MDT Disc wheel. Cost £500. Quite light. Good Value

Buying a disc wheel is one of the best ways to improve the aerodynamic performance of your time trial bike. They are expensive – you can easily pay £500 (and much more). But, they do make a difference. Also, the faster you go, the more aerodynamic drag they save. Disc wheels work by smoothing the passage of side wind. Less wind turbulence means less drag and faster times.

A flat carbon disc wheel has an aero drag of 97grams. This compares to an aero drag of 154grams for a standard 18 spoke wheel (source: bsn)

The weight of a disc wheel is not as important as the aerodynamic aid. Even on the hilliest of time trial courses, you will go quicker on a solid disc wheel. Chris Boardman used a disc wheel for winning the national hill climb championship. I don’t advise this, but aerodynamics are much more important than weight. Also if you are going to be doing a lot of hilly time trials, look to buy a light weight carbon disc – some of them are surprisingly light.

Zipp Disc Wheels

• Zipp 900 Rear Tubular will cost over £1,400 but is one of the top disc wheels for aerodynamic performance.
• Available in clincher and with power tab
• Weight: 936g (with cassette hub). This makes it one of lightest disc wheels, which is a real advantage for any hill time trials.
• Dimpled surface, adaptable for track. One of fastest disc wheels on market.

• Slightly heavier at 1009 grams
• The Zipp Sub 9 combines rim technology of Zipp 1080 and Zipp 808 to try and improve aerodynamics
• Zipp claim ’80g of forward lift at certain wind angles’

Zipp Disc Wheels at Wiggle

Mavic Comete Disc Wheel

One of the best disc wheel on the market. The Mavic comete is not completely flat, but lenticular shape. It weighs 1,285grams (tubular or clincher)

Fast Forward Disc Wheel

For those on a tighter budget, the Fast Forward disc wheel offers great value. At under £750 it is£ more affordable than the Zipp 900, but has excellent design and aerodynamics. However, it is a little heavier. Weight Clincher: 1445 grams. Weight Tubular: 1195 gram. This is fine if you are doing flattish time trials. But, if you are doing many hill time trials, you might like to save the extra 200 grams.However, this weight is not so critical (for world Hour Record O.Sojenska actually chose a heavier rear discwheel for a ‘flywheel effect’ The Fast Forward disc is stiff and rigid. It comes with cork brake pads for the carbon rim.

Fast Forward Disc Wheel at Wiggle

When Should You Ride A Disc Wheel and When Should You Ride a Deep Section Wheel?

Using disc wheel in Circuit of the Dales (over 1,000 metres of climbing 50 miles)

• Generally, a disc wheel is going to be quicker – even on hilly time trial courses. I have known riders use discwheels in certain hill climbs (like constant gradient of 3%)
• The aero benefits of a disc wheel offset the slight increase in weight.
• At certain wind speeds, disc wheels make controlling the bike more difficult (and less safe). This loss of control may lead to more cautious riding and so the disc wheel is a disadvantage. You have to get to know what kind of wind speeds are acceptable. But, be wary of gusts than can occur when you go from sheltered to exposed.
• Another disadvantage of a disc is that it reduces the cornering performance when riding. For criteriums, disc wheels would be a disadvantage (even if they were allowed). The extra weight makes it harder to accelerate out of corners and it is less responsive when cornering. HOwever, in most time trials, it is unlikely to be so technical this becomes an issue.
• Generally, I will always try and ride the disc in a hilly time trial, unless I feel the wind is high.

Other ways to Improve Aerodynamics

If you want to improve aerodynamics, there are also cheaper ways than a disc wheel. Even a simple aero bottle can make a big difference to aerodynamic drag. See: Improving aerodynamics

Making Your Own Disc Wheel

Some try to make their own disc wheel and save a lot of money.

Related

• Training for a 10 mile time trial
• Improving Times for 10 Mile TT
• Position on a time trial bike

Zipp 404 weight pair Tubular front 568g – rear 696g - 1266 grams

Why Do People Say Weight of Your Wheels Counts Double?

It is to do with acceleration and the fact the top of your wheel travels twice as fast as your bicycle. Thus to accelerate, the energy taken to push the wheel is greater than for the bike. Once you have maintained a constant speed, then the weight of your bike and wheels count for the same. But, if you slow down and then accelerate, the energy to move the mass of your wheels is greater than for the bike.

Therefore, a secret of climbing is to try and maintain constant speed and effort. Keep the action smooth (an advantage to maintaining a high cadence and smooth pedalling power). If you have a twisting climb of varying gradients then the effort to move your wheels will be proportionately greater.

Zipp 202

• Zipp 202 front 477 grams -(front – £728)
• Zipp 202 rear 604 grams total: (rear – £924)
• Total Zipp 202 1,081 grams
• Zipp 202 pair at Chain Reaction Cycles (764 + 944)
• Zipp 202 at Evans Cycles ( 679 + 839)

Was actually used in Paris Roubaix for 4th place finisher. Used also by Carlos Sastre in high mountains during his Tour win.

I bought a Zipp 202 rear for £750 in January. when on special offer at Wiggle. If you can be patient, keep an eye on price and wait for a sale to get wheels at discount. It is worth the wait!

Lightweight Clinchers

Clincher wheels tend to be slightly heavier with tyres and inner tubes and bigger rims. However, recent developments, have helped reduce weight of clincher wheels. Quite a few now come with carbon rims to help reduce weight.

The Mavic Kysriums are relatively good value.

See: Review: Mavic Kysriums SL and SLR

Lightweight Wheels

Lightweight Ventoux – 999grams (link) $3,000 – $5,000 a pair

Campag Bora

• Campag Bora – 1,310 grams (deep section)

Campagnolo

• Campag Hyperon 1,231 grams

Shimano Dura Ace

• Shimano Dura Ace 7850 C24 1386 grams

Lightweight Clinchers

• Fulcrum XL Lightweight wheels 1245g pair £2,257