EB14: THM’s New Clavicula SE Crankset Drops More Weight

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THM debuted the newest iteration of their superlight carbon fiber crankset at Eurobike – the Clavicula Sine Exceptione, following on their latin naming this one sticks with the clavicle/collar bone name with a ‘without exception‘ subtitle. Certainly nothing was spared in this design either. The entire crank is made of carbon fiber with only the pedal inserts and clamping bolt being alloys. The big feature to note here is that carbon fiber spindle with THM’s standard spline interface molded in, and the new-in-carbon clamping surface on the lefthand crank arm. Read on to see how much weight they saved and where they are going next…

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THM has refined the decade-old Clavicula design with a new geometrically optimized spider, placing more material in the structural load path to increase shift quality while dropping weight. They also seem pretty excited about the axle and non-drive crank arm attachment, as it is a first for a carbon-carbon interface in a crankset. In the end the same textures and carbon fiber composition of the two mating pieces actually reduced the movement between the two pieces, which results in more secure clamping, less wear over time, and no source for the development of creaking.

The two Clavicula SE samples on display at the show had molded in stainless steel bearing races, but we were told that during testing they realized that these weren’t necessary, and would be not exist on the production cranks in the spring. While a road standard 130 chainset was on display, the compact 110 will be first to market in the spring. No timeline for a mountain version was mentioned, but THM alluded to the fact that a MTB version was already in the works, and could certainly be expected to make it to market in the near future as well.

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The German-made standard 130BCD crankset drops 60g off of the classic Clavicula to a staggering 360g including BSA bearings (that’s just 287g! with only the crankset itself.) With a set of Praxis chainrings it tops out at just 509g (and down to just 495g for the 110 compact setup.) The cranks will be available in 170, 172.5, and 175mm lengths with a q-factor of 148mm. Max rider weight is set at a conservative 120kg/265lbs, actually an increase from the previous version. Bottom bracket compatibility is claimed for BSA, Shimano Pressfit, BBRight, BB30, PF30, and 386 EVO.

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Clavicula SE pricing is expected to be €1270, including the crankset, BSA bearings, a set of Praxis Works classic forged chainrings, and THM alloy chainring bolts. The 110BCD version will be available to customers in April 2015, with the 130BCD version a month later.

THM-carbones.com

Comments

uncle - 08/31/14 - 8:28pm

(deleted)

Sam - 08/31/14 - 11:03pm

maybe we need carbon fiber cartridge bearings to eliminate all movement in press-fit interfaces.

Solarider - 09/01/14 - 12:04am

With 4 arm chainsets becoming the norm, this might start to look like a very bling piece of yesterday’s news quite quickly.

I am not making a comment on performance since I personally don’t have a problem with the current 5 arm standard and can’t comment first hand on the performance difference.

There is no denying the weight, performance and stiffness of this is amazing, but it might be a really good CD player just as the world moves into iPods!

PR - 09/01/14 - 12:54am

Performance difference between 5- and 4-arm?

…seriously?

Psi Squared - 09/01/14 - 1:18am

Ah the old “cranks start snappin’ in the peloton” fear. I guess that means we’re passed the old “carbon fiber frames start snapping’ in the peloton” fear.

anonymous - 09/01/14 - 1:31am

The only advantage of 4-arm is stiffer rings at lighter weight. They’re also proprietary to each system.

You didn’t see flat rings die with 7900/6700 hollow rings because they’re too proprietary, and I think the weight of the arms more than makes up for slight increases in ring weight.

It would be interesting to see 3rd parties move to 4 arm though, because Campagnolo is the only 3rd party friendly new design. It uses flat rings, and different BCDs for each ring so the spider provides stiffness instead of needing special equipment to make special hollow rings, with special shapes meant to match the shape of the arms.

Solarider - 09/01/14 - 2:01am

PR – my point exactly. I am not commenting on the advantage or disadvantage of 4 vs 5 arm chainsets.

I don’t see a performance advantage either TBH, but my point was more that is the industry moves to 4 (Shimano, FSA, Campagnolo already have), that this will become the norm.

Now, maybe THM can produce the lightest, stiffest cranks on the market even in 5 arm whilst the other manufacturers have to resort to 4 arms to get anywhere near the weight. But that means that 4 arm must be inherently lighter, and consider therefore what THM could do with weight if they only used 4 arms.

The answer lies in scale I am afraid. Shimano et al are capable if introducing a new standard and supplying it in volume. THM are just too small to dictate a new standard, and even the likes of Praxis are too small to cope with the tooling and production of a myriad of standards.

My comment wasn’t pro-4 arm and anti-5 arm. As I said, I don’t have a problem inherently with the 5 arm standard. It was more that if the industry moves to 4, small manufacturers that don’t have the scale to manyfacture their own rings too might look (aesthetically if nothing else) a bit out dated.

Rico - 09/01/14 - 3:07am

I love Q-Rings! Old schoolers I race with get a kick out of it.

Btw, I also use the QXL rings on my crit bike and I noticed the finish comes off when I degrease the drive train. I think I got like an early prototype because I got it from the team before it went retail and the paint is a little more generic. Does anyone know if the current models paint runs or stays put? My big ring is due for a change.

Rico - 09/01/14 - 3:09am

Oh snap! Just realized i commented the wrong post. Those THMs are way above my pay grade. But I do like those expecially with the more subdued gray logo. The first iteration had a monster logo that said “Classic” or something. This looks way nicer.

anonymous - 09/01/14 - 4:27am

FSA is an asymmetric 5-arm like the older campy. That’s why the arms look different from Shimano and are so asymmetric. Considering FSA’s niche as the OEM budget crank supplier, I have serious doubts that those proprietary chainrings will ever trickle down.

Campagnolo and Shimano also use different, completely incompatible standards, and chances are, they will never come to a shared standard.

Shimano takes advantage of their metalworking capability to produce stiff big rings that work even on a small 110mm BCD.

Campagnolo is a workaround. Even though it has the universal standard thing for all size rings going on, the philosophy is completely different. Stiffness is from the arms, and BCD is maximized for each ring to give better support. The stiffness of the big ring doesn’t have to rely on BCD requirements for the small ring.

Aftermarket cranks are likely to stick to 130BCD. Even Shimano isn’t giving up 130BCD, they will continue producing 5 arm cranks according to their press releases. Aftermarket rings also will likely keep producing 130BCD as well.

Rotor is likely to keep 5-arms because I imagine 5 bolts support their OCP holes better.

Convergence of standards in the 4-arm arena is unlikely, meaning 5-arm will be here to stay for quite a while. If they do converge, they’re going to converge towards Campy, since that design can be utilized even with a cheap forged alloy crank and stamped chainrings, and no one lacks the manufacturing capabilities to make it.

abc - 09/01/14 - 7:24am

@Sam: Or maybe it’s time to admit press fit BB are sh*t and it’s time to get back to the good old proven threaded BB design…

alvis - 09/01/14 - 8:40am

Standards should not be a plural! join the campaign that unless its got 85% of the market its a format. Common sense for BB’s and now chain rings. Oh, and four bolts are lighter and stiffer IF you have Shimano technology to proiduce a US$500 chain ring, a forged or machined ring will need to be plenty thick to span that extra gap and the weight saving is lost. Its a fashion trend to obsolete the chance to use replacement AM rings. Coincidence that Praxis have reached close to Shimano shifting with five arms that the big guys screw them and the consumer over by changing FORMAT now?

wuffles - 09/01/14 - 1:51pm

Oooo… pretty.

That’s about all it has going for it. Fragile and waaaaayyyy too expensive.

I’ll stick with the Race Face Next SL on the cross bike. Within 10 grams for a 2x setup at 1/3 the cost. Also durable as hell.

nunyab - 09/02/14 - 10:01am

@wuffles, while the Next SL is a nice crank for a CX bike, saying it’s “within 10 grams” of the THM is completely absurd. A Next SL (381 grams), 104 bcd spider (66 grams) double chain ring set (102 grams) BB (92 grams) That totals out to 641 grams. The THM (287 grams including spider) double chain ring set (125) and bb (72 grams) totals out at 484 grams. That’s 157 grams difference. A massive difference when you’re already at the lighter end of the scale.

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