Presta valve stem reinforcement

Not quite a remix of the [Valve stabiliser for carbon road bike wheels](https://www.thingiverse.com/thing:149709) as I modeled it from scratch, but definitely an inspiration, so wanted to give the credit.

Sometimes a Presta nut doesn't sit quite right on a rim profile, generally because of a curve in the rim. I've printed RodLaird's design before, but I don't have carbon aero rims, so it doesn't fit _quite_ right. Working on a fat bike wheelset with a curved center channel, I thought of this design and thought I should give a try at modeling a parametric version.

Mine isn't as fancy as RodLaird's as his has nice, sculpted transitions, and mine is a straight loft, but if it's printed smaller, that's less obvious.

To change the design to fit your rims properly, you'll need Fusion 360 and the F3D file. You can measure the curvature on the rim with any of the awesome radius gauges available here on Thingiverse, then feed that into the third sketch. The 280mm dimension came from th