nexus 7 speed coaster hub

[5speed]

what is the difference between the nexus 7 speed coaster hubs?like sg-7c25 and sg-7c26 ,different sprocket?thanks

 

[socal_jack]

I think it's more of a rev lettering the 26 being a later model full hub exploded views from Shimano here both came with anything from 18T to 22T sprockets.

http://techdocs.shimano.com/techdoc...<>ast_id=1408474395181679&bmUID=1236480752414

 

[Rooski]

The 25 and 26 are almost identical, with the only difference being a few parts that make up the drive side seal.

As far as comparing all if the past NX7 coaster brake versions, besides the obvious fact of some having an alloy hubshell, and others have a steel shell, the small differences have to do with the improvement of the drive side seals, over time. I have found the complete internal assemblies are, for the most part, completely interchangeable among different versions, as long as the drive side seals mate properly to the drive side of the hubshell. I've swapped internals between the 16, 18 (both steel), 21, 25 and 26 (all three alloy), with no issues.

The biggest difference between the steel and alloy versions, is the way the the large drive side seal fits against the hubshell.

Besides the 5 different versions I mentioned above, I'm also aware of a 15, 30 (both steel), and 22 (alloy), but have never had any of these in my possession, to play with.

 

[B607]

Can you tell at a glance if the NX7 shell is alloy or steel? Gary

 

[kensmurray]

My alloy nexus has a satin finish, instead of the chrome finish like you would see on handlebars.
Gary here's a picture of my alloy hub. Mine is a SG-7C18
Kenny

 

[Rooski]

Can you tell at a glance if the NX7 shell is alloy or steel? Gary

Yes, even if they were painted. The alloy one on the left is larger, looks more rounded off, and is one piece (besides the steel inserts, inside the shell). The the outer lip of the large drive side dust cap fits in a groove.

The steel one on the right is smaller, has 3 piece construction (pressed on flanges), the brake side flange has slots cut into it, and the outer lip of the large drive side dust cat fits over the end of the shell.

Because of my preferred style of bike, I mostly prefer the looks of the alloy ones. Plus, I also like to run a Sturmey XF-D front drum brake, which is a good visual match for the alloy NX7's.

The steel ones are great for the proper look on a vintage bike, although the finish on the very common 7C18 looks far from chromed. The 7C16 has a shinier finish, and looks best, but seem to be much harder to come by.

Here's a 7C16 I installed on my 95 Phantom. I did it with a 2 cross spoke pattern, so the spoke angles are close to the original look.

In this pic, you can see the slight difference in the finish, between the 18 (left), and 16 (right).

The steel ones are also great for making a trike hub

 

[Rooski]

Gary here's a picture of my alloy hub. Mine is a SG-7C18

Your 7C18 is steel. The 18's have some sort of protective finish, and looks sorta like very thin silver/gray paint. The NX3's look the same way. The steel 16's look more like bare metal with a clear protective finish.

 

[kensmurray]

Wow I had no idea it was steel. I just took for granite it was alloy looking at the finish.
Sorry Gary for steering you wrong.
Kenny

 

[B607]

Thanks for all the info. Mine is an alloy. Works great and I love it. Gary