paulincayman
Hero member
- Location
- Cayman Islands
As above looking to replace my ally mount plates. Any links appreciated.
TIA
Paul
TIA
Paul
3CL engine mount plates stainless
- Thread starter paulincayman
- Start date
helicopterjim
Hero member
- Location
- near Lone Butte, BC, Canada
Why stainless? I suspect they would be very susceptible to cracking.
Jim
Jim
Dellortoman
Hero member
- Location
- Tasmania, Australia
Are you referring to the triangular plates at the top front engine mounts? (they're the only engine mounting plates on a 3C that I'm aware of)
They're steel, not aluminium. If yours are aluminium, they're definitely not original. Some dickhead previous owner has made them. If they're cracking, that'll be why.
You can probably buy them from the usual parts suppliers, but it's a simple matter to make some steel ones. If you want stainless, you'll have to make them anyway because they're normally mild steel.
They're steel, not aluminium. If yours are aluminium, they're definitely not original. Some dickhead previous owner has made them. If they're cracking, that'll be why.
You can probably buy them from the usual parts suppliers, but it's a simple matter to make some steel ones. If you want stainless, you'll have to make them anyway because they're normally mild steel.
Cccg
Full member
- Location
- Western Australiarkjf
Plenty in stock here at Italbrit Classic Motorcycles .
Made from steel as the originals, cnc cut for accuracy. They are primed only due to requests for different colours.
Price $18 aud.
Made from steel as the originals, cnc cut for accuracy. They are primed only due to requests for different colours.
Price $18 aud.
helicopterjim
Hero member
- Location
- near Lone Butte, BC, Canada
Mine have been holding up great for the last 20-odd years, Cam.
5mm 6065 Al plate, with a big hole in the middle. About 1/3 lighter than the originals with more bend resistance than mild steel.
dickhead piet
Dellortoman
Hero member
- Location
- Tasmania, Australia
Well mate, sometimes even dickheads can be luckydickhead piet
At least 5mm is a reasonable thickness, and it might as well have a hole in the middle since the middle of the triangular plate doesn't carry much stress. I guess it's no big deal if that little plate does fall apart anyway. The bike isn't going to break apart and kill you.
But I must admit I'm surprised. Aluminium work hardens pretty easily. I'd have expected such an application to crack from fatigue in a reasonably short time. You've only gotta look at the prevalence of cracks in aluminium fuel tanks. And aircraft designers are keenly aware of the limitations of aluminium. I've used aluminium for brackets and similar applications, and it's sometimes failed due to fatigue cracking from vibration. Maybe the 6000 series alloy is quite resistant to that sort of thing. Good job getting it to work. Did you use rubber bolts?
piranha-bro2
Hero member
- Location
- Melbourne
If they're in a pos that is very rigid (to limit lateral movement/vibes) then I can see it working. I reckon the Argy only causes vibes in a vertical plane in that pos.
Would I use alu plates for the lower SF engine mounts? No.
Would I use alu plates for the lower SF engine mounts? No.
Laverda1000.de
Hero member
- Location
- Haßberge, Germany
My Harris cracked 8mm plates. (That was the rear mount)
Just in case anyone wants to follow the dickhead route. When I made mine, it wasn't a case of stabbing at a bit of any-old alu with a drill. I chose the material carefully, getting the right temper and making them very precisely, with each side made to fit absulute cock-on and with next to zero clearance around the bolts - thus taking out any slop which could lead to movement, wear, and cracking. LH will not fit RH. Over the top? Sure, but a satisfying little job for a mild OCD boy.
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You remembered Clem! Yep, that's my mantra
piranha-bro2
Hero member
- Location
- Melbourne
On a bike that weighs 220kg+ dry I'm not sure trying to skimp on metal for something as small (and important) as an engine mount makes much sense. I went thicker on all the rear mounts on my SF frame (that had cracked or deformed over time).
Way to go...
The bolts need to fit snugly, with all possible play eliminated.
Did the same with my old brit thumper, all engine plates are alloy, they actually hold the frame together! Went to the pains of making my own bolts and studs to get rid of the imperial threads, many of the old bores were rather shagged anyway. All reamed out cleanly with fasteners to suit. Done a good 16000km with them, no signs of fatigue yet.
This sort of precision also helps in reducing vibes.
piet
Agree Quentin,
Of course there's not much sense in doing it. But, I did it because I could. I guess you know the feeling too, set something in your mind and find out if it works. At the very least, it keeps us from commiting other mischief.
piet
