TrackSmart

I saw an auction for a "Nexus internal hub" wheel on ebay that was only at $1.25 with minutes to go. The auction did not tell which hub it was among the various Nexus models, aside from being "disc capable"! I figured it's got to be worth $10, whichever model it is, so I bid. I ended up winning it for $8.27

It's built-up as a 36h rear wheel on a generic rim. The hub doesn't match the photos I can find online.


What hub did I buy???

3 speed?
4 speed?
7 speed?
8 speed?

Something else entirely?

TrackSmart

Wow. Does anybody recognize this hub?

It doesn't look like the 7-speed nexus hubs, but maybe it's an older version? Can those with older versions of the Nexus-7 verify that their hub does (or doesn't) look like this?

It doesn't look like the 3-speed, either, which is very compact and has about equal diameter across the hub. This one has a bulbous part and a narrow part.

That leaves the 4-speed hub by default. Can anybody with a 4-speed Nexus hub verify this?

MichaelW

Are you sure it is a rear hub and not a front dynohub?

skovsen

Doesn't look like the Nexus 7-speed I have/had (broken)...

TimJ

That looks like a drum brake model, thta's what the bulge is. I'm guessing, that is.

TimJ

Oh yeah- it's definitely not disc capable. Unless I'm mistaken the only disc capable shimano internally geared hub is the brand new alfine hub.

I don't know if you got screwed being that the price was so low, but that ain't what the dude said it was.

The Great Stonk

/me *fires up the Sheldon Brown sign and points it skyward*

mycoatl

I'm in agreement with MichaelW--it looks like a dyno hub to me. Can you provide shots of each side of the hub? That might help us figure it out.

TrackSmart

Ha ha. For $8.27 I was willing to take the risk of it being almost ANY kind of Nexus hub. I'm guessing it's NOS ("New Old Stock") that some shop found in the storage room. I think it might be an older Shimano 3-spd or 4-spd model.

Evidence:

--- It's definitely a rear wheel
--- It has the splines to accept a sprocket
--- It says "Shimano Nexus" on the hub


Still waiting for someone to solve this mystery! Then I can start searching for a shifter and some anti-rotation washers so I can install it on a bike.

humble_biker

If I'm not mistaken it is in fact the four speed model. You can look at the schema's at shimano's web site and match the hub shell profile.
It does take a brake that is similar to a drum brake but it isn't a drum brake. It clinches at several contact points inside the brake unit. It fits on the left side of the hub where the splines are in your photo on the right. And bolts down.
The drive side cog unit is more or less the same set up as a coaster brake with cog and snap ring to hold it down.
The gear shifting mech is also attached on the drive side and usually involves two simple pieces and a locking device. You'll have the stabilizer and the piece that actually moves the cable so it will shift.
You shouldn't have much trouble finding the parts for it.
I know nycbikes.com deals with quite a few of Shimano internals so you might try them for more N.O.S parts. Enjoy and good luck!

TrackSmart

FANTASTIC! May I pick your brain about what parts I'll need to make this thing work?

I found a source for the shifter ($15 for the shifter with cable or $20 for the shifter, cable and "anchor clamp"). Does "anchor clamp" mean the the anti-rotation washers for the dropouts? Or is he talking about the piece that attaches to the rear-stays to hold the roller-brake in place (a brake that I don't have)?


I presume that using/attaching the brake part is optional, right?

So I just need the shifter and the cable that comes with the shifter and I'll be good to go? Oh, and a sprocket of course.

Sheldon Brown

That's a discontinued Nexus 4 speed. The splnes on the left end (right in the photo) are to attach a Rollerbrake, which I don't recommend.

Sheldon "Neck's Us" Brown

TrackSmart

Thank you for the confirmation Sheldon!

I've been wanting to try some internal gearing for a while now and this is an easy entry-point. If I really like this thing I'll have to build-up that "dream commuter" I've been thinking of. Something along the lines of the San Jos8 bikes that your shop sells. This will be a nice test before I jump into the deep end and build a shiny new Nexus 8-speed bike. [EDIT: Or decide that internal hub gearing is not the joyful, trouble-free experience I'd hoped it would be. We shall see!]

wroomwroomoops

What is the problem with rollerbrakes?

dcullen

Too much roll, not enough brake?

humble_biker

Nah they grab, there is very little "feathering" with this type of brake. And the ones for the front generated enough torque that they would bend the fork leg.

nycbikes

Yup, 4 speed roller brake, and yup we have all the parts. We're big fans of the internal gear thang. Straight chainline, low maintenance, easy set up -all things fixed and single offer, but low gears for the bridges and a high gear for when the lights are in your favor. The roller brakes have great stopping power, but the attachment is HEAVY. Ideal for an industrial bike, but... We have replacements for those too.

BTW - if you want to use a nicer shifter (or should I say, just different) then you can use a 7 or 8speed ESP shifter (Sram).

TrackSmart

Excellent! Do you folks at NYC bikes ship parts? (nevermind, I'll just find the website).

I'd be interested in:

1) Shifter - Does the SRAM shifter require two shifts between gear changes? Or just have extra unused 'clicks'
2) "Cassette joint" - the part where the shift cable attaches to the hub
3) Snap ring - to hold on the cog
4) Anti-rotation Washers for horizontal dropouts (not track dropouts)
5) Dust cover - do I need this? or is this just for looks when not using the roller brake?

Bikedued

I have a roller brake as the only brake on this heavy stretch cruiser. It works fine?? Very powerful, and
feathers pretty good? Not sure why all the negativity about it here. If I lift my butt off the seat and pull hard, I can make hockey stick skids without too much effort. I can find nothing bad to say about them?,,,,BD

I got it from Sheldon, actually. I also need another shifter setup for the same model of 7 speed hub.