RoadTarmacTec

Tarmac: SRM Tri-Lobe and Pedal Installation

The finish line is near, the “flamme rouge” is in sight… Today will be the installation of the SRM/LOOK Tri-Lobe inside the Origin Powermeter and the Dura Ace pedals. Then only a few little things to go.

These tools are needed:

  • Bike Stand
  • 8mm Allen
  • Torque Wrench
  • Carbon Paste
  • Anti-Seize

Post as guidance? No warranty in ANY case of damage!

As said during the crank installation the SRM/LOOK Powermeter features a Tri-Lobe Design which makes it possible to choose three different length: 170 / 172.5 / 175

The weight on the tri-lobe parts is 29.9grams which is quite heavy but maybe necessary.  The material is anodized steel. The Dura Ace pedals hit the scale with 233.9grams, that’s ok.

Now for the preparation of the tri-lobe parts. Every side is marked (left/right) and consists of two parts: the tri-lobe inlet and the plate.

The SRM manual dictates a dry fit but I noticed a creaking noice during wet conditions from the tri-lobe/pedal section. So I switched to a “tighten fit” with carbon paste. This will lead to a strong fitment and prevents creaking.

Long term experience
I ran this combination for quite a half year without any problems. Only downside on this is to remove the tri-lobe the “easy way”. Because of the carbon paste this is a really strong boundary. To loosen it I inserted an old pedal axle and wiggle the tri-lobe out.

After covering the crank arm with a small amount of carbon paste the tri-lobe can be inserted. My choice is 172.5mm. The cover plate also indicates the chosen crank length.

The pedals must also be prepared. Anti-seize on the threads prevent locking and corrosion.

Last step is the pedal installation itself. Remember: Left pedal clockwise, right pedal counter clockwise.

Torque on both pedals should be around 20-40NM for the SRM Origin Carbon Powermeter Crank.

And its done…