The arm of Shimano that makes things other than gears and brakes, PRO Bike Gear produces a nice range of components. The XCR stem we have here is a very lightweight stem with a distinctive faceplate.
The top of the faceplate slots into the top of the stem. PRO call it the 'Puzzle Clamp' on account of its similarity to a jigsaw puzzle, and that's the best way to think about how it works. Two 4mm Allen bolts secure it in place at the bottom.
The downside is that you can't flip the stem unless you don't mind the graphics being upside down. That rather limits you when setting the bike up, but it is available with a choice of +5 or -5 degree rise.
Does the faceplate offer any advantage? PRO claims the clamp better spreads the clamping forces and reduces weight. Certainly installing the handlebars into the stem is a quicker process as you only have two bolts rather than the more common four to tighten up, and it's easy to get a good clamp with just the two bolts.
While riding it's not possible to detect any significant difference. It's certainly as secure and stiff a set up as a regular stem with a four bolt faceplate.
At 110g on our scales for a 110mm example it's as light as PRO claim, making it a a good option for cross-country types. It comes in lengths from 80mm so if you're looking for a light stem for your trail bike you're catered for.
It's constructed by 3D forging a lump of 7075 aluminium with a triangular profile. Two opposing bolts clamp the stem to the steerer tube, a pointless and annoying design quirk (the clamp and steerer don't care which direction the bolts point; all opposing bolts do is slow down fitting). Its finish is of the highest quality with smart decals that look good on most bikes and the polished faceplate gives a good finish to the front of the bike.
It's a little on the pricey side and the faceplate does rather limit its versatility, but if weight is important the PRO XRC is a featherweight option.
Clamp is easy to use
More information: Pro XCR Stem
UK importer:Madison Cycles
What PRO says about the XCR stem
- Innovative new Puzzle Clamp System for convenience & lower weight
- Triangular body-shape for increased rigidity
- 3D Forged AL 7075 T6 construction
- Angle: Available in +5 and -5
- Extensions: 80-130mm
- Diameter handlebar clamp: 31.8mm
- Suitable for 1-1/8" forks
- Colour: Black with Polished Silver front-clamp