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By stinkwheel
#92356
Have a look at some pictures of pukka twinshock competition trials bikes. Ones with alloy mudguard stays are few and far between. They could have used alloy but they didn't. These are people who even drilled holes in their gear levers to save weight.

I suspect this is primarily for the bracing effect the steel ones have.
#92357
Quote 'If your alloy stays are fracturing then they're either not thick enough or the wrong grade of aluminium!
Forks flex and twist.'
And that is why steel brackets and stays are better for the job, with little, if any extra weight.
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By Nitrowing
#92359
Beezabryan wrote:
Fri Aug 21, 2020 6:49 pm
Maybe you would be better arguing the toss with your supplier ie our host.
I've already done that. They gave their explanation and offered to take it back.
There's no 'arguing the toss' in engineering - it either works or you re-engineer it.
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By stinkwheel
#92362
Another factor is if you bend an alloy stay, it's pretty much junk because it'll snap when you try to bend it back.

If you want to go very light, I have used heavy-guage stainless wire attached with rivetted on mikalor P-clips for mudguard stays before today. Like a supersized version of bicycle ones. It's a total sod to work with though, it will not bend how and where you want it.
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By Nitrowing
#92364
stinkwheel wrote:
Fri Aug 21, 2020 11:25 pm
Another factor is if you bend an alloy stay, it's pretty much junk because it'll snap when you try to bend it back.

If you want to go very light, I have used heavy-guage stainless wire attached with rivetted on mikalor P-clips for mudguard stays before today. Like a supersized version of bicycle ones. It's a total sod to work with though, it will not bend how and where you want it.
The problem with using aluminum is that; to be thick enough to provide equal (or greater) stiffness as steel it needs heating or it will fracture (even if it looks ok - it's not). That's why fork braces are machined and don't snap.
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By stinkwheel
#92367
Aluminium needs annealing to form it, then tempering then age hardening to be properly structural. A process that needs repeating of you heat or bend it to any significant degree. I've annealed, straightened and re-tempered control levers before, then it occurred to me that I probably used enough gas and electric in doing so that I may as well have bought a new one.

With the likes of a mudguard stay, you'll find you could have simply bent and brazed something up from decent steel tubing for a fraction of the cost, less bulk and a similar weight that is actually stronger.

Getting a relatively small radius, 180 degree bend in small diameter tube would be a nightmare. You'd probably need to extrude it in the bent form. I can't find anyone offering stuff less than 3/4" diameter with a 180 degree pre-bend.
By Beezabryan
#92370
Maybe you would be better arguing the toss with your supplier ie our host.

I've already done that. They gave their explanation and offered to take it back.
There's no 'arguing the toss' in engineering - it either works or you re-engineer it.


In that case why are you not "engineering" your own stays?
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By Nitrowing
#92373
Beezabryan wrote:
Sat Aug 22, 2020 11:24 am
Maybe you would be better arguing the toss with your supplier ie our host.

I've already done that. They gave their explanation and offered to take it back.
There's no 'arguing the toss' in engineering - it either works or you re-engineer it.


In that case why are you not "engineering" your own stays?
I'd stupidly believed that, as the bike had been in production for an eternity, someone had already done a proper job. Instead, I found that people prefer 'looks' rather than doing a proper job.
Brass do-dads, yeah, no problem.
Aluminium gear shifter? Whaaaat?!?
Aluminium silencer? Whaaaat?!?!

So, yes - I am engineering. Silencer is underway. Gear lever is underway. Awaiting the titanium for the handlebar clamp. I've already contacted a firm for the mudguard stay (come fork brace).
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#92381
What is the need to lose weight? is it a competition thing?
Start with the simple things, ie.. wheel rims, fuel tank, seat, head stock, rear shocks.
Then start refining - indicators, rear mudguard & rear light assy. bodywork.
Then start digging into your piggy bank - Custom titanium fittings, titanium fasteners, etc.
When it is finished, it will look a sod and still only be good for the same speeds as mine, but will shake you about a lot more due to less mass affecting the damping.
To sort this, you will need to talk to the tuners, piston, crank, cams, carb, head re-work, etc.
An Enfield is not an ideal candidate for a stripped out, souped up, road burner. It can be done, really well, but it comes at a price, money and reliability if you get it slightly wrong.
#92382
That bloody lagging on the exhaust pipe weighs more than the difference between steel and alloy mudguard stays and will help your exhaust valve run hotter than needs be. Engineering? Junk the wrap for starters.

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