..."I'm a welder, I can't fix stupid but I can fix what stupid does", never met me. Things are compounded when stupid (me) is trying to fix my own stupid mistakes. (sigh)
Yes, I've been playing with my new toy....but I'll get to that soon enough, for once I'll try and keep my fuck-ups in chronological order.
Following on from my laboured proselytising re the merits of Ergal/7075 v Titanium (and Steel), I was playing around with some (stupid) shit, had a few 7075 bolts out and thought I'd do a quick real world comparison vs Titanium:
If the 7075 bolts had been conical head (they are freely available) as per the Ti the difference would be slightly greater again (steel equivalent would be around 60gm). Yup, it's only a few grams here, but given the 100's of bolts on a bike, many much bigger than these, it all adds up, and why wouldn't you when 7075 bolts are relatively inexpensive?
Yeah yeah, I can feel you giving me the "Is that all you got?" side-eye. Ok, what about giving something with a bit more meat on it the intermittent fasting treatment? Lets quantify the weight saving with that previously mentioned RS Ergal swingarm pivot shaft.
So this is the datum, the OEM steel pivot shaft and bolt:
If you recall I had the genuine Corse RS Ergal pivot shaft, but not the RS bolt. The 7075 bar stock I'd ordered had arrived, so first things first was making said bolt. I don't have a rotary table or dividing head for my milling machine so it was just marking-blue and careful (not a strongpoint!) marking out, then waiting to see what emerged from the swarf. The machining gods must have been fresh back from the pub and in a good mood:
FYI, I under-guesstimated the flange size on the OEM bolt when ordering the bar stock while away at work, so admittedly the 7075 bolt flange is -1mm vs OEM, but as per other Ergal parts I'd seen I left just a tad more meat on it by drilling a slightly smaller hole so the material difference evens out almost exactly (Aluminium is approx 1/3 the weight of Steel):
And the bottom line all up? A 220gram saving:
Now while I'd been poking around every nook and cranny of the internet looking in vain for the bolt I just made, I bumped into my ol' mate Dragos Leonard Panaitiu, who machines/sells all manner of lovely Corse replica parts and other great bits and bobs (like that O-ringed deep sump oil screen cover I'd already fitted). Just first class work:
He was good enough to do a very fair price for a complete 7075/Ergal rear axle (and underslung brake caliper carrier if you need it, which I didn't). So, chronological fuck-ups and all that, I actually had the 7075 axle assembly weighed before I had the OEM out and on the scales:
A couple of things worth mentioning:
1. The axle is supplied with a 7075 wheel spacer, but as I've had to machine my own to suit the Galespeed wheel etc I haven't included it.
2. The 7075 axle wall thickness is slightly more than the OEM steel unit (forgot to measure!) and the axle nut is 38mm AF, vs 36mm AF OEM. Just nice lil' "fat factors" erring on the side of component safety.
Aaaaaand the OEM steel equivalent is:
So near enough to half a kg (467gm) in unsprung mass, gone. Include my custom alloy wheel spacer vs the OEM steel unit and it would be virtually bang on 500gm. I'm pretty happy with that; perfect fit, and realistically there aren't too many other ways you can lose that sort of weight in 5min that don't involve laxatives.
Righto, now that I've picked the last of the low hanging fruit, it's time to step out of my comfort zone.....
Do you remember my radiator/oil cooler issues? Basically the CDR Racing radiator/cooler set up I'd installed, complete with bonus filler cap, ended up being a total honey trap. It's abeautifully made set-up but the filler cap which I thought got me out of the poo (the RS water tank not fitting the fairing brace meant I needed a filler cap somewhere else), actually dropped me further in it, the rad neck/cap filling the exact space needed for the RH air duct.
Seen here against a Corse MB Motorsport radiator:
So just swap them out right? Nope. The CDR rad/cooler are a matched set, in both manufacturer and mounting arrangement, but looking closely you'll see the MB unit has slightly different cooler mounting tabs. I just happen to have a damaged-in-storage-but-still-serviceable MB Motorsport Oil Cooler that matches the MB Motorsport rad....but it also has the CDR-style mounts (996/998/999/1*98 RS's all used the same MB Motorsport radiator just with slight variations in cooler/mounting arrangement). Look even more closely and the top MB rad mounts are badly cracked, needing repair. So two options present themselves:
1. Blank off the filler neck on the CDR unit
2. Reconfigure/repair both mounts on the MB unit
With a welder now available, albeit still a mystery, both options are do-able but I thought the intact CDR setup might just be handy for something else down the track: option 2 it is.
Unfortunately I hadn't even started and I already knew I'd boonted myself up the bum! To most folks this would be a straightforward TIG job...but in all my researching various machines, reviews, deals being offerred, and watching welding vids I somehow missed the fact the best deal, my new "Wonder Welder", is DC TIG only....not AC TIG. Important? You betcha, you need AC TIG to weld aluminium as the AC cycle is what breaks down the inherent oxide layer. Yes, after all these years I still manage to amaze myself....and not in a good way.
On the upside, the Unimig welder I'd bought is a pretty flash MIG machine, not just "Pulsed", but "Double Pulsed", putting much less heat into the work, great for this small stuff And the Synergic settings (preconfigured for various materials and thickness) make setup a breeze.
So there's only one thing left to do: have a go....
...and I'll be buggered if it didn't come out too bad. Not professional quality but not a dog turd either:
Just a lil' FYI: CDR Racing is Casa Del Radiatore (Italy), they produce some beautifully made cooling solutions, and can be found here:
