PRO Tharsis stem - in brief review£64.99

Monocoque aluminium trail stem

BikeRadar score3/5

Named after a mountain range on Mars, the PRO Tharsis stem looks more ‘alien mountain’ than all-mountain! Despite its space age looks, the performance is relatively down to Earth.

The big box-section 7075 aluminium unit comes in 10mm steps, from 60mm to 90mm. Despite a sturdy 186g weight for the 90mm, stiffness is decent rather than dramatic, so there’s some flex with a wide bar. 

The creak-free stainless steel steerer clamp bolts are round the side away from crashing knees, though, and the broad interlocking four-bolt faceplate spreads the load on carbon bars. 

This article was originally published in Mountain Biking UK magazine, available on Apple Newsstand and Zinio.

Guy Kesteven

Freelance Writer, UK
Guy started filling his brain with cycle stats and steaming up bike shop windows back in 1980. He worked the other side of those windows from '89 while getting a degree in “describing broken things covered in mud" (archaeology). Dug historical holes in the ground through the early '90s, then became a pro bike tester in '97. Guy has ridden thousands of bikes and even more components the world over since then and can remember them all in vivid, haunting detail. Can't remember where the car keys are, though.
  • Age: 45
  • Height: 180cm / 5' 11"
  • Weight: 68kg / 150lb
  • Waist: 76cm / 30in
  • Chest: 91cm / 36in
  • Discipline: Strict sadomasochist
  • Preferred Terrain: Technical off-piste singletrack and twisted back roads. Up, down, along — so long as it's faster than the last time he did it he's happy.
  • Current Bikes: An ever changing herd of test machines from Tri bikes to fat bikes and everything in between.
  • Dream Bike: His Nicolai Helius AM custom tandem
  • Beer of Choice: Theakston's Old Peculier (not Peculiar)
  • Location: Yorkshire, UK

Related Articles

Back to top