gobelin_malefik

So I have 2 pairs of wheels, coming from a Trek 7000 and a Marin Hawk Hill, both typical 90s mountain bikes. I'm trying to adapt a 10 speed freehub body to at least one of these wheels. The 2 back wheels respectively use a FH-MC12 and a FH-M290 hub. I've been searching all over the internet to see if I could find a freehub body that would fit one of the 2 hub and a 10 speed cassette. I know I'll have to redish the wheel, that's fine. I bought one for the FH-MC12 naively thinking those things were standardized and of course it didn't work.

At this point I'm also interested in sending all the parts I bought for a 10 speed transmission and get a 9 speed IF that makes things easier. I've heard that sometimes 9 speed cassettes fit those old 7 speed hubs, what's your experience with that?
Another question, I'm having trouble getting the cassette out of the Marin's back wheel, should I try heat if I plan to reuse the hub?

Thank you!

hokiefyd 

A 9-speed cassette will not fit on a 7-speed freehub body, no. An older 7-speed freehub body will fit ONLY a 7-speed cassette (or fewer speeds, I suppose). 8-speed and above needs the longer freehub body.

There is one exception, or caveat, to this. You can use 8 of 9 sprockets from a 9-speed cassette. This is commonly called 8-of-9-on-7. Because your "8-speed" cassette would actually be using 9-speed spacing, you'd need to use a 9-speed shifter if you want to use indexed shifting (no problem with friction). I've done this before and it works great. Most will just drop the largest sprocket from the cassette, and use the 8 remaining.

gobelin_malefik

Ok,nice trick for the 8 speed cassette but I think I'll continue my quest for 10 speed. I've ordered a new freehub body which look like it could fit, even though they don't say specifically that it is compatible but I guess they cannot confirm that for all the hubs that Shimano ever created. Hopefully it will work.
I have been unable to find something that I'm certain is compatible for my hubs, I guess because they are too old. I'm a bit surprised though that there is no "default" 8-11 speed freehub body reference that fit all the old Shimano hubs on mountain bikes from the 90s, or at least a guide on compatibility. I'm wondering what the most people do when they restore and upgrade a 90s bike to a 1x10, 1x11, etc, do they deal with that every time or do they just buy more recent wheels?

TiHabanero

I literally just did a 7 to 9/10 speed cassette body conversion on a tri-color hub. Although it is a road hub I used a cassette body from a used XT 9 speed hub. I changed the axle as well to get 135mm axle spacing instead of keeping the 130 spacing the tri-color road hub comes with. I'll be surprised if you have a compatibility issue.

gobelin_malefik

I just bought this one:
8-/9-/10-/11-speed Freehub Body for FH-C201 / FH-M475

I can't find any used, maybe I'm not typing the right thing, I don't know. Mine is already 135 which is good, but I'll need to find new spacers for it apparently, that's an issue for future me once I find the right hub body I guess.

70sSanO

There used to be a .pdf freehub interchangeability chart that listed all the older Shimano freehubs and bodies. The chart only provided where a particular freehub body was used. It didn't provide any upgrading compatibility. Your FH-M290 and FHMC-12 used freehub body Y3AP98020.

You can also drive the freehub number into Shimano's Manual website https://si.shimano.com/en/#/ and you can get an exploded view and a parts list, this won't let you know any upgrades, but you can see the drive side cone and seal needed.

In the 90's, Shimano used a deep (thick) or shallow (thin) flange. You will want to get the same style or the freehub body will be too deep on the hub or extend too far out. I've posted this pic a lot, but it gives a quick view of the differences.


The easiest way to convert a 90's 7 speed freehub to a modern 8-10 freehub 20 years after the fact is to figure out the style of freehub body and then buy a "complete" freehub and use the new freehub driveside cone, seal, and maybe spacers. Shimano didn't use the same cones with every freehub body. Also the dust seal style/diameter changed over the years. Trying to track these down individually can be a real pain.

The Shimano C201 freehub body is PN Y3SL98030. If it works, it was also used on FH-C201, FH-2200, FH-RM40, FH-M475, FH-M525. Double check these on the Shimano Manual site and buy one of these complete freehubs.

Good luck.

John

byscott

I’ve done these also, usually to fit road hubs on hybrids that have 135mm rear spacing. As TiHabanero notes, compatibility isn’t usually a problem.

FWIW, there’s a lot of information on freehubs here:

https://sheldonbrown.com/k7.html