The XDS X-LAB RT9 is an exceptionally light climbing bike with a 550g frame, praised for its stiffness, power transfer, and value, but criticized for its stock 50mm deep wheels that make handling twitchy and unstable in crosswinds. The stock build also has limited customization, tire clearance of 30mm, and a 220lb rider weight limit. Availability outside China is improving with a US launch at Sea Otter and a dealer network.
Pros
- Exceptionally light: 550g frame and 5.9-6.2kg complete build1
- Stiff frame and efficient power transfer1
- Significantly lower price than comparable bikes like S-Works Aethos 21
- Comfortable over long distances (19h40m in saddle, 2,000 miles)1
- Lifetime frame and wheel warranty1
- Standard components: threaded BB, round seatpost, IS52 headset allow easy customization213
- Dual-sided power meter and Apple Find My anti-theft technology integrated into crankset1
- Includes accessories: out-front mount, torque wrench, bottle cage, taillight, pump; free post-purchase cockpit swap through dealers1
Cons
- Stock 50mm deep wheels are too deep for a climbing bike, causing twitchy handling and instability in crosswinds1
- Stock tires (Maxxis or Michelin) are poor and compromise ride feel1
- Limited tire clearance (30mm max) and rider weight limit (220 lbs)1
- Limited cockpit sizing options and no customization for bar/stem or crank lengths on stock build13
- Stock build uses house-brand wheels and power meter/crank; power meter tested about 10 watts off but consistent3
- Pricing considered uncompetitive by some compared to Western brands with branded components3
- Limited availability and unclear international distribution strategy3
Key Facts
- Frame weight: 550 grams (size medium)1
- Complete bike weight: 6.1kg (ready to ride, minus pedals) for size medium; 5.9kg for size small; 6.2kg for size large13
- Uses Toray T1100 and M40X carbon fibers with tow-spreading technology; frame walls as thin as 0.4mm1
- Max tire clearance: 30mm (32mm would be better according to one reviewer)1
- Rider weight limit: 220 pounds (100kg)1
- Branta C50 ULR wheelset: 50mm deep, carbon spokes, claimed weight 1,230-1,250g1
- Price: $9,000-$9,150 complete, $3,499 frameset1
- Threaded BSA bottom bracket, standard round seatpost (27.2mm), SRAM UDH, IS52 headset standard213
Reviews & Ratings
08:27The reviewer provides a first look at the XDS X-LAB RT9, the climbing bike that the XDS Astana team will use in the 2025 World Tour. He describes it as a classic climbing bike with cylindrical tubing, a threaded bottom bracket, and a classic seat collar. The bike weighs 6.9 kg, and mechanics are confident they can bring it down to the 6.8 kg weight limit. It shares a similar paint job with the aero model, featuring black on the down tube and forks, white X-LAB lettering, and Astana team colors on the top tube. The reviewer notes that riders will have a choice of Vision handlebars, and the bike is equipped with Shimano groupset, Prologo saddle and tape, and Vision wheels with Continental tires. He finds it 'pretty banging' and appreciates its classical design.
16:12The reviewer tests the XDS X-Lab RT9, an ultralight road bike, during an Everesting challenge. He praises its climbing ability, stiffness, and value but criticizes the stock Branta C50 wheels for being too deep, stiff, and nervous, especially in crosswinds. He replaces the tires and wheels, noting significant improvements. He considers it ideal for climbers and those seeking efficiency, but notes limitations like tire clearance and rider weight limit.
The reviewer describes the XDS X-LAB RT9 as the world's lightest production road bike, featuring a 550-gram frame and a complete build weight of 6.1kg. It is praised for its exceptional lightness, balanced stiffness, and significantly lower price compared to competitors like the S-Works Aethos 2, though it has drawbacks such as an overly stiff handlebar, limited integrated cockpit sizes, and difficult purchasing options.
The reviewer describes the XDS X-LAB RT9 as an exceptionally lightweight climbing bike with a very stiff frame and excellent power transfer, but criticizes the stock Branta C50 wheels for making descents twitchy and crosswinds unstable. The bike offers strong value and comfort over long distances, though the wheels and stock tires are considered drawbacks.
The XDS X-LAB RT9 (also referred to as AD9) is a lightweight carbon road bike discussed by forum users. It's compared to the Specialized Aethos, with users noting its competitive weight (around 6.1kg in a ready-to-ride setup with 50mm aero wheels) and potential as a more affordable alternative. Key attributes mentioned include its use of high-modulus carbon fiber to achieve low weight, IS52 headset standard for compatibility, and mixed signals about international availability. Users debate whether it's a direct Aethos competitor or knockoff, with some noting limited production and high costs. Recently, XDS launched the RT9 in the US at Sea Otter, building a dealer network and selling directly for around $9K with free shipping. However, the stock build has been criticized for using house-brand wheels and power meter/crank (the power meter tested about 10 watts off but consistent), heavy 50mm wheels on an ultralight climber, no customization for bar/stem or crank lengths, and an expensive SLR Boost saddle. Some users find the pricing uncompetitive compared to Western brands with Shimano/SRAM cranks and branded wheels. XDS is reportedly working on a 5kg build, and users suggest easy weight savings like 900g shallow carbon spoke wheels, lighter tires, and a carbon fiber saddle with no padding.
AI Summary
Pros
- Competitive lightweight performance similar to high-end bikes like Specialized Aethos
- Potential price advantage over comparable lightweight bikes
- Uses standard IS52 headset for easy component compatibility
more pros in the review
Cons
- Limited availability and unclear international distribution strategy
- Proprietary handlebar/spacer system that may limit customization
- Reportedly high production costs leading to limited production
more cons in the review
Key Points
- Weight around 6.1kg in ready-to-ride setup
- Uses high-modulus carbon fiber construction
- IS52 headset standard
more key points in the review
Specifications
Attributes
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