Biker Pete 

What’s the difference between Mavic “GP-4” and “Super Champion Competition” tubular tire rims from the 1970s? (besides the finish: dark color of the former, polished metal of the latter)

79pmooney

The big one is the metal. I do not know the metallurgy; this was after my engineering school days and the focus I saw was steel but I know this as a rider: Those dark Mavic rims of the early '80s on are far stronger than the similar weight rims of the '70s with a few exceptions. Fiamme Ergals used an aluminum that was a real step up (but I'm guessing not as good as the later Mavics). The Ergals were also very light. The Mavics may be heat treated which may give them a higher yield strength. (Yield strength - stress to cause permanent bending/denting.

Another factor was weight. And for that, you need a scale. GP4s are "400 grams" to most people. If you weigh then you will see between 400 and over 500. (I've weighed a bunch. Popular weights are 405, 455 and 495.)

And my experience (that isn't an A/B comparison.) In my racing days I rode the "330g" Arc en Ciels on my training wheels. By summer end they were funky enough that next spring I replaced the rims. Every year. My fix gear got "400 gm" whatevers every spring. Those were ridden through the winter and saw many deep potholes. By March they were random polygons.

5 years later I built up a set of wheels for the Mooney. GP4s. Those went 17,000 miles until I dented the rear badly bunny hopping a pavement break and erring slightly. Cause? No sidewall! The brakes! (Pacific NW where the dust is volcanic.) Yes, those rims were treated better than my wheels of race days but no, I was not running bigger tires or more pressure than on those training wheels. They were ridden in the rain a lot (poorer visibility = a tougher life for rims).

The Super Champions were the soft, weak aluminum of the '70s. Don't ride small tires or low pressures. Bottoming out will dent them. (Not dangerous and if you can find a rim puller, perfectly safe to pull to round and ride. The GP4s can withstand a pretty substantial hit without denting but the word its that it is not entirely safe to pull dents out

Biker Pete 

My bad, I thought the made in France Super Champion ‘Competition’ rims were made by Mavic. Super Champion was the maker.

Biker Pete 

Aardwolf

An alternative might be Mavic Monthlery Pro, I've done 500 miles on some so far.
Which look to be the same spec as GP-4 but much shinier, probably may use older alloy mix though.

Mavic GP-4: https://www.velobase.com/ViewCompone...=107&AbsPos=26
Mavic Monthlery Pro: https://velobase.com/ViewComponent.a...1-adc0a9f330e9
Super Champion Competition: https://www.velobase.com/ViewCompone...604ae&Enum=107

Biker Pete 

Thanks for the links to Velobase!

Chombi1 

I thought Super Champion was bought up by Wolber?
Wolber made some very nice tubular rims too. I really like their early aero tubular rims like the Profil 20. They build up into very strong and stiff wheels, even in just 28 spoke epec.