Aluminium Wishbones

[ross009 0]

Pretty straight forward question has anyone made any wishbones out of Ali? If not why not? I notice there available for imprezas etc so there's no strength issues or is it just cost?

[Rippthrough 98]

Testing costs, aluminium components will fatigue even under the lightest of loads, so you need a lot of modelling/testing to ensure it's not going to fail, which means you need a large market to justify it.

[SurGie 54]

You can make more gains by having lighter wheels, lighter body panels etc. Even with loads of testing i would never have ali wishbones, especially if you ever hit a curb when they are a bit old etc.

[ross009 0]

You can make more gains by having lighter wheels, lighter body panels etc. Even with loads of testing i would never have ali wishbones, especially if you ever hit a curb when they are a bit old etc.

 

It wasn't so much for weight, more for ease of machining etc may look into it and post back

[stu8v 68 1 Cars]

You can make more gains by having lighter wheels, lighter body panels etc. Even with loads of testing i would never have ali wishbones, especially if you ever hit a curb when they are a bit old etc.

 

 

They work well and are robust on an Impreza for sure.

[Cameron 16]

As Mr Ripthrough rightly said, aluminium WILL fatigue and fail. To make them durable enough you would have to over-engineer them and make them heavier than they need to be.

 

A lot of people don't seem to realise the importance of the strength-weight ratio of materials, so assume that any steel part should be replaced with ali to save weight. In reality steel has a far higher strength-weight ratio, meaning your component will always be lighter when made out if steel - unless of course it isn't practical / possible to make it thin enough. It also doesn't suffer from fatigue anything like aluminium does.. win - win.

 

Free cutting steel is called that for a reason btw; if you're having problems getting it machined, find another machinist.

[petert 585]

Many of the higher spec aluminium exceed steel in strength-weight ratios. There are many types of "strengths" however and the key area where aluminium alloys are inferior to steels is torsional rigidity. Thus the reason the aluminium bikes are made from much larger sections than older steel bikes.

[fatony1 17]

Ali does indeed fatigue. My boss' car (Aston DB9) had a strange 'knock' under harsh acceleration/braking, turned out the Ali rear hub/knuckle had a 3 inch split where the lower wishbone was attached, it was a re-call he never bothered to get sorted, the car was only 6 years old too!

[Cameron 16]

Titanium wishbones..?

[ross009 0]

Titanium wishbones..?

 

if torsional rigidity is a problem with aluminium then theres no point even looking at titianium, i have no problem machining steel it was simply for speed of cycle time and aesthetics etc as i said im my post weight was not the reason for looking into aluminium.

[guffe 2]

Higher spec steel, CrMo, etc ftw. Light as a feather if you go thin enough. Only if you could get them pass MOT (in F-land)...

[Rippthrough 98]

Tbh, my tubular steel ones are pretty light even with the adjustment/rose joints in there, you'd need some serious work on ally ones to make them lighter.