THM’s Updated M3 Clavicula Crank, Super Light Versatility Available Now


First spotted on the Open AXX1 at Sea Otter, THM’s new Clavicula M3 modular crank is now available through Fairwheel Bikes. The original Clavicula is a popular option among the lightweight crowd, but the introduction of the M3 opens the crank up to all of the modern drive trains. As a big improvement from our standpoint at least, the spindle has been redesigned and is now made from aluminum rather than carbon. The carbon spindle was plenty strong and stiff, but as we experienced – the need to place the crankset in the freezer before installing, and the difficulty of uninstalling the carbon spindle version was a little troublesome. The new alloy spindle should prove more durable, and quite a bit easier to install.

Chainring configuration, BB standard? Take your pick after the break.


Thanks to the new lockring around the 30mm spindle, chainring options are nearly unlimited. THM M3 Spiders

Current spider options include doubles in 104/64 and 120/80 BCD, Single XX1 specific, and triple 104/64 BCD, and we wouldn’t be surprised to see one piece spiderless rings popping up in the future. thm_clavicula_mtb_m3_crankset02Keeping the 8 spline interface and pinch bolt non-drive drank arm of the original Clavicula, the biggest change is obviously the alloy spindle. While the spindle is 30mm, bottom brackets are available in almost every standard including BSA (standard threaded), BB30, PF30, BBRight, Pressfit, and BB386 Evo. Likely due to the new spindle, rider weight limit has been raised slightly to 243lbs, up from 230. Fairwheel notes that there is a lifespan specified by the manufacturer of 10 years or 62,000 miles, at which point it should be sent back in to THM for inspection.


Crank Arms Only 344 grams
Double 104/64 Spider 39 grams
Double 120/80 48 grams
Single XX1 42 grams
Triple 104/64 42 grams
English BB Cups 73 grams


19 thoughts on “THM’s Updated M3 Clavicula Crank, Super Light Versatility Available Now

  1. The spline for the spider looks very much like the one on the Specialized FACT and Lightning cranksets. Are the spiders interchangeable with those?

  2. Beautiful engineering, diggin’ the interchangeable spiders and host of BB options. No worries on the rider weight limit, in fact you could almost get away with two of me on that crank. My wallet on the other hand would have to gain a lot of weight before i could put that crank on my bike, even at shop rat prices.

  3. You had to put the spindle in the FREEZER? Is that a joke? If it’s not, then please explain why anyone would do that. Holy crap.

    1. @Gravity, the previous version’s spindle was carbon. Putting it in the freezer according to the manufacturer causes it to shrink just enough for easy installation in the non-drive arm. Considering how easy it went together and how hard it is to get apart it really seems to make a difference.

  4. I had expected the arms to be lighter. I just upgraded very my old Cannondale Hollowgram SI to the SI SL, so I just measured those. The old was 320g and the new 280g for only the arms. Not to mention the new SI SL2 which is even lighter. But it is a nice looking set of cranks.

  5. @Anders: the weight of the “arms only” also includes the spindle. The Hollowgram MTB spindle is about 75g. So apples to apples is more like 355 for your Hollowgram and 344g for these.

    With all of that said, there’s a reason I have a set of the Hollowgrams and won’t be “upgrading” to these.

  6. FWIW, the Q Factor is 167mm only. Can’t speak for THM as to whether they would ever offer a narrower version.

  7. Only look of right arm i don t like. If right will be same left (Thread pedal a part..) i thinks will be possibke to have easy assembly for all bb

  8. I forgot second that i don t like and this fantastic prodact nee: NAME clavicola is orrible, and remember every time when i broken it…

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