Author Topic: Front Forks - advice on repair  (Read 2313 times)

Online RichardL

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Re: Front Forks - advice on repair
« Reply #15 on: 06.07. 2016 21:49 »
Well, I just got wrapped in the idea of the embedded partcles. Thinking of the whole job, of course you wouldn't reuse that bush. Love the tool with the spring-loaded stones.

Richard L.
Plan on signing up for the world-wide 2020 DISTINGUISHED GENTLEMAN'S RIDEon September 27, 2020 (if it's not cancelled and we are free to move about by then). Watch website at https://www.gentlemansride.com for details.

Online Joolstacho

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Re: Front Forks - advice on repair
« Reply #16 on: 07.07. 2016 00:28 »
I'm still interested in the idea of replacing the tube section with new tubing. I have several sets of unusable sliders that have the 'belling out' issue, where the tubing wears and expands over the area where the bush travels. Honing maybe okay for fixing minor scoring but not heavier wear. Velocette forks can be made like new, because the top and bottom lugs can be removed, and the tubing replaced with new stock, the lugs are soft-soldered on which makes it easier. I was wondering if anyone has tried this with BSA forks.

Offline coater87

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Re: Front Forks - advice on repair
« Reply #17 on: 07.07. 2016 00:28 »
 I dont think a Sunnen hone would get rid of his marks, they look too rough.

 You would have to be a man of steel to hold that fork leg steady without it wobbling so bad the hone actually makes it worse. When I was a kid my best friends dad was a mechanic and had a beautiful Sunnen set-up, with all the hones, the rod sizer, even oil feed. I wrecked a fair number of lawn mower cylinders learning to use it, and it does not take long for your shoulders to start to burn *ex* If the part is badly scored (like that) or even slightly out of round, the hone of course wants to follow what is already there. So you have to nut-up and hold it straight so the hone can true it. With a fork leg you would not have enough leverage to clean that I dont believe, and the walls being as thin as they are it might be tin foil by the time you did.

 BTW, when John retired nobody wanted the business. Everything sat unused for years until the building was sold. They junked the Sunnen, a nice Monarch 10EE lathe, and the rest of the tools he left for the "next owner". *sad2*

 One thing I would try if you can find a small amount is Belzona. It looks like Hocus Pocus but the stuff is amazing and we still have  huge pumps and large DC motors that do not fail using that stuff. Down side is the amount they want to sell you, I am not sure but I think the smallest amount they sell is something like 300 of those funny pounds things you guys buy stuff with.

 Lee
Central Wisconsin in the U.S.

Offline duTch

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Re: Front Forks - advice on repair
« Reply #18 on: 07.07. 2016 02:58 »

 
Quote
I'm still interested in the idea of replacing the tube section with new tubing. 

 Jools, I'm sure someone like one of the ravers did that a while ago- maybe do a search?

 John
Quote
I have heard of "modern" stanchions and proper dampers being fitted into period forks
Has anyone more information on such a mod????
...

 After Trev  said "no sleeves" my first thought was why can't it be possible to male a full- length top bush and use later stanchions and dampers; then I got to your comment. *wink2*

 
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
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Offline coater87

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Re: Front Forks - advice on repair
« Reply #19 on: 07.07. 2016 23:54 »
 In case anyone is interested, the Belzona stuff you would need is 1311. This stuff is used in industrial settings, and it lasts.

 Lee
Central Wisconsin in the U.S.

Offline Tomcat

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Re: Front Forks - advice on repair
« Reply #20 on: 09.07. 2016 08:01 »
G'day Mr Beard,
I read your comment "The inside of the fork is not smooth" and would like to know more about the problem you have. The sliders are usually internally dimpled from clamping them in a vice or just worn out. If worn I would recommend replacement with second hand items. My own sliders were damaged by clamping them in a vice, so I made up a mild steel mandrel (similar to a bush) and welded it to a thick rod. This tool was clamped in the vice and the slider was pushed on till it stopped, then very light taps with a hammer around the damaged area repaired the damage.
Cheers Tomcat
'48 A7 '59 SR '74 850 Commando TDM900

Online Joolstacho

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Re: Front Forks - advice on repair
« Reply #21 on: 09.07. 2016 08:17 »
Eeeek! I can feel the pain!

Offline nimrod650

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Re: Front Forks - advice on repair
« Reply #22 on: 09.07. 2016 18:23 »
G'day Mr Beard,
I read your comment "The inside of the fork is not smooth" and would like to know more about the problem you have. The sliders are usually internally dimpled from clamping them in a vice or just worn out. If worn I would recommend replacement with second hand items. My own sliders were damaged by clamping them in a vice, so I made up a mild steel mandrel (similar to a bush) and welded it to a thick rod. This tool was clamped in the vice and the slider was pushed on till it stopped, then very light taps with a hammer around the damaged area repaired the damage.
Cheers done the same with an old bush two washers and a length of threaded bar

Offline rwbeard

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Re: Front Forks - advice on repair
« Reply #23 on: 10.07. 2016 16:06 »
Thanks to everyone who responded with ideas. I really do appreciate the thought and the time taken to consider solutions to my problem.

The lower fork leg bushes are badly scored, so grinding out any high spots or rough spots with paste might be worth a go, as I will need new bushes anyway.

SRM Engineering suggested having a look at the honing route, and they said that hey we're going to manufacture new RGS fork legs, but that would be the last resort.

I will keep you posted as to how I get on, now that I have been inspired to try a few of the forum member's ideas.

Best wishes to all


Bob

Offline Jules

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Re: Front Forks - advice on repair
« Reply #24 on: 20.07. 2016 11:55 »
my legs were in a similar condition to these and I used a wooden dowel wrapped in wet/dry paper and spent hours working it manually up/down/around as best I could to simulate a "honing" action, then thoroughly washed them out and had new bushes made to fit. The bike is still far from road ready but the sliding action on the legs is good with no feeling of loose/slackness......

Offline Rocket Racer

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Re: Front Forks - advice on repair
« Reply #25 on: 21.07. 2016 06:44 »
The fork sliders on both my outfit and rusty are replica's made with hydraulic pipe. (non standard bushes)
We did the sidecars first as I wanted a leading axle and a fork brace mod. Whereas Rusty we kept stock. We used old rusted sliders as donors for the bottoms and tops.
I can't take any credit, my engineer knocked them up
I understood that new ones were now being made though  *dunno*
Pictured are copies and have A65 damper internals
A good rider periodically checks all nuts and bolts with a spanner to see that they are tight - Instruction Manual for BSA B series, p46, para 2.
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Online Joolstacho

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Re: Front Forks - advice on repair
« Reply #26 on: 21.07. 2016 07:31 »
Trust a Kiwi do do it properly. (And what's that TLS brake?)  *wink2*

Offline duTch

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Re: Front Forks - advice on repair
« Reply #27 on: 21.07. 2016 10:06 »

 
Quote
Quote

    I'm still interested in the idea of replacing the tube section with new tubing. 


 Jools, I'm sure someone like one of the ravers did that a while ago- maybe do a search?

 I had an idea it was you RR- that should've said 'racers' not 'ravers' *eek*..

 [quote(And what's that TLS brake?)  *wink2*][/quote]

 I believe that's from a '68 A65/50 as discussed a while ago
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

Online Joolstacho

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Re: Front Forks - advice on repair
« Reply #28 on: 21.07. 2016 10:23 »
So when did they produce a brakeplate like that, without the air-scoop etc?

Offline duTch

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Re: Front Forks - advice on repair
« Reply #29 on: 21.07. 2016 11:25 »

 yeah ok, I was just looking at the lever action, I'l have to let RR clue you in...I can only suggest it's  a'68 setup adapted to a SLS back plate *dunno*
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia