R31House's alloy nose cone, and which GRK chassis it fits

From the post, dated October 19, 2026:

• GS2MOD alloy nose cone — no price given in the post
• Alloy nose cone GRK4/5 conversion adapter — no price given in the post
• GRK5 carbon servo mount plate, listed as a replacement part — no price given in the post
• GRK alloy spur gear holder plate — 2,200 yen
• GRK low-height adjustable suspension block Ver2 — 4,000 yen
• GRK4 alloy lower arm, purple and red — 5,800 yen

Those are the prices as the maker's blog lists them on the day of the post; it gives no prices for the first three items, and no figures for any market outside its own shop.

What the maker says about the parts, in its own framing: the new alloy nose cone saves weight and adds mounting holes in its lower section so left and right can be tied together, which the post says raises support rigidity. The alloy spur gear holder plate holds a high-precision cut racing spur accurately and suppresses spur runout; moving it from carbon to alloy adds a little weight, and the post says a flywheel effect from that is expected to change the rotation feel when you come off the throttle. That is the maker's expectation, not a measured result. The post credits the spur holder plate's development to a proposal from GRK's Kanto-area advisor, and says the alloy parts are cut at a Japanese factory.

1. Name your chassis exactly before anything else. GS2MOD, GS2 EVO, GRK4, GRK5 and GRK5-R are separate kits in the same family, and this update treats them separately. The kit code on your box or manual is the thing to go by, not "my GRK".
2. For a GS2MOD, the alloy nose cone is the direct item. The post describes it as the alloy nose cone matching the GS2MOD mount, which it says first appeared on the GS2NOB.
3. For a GRK4 or GRK5, you need the nose cone plus the GRK4/5 conversion adapter. The post describes the adapter as the additional piece for GRK4/5, as adopted on the GRK5-R HRP full kit.
4. If you are going down the A-arm route at the rear, look at the low-height adjustable suspension block Ver2 before the arms. The post says Ver2 adds toe control pillow ball holes to the side suspension block, which are needed when fitting A-arm knuckles, and calls it suited to multi-use rear knuckle and A-arm setups.
5. The GRK4 alloy lower arm is the standard lower arm on GRK4 and GRK5, so on those cars it is a replacement in a new color. On a GS2MOD or GS2 EVO, the post presents it as part of a rear A-arm conversion, not a straight swap.
6. Add the GRK5 carbon servo mount plate only if you have broken one. The post lists it as a replacement part for that chassis.

Treating alloy as an automatic upgrade. The nose cone is described as lighter than what it replaces, but the spur gear holder plate is the opposite: alloy instead of carbon, slightly heavier on purpose. Two alloy parts in the same update, two different intentions.

Reading the flywheel effect as a tested result. The post says the change in rotation feel on throttle-off is expected. Nobody in the material reports driving it on carpet, P-tile or asphalt, and no gearing, motor or tire is named alongside the claim.

Buying the lower arms as a rear A-arm conversion on their own. On a GS2MOD or GS2 EVO the post frames the arms as part of that update, and the suspension block Ver2 is what carries the toe control pillow ball holes. The post does not publish a full parts list for the conversion.

Ordering the nose cone for a GRK4 or GRK5 and forgetting the adapter. They are listed as two items.

The parts went up on the maker's own store, DR GRK on BASE, run by SHIBATA's RC division, formerly R31WORLD. The announcement itself is the October 19 post on the R31HOUSE RC blog.

Before you order, open your kit's documents and check how the nose cone, servo mount and suspension blocks are assembled on your version. YAW keeps the maker's manuals and setup sheets for the GRK4, the GRK5-R and the GRK GS2 Modified. If your chassis is a GS2 EVO or a GRK5, the maker's download page is the next place to look — and if a fastener length or a spacer stack is what you are after, that is a question for the manual, not for a shop listing.