Rose Bikes 29'' 2014

En las próximas entradas voy a analizar unos cuantos modelos de la marca Rose Bikes, que este año ha renovado casi por completo toda su gama de Dobles: Tres modelos de 27.5'', un par de modelos de Freeride-DH en 26'' y pequeñas mejoras en el resto de modelos (Mucho trabajo en un solo año). En esta entrada voy a hablar sobre la Root Miller y la Dr.Z, dos 29ers con 100mm y 130mm de recorrido y un clásico sistema FSR.


Como podéis ver en las primeras gráficas el sistema de estos dos modelos tiene una eficacia de pedaleo bastante baja, por lo que va a depender mucho del sistema de bloqueo del amortiguador. El porcentaje de Anti-squat en plato pequeño está en torno al 75% por lo que tampoco se puede decir que esté optimizado para ese desarrollo, pero es donde mejor se va a defender. El Pedal-Kickback (4.5º) como ya os podéis imaginar es muy muy bajo, y el Brake-squat (~60%) también está muy bien conseguido, con un porcentaje bastante bajo.

En la gráfica del Leverage Ratio vemos como los dos modelos son muy progresivos. En el caso de la Root Miller (TrailBike...) creo que el sistema está bastante bien: mucha progresividad y buena efectividad en desarrollos cortos, pero ese mismo sistema aplicado en el modelo de XC es seguramente demasiado progresivo, y ademas lo ideal es que estuviera optimizado para unos desarrollos mas largos (32T-36T).  

Un saludo.

8 comentarios:

Rose Rider dijo...

Dear Antonio,

I own a Rose Dr. Z 2010, 26" model converted to 650b. Works very well except maybe pedaling efficiency. The design of the frame is the same as the one in the above analysis. The shock used is a FOX RP23 with a propedal setting. I run a 36/22 crankset. Even in the Propedal 3 postion there is bob on the large ring. The 22 works better but still not satisfied. Do you think a true lock shock like Monarch RL, XX or DT Swiss 313 would be beneficial? The RT3 and in general all Fox shocks are not true locks. Thank you

Antonio Osuna dijo...

If you really think that is going to work well then do it. If you climb on smooth trails the rear lockout is going to work really well and you still have the open position for the Donwhill.

Best regards,
Tony.

Rose Rider dijo...

Thank you Antonio! I mainly climb fireroads, which are smooth. I used to climb them on my hardtail which seemed a lot faster. With the current bike I cannot pedal from a standing position, but I'm also pretty heavy, 100+ kg, still fit and athletic.

What I wound need is a firm pedaling platform, since this frame does not provide any by itself. I would say it's either poor design or intended for confort, which would be rather strange since they've advertised it as a true XC weapon.

I use my current RP23 in off/on anyways. I would like to have the advantages of a RT3 shock, but I head that does not provided a firm lock. If I run my RP23 with more pressure, then of course I don't get the full travel anymore. What do you think would be the best thing to do considering this frame, other than swapping it :).

Antonio Osuna dijo...

The problem here is that the LR around sag is pretty high (2.8) and that you are a bit heavy, that's why the RP23 feels like it has a weak compression adjustment. In other bikes it's going to feel a lot more powerfull and if you could send it for a rebuild you could get something similar too. The problem is that a rebuild is quite expensive and you can't be 100% sure that it's going to end up perfect, so getting a new shock with a lockout still makes a lot of sense.

Best regards,
Tony.

Rose Rider dijo...

Antonio, thank you for your answer. My RP23 is a velocity tune F(irm) and a Rebound tune (M). According to that, I think it was build already by(for) Rose to compensate a bit the design of the frame.

Still what puzzles me a a bit is that you say "but that same system used in the XC model is probably too progressive, and also ideally that was optimized for a longer development (32T-36T)". But, since the frame is prone to pedal bob, would it not be suited actually with shorter developments, like 22/20T?

Antonio Osuna dijo...

Sometimes the lower tune is not low enough and others the firm tune is not firm enough... It seems that Rose tried to compensate using the firm one in compression, but it didn't work for you.

And yes, as you say the system is going to work better wit very small chainrings so the best option is to use a compact drivetrain (20T-30T-40T) and use the small one as much as possible...

Best regards,
Tony

Rose Rider dijo...

Dear Tony,

Would it be difficult for you to run another calculation with 22T and 20T?
I don't need the bigger rings, since I can extrapolate with the existing ones.

Thank you!

Rose Rider dijo...

Hello Tony,
Thanks for running the calculation one more time for the small dishes. I see many other bikes using the same FSR-like system but with way better results, but they use different anchor systems for the shocks. I wonder what would happen if the shock mounting (the red part in the image above) would have been modified, such that the shock would anchor nearly at the same point or even lower ...

 

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