In terms of compatibility, this is a freewheel, so it will only install on a threaded rear hub (as opposed to the newer cassette/splined freehub designs that are more common today). The threading is British/English, so it's 1.370" x 24 tpi (threads per inch), which was one of the more prominent standards during this period...and very near a couple of other standards. More specifically, there is the Italian standard of 1.378" x 24 tpi with a slightly larger thread diameter and different thread angle, but the same thread pitch as the British/English standard. Then there is the newer ISO standard of 1.375" x 24 tpi (which is the preferred specification of most newer freewheel manufactures) with the same thread pitch and angle as the British/English standard and a thread diameter between the British/English and Italian models. 

When considering the three aforementioned standards, conventional wisdom indicates there is some interchangeability among them...with a few caveats. More specifically the thread pitches are the same, while the thread diameters and angles are close enough that it's possible to install a freewheel spec'd to one standard on a threaded rear hub spec'd to a different standard (among the three included in this discussion). Although, one of the caveats is to avoid switching back and forth between standards, as there is still enough of a diameter and/or angle difference to prematurely wear-out/damage rear hub threading if this (switching back and forth) practice is employed. In other words, it's best to identify a freewheel standard (among the three mentioned) and then consistently use freewheels spec'd to that standard to help preserve the threads on a particular aluminum alloy rear hub. Additionally, we have learned these mix-n-match combinations may not be recommended for stronger riders and tandem applications...where there is additional drivetrain stress...as this combination may also result in premature thread damage to an aluminum alloy rear hub.  I realize this latter commentary is somewhat subjective...and maybe somewhat conservative...but we feel like it's better to error on the downside of product function, so there are no disappointments concerning product performance down the road.

In terms of condition, all of our Suntour freewheels (unless otherwise noted) are new and in their original box...although some of the boxes are shopworn. The boxes aside, we cannot believe anybody will be disappointed with the condition of the freewheels.

A brief word about Suntour and their freewheel...
Like so many of the Suntour components, there was a period of time during the 70's and into the 80's where Suntour was arguably producing some of the finest bicycle components in the industry. Their freewheels were no exception...and even as late as the very early 90's, we have read or been told by respected sources that Suntour index (or AccuShift / AccuShift Plus) technology was on par with Shimano's index (or SIS) technology...but by this time Shimano was so firmly entrenched and so much stronger financially (for a number of different reasons), that Suntour was unable to recover lost market share, which led to it's ultimate demise.

As it relates specifically to Suntour freewheels, by the early to mid 70's they were considered as good or better than anything else on the market. Suntour's beveled teeth were universally accepted as one of the better sprocket designs that improved shifting performance and reliability. During this period, Suntour was already producing significant freewheel quantities, which included the Perfect, Procompe and Winner models.

By the late 70's, Suntour rolled out it's version of an Ultra 6-speed freewheel, which was essentially a 6-speed freewheel made with narrower spacers to fit on a standard 5-speed wheel (with locknut-to-locknut dimensions of 120 mm). Suntour followed this innovation with an Ultra 7-speed freewheel a couple of years later, which was built on the same premise...using narrower spacers, Suntour designed an Ultra 7-speed freewheel that was compatible with a standard 6-speed wheel (with locknut-to-locknut dimensions of 126 mm). This was followed by the introduction of the New Winner and Winner Pro freewheels in the 80's, which included a re-designed freewheel body that allowed for greater interchangeability of sprockets (to create standard and narrow spaced freewheels in the 5, 6 or 7 speed variety using the same body). It was a rather complex system (to build Suntour freewheels on this single body) with different spline, thread and spacer sizes, but it was still technically possible with the correct parts for assembly.

The late 80's and early 90's witnessed the roll-out of the "AccuShift" and "AccuShift Plus" index shifting compatible freewheels and cassettes. However (and even though Suntour was able to produce very competive and technically sound index shifting components into the early 90's), Shimano had long since established itself as the dominant bicycle components manufacturer headquartered in Japan, which signaled the end for Suntour shortly thereafter.

Note to international customers regarding customs...
We also apologize to those that feel their country import taxes, duties and brokerage fees are excessive. As a small US business, we are required by customs' laws to declare each order as a retail sale. Additionally, the declared order value must be equal to total store purchases and/or winning auction bids (less any shipping costs, as these are not considered in the declared value). As a result, each customer will be responsible for paying his/her own country taxes, duties and brokerage fees, which will be collected upon delivery. Again, we apologize for these additional costs, but we cannot afford the penalties and fines that come with breaking customs' laws...so we have to strictly abide by them.