Starting in 2000, SRAM decided to merge the DI.R.T. designs that they had inherited from Sachs with their own ESP 1:1 actuation designs. Both traditions shared a love of composites and of innovative cable routing.
SRAM decided to go for stiffness with very wide parallelogram plates, something that most derailleur manufacturers have since adopted. SRAM also went for the DI.R.T style straight cable routing. In many ways these derailleurs were the prototypes for the modern classic that is the first generation SRAM X-0.
But there were more than a few flies in the ointment:
- The derailleurs were not light, and, in fact, were heavier than both the Sachs DI.R.T and SRAM's own ESP series.
- In my experience, the composite b-knuckle on the earlier models had a tendency to explode. I found this odd. SRAM were paranoid about b-knuckles exploding - because that was the famous problem with their very first design, the SRAM ESP 900. How did they let this happen again?
- And then there was the look of the beast. It is strangely clunky and uninspiring.
I think that this is an early example of the plain vanilla SRAM 9.0. Its features are:
- It is black.
- The b-knuckle is composite.
- The inner parallelogram plates are steel.
- It has a long, 92mm, pulley cage.
- The pulley cage plates are the earlier curvaceous shape.
- The inner pulley cage plate is composite.
- The pulley wheels have plain bearings.
- The small plate on the inside of the b-knuckle that bears on the gear hanger is made of aluminium.
And it weighs a chunky 250g.
- Derailleur brands: SRAM
- Categories: SRAM - the X series
- Country: USA, manufactured in Taiwan
- Date of introduction: 2000 for the 2001 model year
- Date of this example: The inner pulley cage plate is labelled 'SEP 11 01', which may mean 11th September 2001
- Model no.: T500-535-1?
- Weight: 250g
- Maximum cog: 34 teeth
- Total capacity: 45 teeth
- Pulley centre to centre: 92mm
- Index compatibility: 9 & 8 speed
- Chain width: 3/32”
- Logic: top normal
- B pivot: unsprung
- P pivot: sprung
- Materials: Grilon composite knuckles and inner pulley cage plate, steel inner parallelogram plate, aluminium outer parallelogram plate and outer pulley cage plate.