Bicycle Mechanics - Old style threaded freewheels-8 or 9 sp?

Howdy all, it's been a while.

I just acquired a HED disc which has the older threaded hubs with a 7 sp freewheel on it. It is not so bad because if the terrain or wind was so bad that I needed my 9 sp., I probably shouldn't be riding the disc anyway. However, I don't think I should be breaking my chain off everytime I need to change to and from the disc. If I could find an 8 sp. or even better a 9 sp. threaded freewheel I could just use the same chain. Do they even exist? I could have sworn I saw some in the past, but can't seem to find any on the net.

Better yet, does anyone know if there's a way to change my disc over to cassette?

Thanks as always for any info.

There are no 8 spd freewheels.
To change to cassetee you will have to replace the hub.

There are no 8 spd freewheels.
To change to cassetee you will have to replace the hub.BS...There are 8 speed freewheels.

I stand corrected 8 spd fw do exist but they are quite rare:

REGINA AMERICA 1992 7 & 8 SPEED FREEWHEELS

America 92 freewheels are available in both 7 and 8 speed versions. The way you can tell Regina America freewheels made previous to the 1992 model is the color of the freewheel body. Older America freewheel bodies, (90 and before), are Black in color, while the 1992 series is Silver in color, because both the inner and outer body parts are Chromium treated, which increases their wear life, and diminishes the effects of rust, and oxidation.

Check ebay for 8 speed freewheels....they appear regularly. Also Sunrace is manufacturing them new. Initially the Sunrace quality was rather poor, but from what a few folks have told me, it has improved.........

Mark

I stand corrected 8 spd fw do exist but they are quite rare:

Wrong again.

Why are you changing the chain? A 9-speed chain will work fine with a 7-speed FW or cassette.

An 8-speed FW may not work on that wheel. It may protrude too far and grind against the chain and seat stays. Adding axle spacers to the drive side to solve this would offset the rim and you can't redish a disc wheel. So you'd have to add spacers to both sides to keep the wheel centered, but then the OLD may be too large to fit your frame. Perhaps OK if it's steel (simply spread the rear triangle) but not a good idea if aluminum or carbon fiber.

As for "converting" to cassette, you'd have to get a whole new wheel. The hub is bonded to the disc and it is not easy or worth replacing it.

8s freewheels were/are* available from a number of manufacturers.

Regina - already mentioned (not sure if company exists any more)
Sachs - high quality and shimano spacing (no longer in bike business)
Campagnolo - long time ago for a short period (early 90s)
Suntour - alloy and steel 8s freewheels (company/ies gone but brand remains on much cheaper stuff)

I doubt that the above list is conclusive (as mentioned, maybe SunRace?)

As far as I am aware ShimaNO did not ever produce an 8s freewheel.

*would all be NOS now - check eBay or Rivendell, Grant has always been good with this type of stuff. I'll also check through the garage, may have a Alloy 8s Suntour New Winner or two. If I have two (so I can keep one for myself), I'll post again if you are interested in getting it from oz?

An 8-speed FW may not work on that wheel. It may protrude too far and grind against the chain and seat stays. Adding axle spacers to the drive side to solve this would offset the rim and you can't redish a disc wheel. So you'd have to add spacers to both sides to keep the wheel centered, but then the OLD may be too large to fit your frame. Perhaps OK if it's steel (simply spread the rear triangle) but not a good idea if aluminum or carbon fiber.

You could be really lucky.

1. Assuming your wheel is designed/manufactured for 7s, then it's spacing (overaxle locknut) will be about 126mm, and those older wheels tended to run the smallest cog of freewheels well inboard of the drop out/locknut face. Certainly more inboard than 8s and 9s systems do now.

2. 8s/9s spacing is 130, so you can replace the axle with a slightly longer one, and put a 2mm spacer/washer on each side to push the overlocknut dimension out to 130mm. This assumes you are riding a late model frame built to the latest (130mm) specs.

3. 8s cog spacing (between cogs) is tighter than 7s, so an 8s Shimano cassette (remember there were no clusters) IS NOT 1/7th wider.

Conculsion: The extra 2mm on the drive side, and the extra space (between smallest cog and dropout) that seemed to be the case on older hubs, and the smaller cog spacing MIGHT mean you can get an 8s in there.

I'll bet your house on it anyway.

Let me know how you go.

PS: whatever happens, resist temptation to space the wheel "out of dish" to get an 8s cluster on - the wheel will not sit in the centre of the frame, creating handling and strength issues. Speked wheels might be able to deal with it, but I doubt a disc will like it.

3. 8s cog spacing (between cogs) is tighter than 7s, so an 8s Shimano cassette (remember there were no clusters) IS NOT 1/7th wider.

Well,then why is it that when you put an 7 speed cassette on a 8/9 hub body there has to be an additional 4.5mm spacer to take up the extra width.

Sydney,

ShimaNO 7 speed spacing uses:

4 x 3.1mm spacers, and
2 x 3.3mm spacers

ShimaNO 8 speed uses 3.0mm spacers.

Ignoring thickness of cogs (as far as I know I have always used them interchangeably between 7s and 8s):

7 speed total spacers = (4 x 3.1) + (2 x 3.3) = 19mm

8 speed total spacers = 7 x 3.0 = 21mm

The rest of the difference 4.5mm - (21mm - 19mm) = 2.5mm would be explained by the additional cog.

Voila!

Oh Sydney,

I see where you are coming from - there is not size reduction as a result of cog spacing - yes, but 1 and 2 still hold true.