Skip the bike shorts under your wetsuit. The chamois pad, the seams, and the extra fabric all work against the way a blueseventy wetsuit is meant to fit and move. You can get them on, but you'll likely finish the swim with chafing, a heavier suit, and a slower transition.
Why bike shorts cause problems inside a swim wetsuit
A cycling chamois is built for saddle time. It absorbs sweat and cushions pressure from a bike seat. In the water, that same pad soaks up water and holds it against your skin. The result is extra weight around your hips and a wet, bulky layer between you and the neoprene. That layer can restrict your hip flexors as you kick, which fights the freedom of movement that matters in open water.
Seams and grippers also create a snag risk. A blueseventy wetsuit is cut from flexible Yamamoto neoprene and is designed to sit close to the skin. Bicycle shorts often have exposed seams, zippers, or silicone leg grippers, and pulling a snug neoprene leg over those details can catch, which is how small nicks and tears happen in the suit. blueseventy's one-year warranty covers manufacturing and materials defects. It does not cover punctures, heel tears, or zipper damage from force.
Fit changes when you add a padded short. blueseventy suits should feel snug on dry land and more comfortable once you're in the water. That fit depends on the suit hugging your hips, glutes, and thighs without folds or gaps. A thick chamois changes the shape of your leg and can prevent the suit from sealing correctly. Water then moves through the suit more freely, and the thin warm layer next to your skin becomes less stable.
What to wear instead
For open water swimming, a thin, smooth swim bottom is the right layer. These options won't bunch, won't hold much water, and won't damage the neoprene:
- Swim briefs
- Jammers
- A simple training swim bottom
Some swimmers prefer nothing under the suit. That works because the suit is designed to be worn against the skin.
Triathlon calls for a different underlayer. Choose a tri suit or tri shorts with a low-profile, quick-drying pad. These are made to go from swim to bike to run, and they won't turn into a waterlogged cushion in the lake. blueseventy carries tri apparel designed for that purpose, so you can leave it on under the wetsuit from the start.
Change before you suit up if cycling shorts are your only option. It costs a few minutes at the car but saves you a slower swim and a long walk back with wet cycling shorts.
Transition notes
The fewer layers you need to add or remove in T1, the less time you spend standing over your wetsuit. If you wear bike shorts under the wetsuit, you either swim in them or strip them off after the swim and then pull on dry shorts, shoes, and everything else. A tri suit removes that problem. You swim in it, bike in it, and run in it. The wetsuit comes off, you grab your bike, and you go.
Wetsuit fit and care when layering
Use the size chart instead of sizing up for a bulky layer. If you are between sizes, select your blueseventy size based on height, weight, and build, and wear the same thin layer during sizing that you plan to race in. A suit sized with a padded layer underneath will be too loose with a swim brief, and a loose suit flushes water and reduces body position benefits.
Pull the suit on with the pads of your fingers, not your fingernails. Roll the legs up gradually and avoid gripping the zipper or yanking on the collar. Any sharp seam or zipper on an underlayer makes that process riskier for the neoprene. After the swim, rinse the suit in fresh water and dry it inside out. If you wore a chamois underneath, rinse the suit well and let it dry completely before storing.
The takeaway
Bicycle shorts belong on the bike. Under a swimming wetsuit, the pad and seams create chafing, drag, and a poor fit. Wear a thin swim bottom for open water or a tri suit for race day, and your blueseventy wetsuit will fit and move the way it was cut to. If you are unsure about fit, take a Test Swim. You can return or exchange a suit within 30 days if it's clean and dry. Happy swimming.
