{"id":52932,"date":"2023-08-08T10:00:25","date_gmt":"2023-08-08T08:00:25","guid":{"rendered":"https:\/\/www.bikeradar.com\/?p=742255"},"modified":"2023-08-08T10:36:00","modified_gmt":"2023-08-08T08:36:00","slug":"new-ridley-dean-fast-time-trial-frame-puts-uci-rule-changes-to-aerodynamic-advantage","status":"publish","type":"rss_feed","link":"https:\/\/c01.purpledshub.com\/cyclingplus\/rss_feed\/new-ridley-dean-fast-time-trial-frame-puts-uci-rule-changes-to-aerodynamic-advantage\/","title":{"rendered":"New Ridley Dean Fast time trial frame puts UCI rule changes to aerodynamic advantage"},"content":{"rendered":"

Frameset comes with a mountain-bike style Universal Derailleur Hanger <\/p>

By Jack Evans\n \t\t<\/p>

Published: Tuesday, 08 August 2023 at 08:00 AM<\/p>

\n\n

Ridley has taken advantage of UCI rule changes with its new Dean Fast time trial bike to improve aerodynamic performance.<\/p>\n

The Belgian brand claims the updated version of its time trial bike<\/a> produces less drag due to a reduced frontal area and elongated tube shapes.<\/p>\n

The Dean Fast comes with a mountain-bike style Universal Derailleur Hanger and can accept up to a 60T chainring in a 2x configuration.<\/p>\n

We expect Ridley-sponsored men and women to race the Dean Fast in 2023 UCI World Championships<\/a> time trials.<\/p>\n

Drag reduction measures<\/h2>\n
\"Ridley<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>
The Dean Fast frameset is a blank canvas to be specced as the rider pleases.<\/span><\/figcaption> Ridley<\/i><\/span><\/div>\n

The \u20183:1 rule\u2019 meant the length-to-width ratio of bike frame tubes used in UCI competitions could not exceed three.<\/p>\n

UCI rule changes <\/a>relaxed the ratio to 8:1, allowing manufacturers to deepen tube shapes into a more aerodynamic profile.<\/p>\n

Ridley has capitalised on the relaxed regulations by elongating the head tube of the Dean Fast.<\/p>\n

The brand claims this reduces the amount of turbulence that flows behind and causes drag.<\/p>\n

Ridley says it has also benefited from the UCI easing restrictions on tube shape design.<\/p>\n

\"Ridley<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>
The stem sinks into the head tube, which extends back further than before in an hourglass shape.<\/span><\/figcaption> Ridley <\/i><\/span><\/div>\n

The new hourglass shape of the head tube \u201cstrategically shapes airflow\u201d and diminishes the frame\u2019s front profile, according to the brand.<\/p>\n

As before, the stem sits flush with the top tube, which is also claimed to reduce drag.<\/p>\n

Ridley has applied a textured surface, similar to the dimples on a golf ball, to certain areas of the Dean Fast to improve aerodynamics.<\/p>\n

F-Surface Plus technology, first used on the Ridley Noah Fast Disc, comprises small grooves which, by creating a little turbulence, cause air to flow closely to the surface of the frame.<\/p>\n

This reduces wind resistance on the rider and helps them go faster for the same amount of power, according to Ridley.<\/p>\n

The brand claims the Dean Fast\u2019s PF30 bottom bracket<\/a> further contributes to the frame\u2019s sleek profile and aerodynamics.<\/p>\n

Universal Derailleur Hanger on a time trial bike<\/h2>\n
\"Cassette<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>
The Dean Fast is the only time trial bike we know of that uses the UDH.<\/span><\/figcaption> Ridley<\/i><\/span><\/div>\n

SRAM introduced the Universal Derailleur Hanger<\/a> to unify mountain bike derailleur hanger standards in 2019.<\/p>\n

However, Ridley says the technology can benefit road bikes and has specced it on the Dean Fast.<\/p>\n

Ridley isn\u2019t the first brand to adopt the UDH standard outside of mountain bikes \u2013 the Specialized Crux<\/a> and Ventum GS1, for example, both use the standard.<\/p>\n

However, as far as we\u2019re aware, this is the first time trial bike to adopt the UDH standard.<\/p>\n

The Dean Fast\u2019s bolt-on front derailleur<\/a> hanger is removable and can be covered with a cap if the rider switches to a 1x setup<\/a>.<\/p>\n

There is one front derailleur clamp for 53-40T chainrings and another option for a 60-47T combo.<\/p>\n

The Dean Fast is only compatible with electronic groupsets<\/a>. Removing the provision for mechanical cable routing gave the frame designers and engineers more freedom, according to Ridley.<\/p>\n

Multiple bottle cage mounting points<\/h2>\n
\"Ridley<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>
There is a lower bottle cage mounting position for racing and a higher training position.<\/span><\/figcaption> Ridley<\/i><\/span><\/div>\n

On the down tube of the Dean Fast, there are two bottle cage mounting points.<\/p>\n

The higher position is designed to be used for training because it is easier to reach, according to Ridley.<\/p>\n

The brand says the lower position is less accessible but more aerodynamic and therefore optimal for racing.<\/p>\n

How was the Ridley Dean Fast tested?<\/h2>\n
\"Ridley<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>
Ridley says its designers harnessed looser UCI rules to make the Dean Fast more aero.<\/span><\/figcaption> Ridley<\/i><\/span><\/div>\n

Ridley says it used Computational Fluid Dynamics (CFD) to identify new designs that would minimise drag at 55 km\/h \u2013 a very high speed for most of us, but one that is regularly attained in top-level time trials.<\/p>\n

The brand tested the most promising designs in a wind tunnel at Bike Valley in Beringen, Belgium.<\/p>\n

The winning frame design became the Dean Fast.<\/p>\n

Sizing and geometry<\/h2>\n

The Ridley Dean Fast will be available as a frameset (including base bar) in small, medium and large sizes. Ridley will not offer the Dean Fast as a complete bike. Pricing is TBC.<\/p>\n

Ridley claims the Dean Fast frame weighs 1,250g in size medium, the base bar 341g and the fork 460g.<\/p>\n

Ridley says this gives riders the flexibility to customise the Dean Fast as they wish.<\/p>\n

<\/colgroup>
\ufeff<\/th>Saddle height (mm)<\/th>Seat tube length (mm)<\/th>Top tube (mm)<\/th>Head tube length (mm)<\/th>Seat tube angle (effective, mm)<\/th>Head angle (degrees)<\/th>Chainstay length (mm)<\/th>Bottom bracket height (mm)<\/th>Wheelbase (mm)<\/th>Standover height (mm)<\/th>Stack (mm)<\/th>Reach (mm)<\/th><\/tr><\/thead>
S<\/td>790<\/td>500<\/td>510<\/td>90<\/td>74.5<\/td>71.5<\/td>405<\/td>75<\/td>964<\/td>763<\/td>495<\/td>373<\/td> <\/tr>
M<\/td>790<\/td>500<\/td>532<\/td>90<\/td>74.5<\/td>72<\/td>405<\/td>75<\/td>977<\/td>767<\/td>499<\/td>394<\/td> <\/tr>
L<\/td>830<\/td>540<\/td>555<\/td>110<\/td>74.5<\/td>72<\/td>405<\/td>75<\/td>1,001<\/td>786<\/td>518<\/td>411<\/td> <\/tr><\/tbody><\/table>