Shimano Nexus 8-speed Hubs

Sheldon Brown writes:
It's been over a year since we first placed our order, but we finally
have received Shimano Nexus 8-speed hubs.
I bought one myself, I'll be doing it up with 650B rims...
See: http://harriscyclery.com/shimano-nexus
I've also scanned and put up the Service Manual for these hubs at:
http://sheldonbrown.com/nexus8

Jim Smith wrote:
Do they make them without the brake?

SG-8R25, SG-8R20 are 8 speed hubs which can accept a roller
brake.
SG-8R25-VS, SG-8R20-VS are the eight hubs which cannot ("VS"
for "use a V-Brake")

--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

Besides the extra gear, and the silent clutch, are there any differences
in terms of perfomance, durabilty and weight between it and the Nexus 7
hub?

thanks
~PB

Sheldon:

I am curious why you are going to lace the Nexus hub to a 650B rim.
Isn't that an archaic size? Why not use the common 559mm instead?
Zach Kaplan

On 1 Feb 2005 06:46:05 -0800, "Zach" wrote:

Sheldon:

I am curious why you are going to lace the Nexus hub to a 650B rim.
Isn't that an archaic size? Why not use the common 559mm instead?

Ahhh, but that's what they'd be expecting.

This is Sheldon "why be normal" Brown we're talking about here.

Ron

I wrote:

It's been over a year since we first placed our order, but we finally
have received Shimano Nexus 8-speed hubs.

I bought one myself, I'll be doing it up with 650B rims...

Ryan Cousineau wrote:

Okay, I've read the Rivendell ode to this rim size, but aside from
acting as some sort of revivalist preservation of the rim and tire
standards so future generations can roll along on mid-century French
bicycles, the attraction is purely aesthetic, right?

Or is there some advantage to spanning the 559-622 mm interval I haven't
perceived? Maybe a compromise for 29er-like off road virtues but with
stronger wheels?

There are a very large number of very fine older bikes that only work
for this size wheel. It would be a shame if they were to go the way of
127 film cameras and become unusable for want of supplies.

Given that rims and tires are likely to continue to be available, albeit
in limited distribution, it's not unreasonable to find other
applications for the size.

For me the advantage is that I've got a couple of 700c "modern" bikes
with excessively tight tire clearance. One's an IRO, currently a fixed
gear, aluminum frame with a plastic fork, but I've found it
uncomfortably harsh to ride, and un-fenderable.

I'm hoping that switching to 584 wheels with medium-width tires will
cure this without screwing up the geometry.

There have been a number of reports on the BOB email list of people
upgrading racey bikes this way with great success.

This size is also a potential saviour for all the poor suckers who were
victims of GT's "700D" debacle.

The 584 size has real value for smaller riders compared with 622 (700C)
though it isn't clear that it has any serious advantage over 559 (26"
decimal.)

Sheldon "Gonna Give 'Em A Whirl" Brown
+---------------------------------------------------+
| The important thing is not to stop questioning. |
| Curiosity has its own reason for existing. |
| --Albert Einstein |
+---------------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

Zach Kaplan asked:

Sheldon:

I am curious why you are going to lace the Nexus hub to a 650B rim.
Isn't that an archaic size? Why not use the common 559mm instead?
Zach Kaplan

These wheels are going into a frame or frames made for 622 wheels.
Going from 622 to 559 lowers the bottom bracket excessively, likely has
too much effect on the handling, and requires more heroic measures to
make the brake reach.

It will initially be going on an IRO Jamie roy, though I also have a
plastic Trek frame hanging around that may be used with this wheelset
eventually. Both of these frames suffer insufficient tire clearance,
and I've found both of them uncomomfortably harsh to ride with 622 tires
that would squeeze into them.

Sheldon "It's An Experiment" Brown
+-------------------------------------+
| Only those who attempt the absurd |
| will achieve the impossible. |
| --Albert Einstein |
+-------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

Pete Biggs wrote:

Besides the extra gear, and the silent clutch, are there any differences
in terms of perfomance, durabilty and weight between it and the Nexus 7
hub?

The Nexus 8 is supposedly more efficent and durable, and better able to
withstand shifting under load. It is also heavier, about 1.8 kg.

Sheldon "Win Some, Lose Some" Brown
+---------------------------------------------+
| Do not needlessly endanger your lives |
| until I give you the signal. |
| --Dwight D. Eisenhower |
+---------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

Sheldon Brown wrote

2.7 mm is a "heaping helping" of asymmetry? Most
non-flip-flop hubs have at least this much asymmetry.

See: http://sheldonbrown.com/nexus8/pages/28.htm

Even typical track hubs are more asymmetrical than this, viz:

Campagnolo 5-13 depending on model,
Miche at 15,
Phil Wood at 14 mm,
Sun Tour at 6 mm.

Is this a fair comparison?

Correct me if I'm wrong, but the numbers given for Campi,
Miche, Phil, SunTour are WL-WR, where WL and WR are
flange-to-center distances, as defined on the page at
http://sheldonbrown.com/rinard/spocalc.htm

WL-WR for the Nexus 8 is 5.4mm, not 2.7mm.

0mm would be nicer, but I don't think 5.4mm is an awful lot.
At least Shimano went with 36 holes instead of 32.

Setting practical matters aside for a moment, does
anyone like the look of this hub? I think it's ugly.

Tom Ace

I wrote:

2.7 mm is a "heaping helping" of asymmetry? Most
non-flip-flop hubs have at least this much asymmetry.

See: http://sheldonbrown.com/nexus8/pages/28.htm

Even typical track hubs are more asymmetrical than this, viz:

Campagnolo 5-13 depending on model,
Miche at 15,
Phil Wood at 14 mm,
Sun Tour at 6 mm.

Tom Ace demurred:

Is this a fair comparison?

Correct me if I'm wrong, but the numbers given for Campi,
Miche, Phil, SunTour are WL-WR, where WL and WR are
flange-to-center distances, as defined on the page at
http://sheldonbrown.com/rinard/spocalc.htm

WL-WR for the Nexus 8 is 5.4mm, not 2.7mm.

You're right, I misread the diagram.

0mm would be nicer, but I don't think 5.4mm is an awful lot.

Right.

At least Shimano went with 36 holes instead of 32.

I'm guessing this is a dig at Rohloff. Rohloff is stuck with 32
onacountta the 8 bolts that hold the left end of the hub to the shell.

While I've long been an advocate of 36 spoke wheels, The Rohloff hub has
such huge flanges, as does the Nexus 8, as to give an unusually generous
lateral bracing angle.

I've sold a LOT of Rohloff hubs, many to very abusive riders, and have
yet to hear of a broken spoke on a Rohloff wheel.

We tend to get used to the inherently weak highly-dished wheels used on
derailer bikes, and to forget how very much stronger a one-sprocket
wheel can be.

Setting practical matters aside for a moment, does
anyone like the look of this hub? I think it's ugly.

Yep. Fortunately, I can't see the rear hub when I'm riding.

This is also partially offset by the super neat shift cable routing.
Shimano's system of keeping all of the moving parts inboard of the
chainstays makes them less kludgy looking as well as less prone to
impact damage than virtually all other multispeed systems.

Sheldon "Huit" Brown
+--------------------------------+
| One does not win at chess by |
| seizing every opportune pawn |
| -- Michael Flynn |
+--------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

On Mon, 31 Jan 2005 15:55:54 -0500, Sheldon Brown
wrote:

I've also scanned and put up the Service Manual for these hubs at:

http://sheldonbrown.com/nexus8



Thanks!

I have this on my Bianchi Milano, works great, very easy to
shift. Not sure I would want to take one apart, looks complex.



---
"BitwiseBob" - Bob Anderson
Eugene Oregon