Colnago Y1RS Expander Bolt Kit Titanium 49.1 g vs Stock 98.5 g (49.4 g Saved)

The Colnago Y1RS expander bolt kit — the complete set of fasteners that holds the fork steerer, handlebar, seatpost clamp, front derailleur, and headset together — weighs 98.5 g in stock steel (XS size, zero spacers). TiNE's Grade 5 Ti-6Al-4V replacement kit brings the entire set down to 49.1 g, saving 49.4 g. That is the largest single-kit weight reduction in TiNE's entire product catalog — over 50% of the stock weight eliminated in one swap.

Expander Core: Three Pieces That Lock the Fork to the Frame

The heart of the kit is the expander assembly — a three-piece system that grips the inside of the carbon steerer tube and provides the anchor point for the headset top cap and handlebar. On the Y1RS, this assembly sits inside the steerer above the head tube, expanding outward to lock the fork in place.

The shaft alone saves 18.0 g — the single largest component in the entire kit. The locking ring and main bolt add 7.2 g and 3.5 g respectively. Combined, the three-piece expander core accounts for 28.7 g of the kit's 49.4 g total savings.

Remaining Frame Bolts: Seven Positions Across the Bike

49.4 g — the biggest kit in the catalog. The Y1RS expander kit saves more weight than any other TiNE product: over 50% of the stock 98.5 g eliminated. The expander core (shaft + ring + bolt) contributes 28.7 g of that total; the remaining 10 frame bolts add 20.7 g. For a Y1RS rider, this single kit delivers nearly as much weight savings as the entire Shimano hydraulic bolt set (17.2 g) and derailleur bolt set (13.6 g) combined.

Sizing: Shaft Weight Increases with Frame Size

The Y1RS expander shaft is sized to match the frame — larger frames need longer shafts. Each size increment adds 0.4 g to the TiNE titanium shaft and 0.9 g to the stock steel shaft. This means the savings actually grow with frame size: a larger frame shaft saves roughly 0.5 g more per size step than the XS baseline (18.0 g saved).

Handlebar Screw Selection: Match to Spacer Stack

The four handlebar screws must match the steerer spacer stack height. Each spacer is 5 mm; every additional spacer step requires longer screws. TiNE provides six configurations, each containing two shorter and two longer M6 screws:

Grade 5 Ti-6Al-4V, CNC machined, 8 anodized colors (gold, blue, rainbow, silver, black, pink, green, multi). 13-piece kit: expander core (shaft + ring + bolt) + 10 frame bolts. XS baseline total 49.1 g vs 98.5 g stock, saving 49.4 g. Shaft sized per frame; handlebar screws matched to spacer stack. Designed specifically for Colnago Y1RS.