed to be the fork legs though, even the old bushes which were more worn than a prostitutes knickers struggled to fit without sticking. All nice now though.
Moral of the story is the legs should be free like in the posted "boring video" :lol: before fitting to the bike otherwise you'll be giving yourself much more work in the end.
 
Yes. And remember, fit everything up loosely, then tighten from the axle to the yoke stem, bottom to top, depressing and releasing the suspension between steps.
 
Gino Rondelli said:
What a farce I've just had with a similar thing. I got one of John's most excellent Lansdowne damping kits and decided my old bike needed a full front end overhaul. So renewed everything and on Friday I finished, all exited to see how the front end would feel, bloody stiffer than a 12 week old corpse!!
So left it over the weekend to take solace in whisky before attacking it again today. My fault of course thinking that the new parts would actually fit, why I'm not sure, had a Commando most of my life so should know by now. The forks did move but were very stiff and notchy, a day spent with fine emery and a nice easy sliding fit now, all rebuilt and actually working like suspension should nowadays rather than how it worked (or didn't) 50 years ago.
Main issue seemed to be the fork legs though, even the old bushes which were more worn than a prostitutes knickers struggled to fit without sticking. All nice now though.
Moral of the story is the legs should be free like in the posted "boring video" :lol: before fitting to the bike otherwise you'll be giving yourself much more work in the end.
Click to expand...

How did you get them assembled the first time? Did you take a hammer to the legs and beat them in?

Just to re-iterate, I think the new bushes come slightly oversized for a reason.

Think of it this way, a 30-40 year old pair of legs (on the forks, not mine) have had steel bushes sliding on the aluminum for x number of miles. My guess is that the aluminum is going to wear and not the steel bushes. So if the new bushes were to the original specs, you'd be pissed that they were loose.

These means one of two things: One, the bushes are oversized and must be fitted AND most/all suppliers do not let their customers know. Two, the bushes aren't made to spec and we just lucked out that ours were oversized and, with a little fitting, work perfectly. :mrgreen:
 
Gino...I think it's time to get the sliders reamed over size..i have toyed with this idea for ages,,infact i have just bought off Ebay a 39mm reamer,,,ready to have it ground down to plus .005 over the internal leg size..and some lead bronze cored bar,,and some P,T.F.E for the top bush's...From an Engineering angle its not easy to produce a good finnish and follow the original bore..i'm thinking a floating reamer is best, Iv'e a few broken pinch bolt legs to try with...we will see. Best regards John Lansdowne Eng
 
How did you get them assembled the first time? Did you take a hammer to the legs and beat them in?
Click to expand...

No I managed to get them in and moving by hand........................................but I have big hands!

If i ever resort to a hammer its to hammer nails in, not motorcycle parts!!!

John
Now that sounds good, why do we fit new parts to 35 year old legs? still beyond me but to replace the legs with every fork rebuild gets a bit expensive, let me know how you get on I'd be intererested.
 
I guess I am lucky, all my bushings fit like the proverbial glove, or maybe like the Excalibur in the Rock?

Dave
'69S
 
DogT said:
I guess I am lucky, all my bushings fit like the proverbial glove, or maybe like the Excalibur in the Rock?

Dave
'69S
Click to expand...

Either the bushings were the right size or your fork legs were so worn. :mrgreen:
 
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