Hairline cracks

[uktom77]

So the leaking forks conundrum has been solved. Having tried dowty washers, correct washers, different dampers, and each time thinking it's solved the problem I have discovered the reason...... two hairline cracks, one on each side of the damper hole (slider). To be fair Steven (Surbey) did suggest this might be the issue so tonight I got a mirror and light out (they were still on the bike at this point) and there were the little blighters.

So, a question .... before these get relegated to the 'sit on a shelf because I can't bare to throw them away' position. Are they completely unusable (I'm 99.9% sure of the answer), just in case someone has a miracle cure for this????








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[Andy51]

Looking on the web, welding seems to be the way to fix cracks in alloy castings. However, it seems you have to grind out the crack into a V shape so it can be filled with weld - could be very difficult given the crack location. You could speak with a good welder, or put a wanted notice for a replacement part on this forum. Andy

[Mick D]

Hi

I'd try fitting an additional fibre washer between the damper tube and slider, get one that closely matches the spigot on the damper tube and has an OD at least that of the damper tube, also use Wellseal as an assembly fluid and don't over torque the securing bolt.

In view of the location I don't think welding will be anything but a risky and expensive solution - an 'O' ring fitted to a groove machined into the bottom of the damper tube would be easier and more effective.

Regards Mick

Edited to add a photo of the damper face, (sorry it's so mucky but it's the only one I have) - if you can seal this face you will cure the leak. The fibre washer will do this.

Damper Face.png

Regards Mick

[clive]

Ally welding is certainly possible but once done the slider is going to need machining inside and out so that the damper rod sits flush and does not leak. Not easy I imagine. A repair to the mudguard lug or bolt hole is a lot easier. I would try a wanted advert in the magazine rather than on the forum as it reaches more members, or both.

[uktom77]

I've tried various washers (and mixtures of), not wellseal though.

The cracks appear to be inline (180!degrees apart) with what looks like a seam line. I am a little worried about the integrity (now that I know why it started leaking) of the slider itself.

Think an advert may be on the cards.


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[56G80S]

IKBA but is there a seam or is it just a high point from casting? I doubt that they were made as two halves and welded together back in the day however I'm sure someone will pop up and prove me wrong.

I'm fed up with agreeing with Mick D but that looks like the best approach; Wellseal is really very effective. I also recall a previous thread about "modern" fibre washers being too hard and softening them in hot water. Perhaps I dreamt that but a softer fibre washer may be more effective?

Johnny B

[uktom77]

Your idea about the 'seam' probably stands up. I spent ages thinking 'surely it wasn't made in two halves'.

It's not going anywhere so I'll clean it all up and do some more head-scratching. I have a 'spare' that's going on the bike today, but there's a reason it is a spare, and not a permanent solution.


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[Mick D]

Hi

I'd suggest the damage to the sliders is the result of an historic gentle front ender bending the stanchions and putting strain on the damper to slider joint.

I'd continue to use the sliders and just keep an eye on them for any re-appearance of the oil leak indicating the crack had progressed. As long as the caps are intact the wheel isn't going anywhere.

Regards Mick

[clive]

Damper Face.png

now the state of that looks like one of my spares Mick

[Mick D]

now the state of that looks like one of my spares Mick

Hi Clive

That's not a spare, that's one's now installed. It's how I work - I take loads of reference photos as I dismantle the bike but not many as I re-assemble.

Regards Mick