Aesthetics have played a role for the traditional German manufacturer Diamant from Hartmannsdorf near Chemnitz since its foundation in 1885: even historical models often showed a desire for good design, a tidy silhouette and a pleasing appearance. In September 22, the Saxon company, which has been part of the US manufacturer Trek for several years, presented its updated Rubin series: versatile, lightweight bikes suitable for everyday use with simple, reliable technology and an extra touch of chic and esprit for everyday use.
The structure of the diamond ruby
The basic "Rubin" model is the most affordable bike in the series of three models. It has been given a newly designed, slightly lighter aluminium frame, which it shares with the next most expensive model, the Rubin Legère. The frame is available as a trapezoidal or diamond frame with an elegant curve in the top tube, filigree rear triangle and fork and has a dynamic look. The gear cables and brake cable disappear into the frame at the head tube and only emerge once they have reached the respective component. The front light cable is a breakaway from the clean lines. It runs around the outside of the bulky head tube and into the down tube.
However, the clear look returns with great clarity at the latest on the strutless luggage rack: just like the slim mudguard, the rack sits on a simple steel bracket hidden under the long mudguard. Unfortunately, this offers relatively little lateral stiffness, so that the carrier and luggage start to sway noticeably from a load of around twelve kilos. The trapezoidal construction of the frame also contributes to this, with a low top tube that does little to counteract lateral impulses from luggage or pedalling. Unloaded or with a light load, however, the Diamant Rubin rolls relaxed, manoeuvrable and confidently along urban roads and paths.
The finely balanced geometry shows the makers' many years of experience: the riding position is relaxed and sporty, the wide handlebars sit comfortably in the hand, they provide a lot of steering control and you keep an overview of the traffic. The steering is neutral, the wheels roll nimbly and light-footedly on good tarmac. However, if the surface becomes loose, the narrow, low-profile tyres, which are only 35 millimetres wide, lose traction. Their low volume requires high pressure (more than 4.5 bar), which generates little comfort overall.
Design versus service
If you ever have to replace the internally routed shift cables with continuous sleeves or remove one of the brake callipers, the fork or the headset, it becomes extremely time-consuming: Two shift cables and the two hydraulic lines of the disc brakes run vertically through a window in the upper bearing cap into the head tube and on into the down tube. To replace these parts, you have to open and remove all four cables. However, this is almost impossible to do yourself as it requires specialised tools and knowledge. In addition, brake line assembly in particular takes a lot of time, which will also be charged for in a professional workshop.
The most important facts about the diamond ruby
- Model: DIAMANT Ruby
- Price: 1149 Euro
- Frame sizes: S, M, L, XL
- Test bike weight: 15 kg
- Permissible total weight: 136 kg
- Frame: Aluminium, welded
- Fork: Steel, disc
- Circuit: Shimano Alivio/Acera, Rapidfire
- Translation: 46/30, 11-36 t., 2x9, 502 %
- Brakes/ø: Shimano MT201 Disc/160 mm
- Tyres: Bontrager H2 35-622
- Lighting system: Spanninga Brio, Viva; Shimano DH-3D37 hub dynamo
Advantages and disadvantages
- Plus: Light, manoeuvrable and agile; good gear ratios; top brakes
- Minus: Luggage rack with little lateral stiffness; meagre light field of the headlight
Conclusion on the diamond ruby
Internally routed cables and lines are currently an overpowering trend in the bicycle industry: this is visually elegant, but even for minor wear and tear repairs, an appointment with a professional workshop is unavoidable. The time required there is quickly reflected in a hefty bill.
