EZ Gains Rear Wheel Disc Cover

One of the first areas riders look to upgrade for aero improvements are their wheels. In time-trial and triathlon racing, many people equip their bikes with a completely covered rear wheel or a full rear disc wheel. This blocks all air from getting caught in the rear wheel and keeps it moving past quickly.

On windy days, the disc may also create a sail effect, pushing the rider even faster. But bolting one of these on is not cheap. Just that rear wheel alone can cost anywhere from £1,000 to £4,000.

To make this rear wheel advantage more accessible to the masses, the team at EZ Gains has created an elegant solution. We’ve developed a simple cover made of durable and lightweight material that slips over your existing wheel, connecting securely and creating the SAME aero gains as if you purchased a fancy rear wheel.

In fact, some testing suggests that depending on the wheel you install it on, the cover may perform better than a full disc wheel. If you already have a good quality wheel and add the EZ Disc, this can enhance your gains, as the aero gains between a Disc and EZ Disc are identical.

Testing this out ourselves, we found that installation was quite simple and could be done at home with the appropriate tools (most will need a lock ring tool). Once on the bike, the feel and performance were evident. It really showed its stuff on those fast descents, capturing an extra mile or two per hour in comparison to our 80mm deep section rear wheel.

2021 Wind Tunnel Tests

One of the first tests EZ Gains did was at Silverstone Sport Engineering Hub wind tunnel, using just a bike and no rider to identify if an EZ Disc added to a wheel was as fast as a disc wheel.

We tested with wind speeds of 30, 40 and 50 kmph, with wind angles of -15 degrees through to 15 degrees. The results were unequivocal!

This graph shows aerodynamic drag (CDA), including the bike, against the wind angle (yaw). The lower the CDA, the better. The EZ Disc, even without the latest rim tape and aero screw covers, tested as fast as high-cost and low-cost disc wheel brands.

Outdoor tests using Golden Cheetah confirmed that using an EZ Disc vs a Disc wheel gave matching results. EZ Gains can confirm this was the case.

2023 Wind Tunnel Testing with Donald Brooks

At Silverstone Sport Engineering Hub, we had the pleasure of Donald Brooks joining us – Ironman Kona 45-50 Age Group World Champion.

The images below are taken from a video camera in Silverstone Wind Tunnel over a 20-minute period. The testing protocol, set by Silverstone Sports Engineering Hub, ensures accuracy and consistency. It’s the same process used by top athletes and equipment testers worldwide.

£2,500 Disc Wheel vs Zipp 808 + EZ Disc

At 40kph, power required live was slightly lower using an EZ Disc vs a £2500 Disc Wheel.

2024 Confirmation Tests with James Teagle

Professional athlete James Teagle, being at the cutting edge of the sport where every second counts, wanted confirmation the EZ Disc was as fast as his Disc wheel. We are happy to say it was!

£2,000 Disc Wheel vs EZ Disc Super Lite + MVR Wheel 50mm

At 45kph, similar watts were required across the range of YAW angles.

At 50kph, again, similar watts were required across YAW angles.

Rolling Resistance Rig Tests

Silverstone Sports Engineering Hub has recently developed a rolling resistance rig. This identifies which wheels roll at lower watts under identical conditions.

EZ Gains tested a sub £900 wheel + EZ Disc against a £1,000 Disc wheel. The results favoured EZ Gains!

Across a range of speeds, the EZ Disc + CES Wheel rolled better than the disc wheel under the same conditions.

Final Thoughts

• The new EZ Disc Super Lite is as strong – if not stronger – than a disc wheel.
• When added to your own wheel, the weight can be as light as a disc wheel (only 400g-600g).
• At 40kph, the EZ Disc showed a lower CDA than a top-end disc wheel.
• The EZ Disc has been proven to add stability and structural integrity, acting like a disc wheel and producing the same “whooshing” sound.
• Outdoor testing showed an average saving of 2 minutes and 30 seconds over a 90k route.
• Buy one wheel and add/remove the EZ Disc as needed – saving money and offering flexibility if disc wheels are banned in certain events.

In short: it’s as fast as a disc wheel, stronger than a disc wheel, saves buying two wheels… it’s an absolute no-brainer!