Shimano 8sp freehub body to hub compatability

Does any one know if in general the way an 8 speed shimano compatible freehub body fits to the hub itself is standard or manufacturer specific. - ie if I have a shimano free hub will it fit to most aftermarket hubs that were 8 sp compatible? Or is the outer splined but the only common piece?

Most aren't compatible. shimano will typically marry with shimano hubs, but hope etc...wont marry shimano, etc...

My knowlwdge rests with shimano -89 to present and, with 8sp like stx-rc-deore-XT etc are similar but have slight differences with grease guards and other o-ring seals

For example, the splines at the rear of shimano freehub bodies are the same on 90% of shimano freehub bodies. I think RM30 and so-called 'silent clutch' were diffe-rent. some other maybe too.

But, as daft as it sounds i could remove the FHB from my exage HG50 hub and install it to my XT 750 hub, now, the obvious differences apply there, suddenly i'm 7 and not 8 sp and i would have to swap spacers, seals and all sorts of other bits and pieces, just to make it work but, it would work as the spline interface is the same.

Are we talking shimano here?

If so, there is a shimano tech pdf for matching up compatibilty with hubs. Also, if you stay close to existing (pressumed knackered) hub, then you should be ok, although swapping some spacers and seals may be necessary to get it all installed nicely.

From experience, ritchey and shimano FHB's are different. Hope is in it's own world(good stuff though).

Let us know what you have in mind, i'm sure some useful links will crop up.

cheers.

There were quite a few early aftermarket hubs that used a Shimano free hub. From experience I can tell you for sure that most old school Nuke Proof hubs have a Shimano splined interface and a Shimano free hub. I just swapped out an old 7speed freehub body for a titanium Dura Ace 9 speed body on my Nuke Proof rear hub.
Also first gen. Spinergy Spox Wheels have a Shimano free hub body. I swapped out the Ultegra 6500 free hub and axle for a much lighter XTR one. I don't know what other brands used the Shimano free hubs but there might be more. The two I mentioned above have it for sure. Some of the smaller companies back in the 90's didn't want to bother to develop their own free hub so the used the widely available Shimano ones. (which can be a blessing when trying to find spares for those)...

I think I'm going to have a few problems - I have a sachs new success hub - that I'm looking to do a 7-8sp speedhub conversion on. From what I've been able to find out so far the sach freehubs are held on with a 17mm Allen headed bolt - I think shimmy's are 14. If this is correct my only possible chance is to find a rare sachs 8speed hub and take a look at that.

Although I should also try to keep a lookout for a sachs 8speed cassette - the did both shimano spacing and their own - it may be possible that their freehub bodies are slightly narrower than shimano's.

You will be very lucky if you ever find a Sachs compatible freehub body. If there is anyone out there who knows where they can be sourced then I will also be very grateful for the information.

In terms of Shimano, they are often interchangeable but there are also many exceptions.
This is quite useful: -->
You will need to copy and paste it.