1953 G80S Front Forks

[Brian 54G80S]

The next stage in my G80S restoration is the front forks. I intend servicing them myself as I have successfully done the Jampots recently.
I like to buy my parts through the club but my current parts list including freight to Australia is over 700 UK pounds which is a stretch for me.
A large portion of this cost is 2 x replacement fork tubes at around 130 pounds each plus freight.
My question is, in other members experience, how likely is it that I will need to replace the fork tubes?
I know some of you will say do the disassembly first and then order the parts but for me, that can mean a three month wait before I can do the reassembly, I'm trying to avoid that wait period.
Appreciate your thoughts.
Brian

[clive]

It may depend on where it has lived. In the UK rain penetrates the headlight ears and sits above the bottom yolk resulting in a neat ring of rust which can go quite deep. If the bike has stood unused for sometime humidity and salty air could have resulted in rust down the rest of the length.betwee. the slider and the yolk. Yours will be 11/8 forks so they can also be bent.
So yes take them off to have a look.

[SPRIDDLER]

As Clive has said because you don't know its history, but I can't see why checking them visually will result in a 3 month delay as you can strip the forks in just one day. Is it because if new stanchions are shipped then they and your other small bits (seals etc) will have to come by sea rather than by the faster post/air method? If they are corroded it's largely just the range of the stanchion that runs inside of the seal that might justify replacing them unless other areas are corroded (rust usually) that has weakened them. Minor rusting or pitting can be cleaned up but in any case you'll certainly need new seals to prevent leakage.
You'll get an idea of what to expect when you drain the oil before disassembly. If no oil at all or rusty oil/water comes out you may expect corrosion.
I don't think you've ridden it yet but if they jam when fully extended or fully compressed then one or both legs may be bent or there's substantial corrosion.
Separating the stanchions from the sliders can be a struggle because you are pulling against the lower buffer/rebound spring but there are several ways to make this easier if you browse the 'Technical articles' section or use the 'Search' facility for previous posts.

[Brian 54G80S]

I think it is shipping related to bulky items. If I order gaskets and seals etc I can have them sometimes within 7 days which I think is outstanding. As soon as I get bulky items it takes weeks. My last order was for the jampots, weighed 3.25kg total and took over a month to arrive. I will take the advice and pull the forks apart and inspect before placing the order.
I have actually taken the bike for a shake down ride now. Great to get her on the road after a minimum of 25 years in storage! Have identified a few oil leaks here and there but nothing to serious. I need to look at electrics next. I have output from the dynamo but nothing going into the battery, suspect regulator or wiring issue.
So, front forks, few oil leaks and electrics and the bike is mechanically sound and ready to ride. Will do cosmetic stuff ( paint etc ) after that.

[SPRIDDLER]

I need to look at electrics next. I have output from the dynamo but nothing going into the battery, suspect regulator or wiring issue.

Whilst I'm on here...........
How did you check the dynamo output? If you just used a voltmeter to check the voltage it won't tell you much as a load needs to be applied to verify the health of the dynamo. On 6v dynamos I use a 12v headlight lamp connected to the F and D bridge to avoid it blowing because the unregulated voltage will rise rapidly with the revs to around 20v and quickly blow a 6v lamp. The lamp should light brightly without a fistful of revs.
There's an excellent guide here: https://www.matchlessclueless.com/
This is the rig I use:

Dynamo test rig (640x480).jpg

Link 2 (640x407).jpg

[Brian 54G80S]

So, removed and dismantled the forks which was quite the challenge with the fork tubes badly corroded. One day Ill get around to publishing my special tools and method for others who may be interested.
My tubes are shot but have been able to source some locally here in Australia. Ill order all the other required parts from the club in the next few days when the Parts team are back from leave.
One question, does anyone have any recommendations re finish on the bottom alloy legs? Im thinking light sand and polish but do people spray them with a clearcoat after polishing or are there any other recommendations?

[Andy51]

When it comes to finishing fork legs, there's no substitute for elbow grease! Depending on their state, you will need 240, 400, 800 and 1200 grade wet and dry to get a good finish on the alloy should take an hour or so. Follow up with Solvol autosol or similar until you get the required shine, finish off with a good auto polish - do this before you assemble the forks, it's much easier. To maintain, wash, polish with Autosol and auto Polish every few months dependant on weather and usage. Good shining! Andy

[Invicta]

Not sure of which year the lower fork legs changed from being black to polished alloy. Both my 1949 and 1950 model 18's were orinally painted black. Now powder coated, no plishing required.