Shimano Hubs - Freehub Bodies
09-21-20, 11:59 AM
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Shimano Hubs - Freehub Bodies
I'm sure someone has posted this information before, but I thought it might be useful to someone.
I recently had a couple of projects I had been pondering. One was replacing a free hub on a 7 speed hub and the other was fitting 130mm wheel into 126mm dropouts (I've read a lot on the different options). I bought a Shimano FH-M732 for the former that solved the latter. Since then I have bought a few other freehub bodies for other potential projects. I can't speak for modern freehub bodies, or the odd duck out there but this is what I stumbled upon.
Shimano made shallow and deep recessed hubs and that determines which freehub body will work. The one on the left is an MT-62 and the one on the right is an M732. They are both 7 speed UG/HG, but the recesses are not the same.
The following are Shimano freehub bodies that fit shallow and deep hubs. The ones (MT-62-7, 6402-8) on the left are for shallow and the right are deep (M732-7, 7700-9).
What I discovered was the M732 freehub body had too deep a flange and wouldn't work with the shallow hub, but it fit on my 7700 rear hub and converted it from a 9 speed to a 7 speed and fits into a 126mm wide dropouts. Not only that, I am able to use a threaded uniglide 14t with the hyperglide cassette giving me a 14-34 cassette. For years I have heard about swapping freehub bodies, but never realized that even though the same splines work, the depth of the hub to the freehub flange is the determining factor.
John
I recently had a couple of projects I had been pondering. One was replacing a free hub on a 7 speed hub and the other was fitting 130mm wheel into 126mm dropouts (I've read a lot on the different options). I bought a Shimano FH-M732 for the former that solved the latter. Since then I have bought a few other freehub bodies for other potential projects. I can't speak for modern freehub bodies, or the odd duck out there but this is what I stumbled upon.
Shimano made shallow and deep recessed hubs and that determines which freehub body will work. The one on the left is an MT-62 and the one on the right is an M732. They are both 7 speed UG/HG, but the recesses are not the same.
The following are Shimano freehub bodies that fit shallow and deep hubs. The ones (MT-62-7, 6402-8) on the left are for shallow and the right are deep (M732-7, 7700-9).
What I discovered was the M732 freehub body had too deep a flange and wouldn't work with the shallow hub, but it fit on my 7700 rear hub and converted it from a 9 speed to a 7 speed and fits into a 126mm wide dropouts. Not only that, I am able to use a threaded uniglide 14t with the hyperglide cassette giving me a 14-34 cassette. For years I have heard about swapping freehub bodies, but never realized that even though the same splines work, the depth of the hub to the freehub flange is the determining factor.
John
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09-21-20, 01:02 PM
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This was a good public service announcement, since there has been online info suggesting that these freehub bodies can be swapped willy nilly.
There may even be more than two "depths", with more subtle differences.
I had noticed that the 64xx-series 8s freehub used a shallower freehub body than the titanium 7700 freehub body, and that various of the Shimano MTB freehubs used different-depth bodies.
And it's usually important to carry over all of the drive-side axle hardware including cone, washers, seal, shield and spacer(s) that go with the particular freehub body.
There may even be more than two "depths", with more subtle differences.
I had noticed that the 64xx-series 8s freehub used a shallower freehub body than the titanium 7700 freehub body, and that various of the Shimano MTB freehubs used different-depth bodies.
And it's usually important to carry over all of the drive-side axle hardware including cone, washers, seal, shield and spacer(s) that go with the particular freehub body.
09-21-20, 01:48 PM
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This was a good public service announcement, since there has been online info suggesting that these freehub bodies can be swapped willy nilly.
There may even be more than two "depths", with more subtle differences.
I had noticed that the 64xx-series 8s freehub used a shallower freehub body than the titanium 7700 freehub body, and that various of the Shimano MTB freehubs used different-depth bodies.
And it's usually important to carry over all of the drive-side axle hardware including cone, washers, seal, shield and spacer(s) that go with the particular freehub body.
There may even be more than two "depths", with more subtle differences.
I had noticed that the 64xx-series 8s freehub used a shallower freehub body than the titanium 7700 freehub body, and that various of the Shimano MTB freehubs used different-depth bodies.
And it's usually important to carry over all of the drive-side axle hardware including cone, washers, seal, shield and spacer(s) that go with the particular freehub body.
Yeah, I've used the cones and and seals that are associated with the hub/freehub body. But, one day I am going to see if I can mix-n-match DS cones and substitute a shorter one to accommodate a wider freehub body and still keep the OLD the same without dishing.
John
