Repairing scored fork stanchions

[Guest Nigelstephens]

Just wondering if anyone has a repair method that works for scored surfaces on forkes.

 

I have upsidedown MP forks on my Sport I 1100 1997. On one stanchion tube I have some long narrow scores.

 

My idea is to clean and apply epoxy. When set to rub down smooth.

Has anyone had any success doing this?

 

I have some new Guzzi seals to insert so I want it to be right in one go.

 

Thanks

Nigel

[Guest Gary Cheek]

If you are considering epoxy on the fork tubes, it may be better to get a new pair. The epoxy could be a lot more trouble than cure. Better check the bushings too. Whatever scored the tube may have imbedded itself in the softer bushing. If the cost is an issue the high spots on the scores may be carefully leveled with an oilstone then polished. Still check the bushings and clear any hard spots.

 

Replacement of the parts is still far and away the best solution.

[mike wilson]

Epoxy might work as a very temporary fix but it is almost impossible to get the pits clean enough to get good adhesion and epoxy hardens too much and comes out when the stanchions flex.

 

The only cure I know of that works for sure is to have them ground smooth, hard chromed (not the same as decorative chroming) and then reground to diameter, if needed. It's probably not worth having this done unless you can't buy them new any more. For places that do it (I'll be astonished if there is one locally) try the classic berk press.

 

Be prepared to open your wallet and say "Help yourself". Cost me £30 to get a set done in the mid 1970's.

[callison]

The fork tubes on my Sport 1100i also got scored lightly because I didn't change the fork fluid in 58,000 miles. Fortunately, the scores weren't so deep that I couldn't have the tubes turned down in a lathe by a machine shop and then all of the seals replaced and so forth. It still cost me $500 for the work. At that, I did the removal of the tubes from the bike and took them to Moto Italiano to get the work done. That saved some on the cost but I know longer take it for granted that fork oil doesn't get contaminated.

[Baldini]

I've used HCP&G in the midlands a couple of times for grinding/plating forks & found them very good. As said it's not cheap, but finish is excellent. I'll dig out their details if you want.

 

I did once use epoxy to repir a small pit in fork. I got it real clean & it worked fine as I remember. But it was only a small single chip, scores may be tricky to do successfully.

 

KB

[Greg Field]

If your other efforts do not solve the problem, we have a new tube that's been on the shelf for years at Moto Intl. that I would sell at a substantial discount. Shipping it to England would also likely be substantial, though.

[Guest Nigelstephens]

My next question I should ask is if I put new seals in, how likely is the fork to leak past the seal? How long is a piece of string?

 

However, that I guess depends on the depth of the scores. There will undoughtedly be some oil that gets past the seal but if it is only a little I might try it and see. I have an MOT (annual government safety test) coming up and I use the bike daily so must fix it somehow.

[Guest Gary Cheek]

Very unlikely the epoxy will stay put. When, not if it comes loose it could create some havoc of it's own. The tube offered by Greg sounds like a deal especially if you can get reasonable shipping rates. Should travel nicely in a tubular mailer made for drawings.

 

Forking by Frank will make just about any tube you need very reasonably and they are almost always far superior to the factory part.

 

That aside leveling and polishing would probably serve better than an attempt at filling with glue.

[Alex-Corsa]

My next question I should ask is if I put new seals in, how likely is the fork to leak past the seal? How long is a piece of string?

 

Last summer in German ebay it was raining new WP forks for the sport (something like 10 of them were sold in less than a month or so, with prices ranging on 280-360Euros) and up and then pops up something if you have some patience for search. I didn't got any ,yep that was a bit foolish to miss these bargains,but they pop up and I'm here.

There is also HMB that sells them new but about 1000Eur. is think.

Can direct you to a couple of ebay Guzzisti that were selling some forks,if you need.

[pasotibbs]

I'll also suggest HCP&G (they are, or at least used to be, in Ollerton, Notts.)I used them several years ago for the rusty pitted forks on my GPz550 and the finished result was superb (not as shiny as before but much better quality)

[Guest Nigelstephens]

I have had a go at grinding out the scores with a wet stone and finishing smooth with 800 grade silicon carbide. They do look very good now. I fitted a new genuine MG seal and plenty of oil whilst fitting together.

I could not find any contamination of the soft bearing rings. So no idea waht caused the scoring.

 

Time will tell if this stays oil tight.

[Dan M]

 

Forking by Frank will make just about any tube you need very reasonably and they are almost always far superior to the factory part.

 

 

Frank made tubes for both my T120 and my Atlas. Very reasonable. Nice quality. Not sure if he does late model stuff though. Phone 1-847-869-6792

[Guest Nigelstephens]

2 months on and about 1k miles I can report that the fork is oil tight and all is well.

[Guest ratchethack]

Nice job, Nige. It's an inspiration to know that a re-work like you've done achieved good results.

 

QUESTION: Now that you've evidently resurrected your forks from the beckoning arms of the scrap heap , do you plan on using gaiters or fork shields to protect 'em from slipping back toward a similar fate again? Maybe you've already got this covered?

[Guest Nigelstephens]

Rachet

I haden't even thought...

the upside down forks are better protected than convensional but gaiters? I did fit gaiters to my T3 many moons ago (25years X 12) and never had to worry again about grit and pits.

 

Anyone know of a supplier for 41+mm ID gaiters for a sporti?