Triples Material - Cast Iron vs Aluminum

[Groover]

Appears the older guzzi bikes, such as the Ambassador used cast iron triples. Newer stuff (mid 70's is newer I guess...) till today on most bikes (that I'm aware of), the triples are made of aluminum, with the exception from what I understand, the 85-ish Le Mans geometry update triples package which were also made of stamped steel for some reason.

Is there a benefit of one material over the other? Is it a cost savings type thing going with aluminum, or general performance (fit, flexibility range) type thing.

What do you guys think?

[Antietam Classic Cycle]

The "geometry update" kit and triples fitted to the '86 Le Mans was likely done in cast-iron/steel simply because it was the easiest to do, so a quick way to make them available. Maybe a little extra weight on the front end helped too. 

[Groover]

The "geometry update" kit and triples fitted to the '86 Le Mans was likely done in cast-iron/steel simply because it was the easiest to do, so a quick way to make them available. Maybe a little extra weight on the front end helped too. 

I was wondering about the weight factor for that update as well, since I believe one of the improvements was also to use heaver bar end weights I think.

[swooshdave]

I have seen triple clamps made out of sheet metal so I'm not sure what the forces on those parts are. They just need to hold the forks and turn, right? 

CB400 for example.

[mtiberio]

yea, added inertial mass to dampen oscillations (tank slappers).

[Northern Bill]

On a triple related topic.  I got an extra set of T3  triple clamps on ebay with the aim to cutting off the handlebar clamps and then grinding them smooth so they look like Le Mans triples.  Because they are aluminium, this would be pretty easy to do but do you think the integrity of the clamp might be affected?

[swooshdave]

On a triple related topic.  I got an extra set of T3  triple clamps on ebay with the aim to cutting off the handlebar clamps and then grinding them smooth so they look like Le Mans triples.  Because they are aluminium, this would be pretty easy to do but do you think the integrity of the clamp might be affected?

You should probably be ok.

[Chuck in Indiana]

I wouldn't think it would hurt a thing..

[rocker59]

Appears the older guzzi bikes, such as the Ambassador used cast iron triples. Newer stuff (mid 70's is newer I guess...) till today on most bikes (that I'm aware of), the triples are made of aluminum, with the exception from what I understand, the 85-ish Le Mans geometry update triples package which were also made of stamped steel for some reason.

Is there a benefit of one material over the other? Is it a cost savings type thing going with aluminum, or general performance (fit, flexibility range) type thing.

What do you guys think?

Well, I'm pretty sure cast steel triple trees are still in wide use.  Usually on lower end models.

Aluminum is light, strong, and more expensive.  Plus, aluminum can look better, if shaped and finished nicely.

[Groover]

Ok, thanks guys. The reason I ask is because I'm replacing the triples on a new project (1987 Le Mans 1000 SE) and I have a choice now to replace the damaged ones with either option since I was able to locate both types. Just trying to determine which set of triples would be best for this particular application since I plan on keeping the 16" front wheel.

I guess the real solution to this dilemma would be to have TWO Le mans project, then use the iron in one, aluminum in the other 

[jas67]

I would think that the triples being called "cast iron" are more than likely forged steel, or at least I'd hope that to be the case.

[Dukedesmo]

Aluminium is used on modern bikes because it's lighter, some fancy race parts are magnesium as it's lighter still.

[Antietam Classic Cycle]

Ok, thanks guys. The reason I ask is because I'm replacing the triples on a new project (1987 Le Mans 1000 SE) and I have a choice now to replace the damaged ones with either option since I was able to locate both types. Just trying to determine which set of triples would be best for this particular application since I plan on keeping the 16" front wheel.

As long as you stay with the "update"/'86 onwards triples, you'll be fine. I'm not sure I'd use the '85 triples with less offset.

Jay: they appeared to be cast (in sand) since the surface was rough and they looked quite crude. Forging would have resulted in a much smoother surface, no?

[Rough Edge racing]

I would think that the triples being called "cast iron" are more than likely forged steel, or at least I'd hope that to be the case.

 Yes forged or at the least, cast steel (malleable iron)  ...And they are yokes 

[Antietam Classic Cycle]

Yes forged or at the least, cast steel (malleable iron)  ...And they are yokes 

Yokes are what's inside an egg! 

[Rough Edge racing]

Yokes are what's inside an egg! 

 then the triple trees must be Yolks..............