Specialized’s World Cup-winning Demo 29 finally hits the market

The bike has been in open development for several years

Specialized Demo Race 29

Specialized has launched the latest incarnation of its popular Demo downhill bike for 2019, and now it’s built around 29-inch wheels.

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Any fans of downhill racing, particularly those who follow the French gent Loic Bruni and his teammates at Specialized Gravity (Finn Iles and, until this year, Miranda Miller), have been waiting for this moment.

The Californian brand has been conspicuous in its development of the Demo 29. Versions of the prototype were rolled out for racing in 2018 and then shelved again, sent back to R&D for fine-tuning, with the team running the previous Carbon Demo to great success — Bruni of course won the 2018 World Championships in Lenzerheide, Switzerland.

Specialized Demo Expert 29
The less costly Demo Expert 29 is the ‘journeyman park and race bike’, according to Specialized.
Specialized

By UCI Downhill World Cup 2019 Round 1 in Maribor, Slovenia, Bruni and Iles were ready to race the bike at the highest level. Both riders proved exceptionally fast, with Bruni taking that opening race win and two further victories since.

That’s three out of four 2019 World Cups for Bruni on this new bike – more wins in one season than his pre-2019 total. The bike clearly works. There is a caveat to this fairy-tale beginning, but we’ll address that later.

Specialized Demo 29 development and geometry

Specialized explains the months and years of hard work that has gone into the bike in simple terms. Its aim through development was a bike that was built around 29-inch wheels because they “better maintain their momentum in rough sections”, carried speed more efficiently over square-edged hits through refining suspension action, were more stable under hard braking and pedalled well when it was time to get on the gas.

A refined, more rearward axle path is, according to Specialized, the key to bettering performance in square-edged hits. It hasn’t gone to the extremes here, because it believes in balance and not focusing on one characteristic at the expense of another. Too much and the bike’s geometry can noticeably change through the suspension cycle, as well as create excessive chain growth and sacrifice small bump sensitivity.

It opted not to include an idler pulley (such as that on Commencal’s Supreme DH), which can help eliminate pedal kickback and allow a more rearward axle path, to avoid the extra friction incurred by this solution and because “the right amount of chain growth can help create effective anti-squat and improve pedalling performance”. Anti-squat on the new Demo 29 is increased by 300 percent over the previous model.

Specialized Demo 29 geometry chart.
This geometry chart shows the difference between the old Demo and the new Demo 29.
Specialized

Likewise, anti-rise increases by 70 percent, a move Specialized says was made in order to better the ride under braking. This increase means the bike compresses less during braking; more stable geometry means the rider moves around less to compensate.

Geometry-wise, the Demo 29 is mostly bigger, longer and taller. Stack height is increased by 19mm to 633mm, bottom-bracket height is up by 8mm to 350mm in order to “balance the bike’s ability to corner, yet not hit pedals in pedalling sections of DH tracks”, head angle is slackened by nearly one degree to 62.7 degrees, front-centre, wheelbase and chainstay are all longer than before.

Specialized Demo 29 wheel size

All-in-all, the Demo 29 seems like a fierce speed machine that is likely to sell like hotcakes to the racing community. The caveat is that Specialized Gravity is gaining all its success with a 27.5-inch rear wheel on the bike (a recent change in UCI ruling means racers can compete with different size wheels, something previously not allowed).

In Specialized’s own words, the “Demo is R&D in motion”, and we shouldn’t rule out the introduction of a 27.5-inch kit in future. Constant development is also the reason this bike is alloy, not carbon.

The Demo 29 is available in three sizes, with two full-build options and a frame-only option.

Specialized Demo 29 frame only
A frame kit, including shock is available.
Specialized

Specialized Demo Expert 29

  • Frame: Demo 29, M5 alloy, 200mm travel
  • Colour: Gloss-Storm Grey-Rocket Red
  • Rear axle: 148mm
  • Fork: RockShox BoXXer Select 29 fork
  • Shock: RockShox Super Deluxe Coil Select Plus
  • Brakes: SRAM Code R 4-piston
  • Drivetrain: SRAM GX DH 7-speed
  • Price: £4,499 / $5,000

Specialized Demo Race 29

  • Frame: Demo 29, M5 alloy, 200mm travel
  • Colour: Gloss-Metallic Black-Burnt Yellow
  • Rear axle: 148mm
  • Fork: Öhlins DH 29
  • Shock: Custom Öhlins TTX
  • Brakes: SRAM Code RSC 4-piston
  • Drivetrain: SRAM X0 DH 7-speed
  • RRP: £6,499 / $6,500
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Specialized Demo Race 29 frameset

  • Frame: Demo 29, M5 alloy, 200mm travel
  • Colour: Gloss-Acid Mint-Burnt Yellow
  • Rear axle: 148mm
  • Shock: Custom Öhlins TTX, trunnion-mount rear shock
  • Price: £2,749 / $2,500