My memories of SunRace derailleurs are a little foggy, and I have terrible trouble finding historic SunRace literature - so treat what follows with a touch of scepticism.
I kind-of remember the SunRace 590 as being a cheap, plastic, derailleur found on many of those, how-shall-we-say-it, tacky, inexpensive, no-name, mountain bikes you find in big-box retailers. When I look at it today, I see that it contains very little plastic, and seems rather solidly constructed.
I also remember it as appearing at about the same time as the SunRace 595.
- Derailleur brands: SunRace
- Country: Taiwan
- Date of introduction: 1997?
- Date of this example: unknown
- Model no.: 590
- Weight: 296g
- Maximum cog: 32 teeth? (roughly based on Shimano Deore XT (M739 SGS))
- Total capacity: 38 teeth? (roughly based on Shimano Deore XT (M739 SGS))
- Pulley centre to centre: 87mm
- Index compatibility: 8 speed?
- Chain width: 3/32”
- Logic: top normal
- B pivot: sprung
- P pivot: sprung
- Materials: largely steel with an aluminium b-knuckle and a plastic p-knuckle