Originally Posted by Ciufalon
Thanks for your help Tmar. Couple of questions. Does this mean my bike is mid-range or lower midrange? Do you think mine is also made of Tange tubing? Because I have heard that only the top of the line "prestige" Tange tubing is good. Also, is the sign I referred to on deraillers Alpha? It kind of looks like a fish pointing left.
The fish swimming left is the Alpha symbol, which was the first letter of the Greek alphabet. SunTour made 5 models of Accushift road derailleurs in 1987-1988. In order from bottom to top they were; Alpha 3000, Alpha 5000, Alpha 7000 Cyclone, Alpha 9000 Sprint and Superbe Pro.
There is a good chance that your frame is also made of Tange Infinity tubing. It was not uncommon for bicycle manufacturers to create 2 or 3 different models by using the same frame and specifying different levels of components. Given that the model 550 has Alpha 5000 derailleurs and probably a few other upgraded components, it would be reasonable to suggest the same frame was used.
Tange does/did not make "bad" tubing. Every tubeset is designed for a specfic purpose and pricepoint and therefore has specific tradeoffs. During this period Prestige was Tange's top line tubeset and came in two different grades. It was very light, very strong and intended for competition models. However to achieve this, it was expensive and bicycles with this tubeset typiclly cost $1000 or more, depending on the components. The butted tubests below Prestige in descending order were; Tange No.1, Tange No.2, Infinity and Mangalloy 2001. As you go down the line the line, the tubesets get heavier and less expensive. Inifinity was about 350g heavier than Prestige and was actually about equivalent to No.2 in weight. The material and thickness were the same as No.2, but instead of being drawn as a extruded tube, it was formed from a flat plate which was welded into a tube and is much cheaper to produce. Many people feel these "seamed" tubests are inferior, but I have yet to see any fail from tube manufacturing problems. The Mangalloy tubests were the only non-CrMo butted tubests produced by Tange.
While the properties of tubing have an effrect on the frame, the only noticeable characteristic to most cyclists is the weight. Other noticeable characteristics are more the result of geometry and the techniques used by the particualr framebuilder. Given frames of identical geometry, manufactured by the same framebuilder, using the same techniques, the vast majority of cyclists could not tell the difference between various grades and makes of tubesets. If you need a replacement tubing sticker, I have several new, old stock Infinity labels.
Given the era, the bicycle could be considered upper entry level, or lower mid-range. The components lean towards the former, but the frame leans towards the latter. Many paople would draw an arbitrary lean at the $500 price point and consider it the former.