This offering is for a new-old-stock Shimano HyperGlide (HG70) model cassette with 8-speed 12-13-14-15-17-19-21-23 gearing. These HG70 cassettes coming out of Japan are very good quality and the equivalent of what Shimano intended for use on some of their 105 drivetrains (when that particular 8-speed drivetrain was in production...in the mid 90's). Now these cassettes are production date coded from 1998 (so at the end of the 105 8-speed drivetrain era), but I know Shimano was still producing these HG70 cassettes out of their Japanese factories for several years after they moved on from their 8-speed drivetrains (because they knew a lot of these drivetrains were still on the road). I am not exactly sure when Shimano ceased production of their HG70 cassettes and started producing lower level offerings in other locales, but I've come across production runs as late as 2007 coming out of Japan for the HG70's. As most folks know, Shimano's current production 8-speed cassettes are HG50's or lower and none of them are coming out of Japan.

I guess they are best described as one of Shimano's competition-level cassettes from this era, but probably at the lower-end of their competition-level offerings. So very good Japanese quality, but Shimano still made a few other better quality units. We should also note there are many more applications for these cassettes then just the 105 drivetrains from the mid 90's. More specifically, this cassette will mount on just about any Shimano 8/9/10-speed HyperGlide freehub with few exceptions.

Having said the above, we measured the "stack height" (for lack of a better term) of this cassette and noted it to be about 37 mm (using our digital calipers). We thought this additional measurement would help ensure compatibility, should you want to measure the width of the intended splined freehub body and compare it to our measurement. One final comment on compatibility...please note the HyperGlide cassette design includes a separate threaded lockring that threads into the underside/inside of a freehub body (and this is Shimano's preferred freehub design since the early 90's). As a result, most Shimano freehubs on today's market will be HyperGlide compatible, but please be mindful of Shimano's older freehub bodies with visible external threading at the end of the freehub body, as this older design is generally not compatible with one of these HyperGlide cassettes.