Author Topic: Fork Leg Remedial Fix  (Read 3029 times)

Offline RichardL

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Fork Leg Remedial Fix
« on: 15.08. 2022 04:12 »
(Topic former title: "Quick Gaiter Replacement")

Today was the annual vintage motorcycle show held by the Chicago Norton Owners' Club, of which I am a member for lack of a BSA version. Yesterday, about 2:00 PM, I decided I should replace my torn and ratty gaiters so my A10 would look better in the show. I figured this should take about an hour, maybe less, but no more than 90 minutes, so it would fit in my plan for the rest of the day. So, I set about dropping the whole front end. No problem, really, and I was pleased with myself in realizing beforehand that I needed to prop the rear wheel to keep the bike from falling backwards off the stand when the weight of the front end was dropped. I was disturbed to find that the right stanchion would not move in the fork leg. Now, where to work on this, because table space in my garage is gone? I moved the whole front end to the front lawn and set up shop, on the ground there, with the grass providing the cushioning for the paint.

Alright, I'm already into too much detail. I'm not trying to write a book.

In thinking that maybe there was just a little rust, I decided to flood the leg with penetrating oil. Out comes the plug screw and rolls immediately into the deep grass and is gone forever. I did manage to extract the stanchion by holding it with vise grips and pounding on same with a big rubber mallet. I figured the region on the stanchion I was marring was not critical, and they are replacable, as are the fork bushings. So, I undertook to reduce the diameter of the lower bushing until I had a working fit. I also ran a custom sanding bar (made for my A7 project) into the fork leg to remove surface rust. Yay! for having a lathe that made working on the bushings practical. Not wanting to take off even a little bit more than necessary, it took about six rounds of diameter reduction on the lower bushing before I thought it was OK. Now, go for the fit of the lower and upper bushings together. What a surprise, the upper needed a reduction in diameter. Done. OK, now it's midnight, and ready to reassemble. On trying to draw the first stanchion into the upper tree, I found it was not aligning with the hole in the tree. I was trying to push and shove until the puller nut and stanchion could get into the hole, but, no go. Decided to remove the puller to try it on the other stanchion. As I tried to remove the puller, I heard the sickening sound of the nut that had been on the backside falling to the bottom of the leg. I tried one of my magnetic reach tools, but it was too short. In any case, I figured the steel nut could not be withdrawn from the steel fork. OH, what a brilliant idea! I'll use a piece of gum on the end of a long stick. (No need to describe, you get it already). OK, 1:30 AM this morning (the work was not continuous, by the way), I was exhausted and temporarily defeated.

Good morning, 6:30 AM Sunday! Do you have to get out of bed right now to check two other ideas? Yes you do. First, there's that longer magnet extender in the tool box that you had forgotten, may as well try that. Nope. Then, make a hook from brazing rod that might help fish it out. Nope on the nut, but, as a small success, the gum came out. Yuk. Decided I needed a better look at the bottom of the fork so I made up a flashlight bulb at the end of long wire taped to a piece of brazing rod. Hey! there doesn't seem to be anything in there. It must be good to go. But why? (he wisely asked himself). OK, tie a nut to a piece of thread to see what it would look like if it was there. Oooh! the puller nut, like the nut on the thread, had fallen through the hole in the bushing retainer at the bottom of the stanchion. Ugh! this is looking bad (NOW you think it's looking bad?) and it looks like I will have to completely disassemble the fork leg (this is the other leg). Last hope, turn the whole assembly upside down and try to shake it out. I can lift and manipulate the front end assembly for short periods, but this needed a different approach, so I hung it upside down from a hook in the ceiling and started hitting it with the rubber mallet and manipulating it in all axes. HIP HIP HOORAY! for the beautiful sound of a nut hitting the garage floor.  Well, that was about 10:00 this morning and I made the call that, no way, could I have the bike back together for the show, and that meant I could recuperate strength and put the bike together later in the week.



Long story, I hope it was amusing. I'm sure there are some good tips coming my way about how this all could have been done in 20 minutes or completely avoided, if only...  Those and the admonishments for bad practice are welcome. Even in my haste, I tried not to destroy anything that is hard to replace. Also, no animals were harmed in the making of this story, unless they were of the insect type that got squashed by me laying on the grass working on motorcycle parts. Finally, the pictures are in no particular order. Sorry about that.

Richard L.

Offline RichardL

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Re: Fork Leg Remedial Fix
« Reply #1 on: 15.08. 2022 11:21 »
I know, it's too long to read. That's what happens when one tries to deacribe  a mechanical comic opera.

Offline RDfella

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Re: Fork Leg Remedial Fix
« Reply #2 on: 15.08. 2022 12:09 »
I am confused. Yes, I know I'm 'getting on a bit' but ....
When I started reading, I assumed Richard was replacing fork gaiters. Then we come to a fork leg that is apparently jammed. How can that be, on a bike that's been ridden recently? Even if a bike has been left standing a while, that should never happen - maybe if a part has been left on a shelf for 30 yrs, but this wasn't.
Then, parts need relieving. Parts that fitted together perfectly before, or are these new bushes being fitted?
Lastly, when parts disappear 'down below' I've almost always been saved by a small cylindrical magnet I heep on the bench (about 1/4" dia x 1 inch). I push that into the end of a length of fuel hose and prod around with that. Last used a couple of weeks ago to retrieve the broken bits from the end of the clutch release rod from inside the gearbox cover of my GF.
'49 B31, '49 M21, '53 DOT, '58 Flash, '62 Flash special, '00 Firestorm, Weslake sprint bike.

Offline RichardL

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Re: Fork Leg Remedial Fix
« Reply #3 on: 15.08. 2022 12:18 »
RD,

First, thanks for reading. I want to respond right now, but some dang work issue in the way. I'll be back. (No reference to Arnold.)

Richard L.

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Re: Fork Leg Remedial Fix
« Reply #4 on: 15.08. 2022 17:07 »
Thank you Richard. It's good to know i not alone when it comes to making things worse than when i started.
 *idea* *doh* *work* *pull hair out* *whistle*
Jamie,  Supporter of Distinguished Gentleman's Ride

Offline RichardL

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Re: Fork Leg Remedial Fix
« Reply #5 on: 15.08. 2022 19:30 »
I am confused. Yes, I know I'm 'getting on a bit' but ....
When I started reading, I assumed Richard was replacing fork gaiters. Gaiters, only, was the original purpose for dropping the front end.Then we come to a fork leg that is apparently jammed. If comparison to the other, which moved freely except for oil dampening, it was more certain than "apparently"How can that be, on a bike that's been ridden recently? Even if a bike has been left standing a while, that should never happen - maybe if a part has been left on a shelf for 30 yrs, but this wasn't. I started questioning myself, wondering if, 17 years ago, the first and last time I put together a front end, and knowing very little (even less than now), that, perhaps, I had put it together like that. However, I know I have done the front-end compression test many times, but not so recently that I recall the last time. I don't ride on real rough roads so I wonder if the suspension due to air in the front tire convinced me all was still OK. As a rider, I may have about 12K total miles, so not that experienced. As for the cause, my only guess is moisture or water got in that leg and caused enough light rust to make it stick. I've added a picture of my fork leg sander (made from and old stanchion) with the emery cloth that was in it. I think it shows a bit of rust. Seemed mort rusty when I first retracted it.
Then, parts need relieving. Parts that fitted together perfectly before, or are these new bushes being fitted?They were new 17 years ago. Now they're modified.
Lastly, when parts disappear 'down below' I've almost always been saved by a small cylindrical magnet I keep on the bench (about 1/4" dia x 1 inch). I push that into the end of a length of fuel hose and prod around with that. Last used a couple of weeks ago to retrieve the broken bits from the end of the clutch release rod from inside the gearbox cover of my GF. As I mentioned, I did try my second extension magnet. I'm pretty sure it got through the hole in the bushing retainer nut (correct name: front fork shaft plug), but that did not work. It is pretty unlikely that you can magnetically retrieve a steel nut from a steel container when the nut is using the same magnetism to hold itself to the container, not to mention the small hole the must be navigated.
[/size]

Richard L.

(I took it out of the quoted region so it would be readable. The iterations at getting the right size remind me of the obsession with getting the fork bushing the right size.)


I am confused. Yes, I know I'm 'getting on a bit' but ....
When I started reading, I assumed Richard was replacing fork gaiters. Gaiters, only, was the original purpose for dropping the front end. Then we come to a fork leg that is apparently jammed. In comparison to the other, which moved freely except for oil dampening, it was more certain than "apparently." How can that be, on a bike that's been ridden recently? Even if a bike has been left standing a while, that should never happen - maybe if a part has been left on a shelf for 30 yrs, but this wasn't. I started questioning myself, wondering if, 17 years ago, the first and last time I put together a front end, and knowing very little (even less than now), that, perhaps, I had put it together like that. However, I know I have done the front-end compression test many times, but not so recently that I recall the last time. I don't ride on real rough roads so I wonder if the suspension due to air in the front tire convincec me all was still OK. As a rider, I may have about 12K total miles, so not that experienced. As for the cause, my only guess is moisture or water got in that leg and caused enough light rust to make it stick. I've added a picture of my fork leg sander (made from and old stanchion) with the emery cloth that was in it. I think it shows a bit of rust. Seemed mort rusty when I first retracted it.
Then, parts need relieving. Parts that fitted together perfectly before, or are these new bushes being fitted?They were new 17 years ago. Now they're modified.
Lastly, when parts disappear 'down below' I've almost always been saved by a small cylindrical magnet I keep on the bench (about 1/4" dia x 1 inch). I push that into the end of a length of fuel hose and prod around with that. Last used a couple of weeks ago to retrieve the broken bits from the end of the clutch release rod from inside the gearbox cover of my GF. As I mentioned, I did try my second extension magnet. I'm pretty sure it got through the hole in the bushing retainer nut (correct name: front fork shaft plug), but that did not work. It is pretty unlikely that you can magnetically retrieve a steel nut from a steel container when the nut is using the same magnetism to hold itself to the container, not to mention the small hole the must be navigated.


Richard L.

Offline RichardL

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Re: Fork Leg Remedial Fix
« Reply #6 on: 15.08. 2022 21:13 »
I don't ever remember having to remove the fork legs to replace the gaiters on my A50/65's.

I just took off the front wheel, guard and stays and after cutting off the old one just feed the new one slowly up the fork leg taking care not to tear it on anything.

Didn't remove the legs. Removed the top of the stanchions from the trees. If all had gone well, dropping the forks is just the two top nuts and the front brake cable. All didn't go well, apparently.

The sticky bush would possibly have been because it is not in it's normal range of travel.  I don't think surface rust would be an issue inside a fork leg, it would clean off itself. The oil would be a bit grody but it's just a fork leg. *smile*

It wasn't outside of range-of-travel when test fitting each iteration of bush reduction with the stanchion in hand. I'm not saying to a certainty that it was rust. But I think it would take very little rust with standard-clearance legs, bushes and stanchions. Also, I think it was Groily who recently mentioned that torn gaiters could result in rusty legs.

Give my best regards to your coke dealer. ;)
Long dead, I think.
[/quote]

Richard L.

Offline RichardL

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Re: Fork Leg Remedial Fix
« Reply #7 on: 15.08. 2022 23:42 »
Let's face it, my replacing the gaiters (yet to be completed) turned into a complete s*** show. Body and mind may still be bruised from the experience. Definitely the body, as evidenced by four cuts on the hands, and legs cramping up too easily after all the ups and downs (figuratively and literally). I was not offended. My response to you was as much me repeating to myself that I didn't go too far astray as it was the straight technical points. I'm glad you appreciated the post. It was intended to be amusing enough to get read. It was a choice between laughing and crying. If the nut had stayed in the fork, the choice may have been the latter.

I did not catch the Jack Kerouac reference and went straight for "first person" relevance, possibly revealing more truth than necessary.  I think there may be safety in 40 years separation from the past.

Richard L.

Offline RichardL

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Re: Fork Leg Remedial Fix
« Reply #8 on: 16.08. 2022 02:14 »
OK, I have to get this off my chest now, because it will get known eventually. For two (or twenty-two) of my friends here on the forum who were concerned but too kind to say, yes, the modified fork appears to be too loose for safe or, at least, comfortable riding. I have to give it another go, but not tonight. I decided I would just clean up the disaster in the garage following the weekend's tornado (figuratively speaking, as I live in a potential real tornado zone). In a day or so I will pretend to have a peaceful zen and go about the next try. If I succeed, the zen might even be real, or I'll just party like it's 1999.   *smile**work* *bash* *problem*

Richard L.

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Re: Fork Leg Remedial Fix
« Reply #9 on: 16.08. 2022 15:17 »
Hi Richard ,hilarious stuff but not if its happening to you. Hope you sort it soon, I'm sure you will.  I have got to replace a gaiter on the drive side of the forks looking from the front. I had planned to try to remove the axle single sided 8" brake just enough to allow the gaiter to move upwards and also  loosen/remove the fork stays i was hoping enough room to wangle it into position but seeing the number of things the gremlins can throw  at a job like this I may just leave it till the winter !
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Offline RichardL

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Re: Fork Leg Remedial Fix
« Reply #10 on: 19.08. 2022 05:54 »
Well, I need some advice from some of you smart motor forkers. I've got my misbehavin' stanchion out of the questionable leg. Readers may recall that I over-reduced the lower fork bushing to get it to fit in the leg and ended up with much too much play. As a new test, I sent the stanchion down with a near-new busing until it bound up about half-way down. Please look at the pictures of the stanchion. There is a rust or corrosion ring about 5" from the bottom and at the same angle as the headstock. Since the stanchions were new in 2005, the bike has either been continuously garaged or ridden in sunshine. When I look down the leg, there appears to be some rust or corrosion corresponding with where it is on the stanchion. I just can't imagine condensation over various winters would result in 5" of water. (I've purchased an endoscope but don't have the right adapter for the phone, yet). I don't want to get too long with this so, a few questions:

  • What's the best way to refinish the inside of the fork leg? (I have lots of ideas, but I want to hear yours.)
  • Will the rust/corrosion ring on the stanchion travel up into the upper bushing and get stuck? l
  • Anyone know a shop in the USA that specializes in fork leg restoration?
  • Should I just stick it together with gum?

Thanks, in advance, for your thoughts and ideas.

Richard L.


Offline RDfella

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Re: Fork Leg Remedial Fix
« Reply #11 on: 19.08. 2022 09:39 »
Definitely been water lying in there. How / why is not clear but will need to be addressed to prevent re-occurrence. In the meantime, that stanchion either needs hard-chrome plating or replacing. The latter is likely to be the most cost effective. Some endoscope pics of the fork leg would be useful to determine whether that needs replacing as well (it's too thin to sleeve).
Feel for you, it's always deflating when effort and money has been put into a job with good intention only for it to fail later. BTDT
'49 B31, '49 M21, '53 DOT, '58 Flash, '62 Flash special, '00 Firestorm, Weslake sprint bike.

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Re: Fork Leg Remedial Fix
« Reply #12 on: 19.08. 2022 10:23 »
I'm not a smart motor forker Richard, being one who tries to go as long as possible before taking the darn things to bits.
But I think you are in fairly tough territory here and can only agree with RD. Moisture's what's done it, no debate there I think. Looks just like one or two of my discarded teledraulics.
New stanchion probably cheaper than hard-chroming, and if the slider is oval, rusty, dinged or bent  . . . probably a replacement there too - ouch and oh bugga. We await endoscopic test results!

Bill

Offline RichardL

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Re: Fork Leg Remedial Fix
« Reply #13 on: 20.08. 2022 23:07 »
Yes, everyone has their own thing they want to talk about. Right now, I am still talking about fork legs.  As threatened, here is a video of the endoscope into my troublesome fork leg. It's pretty hard to interpret, so feel free to view or not (not that you need me to tell you that). From the endoscopes point of view, little stuff seems really big. For example, the field of black speckles are little rust spots that can't be felt with a fingernail. The reddish rust is on the surface, I believe, without pitting. The does appear to be some pitting down by the bottom pin, but that could be from when the bike sat in my mother's outdoor side yard in Los Angeles from about 1990 to 2003.  My next step will be a very light sanding with my homemade flapper to see if I can get a close-to-standard diameter bottom bushing to smoothly slide in.

https://youtu.be/tE4St8OuQl4



Richard L.

Offline RichardL

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Re: Fork Leg Remedial Fix
« Reply #14 on: 20.08. 2022 23:18 »
...and the use of the endoscope is kind'a bad, being my first time.

Richard L.