By now, riders at the Giro d’Italia have had ample opportunity to lick their wounds and wrap themselves in Tegaderm, battle scars left over from wet and frantic sprint stages. And those of us watching can finally look forward to some uphill excitement.

It’s time for the main event. Stage 13 is the first big climbing day on the Giro docket, which means teams can finally shake the dust off climbing bikes and equipment.

What you will see on TV:

Lightweight bikes will rule the day, but what will be different this year than in years past? For starters, expect to see disc brakes — yes, even on climbing bikes. The traditionalists in the peloton will still ride rim brakes to save a few grams, but disc brakes seem to be coming into their own this year, even on lightweight pro bikes, largely thanks to the superior stopping power.

And as all-around bikes evolve, they tend to incorporate features from other bike categories. You will notice dropped seat stays on some all-around bikes like BMC’s Teammachine, beneath Dimension Data riders, and the Specialized S-Works Tarmac, beneath Deceuninck-Quick Step and B0ra-Hansgrohe riders. That’s a staple of aero bike design because it allows some up and down flex for comfort without sacrificing lateral rigidity.

BMC Teammachine SLR01

Keep an eye on drivetrains. You won’t be able to make out specific gearing, but you will be able to spot things like oversize pulley wheels. These big beasts stand out because of the large stature; they’re designed to help reduce drivetrain friction by opening up the angles at which the chain runs through the pulley system. Less chain articulation generally means less drag.

Ceramic Speed OSPW pulley

It’s always fun to watch for disappearing water bottles. Riders will sometimes ditch their bottles to lose some weight on the climbs. Others might hold onto theirs for the climbs, then ditch them after taking a swig at the top in preparation for the descent. (Chris Froome notoriously attacked Nairo Quintana at the top of the Col de Peyresourde at the 2016 Tour de France climb as the Colombian reached for his water bottle.)

Bonus: Watch out for domestiques toting water bottles for their teammates using a Water Bottle Vest from Sportful. These nifty vests allow domestiques to deliver water to teammates without stuffing the bottles down their jerseys, which is cumbersome and uncomfortable. The vests make it easy to carry a large number of bottles at once, then quickly ditch the vest once it’s empty back in the team car.

Once summertime rolls around, venting and cooling is important for helmets and apparel. Seeing as there’s still several feet of snow on top of Passo di Gavia, it’s more likely we will see some cold-weather gear during the Giro’s mountain stages. We’ve come a long way since the days of newspapers shoved down the front of jerseys (though this will still do in a pinch). Now riders get treated to waterproof and somewhat breathable garments made to keep them warm and dry in the worst conditions.

Look for jackets made from Gore-Tex or similar membranes that allow moisture to pass through in one direction, while blocking moisture in the other direction. Packability doesn’t matter as much here, since riders can stow their jackets back at the team car.

While aero road helmets are generally reserved for flatter stages, don’t be surprised to spot a few in the peloton in the mountains. These helmets tend to be far less vented than lightweight road helmets, which means they’ll likely trap more warmth if the temperatures dip.

If you’re on the lookout for new and cool gear, keep an eye on riders’ shoes. Current trends focus on light weight and stiffness, so if there are new kicks to be seen, Stage 13 would be a good time to spot them. The same goes for helmets, assuming riders aren’t battling cold and snowy conditions. While not exactly new at this point, you might see Specialized’s S-Works Exos shoes on display here. It will also be interesting to see what Trek-Segafredo riders choose for headwear if the days turn hot. It might be a good test to see if Bontrager’s new WaveCel technology can vent well enough to be a climber’s friend.

Of course, if the temperatures start to climb, look for lightweight, breathable everything. From helmets to shoes, and everything in between, riders will opt for feathery garments and accessories that focus on venting, since they can’t rely on breezes from high speeds to cool them off.

What you won’t see on TV:

Ceramic bearings aren’t exclusive to climbing bikes, but you can be sure the climbers will be running them. Ceramic bearings in the hubs and bottom bracket help reduce friction because they tend to be rounder and smoother than plain old steel ball bearings. It’s a small gain, but it’s all part of a larger equation to reduce friction in all moving parts.

Gearing choices can change based on each stage. Big days like stage 13 will require forgiving gears to counter the very steep pitches. Look for 11-28, 11-30, and in some cases even 11-32 cassettes. SRAM’s eTap AXS system throws a wrench into that rule of thumb, since this 12-speed system uses smaller chainrings and smaller jumps between cogs in the cassette.

It’s almost a given that riders will be on tubular tires. While some teams are experimenting with tubeless setups, and TT stages may see riders using clinchers and tubes, climbers will likely stick to tubulars because you can continue to ride them if you get a flat.

That’s perhaps most important on high-speed descents. A good glue job will prevent the tire from coming off the rim even when flat, while clinchers and tubeless setups can easily separate from the rim if they go flat, posing an extreme danger to descenders. Of course, it’s not guaranteed a tubular tire will stay put either, but riders will hedge their bets here.

Tubular tires