Rohloff Hub

Tom Anderson said:

Is anyone using Rohloff gears on their bike or tandem?
Was it original equipment or an upgrade?
If an upgrade was it easy to fit?

If you've done a few it gets easier 😉
Thorougly investigate all the options befoere ordering (EX, not EX,
torque arm or speedbone etc)
Order the proper spokes with your hub (26", 2x's are short!), get the 4
bolt disk if required and think about your double cable run beforehand.
Rohloff sell some nifty double cablestraps (by Sachs) well worth looking
into.

--
---
Marten Gerritsen

INFOapestaartjeM-GINEERINGpuntNL
www.m-gineering.nl

m-gineering said:

Tom Anderson said:

Is anyone using Rohloff gears on their bike or tandem?
Was it original equipment or an upgrade?
If an upgrade was it easy to fit?

If you've done a few it gets easier 😉

Indeed. Have 2 Speedhubs, one migrated from Streetmachine to Baron,
and then to second Baron (new frame due to hairline cracks). The
other's on my third-hand faired trike, where I also went from 24" to
20".
I let my recumbent dealer lace the wheels, and do the first fitting,
did the second fitting myself in his shop, with assistance, and now I
fit them myself. Rohloff have a very good manual, in several
languages.
Keep your cable runs as free-running as practical to keep the shifting
effort low.

Mark van Gorkom.

in message <[email hidden]>, Mark van Gorkom

(') said:

m-gineering said:

Tom Anderson said:

Is anyone using Rohloff gears on their bike or tandem?
Was it original equipment or an upgrade?
If an upgrade was it easy to fit?

If you've done a few it gets easier 😉

Indeed. Have 2 Speedhubs, one migrated from Streetmachine to Baron,
and then to second Baron (new frame due to hairline cracks).

Do you find the extremely long chain on the Baron causes any problems?
Do you think there would be any efficiency benefit in using front wheel
drive to eliminate this?

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

;; this is not a .sig

Simon Brooke said:

Do you find the extremely long chain on the Baron causes any problems?

Depends how one defines "problems". Lowracers tend to run with free
chains for racing where sharp turns of the bars tend not to happen, but
rather more elaborate routing for Normal Use. This in turn suggests
that the more elaborate routing loses you something, and that the free
run isn't terribly good on a bike in Normal Use...

Quoted message said:

Do you think there would be any efficiency benefit in using front wheel
drive to eliminate this?

Again, not a case of an absolute. The main problem with FWD again comes
with more major turning of the steering as that will either twist the
chain on a design like the Zox lowracer or twist the cranks relative to
the rider, on a design like the Flevo Racer.
Some folk have suggested FWD and rear wheel steering to get around this,
but in an answer in C+ I once read a Mr. M. Burrows suggested that
though it was nice in theory, in practice such machines would tend to
piloted by folk with large feet and red noses who went by the name of Koko.

Of course, with a LWB project you have a more fundamental issue than
drive efficiency to address with FWD, and that will be can you actually
get enough traction, especially up a big hill, for your more efficient
drive to actually translate to movement relative to the tarmac!

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email hidden] http://www.dundee.ac.uk/~pjclinch/

Peter Clinch said:

Again, not a case of an absolute. The main problem with FWD again comes
with more major turning of the steering as that will either twist the
chain on a design like the Zox lowracer or twist the cranks relative to
the rider, on a design like the Flevo Racer.

not necessarely so: www.m-gineering.nl/caferace.htm

--
---
Marten Gerritsen

INFOapestaartjeM-GINEERINGpuntNL
www.m-gineering.nl

in message <[email hidden]>, Peter Clinch

(') said:

Simon Brooke said:

Do you find the extremely long chain on the Baron causes any
problems?

Depends how one defines "problems". Lowracers tend to run with free
chains for racing where sharp turns of the bars tend not to happen,
but
rather more elaborate routing for Normal Use. This in turn suggests
that the more elaborate routing loses you something, and that the free
run isn't terribly good on a bike in Normal Use...

Quoted message said:

Do you think there would be any efficiency benefit in using front
wheel drive to eliminate this?

Again, not a case of an absolute. The main problem with FWD again
comes with more major turning of the steering as that will either
twist the chain on a design like the Zox lowracer or twist the cranks
relative to the rider, on a design like the Flevo Racer.
Some folk have suggested FWD and rear wheel steering to get around
this, but in an answer in C+ I once read a Mr. M. Burrows suggested
that though it was nice in theory, in practice such machines would
tend to piloted by folk with large feet and red noses who went by the
name of Koko.

Of course, with a LWB project you have a more fundamental issue than
drive efficiency to address with FWD, and that will be can you
actually get enough traction, especially up a big hill, for your more
efficient drive to actually translate to movement relative to the
tarmac!

Yup. But my problem isn't to build a practical bike. I don't much mind
if it can't negotiate normal road junctions and I don't much mind if it
can't climb hills. It doesn't have to be able to accelerate desperately
fast. The rules don't specify but I think I can rely on the
acceleration zone being a mile long. So under those circumstances

(i) steering deflection isn't great, so neither twist in a front wheel
drive, nor chain interference in a rear wheel drive configuration is a
problem (indeed, as prototype #1 is long wheelbase, chain interference
with steering is a non-issue, although it may become an issue if I
abandon the long wheelbase idea)

(ii) traction isn't that much of an issue because the vehicle doesn't
have either to climb or to sprint.

So what this comes down to is

(i) mass and inertia of chain - is this a problem?

(ii) friction along the chainline - can we achieve a lower friction
chainline with rear-wheel or front-wheel drive?

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/
;; If Python is executable pseudocode,
;; then Perl is executable line noise
-- seen on Slashdot.

In article said:

Peter Clinch said:

Again, not a case of an absolute. The main problem with FWD again comes
with more major turning of the steering as that will either twist the
chain on a design like the Zox lowracer or twist the cranks relative to
the rider, on a design like the Flevo Racer.

not necessarely so: www.m-gineering.nl/caferace.htm

http://www.stitesdesign.com/hpv_chameleon_fwd.htm is another setup
with a universal joint to avoid the twist.

in message <[email hidden]>, m-gineering

(') said:

Peter Clinch said:

Again, not a case of an absolute. The main problem with FWD again
comes with more major turning of the steering as that will either
twist the chain on a design like the Zox lowracer or twist the cranks
relative to the rider, on a design like the Flevo Racer.

not necessarely so: www.m-gineering.nl/caferace.htm

JPEG?

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

Do not sail on uphill water.
- Bill Lee

Simon Brooke said:

So what this comes down to is

(i) mass and inertia of chain - is this a problem?

Possibly, but I'd imagine it's quite small. You could always get one of
the SRAM chains with the little cutouts in the plates.

Quoted message said:

(ii) friction along the chainline - can we achieve a lower friction
chainline with rear-wheel or front-wheel drive?

One possibility that might be worth exploring would be to have a
jackshaft (IIRC) which uses a fixed chain run for the long section, with
a standard derailleur system making up the shorter run. This should
solve some of the problems of chain droop that a long chain run can
cause. I don't know whether it'll be more efficient though. :-)

Jon