Shift Your Style: Customizing GrimmSpeed Shift Knobs with Bike Stem Caps

Shift Your Style: Customizing GrimmSpeed Shift Knobs with Bike Stem Caps

Contrary to popular belief, the staff at GrimmSpeed does have interests outside of Subarus (shocking, right?). Occasionally, inspiration strikes and we come up with ideas for some amazing crossover products—and our new Shift Knobs are one of those results.

One of the standout features of our new GrimmSpeed Shift Knobs is that the included caps can be swapped with standard bike headset/stem caps and handlebar end caps. This opens up a world of possibilities since these can be found in a variety of colors and designs—and even fully customized with your own artwork!

Before you get too excited, note that GrimmSpeed is not planning to enter the bike stem cap market. Keep an eye out for some “Limited Drop” O-ring fit caps using the same design as our included shift pattern caps—but we will not be offering custom design bike stem caps (probably). That said, we did do some R&D on cap designs from other companies to make the process as seamless as possible for those who want a truly one-of-a-kind shift knob.

Our testing showed that there is some variation in caps from different companies, so here are a few suggestions.

We had great results with Kustom Ventures, which offers a wide selection of caps and allows for fully custom designs—including single-color laser etching and full-color screen printing. The most common cap shapes are:

  • DOME face for the headset caps

  • FLAT face for the handlebar end caps

Both styles can be used, but the designs on the bottom differ, which affects final fitment with our GrimmSpeed Shift Knob.

To help achieve the best fit for your bike stem cap, we’ve included extra components with the shift knob. These are to be used depending on the cap style you choose.

For DOMED headset caps, we include a small 3.4mm-thick M6 spacer that fits underneath the cap. We recommend using this, as it helps the cap sit flush with the top edge of the shift knob.

                        

For FLAT caps, no spacer is required. These sit flush on both the Lightbulb and Piston style knobs.

If your new bike stem cap comes with a bolt, it’s likely too long and may interfere with the shift lever. Please use the included M6x1.0x12mm socket cap bolt instead (the shorter stainless bolt). This installs using a 5mm hex key.

We do have our preferences—domed caps look great with the Lightbulb knob, and flat caps pair well with the Piston knob—but your choices might vary based on your own taste or the cap design.

Here are some example photos comparing the domed (with spacer) vs. flat cap designs:

Lightbulb:

Piston:

We should also mention that we encountered a few bike stem caps from other companies that did not fit our shift knob. These typically had a different top-face diameter that either didn’t seat inside the bore of the GrimmSpeed Shift Knob or left a visible gap around the edge. We can’t control how other companies manufacture their caps, so be cautious.

Given that, we highly recommend testing before ordering any expensive custom caps—or just stick with Kustom Ventures like we did.

Already installed your GrimmSpeed shift pattern cap and want to swap it out? Easy peasy! The M6 thread for the bike stem cap goes all the way through the knob. Just flip the knob over and thread in the included longer black M6x1.0x30 bolt from the bottom (using a 5mm hex key) until it pushes the cap out.