Web editor Pete Scullion has been testing the ‘lightest production DH-rated carbon cranks’ over the last few months and this is what he made of the RaceFace SIXC Cinch chainset after many wet, mountainous hours in Scotland.
Rather than launch an all-new carbon chainset with the SIXC moniker attached, what RaceFace did instead was attempt to make their top of the line DH-rated carbon chainset future-proof. 
Pete has had the RaceFace SIXC cranks on his Saracen Ariel over the winter to see what they can handle by way of being covered in the Scottish slop or clattered of the schist and granite of the local hills. Here’s what he made of them.
- 540g (36T DM, 165mm, 83mm spindle, w/o BB).
- New Sinch interface allows unlimited axle/ring configurations.
- 30mm axle.
- £389.99 (arms only).
If the shoe fits…
Working out how to fit the outsized 30mm bottom bracket (not included, RRP £35.99) took a moment of confused glances before realising that it essentially takes the same tool as the old style XTR bottom brackets. Once in the bike, the larger 6806 bearings look meaty compared to the usual 22mm offerings. From there, the direct-mount chainring is secured in place by what looks to be a flimsy minimal thread washer, but I can happily report that this didn’t come loose once tightened to the correct settings.
After attaching the non-drive crank, it’s a case of tightening up the drive-side bearing preload spacer to the correct setting and securing the ring in place to keep the bearings under load. Failure to do so leads to sideways play in the axle.
On the trails.
In essence, a good chainset should be one of ‘fit and forget’, that really is the baseline criteria. Crank weight it something you’re likely to notice more on the scales that when out on the bike, but these puppies are very light indeed.
The single 32t ring didn’t drop the chain once even low down the block and allowed for quiet, crisp shifting throughout. Even after months of grinding through the local slop, the anodising on the chainring teeth is still almost holding on.
Bottom brackets are one of the few bike parts I tend to kill on a regular basis. I am a big fan of pedalling whenever possible on the downs, and I love smashing a climb. Thankfully the massive 30mm bearings are still running smooth despite the months of abuse.
Normally on a crank arm, owing to my foot placement on the pedal, anodising lasts one or two rides depending on conditions. Obviously there’s no anodising on these but the lacquer hasn’t even been scuffed. The only parts of the crank showing any sort of damage is where they’ve clipped a rock when I’ve been to eager to squeeze the bike through two rocks that aren’t wide enough to pass. Grounding cranks is something I do regularly, and I was concerned that the all-carbon arms wouldn’t hold up against numerous liaisons with the bedrock, but I needn’t have worried.
Better, Best… Bestest?
Other than forgetting to tighten the preload washer on the first ride, these have been flawless. Winter in the Trossachs is never kind on bikes but from the off, the SIXC cranks have been smooth, stiff and quiet. Reliability has been superb.
While more expensive than the 11-speed XX1 offerings, and about the same price as the new XTR chainset, the real winner here is compatibility. The arms will go onto any bike you’ve got with a simple swap of BB and axle.
If you’re after a future and bomb-proof, lightweight chainset, look no further than the SIXC Cinch.
