B.S.A. and SunTour: a perfect match

The more I think about it, the better is Major Tom’s combination of BSA branding with SunTour components. It’s poetic really, both these companies were at one point the leading innovators in bicycle components, and both now effectively extinct (yes, BSA exists in India and SR SunTour continues in Taiwan, but they are not their former selves). I have even seen it suggested that SunTour chose to brand their early products “8.8.8” not just because 8 is lucky but also in order to make it look a little like “B.S.A”, which was a well-respected brand in Japan at the time. (Shimano chose 3.3.3)

Starting off as Maeda Iron Works they originally manufactured sprockets and chainwheels, then branched out into derailleur manufacture in the early 1950s, like many Japanese companies of the time simply copying European components. 


Here starts the great Japanese quality revolution, which can be seen in virtually all manufactured technological goods. They start by producing cheap, poor quality copies. They then start making cheap, good quality copies, with less scrap parts and thus better profitability even at a lower price. Their quality then starts to exceed their European competitors, and then the final killer blow is when they start manufacturing components that are not only cheaper and better quality, they also feature better designs. This is exactly what killed off BSA motorcycles, and many, many other UK and US manufacturing companies besides.

Virtually EVERY cyclist who rides a reasonably high-end bike owes a debt to SunTour. Two words encapsulate SunTour’s greatest legacy: Slant Parallelogram.


I love the slant parallelogram derailleur. It is such a simple, effective idea, and to an engineer’s eye it is utterly beautiful. As well as just moving the chain in and out, it also moves the guide pulley up and down, tracing the cone shape of the sprockets and so keeping a consistently small gap between guide pulley and sprocket. It costs virtually nothing, save perhaps requiring a little extra material to achieve the correct geometry. SunTour developed this in 1964, and held the patent until the mid-1980s. During this time it’s no coincidence many felt theirs were the best shifting derailleurs on the market.

SunTour’s pricing policy was endearingly quaint. It’s a fundamental part of their popularity and their demise. Rather than charging what the market could bear they worked out how much things cost to make and added a modest premium. Given that a SunTour Vx was as well built as a Shimano, shifted much better than Campagnolo, with only slightly more weight, and was cheaper than either, they were fantastically good value. People’s perceptions of value, however, are not entirely rational, and while some wax lyrical about Campagnolos that were so robustly built that “they will shift badly forever” simply because they were so fabulously expensive, so SunTour never quite got the credit they deserve because their low price led people to think they were inferior.


SunTour’s innovations weren’t confined to derailleurs, either. SunTour’s sprockets featured slanted teeth that aided chain pick-up and prevented the chain sliding along on top of the sprockets meaning you lose all drive – something my Maillard freewheel is particularly prone to. They also produced power shifters, which contain a little ratchet to hold tension instead of the basic friction shifter. Major Tom has these and they work fantastically well. The ratchet also featured in SunTour’s very popular Barcon shifters, which fitted into the bar ends and made shifting easier. A few pop up on Ebay now and then and they invariably sell for eye-watering prices. A less common but no less clever innovation were paired levers that trimmed the front derailleur automatically when shifting the rear.


Between the mid-1970s and mid-1980s SunTour ruled the bicycle world. Then, all of a sudden, they came unstuck. It’s quite incredible that several hurricanes should burst on to them all at the same time, but it happened.

Firstly, they were caught slightly on the hop by the trend to mountain bikes. They weren’t totally helpless, but their rushed response proved unreliable in use because one of the springs wasn’t sufficiently sealed. Their good name began to be tarnished as mechanics who swore by SunTour were confronted by frustrated customers. The Superbe Tech range was another blow, a clever new idea for a parallelogram, but they quickly lost alignment and were extremely difficult to fix – unforgiveable for the high-end market it was aimed at.

Next, in 1985 their cherished patent lapsed. They had jealously guarded the slant parallelogram for 20 years, but now their unique selling point was available to all. Shimano incorporated it with almost indecent speed, and suddenly it wasn’t just a SunTour that shifted like a SunTour.


Perhaps the biggest blow was the Shimano Indexing System, though it probably didn’t seem so at the time. Many companies, SunTour included, had played around with indexing from time to time and it had never really taken off, but this time it stuck. Shimano had done their homework in minute detail, with an R&D department 10 times bigger than SunTour’s and with the power to specify a full gruppo that was entirely designed around SIS, and the bottom line is it worked really well. SunTour were lagging behind, and by the time they were in a position to introduce their own AccuShift system they were too desperate for sales to put their foot down when manufacturers started using up old stocks of utterly incompatible components.

Part of the reason for their desperation was the Yen shock. In 1985 a group of leading nations decided (with some justification) that the Yen was horrendously undervalued relative to other currencies, and with their contracts denominated in other currencies, SunTour suddenly found themselves in some dire financial straits. Shimano had already started shifting production overseas from the early 1970s, but again, SunTour found themselves rushing to respond to factors outside their control.

And all of this happened in the space of a couple of years.

Well, it all slowly came to a close. The company was sold, then sold again, and now the Taiwanese imposter that holds the SunTour brand name (but not the IP) specialises, admittedly quite successfully, in mountain bike suspension forks. The most heart-breaking part of it was that the tooling for SunTour’s components, including for the Superbe which was regarded by those who should know as THE BEST friction-shift derailleur ever made, was sold for scrap.

Oh well, like BSA they had their moment at the summit, and every modern bike will include one or two features they owe to SunTour.

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