Cinelli 1R Stem expander replacement part


50 in stock

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Reproduction model 1R stem expander, 3D printed from solid Aluminium (AlSi10Mg) with post-processing (annealing)

commonly asked questions:

Why not titanium or steel?

  • Common sense. As a great engineer once said, assign a point of failure in the system, or the system will create one for you. As it is to my understanding that the first wedges were made from steel, there must have been a reason Cinelli switched them to aluminium.
  • Other reasons to consider: the friction between aluminium on aluminium has a coefficient of ±0.9, titanium on aluminium has ±0.6, meaning you will have to increase the torque on the bolt (which is already weak from factory) and possibly snapping the front half of the stem.
  • I’d rather have one of these wedges snap, compared to one of our customers needing face reconstruction after loosing their handlebars when ‘just riding along’

Is an 1R stem safe to use?

  • given their reputation, I doubt it. But history tells us people like to exaggerate and brag about things. But let’s be honest here, we like them for the looks and nobody is going to win any races with them any more, so use with care.
  • Obviously if it shows any other type if microcracks don’t use it at all

What’s the maximum torque setting for the M7 expander hex bolt on the 1r

  • 20Nm, as tested! No more slippage at 17.5Nm, deformation of the materials at 22.5 ish Nm, 20Nm would be the sweetspot (Wera Torque wrench, upgraded Titanium bolt and 95kg of weight used in the test)


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