FAQ Clavicula

1. Can I fit Clavicula to my frame?

   THM offers a wide range of bottom bracket fitments covering most top-class bicycle brands. See [Manuals] for our full range, and the tools required to fit them.

2. What chainrings can I fit?

   THM recommends and sells the Praxis Works range of chainrings, which are made using a proprietary forging process to manipulate the ring shape and tooth profiles. They are stiff and durable, offering clean, rapid gear changes over a long service life. Rings are available for road and MTB applications, including 1x11 setups. THM offers crank spiders in all current mainstream bolt circle diameters (BCD), so rings from many other vendors should also fit.

3. What chainstay clearance has the Clavicula MTB triple?

   When fitted, Clavicula MTB cranks have approximately 136 mm back-to-back clearance. Mountain bikes generally measure 110–126 mm over the outside face of the chainstays. On bikes with rigid chainstays, 4–5 mm clearance to either side is normally enough to prevent the cranks from hitting the chainstays under load. 

4. Can the Clavicula be built on a BB30 system?

   THM offers its own BB30-compatible bottom bracket comprising a push-in, self-clamping bracket shell (width 68 mm road, 73 mm MTB). External bearing cups space the bearings at 85.5 mm (road) or 93 mm (MTB), providing better support for the Clavicula axle than BB30’s narrow 64.5 mm. (Increase in weight: Road 12 g - MTB 18 g). We also offer PF30 brackets in the same widths, for road and MTB.

5. What are the advantages of hybrid ceramic bearings?

   Our high-quality hybrid ceramic bearings have a longer service life and reduced maintenance intervals and are fitted with high-grade steel rings treated with a special greasing and sealing process. This hybrid construction is not however suited to withstand severe shock loads, so we only offer them for our Clavicula road cranksets.

6. Do you offer a carbon version of the cover plate for the installation of the left crank arm?

   No, we do not offer a carbon cover plate.

7. Which dimensions are the bottom brackets of the Clavicula series?

   We use industrial bearings sealed at either side; dimension Ø 42 / Ø 30 / width 7 mm.

8. Which deviation in the BB shell width is permissible?

   Sometimes the width of a bottom bracket shell deviates from the nominal dimension. This must be corrected if the deviation is more than ± 0.5 mm. If you wish to know how this can be done, contact us.

9. My Clavicula creaks when I ride, why?

   Noise has many causes. If you are totally sure it’s the drivetrain system try these tips.

   • Chainring bolts? Remove the chainrings, apply a thin layer of grease to the contact area, apply a medium-strength locking compound, and re-tighten the bolts in sequence.
   • Not that? Look at the two aluminum cross-pins of the LH crank. Remove the Ti clamping screws and force out both aluminum pins. Reinstall the pins with some grease and insert the screws with (very important!) thread locking compound.
   • If this comes from the left-hand crank, remove the crank and thoroughly clean off the mating surfaces, using for example a brake cleaner. Never, ever apply grease to the contact surface!

   If none of this works, please contact us by e-mail. If necessary, we may need to examine your cranks.

10. How can I protect the crank surface against scratches or abrasion?

    The crank surface can be protected effectively by applying a protective sheet such as 3M Lackprotect.

11. Does THM supply single bearings without bearing cups?

    If the bearings are worn and must be replaced, you should also replace the bearing cups because sooner or later they will fatigue and crack. For this reason bearings are available in combination with cups only.

12. Can I use Shimano or FSA bearing cups/bearings?

    No! Shimano and FSA axles have a diameter of 24 mm. Our crank axle has a diameter of 30 mm!

13. Do you have a crankset that will fit the Trek BB90 bottom bracket?

    Clavicula SE and Clavicula M³ doesn’t fit the Trek BB90 bottom bracket because of the axle-diameter.