Why Your Tarmac SL8/SL9 Needs a Non-Round Titanium Top Cap

The Tarmac SL8 and SL9 have a non-round stem cap shape — the cap flows into the Roval Rapide stem contour as part of the aero package. A universal round top cap won't sit flush against this profile, no matter how well it's machined. That's why TiNE makes a dedicated 6.0 g titanium top cap purpose-built for these frames.

Why a Round Cap Won't Work on SL8/SL9

The SL8 and SL9 use the same Roval Rapide cockpit architecture — the stem faceplate, top cap, and steerer interface all share a continuous aero shape. Mounting a round cap onto this frame leaves a visible gap where the cap meets the stem body, and the bolt preload no longer sits centered over the steerer. The result is a cap that looks aftermarket even when it's not.

The TiNE SL8/SL9 top cap mirrors the Roval Rapide contour on its mating face. It seats flush, the bolt load transfers cleanly through the steerer, and the visible profile matches the rest of the cockpit.

Topology-Optimized Structure

Like the universal cap, the SL8/SL9 version uses topology optimization — material removed where the part sees zero stress, reinforced where the bolt head bears down on the steerer. The bionic rib pattern is on the underside (the surface that contacts the steerer), so the visible top of the cap is clean titanium in any of TiNE's 8 anodized colors. The 6.0 g weight is roughly half of the stock plastic piece.

Fitting the Rest of the Titanium Cockpit

The SL8/SL9 top cap is the final piece in a complete TiNE titanium cockpit stack for these frames: titanium stem cap bolt (4 length options in M6), titanium top cap, titanium Roval Rapide computer mount (10.5 g ultralight or 16.5 g 1050 reinforced), and the SL8/SL9 frame bolt kit (8.3 g set of 8). All four pieces share the same 8 anodized colors, so the cockpit can be matched visually or contrasted deliberately.