Tech & Wearables

The Week in Tech: Transition Sentinel sheds pounds, new SRAM brakes

Transition offers a Sentinel trail bike in carbon fiber, Wahoo has a forearm-mounted heart rate monitor, and much more.

Here’s your Week in Tech — all the gear news you need and none of the marketing gibberish you don’t want.

Transition Bikes Sentinel gets a carbon diet

Transition’s Sentinel will shed a few pounds in 2018. The carbon edition of the Sentinel frame weighs 6.83 pounds, which is 2.5 pounds lighter than the alloy version. The alloy Sentinel introduced Transition’s Speed Balance Geometry (SBG), designed to bring the rider more forward into a central position between the front and rear tire contact points. A 40-millimeter stem and steep seat tube angles help achieve that balance and are supposed to aid in climbing traction and reduce seated sag when climbing. The new carbon frame costs $2,999, which is $1,000 more than the alloy version. A complete bike with an SRAM XO1 build costs $5.999.


SRAM four-piston stoppers at a friendly price

SRAM’s Guide brake family just got a bit bigger with the addition of the Guide T. The T’s four-piston brake caliper does not offer any new technological developments, though it is a less expensive entry into the four-piston arena. The lever and caliper cost $105 per brake ($210 for the pair). The brake weighs 280 grams when used with an 800-millimeter hose, according to SRAM, and is compatible with its drip-free Bleeding Edge technology. The Guide T costs about $30 less than the Guide R.


Wear your heart(rate) on your sleeve

Wahoo gets something off your chest with the TICKR Fit heart rate monitor. The forearm-mounted monitor has ANT+ and Bluetooth capability and comes with two adjustable band sizes to accommodate a wide range of body types. It is water and sweat-resistant and it has a USB-rechargeable battery. Wahoo claims the battery life can last in excess of 30 hours. The unit costs $80.


AbsoluteBlack OVAL chainrings available for Shimano cranks

AbsoluteBlack now offers 2x chainrings designed specifically for Shimano Dura-Ace 9100 and Ultegra 8000 road cranksets. Osymetric chainrings have garnered popularity thanks in large part to Chris Froome (Sky), who has used the chainrings on his Tour de France-winning bikes for years. The new chainrings feature an updated integrated ramp design, which is supposed to improve shifting performance. AbsoluteBlack is offering the chainrings in a variety of sizes: 34T, 36T, 38T, and 39T for the inner ring, and  50T, 52T, and 53T for the outer ring. An inner chainring costs $62 and an outer chainring costs $124.

Rocky Mountain 2018 model recall

Rocky Mountain Bicycles has recalled all of its 2018 Altitude, Instinct, and Pipeline bikes in both carbon and aluminum. Brake cable housing that was not secured properly during manufacturing can cause brake failure, posing a crash hazard. The recall covers over 3,000 bikes between the U.S. and Canada. The bikes were sold at Rocky Mountain bicycle dealers from June 2017 through November 2017 for between $2,600 and $7,300. Consumers should stop using the recalled bikes immediately and contact Rocky Mountain at 866-522-2803 or via email at Rocky Mountain Bicycles can be reached online at