Cast Aluminium Welding

[neonsurge]

Due to incompetent spannering, I've broken the upper yoke on my Rev-3 (right down the middle of the pinch bolt hole). Is this repairable? Could it be welded and the hole retapped or am I looking at a forking over a huge pile of melvins for a replacement casting?

My bike maintenance fund is somewhat depleted of late so I'm pursuing every alternative before making a call to John Lampkins... all advice appreciated!

[badass76]

i had the bottom of my techno fork leg break and had it welded and bored out, this bloke is in prees in shropshire i could get you his number if you were interested?

[nigel dabster]

I'm no metalurgist, and can't spell either but putting both things aside with such an important part that can take some considerable forces, is there no side effect ie weakening by welding cast ally?

[charliechitlins]

The heat would probably make the immediate area slightly softer.

More malleable rather than more brittle.

But the heat is so localized with a TIG that it would have virtually no effect on the integrity of the part.

If you're worried about welds weakening cast aluminum, don't look at too many swingarms

[neonsurge]

Thanks for everyone's advice. I'll drop into my local dealer at lunchtime to see if he's got a yoke from a scrapper and failing that, get a price on a replacement. If my credit card starts to melt, I'll ask around to see if anyone knows a good welder locally.

[ronm]

Neon,

Sorry to hear about your cracked clamp. Regarding welding, there was an Aprillia in our club for several years that had a similar repair on the lower clamp. The bike was owned by several people including a friend of mine who was famous for spectacular crashes. I never heard of any problems related to the repair. That said, I seem to remember some discussion a few years back concerning using the upper clamp from a '98 Techno to allow fitting tapered bars to a Rev3. Based on that, I think there is a good chance that the clamps are interchangeable. But of course, you should check with a dealer first.

[neonsurge]

Some very useful information in this thread - definitely to be filed away under "for future reference"!

After cleaning and stripping the bike yesterday, I think that it's very unlikely that an effective weld would be possible; the part that's broken off is very small and it looks like there are a couple of small fragments missing.

A new part has been ordered. Thanks for everyone's advice (and sympathy!)

[alan bechard]

I know you have already ordered a new piece, but for future reference those type repairs are actually a little easier, and less susceptible too strength problems.

I usually grind off until I can get too the bottom of the threaded area, then clean thoroughly, then start filling it back solid, then grind / sand to original form, then drill, tap and sometimes helicoil and you have a very satisfactory repair.

It does not take as long as it sounds here, and is nothing in welding / work time compared to what heathy is doing on his exhaust.

I guess this is more FWIW info at this point but thought I would pass it on.