I've become kind of a Suntour afficionado and therefore have spent some time researching the various road components that the company produced. It's difficult to locate comprehensive information, so I am putting some of it down here. I'll focus on the higher-end road groups and also some of the interesting and esoteric parts I've come across. I'll try to do it chronologically. A useful source for me has been the article "Sunset for Suntour," although it is more of a historical overview:
The invention of the slant parallelogram rear derailleur seems like a good place to start. Nobuo Ozaki of Maeda (Suntour's parent company) invented the design in 1964, and it was soon patented. The patent would expire in 1984, and Suntour's competitors would adopt the design immediately thereafter. In the twenty year interim, Suntour's derailleurs were typically superior to their contemporaries. The primary benefit of the slant parallelogram design is that the distance between the jockey wheels and rear cogs varies less as the derailleur is moved.
The first slant parallelogram derailleur was Suntour's Grand Turismo model. Suntour also introduced other early advances, such as splined freewheel sprockets.
Another interesting part came in 1966, Suntour's Spirt (not Sprint, or Spirit) front derailleur. It was a "top normal" derailleur, in that you move the lever in the opposite direction to shift up or down. Thus both shift levers move the chain to a higher gear when pressed forward. Apparently the Spirt was produced for some time (it can be found in the 1987 catalog). Rivendell sells 1978 models for $15.
Not much information is around from the late 60s or early 70s. I think the top model from around that time period was the Suntour V.
In 1975 Suntour introduced their Cyclone derailleurs, the new top model. They were quite a bit cheaper than Nuovo Record and shifted very well. 1975 Suntour Parts Catalog:
In 1977 the new top group was Superbe. This year also saw Ultra-6 spaced freewheels, which allowed a rider to run a 6-speed freewheel with 120mm dropout spacing. In 1979 Ultra-7 allowed 7 speeds with 126mm. Superbe remained top of the line until 1981. 1980 Suntour Catalog:
Suntour Symmetric shifters were an esoteric piece of early 1980s Japanese engineering. They could be mounted on frames with a single DT shifter braze-on (like some of the Shimano AX components took) or with a supplied clamp-on belt. They are unique because shifting the rear derailleur automatically trims the front via a cam mechanism. Unfortunately, the trim only works as you downshift the rear derailleur, so as you go back and forth, the trim will eventually move the FD too far inward. Interesting nonetheless.
In 1981 Superbe Pro was introduced. Good stuff, the early to mid 80s Superbe Pro friction group is probably my favorite. Commands a premium price on ebay (I would know, I'm selling a group on there right now). Superbe was now second-best, with Cyclone below that. ARx, AR and BL (Blue Line, which featured interesting blue details on the components) were also introduced. Brakes and brake levers were rebadged Dia-Compes, hubs were Sunshine, stems and seatposts were possibly SR, and I think the cranks and BBs were made by Sugino (all the ones I've seen come with a Sugino marked grease condom, in any case). A picture of the 1985 Superbe Pro group (bottom image, the top is Superbe from 1979):
A note on Superbe Pro BBs: Suntour used a weird taper for their Superbe Pro BBs of the time. The closest match other than a Superbe Pro BB would be Campagnolo square taper, from what I understand. I think this is the approach that Phil Wood recommends.
In 1985 Shimano introduced indexed SIS shifting. Suntour underestimated the necessity of a competing product and postponed development of an indexed system until 1986, at which point SIS had become quite popular. During that year, Suntour Accushift was quickly developed.
In 1986 the Sprint group appeared, a friction group placed in between Cyclone and Superbe (Superbe Pro was dropped for a year). The Sprint shifters included a ratchet mechanism (Suntour Power Shift) that disengaged the friction mechanism as you pulled back. A lot of people like Power Shift levers, and they are often compared to Simplex retrofrictions. There are popular Suntour barcons that use the same design. There had been ratcheting models on lower end Suntour groups previously, and future Accushift models would also have ratchet modes. You can buy Suntour LD-4850 Power Shift levers at Velo Orange. These are Sprint shifters.
In 1987 Accushift was introduced. There were technical problems. Further market share was lost to Shimano. Accushift groups included Superbe Pro, Sprint 9000, Cyclone 7000, α-5000, and α-3000. Non-indexed versions of the second- and third-best groups' RD and levers were referred to simply as Sprint and Cyclone. Superbe was dropped. The easiest way to tell the difference between the newer and the older Superbe Pro groups is the logo font. Newer cranksets used 130bcd instead of 144bcd. Aero brake levers were introduced. 1987 Suntour Dealer Catalog:
In 1989 the lineup was changed again. From top to bottom: Superbe Pro, Sprint, GPX, Olé, and Blaze. Olé was a response to Shimano Santé and featured white details. Didn't really take off. 1989 Catalog and additional scans from around the same time:
Most of the problems with Accushift had been cleaned up by 1990. Superbe Pro was still top-quality componentry, but Shimano had taken over the market. Superbe Pro sealed hubs were of course excellent. Cassette models appeared in the early 1990s. Micro Drive components employed smaller bolt circle diameters to permit smaller chainring sizes: essentially an early compact crankset that was copied by Shimano two years later. This, along with other mountain-specific advances (some of which were licensed from other companies to kickstart declining sales, e.g. WTB Grease Guard bearings) failed to realize its potential due to the market already lost to Shimano. Accushift Plus and Powerflo cogs were shaped to smoothen shifting and competed with Shimano's Hyperglide system. The famous hidden spring brakeset demonstrated Suntour's engineering expertise. It is now quite collectible.
Suntour SL replaced Sprint in 1991. A bit from the 1992 catalog:
Superbe Pro BRS Hidden Spring Calipers:
One last unusual piece of engineering was the Suntour Command Shifter. They were something like STI or Ergo and mounted just inside the brake levers on the handlebars. The front shifter had the ratchet mechanism, and the rear could shift in either indexed or friction modes. They worked well, save for the fact that you couldn't shift from the smaller to the larger chainring from the drops (which is when you would want to do so). If you were clever, though, you could solve this by using the Suntour Spirt derailleur I mentioned before. A picture of command shifters:
Suntour stopped producing components in March of 1995. The name was bought by SR, but the component designs did not survive.
Wooljersey gallery with various Cyclone, Superbe, and Superbe Pro components.
Some Japanese pages with pictures and information on Suntour parts.
Most of this has been cobbled together through online research, so it might not all be correct.