Re: Nexus 8 -Speed Bicycles

Rocketman

"George Goetz" <geogoetz@optonline.net> wrote in message
news:IBygc.52299$_g4.6110499@news4.srv.hcvlny.cv.net...
> I know they're not popular here in the USA but I can't believe how hard
they
> are to find.
>
> Specifically looking for something like the "Avenue Broadway 8-speed",
> danish I believe, or the Trek 7400.

Just wanted to put in my $.02 about the Shimano Nexus rear hub. I had a
brand new 7-speed Nexus rear hub on my 2003 Van Dessel Super Fly last
season. The rear hub really seemed to be eating quite a lot of pedaling
energy. It always felt like I was pedaling uphill or something. I was
shocked to find that there was no 1:1 ratio (with maximal energy
efficiency); but in fact, the mid-range gears were actually *less* energy
efficient (about 85%) than the highest and lowest gears (around 90%). Since
most of us ride predominantly in the mid-range gears, that was a problem.
And it was noticeable. That's not to mention the fact that the Nexus hub is
quite hefty.

Bottom line: I got ride of the Van Dessel, and bought a city bike/cyclocross
frame from NYCBikes.com (nice guys! give 'em a try). I built 'er up with a 9
/ 27-speed Shimano Deore drivetrain, laced up some matching black-painted
Mavic Open Pro rims, and attached Zefal fenders for all-weather city riding.
My cyclocross/hybrid/citybike is *much* faster than the Van Dessel was -
which I attribute primarily to the more efficient derailleur-based
drivetrain. The speed increase is noticeable. The new city bike is also a
couple of pounds lighter, with lighter, faster wheels and cyclocross
knobbies for excellent off-road handling. The cost, including all new
9-speed components and an Interloc straight-blade cyclocross fork: under
$400 total.

> I'm not a fan of the Bianchi Milano.

It looks nice from some angles, and not from others. Looks great in Bianchi
Celeste green.

> Does anyone know where I could get one in the US?

Sorry, no.

> Check out this baby.
>
> http://www.bikebuster.com/shop/foto/110011.jpg

Sweet looking bike!

Rocketman

Chalo

"Rocketman" <rocketman@bikerider.com> wrote:

> Just wanted to put in my $.02 about the Shimano Nexus rear hub. I had a
> brand new 7-speed Nexus rear hub on my 2003 Van Dessel Super Fly last
> season. The rear hub really seemed to be eating quite a lot of pedaling
> energy. It always felt like I was pedaling uphill or something.

The SRAM/Sachs Spectro 7 is noticeably freer-running. And the middle
gear is direct-drive.

FWIW, I feel like whatever hypothetical efficiency one gains by using
a derailleur system is as often as not squandered by poor chainline
and draggy bends around the pulleys. (To say nothing of dumping the
chain every so often.)

Chalo Colina

Matt O'Toole

Chalo wrote:

> "Rocketman" <rocketman@bikerider.com> wrote:
>
>> Just wanted to put in my $.02 about the Shimano Nexus rear hub. I
>> had a brand new 7-speed Nexus rear hub on my 2003 Van Dessel Super
>> Fly last season. The rear hub really seemed to be eating quite a
>> lot of pedaling energy. It always felt like I was pedaling uphill
>> or something.
>
> The SRAM/Sachs Spectro 7 is noticeably freer-running. And the middle
> gear is direct-drive.
>
> FWIW, I feel like whatever hypothetical efficiency one gains by using
> a derailleur system is as often as not squandered by poor chainline
> and draggy bends around the pulleys. (To say nothing of dumping the
> chain every so often.)

Efficiencies for various types of drivetrains have been measured and published,
and the derailer setup still comes out on top. Unfortunately, I can't find the
URLs at the moment.

Cross-chained and small-small gear combos are least efficient, worse than some
internal gear hubs'. I was surprised to see how poor a standard MTB drivetrain
performed in certain gear combinations -- less than 90% efficiency. But the
best combinations are right up there at 97-98%, which hub gears can't touch.

Matt O.

papercut

"Matt O'Toole" <matt@deltanet.com> wrote in message news:<Faahc.12840$Aq.9435@nwrddc03.gnilink.net>...
> Efficiencies for various types of drivetrains have been measured and published,
> and the derailer setup still comes out on top. Unfortunately, I can't find the
> URLs at the moment.
>
> Cross-chained and small-small gear combos are least efficient, worse than some
> internal gear hubs'. I was surprised to see how poor a standard MTB drivetrain
> performed in certain gear combinations -- less than 90% efficiency. But the
> best combinations are right up there at 97-98%, which hub gears can't touch.

Perhaps this one?
http://www.ihpva.org/pubs/HP52.pdf

Jeff Wills

papercut@myway.com (papercut) wrote in message news:<110bd04c.0404200954.995e676@posting.google.com>...
> "Matt O'Toole" <matt@deltanet.com> wrote in message news:<Faahc.12840$Aq.9435@nwrddc03.gnilink.net>...
> > Efficiencies for various types of drivetrains have been measured and published,
> > and the derailer setup still comes out on top. Unfortunately, I can't find the
> > URLs at the moment.
> >
> > Cross-chained and small-small gear combos are least efficient, worse than some
> > internal gear hubs'. I was surprised to see how poor a standard MTB drivetrain
> > performed in certain gear combinations -- less than 90% efficiency. But the
> > best combinations are right up there at 97-98%, which hub gears can't touch.
>
> Perhaps this one?
> http://www.ihpva.org/pubs/HP52.pdf

There's also a follow-up to that article in Human Power #55, comparing
derailleur systems and the Rohloff hub. Recommended reading for anyone
wanting to *really* measure drivetrain efficiencies.

Jeff

(Pete Cresswell)

RE/
>The SRAM/Sachs Spectro 7 is noticeably freer-running. And the middle
>gear is direct-drive.

Any feeling for how Roloff's hub compares?
--
PeteCresswell

George Goetz

Thanks everyone, I'm going to keep looking. The Cannondale Street Roloff
looks great too.


"(Pete Cresswell)" <x@y.z> wrote in message
news:ccbb80hbip07fki3eig5eq8jvsu4qtlkht@4ax.com...
> RE/
> >The SRAM/Sachs Spectro 7 is noticeably freer-running. And the middle
> >gear is direct-drive.
>
> Any feeling for how Roloff's hub compares?
> --
> PeteCresswell

(Pete Cresswell)

RE/
>Thanks everyone, I'm going to keep looking. The Cannondale Street Roloff
>looks great too.

Just be aware that there's nothing about the Rohloff hub that limits it to being
used on any particular make/model of bike except for the axle width (135mm MTB
standard...).

I've got one on my hardtail, one on my Ellsworth Isis FS...and used to have one
on my Cannondale Jekyll when I had it.
--
PeteCresswell

Chalo

Pete Cresswell wrote:
>
> Chalo wrote:
> >The SRAM/Sachs Spectro 7 is noticeably freer-running. And the middle
> >gear is direct-drive.
>
> Any feeling for how Roloff's hub compares?

It's more like the Sachs than like the Shimano in that regard. Just
fiddling with the hub in my hands, my impression is that it's got more
internal drag than the Spectro, but on the street it's very hard to
tell. The Rohloff makes more noise and thus makes me feel like it's
draggier, but that could well be a misconception.

The Shimano Nexus 7 is pretty quiet, has a decent brake, shifts
quickly and reliably, stashes all its shifting hardware inboard of the
dropouts, and dissipates a lot of energy. I doubt that the Nexus 8 is
too different, but I've never seen one so I can't say.

Chalo Colina

Chalo

"(Pete Cresswell)" <x@y.z> wrote:

> Just be aware that there's nothing about the Rohloff hub that limits it to being
> used on any particular make/model of bike except for the axle width (135mm MTB
> standard...).

Well, yes...but chain tensioners-- even Rohloff's-- are cheesy. The
hub is a better match for horizontal or adjustable dropouts, or an
eccentric BB. That really cuts down on the selection of frames.

I mean, why use a gearhub in a system that can dump the chain just
like a derailleur bike?

Chalo Colina

Ryan Cousineau

In article <8b4b7de4.0404211740.2da2a89b@posting.google.com>,
chumpychump@hotmail.com (Chalo) wrote:

> "(Pete Cresswell)" <x@y.z> wrote:
>
> > Just be aware that there's nothing about the Rohloff hub that limits it to
> > being
> > used on any particular make/model of bike except for the axle width (135mm
> > MTB
> > standard...).
>
> Well, yes...but chain tensioners-- even Rohloff's-- are cheesy. The
> hub is a better match for horizontal or adjustable dropouts, or an
> eccentric BB. That really cuts down on the selection of frames.
>
> I mean, why use a gearhub in a system that can dump the chain just
> like a derailleur bike?
>
> Chalo Colina

Hey Chalo, you'll like my latest thought-experiment: a hub-geared BMX
with a tall seat, flat or drop bars, and high-pressure tires. It will be
the world's lousiest folding bike (doesn't fold, y'see), or a great way
of gaming airline bike-handling rules.

Thinking, thinking...
--
Ryan Cousineau, rcousine@sfu.ca http://www.sfu.ca/~rcousine/wiredcola/
President, Fabrizio Mazzoleni Fan Club

Chalo

Ryan Cousineau <rcousine@sfu.ca> wrote:

> Hey Chalo, you'll like my latest thought-experiment: a hub-geared BMX
> with a tall seat, flat or drop bars, and high-pressure tires. It will be
> the world's lousiest folding bike (doesn't fold, y'see), or a great way
> of gaming airline bike-handling rules.

That's almost the bike I've been building for one of my co-workers.
He aimed for "world's lightest BMX bike" but eventually came to rest
on "possibly world's most expensive BMX bike".

It's an aluminum monocoque BMX race frame carefully jacked open and
milled to accept a SRAM 5-speed hub with drum brake. Both hubs are
laced to 20" Velocity Deep-Vs with 110psi slicks. Carbon fork,
aluminum handlebars, Race Face Next LP cranks, Speedplay pedals. Long
31.6mm seatpost. Projected complete weight: 20 pounds.

The front end of a 20" bike is so short, drop bars would be a sick
joke. Flat bars or cowhorns would give a time-trial/pursuit kind of
riding position.

Certainly this bike would be mind-bogglingly easier to travel with
than any of my own bikes.

Chalo Colina

(Pete Cresswell)

RE/
>I mean, why use a gearhub in a system that can dump the chain just
>like a derailleur bike?

My FS dumped the chain a few times, but that was a good year ago before I put a
bash ring where the outside ring would go. No dumps since.
--
PeteCresswell

Ryan Cousineau

In article <8b4b7de4.0404221228.15b21eeb@posting.google.com>,
chumpychump@hotmail.com (Chalo) wrote:

> Ryan Cousineau <rcousine@sfu.ca> wrote:
>
> > Hey Chalo, you'll like my latest thought-experiment: a hub-geared BMX
> > with a tall seat, flat or drop bars, and high-pressure tires. It will be
> > the world's lousiest folding bike (doesn't fold, y'see), or a great way
> > of gaming airline bike-handling rules.
>
> That's almost the bike I've been building for one of my co-workers.
> He aimed for "world's lightest BMX bike" but eventually came to rest
> on "possibly world's most expensive BMX bike".
>
> It's an aluminum monocoque BMX race frame carefully jacked open and
> milled to accept a SRAM 5-speed hub with drum brake. Both hubs are
> laced to 20" Velocity Deep-Vs with 110psi slicks. Carbon fork,
> aluminum handlebars, Race Face Next LP cranks, Speedplay pedals. Long
> 31.6mm seatpost. Projected complete weight: 20 pounds.

Weird! Wonderful! Any likely bugbears?

Why did you decide on the 5-speed hub, as opposed to the 7? Or, for that
matter the Rohloff, since that would get you closer to your new goal .

I'll probably be starting out with a steel frame from the attic, so I
don't anticipate as many issues with frame spreading and such. I'm not
obsessed about the weight or aerodynamics; I want a bike that is sort of
a fast-as-possible cheap-and-transportable bike, or maybe a death-metal
Moulton. Hm. Since I'm going to an island with a lot of stair steps,
maybe I should get a suspension fork and really go to town.

> The front end of a 20" bike is so short, drop bars would be a sick
> joke. Flat bars or cowhorns would give a time-trial/pursuit kind of
> riding position.

Interesting thoughts. I'm thinking a flat bar (maybe with my bolt-on
aero bars brought along for extra sickness) would be the way to go. I
suppose there's no real reason to not use the stock BMX-style
handlebars, is there? Besides looks?

> Certainly this bike would be mind-bogglingly easier to travel with
> than any of my own bikes.

Seems to me that a BMX or cruiser might work for your travelling needs.
I bet even a Co-Motion-style traveling road/mtb frame would be awfully
big in your sizes. Clearly a case where compact geometry would be
functional .

I hope you'll post pictures of this project when you're done. Sounds
like a case of wretched excess at its finest. This is a really, really
admirable project. I think you should send some shots to a BMX magazine
or two when you've finished. Or maybe just Chunk 666.

--
Ryan Cousineau, rcousine@sfu.ca http://www.sfu.ca/~rcousine/wiredcola/
President, Fabrizio Mazzoleni Fan Club