Hub Gears: no need to scoffjaw the warranty

Clive George wrote:

"Andre Jute" wrote in message
...
A concurrent thread on a big gear range made me wonder what width one
could achieve in hub gears by ignoring the recommended chainring/
sprocket ratio, which for Rohloff appears to be a fraction under 2.5
and for the Shimano Nexus 8-speed hub is specifically given as from
2.0 to 2.1. I have no idea how long the hubs would survive under
abusive handling as in some of the examples below. All numbers in gear
inches.

It's a pity you don't understand the simple rules about permitted gearing.

My dear Clive, if you want to get off on finding me ignorant, I'm
happy for you. One of my ten favourite things is being ignorant so
that I can experience the pleasure of learning something new.
Unfortunately for both of us, this is not a case of my ignorance -- be
very surprising to a whole of lot of people who know me better than
you do if I got gear ratios wrong -- but of you failing to put your
mind in gear and in addition being totally oblivious to nuance. Both
failures might be ameliorated by introducing a woman into your living
arrangements.

I was applying several viewpoints and sliding around among them. The
viewpoints were the manufacturer's, the engineer's, plus those of a
reasonable user, an unreaonable user, and the scofflaw. Tom tells us I
should have added another viewpoint, for recumbent riders... Each one
of my comments should be read from the correct viewpoint. For
instance, Shimano specifically says the chainwheel/sprocket tooth
ration should be between 2.0 and 2.1. Thus, from the manufacturer's
viewpoint, anything outside that ratio is abusive, precisely as I
said, whereas from an engineering viewpoint only a breach on one side
of the equation is abusive, while from a user's viewpoint the tyre
size is essential to determine on the road characteristics, and for my
unreasonable user the abusive ratio is irrelevant to the fulfilment of
his desire for the widest band of gear inch developments on the road
(of course) so that he too wants the tire size.

They specify a minimum gearing, ie on a rohloff, 40/17, 38/16, 36/15,
32/13t, or 40/16 etc for 100kg+ riders and tandems. Put a smaller chainring
than recommended, and you'll be putting more force on the hub than it's
designed for.

Thank you, Professor George. The kindie engineers are thataways.

(actually, you can push it, but that's not relevant for the
purposes of this discussion).

No, it is of the essence of this discussion. I said specifically that
those gear hubs are stronger than the makers let on.

So, the 46/16 you claim is not permissible is in fact entirely legit - it's
rather easier on the hub than the minimum permissible gearing.

Certainly to the engineer it is legitimate, but to the manufacturer it
is not permissible because he has stated both an upper and a lower
range. I say again, check the viewpoint from which I make a particular
statement.

Ditto 42/16.

See above, ditto.

Not abusive at all.

Not from the engineer's viewpoint but outside the manufacturer's
recommended specs.

32/16 would be abusive.

By only two (engineers, manufacturers) out of the six viewpoints for
sure, possibly by some of the others on enquiry into what they intend
in each case.

With a 37-622 tyre and the same 46-16 gears as inour first example,
but in this case even more abusive, the Shimano Nexus 8-speed hub
combined with the Schlumpf Mountain Drive would give an even wider
useful spread, 14 unique gears out of 16 covering from a Himalayan low
gear to 127in to pose with in cafe society. (This covers the entirely
unreasonable 18 to 123in someone asked for in a concurrent thread, and
a bit more.)

You'll have that nice range, but using the mountain drive will break it.

Why do you think the words "scoffjaw the warranty" are in the
headline?

The
mountain drive gives the equivalent of a 18t chainring with your 46. The
minimum with a 16t sprocket on the nexus if your 2.1 is correct is a 32t,
though I've seen people using 29/17ish gearing.

2.1 was confirmed in data sheets under my hand; I have two Nexus hub
gear-equipped bikes.

And of course the wheel size makes no difference to the permitted gearing -
it does however make a difference to the effective gearing you end up with.

Yes, that's why I gave it. Refer again to my list of viewpoints.

If you stick a Rohloff in a small wheel, you can get some pretty small
gears.

Of you say so, Clive. That's yet another viewpoint, the
smallwheeler's.

http://www.kinetics.org.uk/html/k_gear.shtml

Unfortunately I use a Mac and it is too much bother to take down and
set up a Windows POS just to do some calculations I can do much faster
on the slide rule bezel of my watch.

is quite cool though.

Presumably to the smallwheelers.

clive

Oh, by the way, I apologize for the confusion I caused by not more
obviously separating the Shimano hub, for which upper and lower ratio
limits are stated, from the Rohloff hub whose makers don't appear to
do anything so unnecessary (from an engineering viewpoint... from my
own viewpoint I would have said "clumsy").

Time to get that woman into your life, Clive, or your insensitivity
will cause more needless correspondence like this exchange.

Andre Jute
http://members.lycos.co.uk/fiultra/B...20CYCLING.html

Dear Carl:

Congratulations on finding your niche in life, googling support for
your betters. I'm sure it will bring you happiness.

In ten years or so of dilligent googlebugging you might even earn
rehabilitation from your crimes. Patience is also a virtue.

You may gofer coffee now.

Andre Jute
St Andre of the Infinite Mercy (in consultation with St Edward Dolan
the Excruciating)

wrote:

For those curious about the details . . .

Here's the short but clear Rohloff page that explains that it's the
ratio between front chainring and rear sprocket that matters to the
hub, not the wheel size:

http://www.rohloff.de/en/info/faq/fa...289/index.html

And here's the Rohloff page that explains the specific number of
front/rear teeth with the lowest front/rear sprocket ratio (not
overall gearing including wheel size) that they think wise:

http://www.rohloff.de/en/info/faq/fa...289/index.html

As the page explains, the 2.35:1 front/rear ratio is the minimum
acceptable ratio for normal use, a 40/17 (2.35:1) being as low a ratio
as Rohloff thinks a normal rider should use. For a heavier rider
(100kg+) or a tandem, Rohloff warns that the minimum should be raised
to 40/16 (2.50:1).

Increasing the size of the front chain-ring is okay. That is, 40/16 is
2.50:1, so adding eight teeth for 48:16 (3.00:1) is fine.

In other words, you can gear a Rohloff's exposed front/rear up higher
and higher--it's fine to use the high-speed 52x12 (4.33:1) instead of
the 39x13 (3.00:1). That's a selling point for small-rear-wheel bikes
that need higher gearing.

But you don't want to go the other way and gear down in hopes of low
mountain-bike gearing--a 39 front and a 28 rear (1.39:1) would be a
bad thing, well below the recommended 2.35:1.

What confuses people is that it's a matter of how the front/rear
sprocket combination feeds into the Rohloff's many hidden internal
gears, not a matter of the simple front/rear sprocket of an exposed
derailleur.

Cheers,

Carl Fogel

Tom Sherman wrote:

Andre Jute wrote:
A concurrent thread on a big gear range made me wonder what width one
could achieve in hub gears by ignoring the recommended chainring/
sprocket ratio, which for Rohloff appears to be a fraction under 2.5
and for the Shimano Nexus 8-speed hub is specifically given as from
2.0 to 2.1. I have no idea how long the hubs would survive under
abusive handling as in some of the examples below. All numbers in gear
inches.

With a 37-622 tyre and 46-16 gears, the Rohloff Speed Hub would give a
range from a notch or two below many mountain bikes to pretty well
beyond what most people could manage on the flat. Fourteen gears in
gear inches developed:

22
25
28
32
37
42
47
54
61
70
79
90
102
116

Just for comparison, here are the gear inches for the 14 gears of the
Rohloff with a more reasonable, and possibly permitted (I've seen it
several times), 42-16 setup. Still a very respectable spread, and
probably more pleasurable to use:

20
23
26
29
33
38
43
49
56
64
72
82
93
106

Adding the Schlumpf Speed Drive to a Rohloff Speed Hub seems
unnecessary: it will add only four useful gears at most, the rest
being duplicated.

Why not consider the Schlumpf High Speed Drive [1] that offers a 2.5:1
step-up, as compared to the 1.65:1 step-up of the Speed Drive?

How many extra unique *and* useful gears would one get on a) an
upright bike and b) a recumbent? Seems to me that you're paying for a
lot of wasted gears. On hand of experience with the Nexus hub, on
admittedly none-too-challenging terrain, I've concluded that the 307
per cent range of the Nexus 8-speed is pretty useful, with the
Schlumpf drive required only for bicycling goatherds and/or Olympic
speed maniacs; if required, the improvement the Schlumpf brings to the
Nexus is pretty reasonably priced because it is a large effective
improvement. But the Rohloff strikes me as pretty near perfect just
the way it is, with the marginal improvement that is possible with the
Schlumpf drive (of any description) costing way out of proportion.

Okay, let's look at the Shimano Nexus 8-speed hub.

With a 37-622 tyre and the same 46-16 gears as in our first example,
but in this case even more abusive, the Shimano Nexus 8-speed hub
combined with the Schlumpf Mountain Drive would give an even wider
useful spread, 14 unique gears out of 16 covering from a Himalayan low
gear to 127in to pose with in cafe society. (This covers the entirely
unreasonable 18 to 123in someone asked for in a concurrent thread, and
a bit more.)

Unreasonable for an upright bicycle, yes.

See what I replied to Clive George about viewpoints in my original
post. I hadn't thought of recumbents... Okay, add recumbents and
stipulate that a bent rider might find 16-127 gear inches on the road
useful.

However, for a recumbent bicycle, that wide gearing range is not at all
unreasonable, but nearer to a necessity. The proper climbing technique
on a recumbent bicycle is unlike that for an upright bicycle, where the
preferred climbing technique of many is to stand and pedal at a
relatively low cadence, while pulling on the handlebars to increase
one's "effective" weight.

Conversely, the proper climbing technique on a recumbent is to use a
very high cadence (e.g. 120 RPM) and to pull back [2] as much as
possible. Trying to use the upright climbing technique will result in
excess lactic acid buildup with the rider then needing to stop or slow
severely to recover.

Those of high blood pressure, a tendency to foam at the mouth. an
inability to think for themselves or outside the box, or who have ever
been insulted by Edward de Bono, should skip this paragraph. Now! Are
you gone?
Okay. //////////////////////////////////////////////////////////////////////
I don't bother with cadence, Tom. That's stuff for athletes, nothing
to do with me. My purpose in cycling is different. I get my heart rate
up to 80 per cent of max and then pedal slower or faster to keep it
there, counting on my Shimano Cyber Nexus automatic gearbox to keep
the box in the optimum gear for the road inclination. It works a
treat. Your friends on the recumbent newsgroup to which you
crossposted this can see my automatic hub gears and adaptive
suspension and the associated computerized control elements at:
http://members.lycos.co.uk/fiultra/B...%20Smover.html
May The Force be with the recumbent riders too.

The (performance oriented) recumbent will also descend faster (where
tight corners or rough surfaces do not limit speed too severely) than
the upright. In particular, on a frontally or fully faired recumbent,
the rider can pedal without increasing drag, so a very high gear can be
used while going downhill.

We might when we exhaust this topic discuss aerodynamics and their
quantification.

I have a couple of lowracer bicycles with gear inch range of 19-120
(achieved with a step-up jack-shaft) and a "bodysock" faired long wheel
base recumbent with a range of 15-125 gear inches (achieved with a
triple crank and 3x7 hub). I have found both the lowest and highest gear
ratios on these bicycles useful.

But is it also true that most recumbent riders do not have such
extreme requirements? Or are you making a case that 15-125 should be a
norm for recumbents?

Gear Direct SMD
1 42 17
2 51 20
3 59 24
4 67 27
5 79 32
6 97 39
7 112 45
8 127 51

I was speaking to a guy in the parts department at Volvo in Gothenburg
a few years ago, and when he heard I planted a Chevy mouse motor in
one of their estates and was now supercharging it and looking to use a
few gennie Volvo parts, he said thickly, "Doncha tell Warranty. Inna
flash Warranty turn your ash to grash." (On a tip from this colourful
fellow I ordered the parts I wanted a lot cheaper from Rolls-Royce
than from Volvo; they bought them the same place but the Volvo markup
was higher...) I imagine Shimano will turn one's warranty, and one's
ass, to grass in a flash if they hear about a 46-16 FR tooth ratio on
one of their Nexus hubs, when they went to the trouble of printing the
ratio warning on the cover of the spec sheet.

So let's try 38-18, which at 2.11 recurring is arguably within the
permitted ratio, and can be built with Shimano's goodlooking and
reasonably priced own-brand parts intended for the hub gear bikes.
With the Schlumpf Mountain Drive, that gives 14 unique gears that
covers everything from loaded goatherding to pretty fast touring:

31 12
37 15
43 17
49 20
58 23
71 28
82 33
94 37

It does look like iconoclasm and scoffjawing the warranty is
unnecessary. With either the Rohloff or the Nexus/Schlumpf combination
you can get nicely spaced gear ratios over a very wide operating band.
The designers of those hubs and geared bottom bracket got it right.

In fact, riding daily in the low rolling hills of West Cork, I find
38-19 sets of teeth just right on the Nexus gear hub without the need
for the Schlumpf geared bottom bracket; it gives me the following gear
inch development for the 8 gears, perfect for day rides on my
particular countryside without ever having to push:

29
35
41
47
55
67
78
89

Would not a higher gear be useful when drafting trucks downhill?

You're wicked, Tom. Even better than drafting and pedalling like mad
is being towed and not pedalling at all.

Sprockets with any number of teeth you can want are readily available,
so for another use, say loaded alpine touring, I would not hesitate to
change the sprocket to give a ratio that is not permitted. I think the
Nexus hub is a lot sturdier than Shimano lets on, and it is widely
known that the Rohloff hub is panzer.

Of course, one can obtain very low gearing when the Rohloff is used in a
small drive wheel, without violating Rohloff's restrictions. Lacing the
large flange Rohloff hub into an ISO 349-mm hub would be challenging, if
one were to use it on a bicycle such as the Tri-Sled Nitro [3].

[1] http://www.schlumpf.ch/hsd_engl.htm.
[2] Clipless pedals with good retention are mandatory.
[3] http://www.trisled.com.au/nitro.html.

I wouldn't go on a public road in a Nitro without first arranging
blocking cars front and rear with big signs reading "SLOW! Madman on
the road." That thing makes you invisible to housewives in big SUVs
who are a danger even to fluorescently visible cyclists.

Andre Jute
http://members.lycos.co.uk/fiultra/B...20CYCLING.html

Nick Payne wrote:

Seeing that Rohloff are quite happy for their hub to be used on a tandem
with the recommended 2.4:1 front/rear ratio, I had no scruple using a lower
ratio on my own bike when I took it to Switzerland for two months in 2004. I
used 38/16 with 38x622 tyres, which gave a bottom gear that I found pretty
useful for comfortably climbing grades up to about 25% with a loaded bike.
That ratio gave gears from a low of 18 up to about 95 inches.

If you look at the actual hub specs, it nominates a maximum torque of 250Nm
at the crank with the recommended 2.4:1 ratio. With 170mm cranks that's
about 150Kgf on the pedal.

Nick

Yeah, that's why I mentioned loaded alpine touring, 'cos I couldn't
instantly think of another example.

Never mind the gear, how do you keep your balance going up a 25% grade
with a loaded bike? Sounds like an argument for credit card touring...

Andre Jute
I wish I were young and reckless enough to try that!


"Andre Jute" wrote in message
...
A concurrent thread on a big gear range made me wonder what width one
could achieve in hub gears by ignoring the recommended chainring/
sprocket ratio, which for Rohloff appears to be a fraction under 2.5
and for the Shimano Nexus 8-speed hub is specifically given as from
2.0 to 2.1. I have no idea how long the hubs would survive under
abusive handling as in some of the examples below. All numbers in gear
inches.

With a 37-622 tyre and 46-16 gears, the Rohloff Speed Hub would give a
range from a notch or two below many mountain bikes to pretty well
beyond what most people could manage on the flat. Fourteen gears in
gear inches developed:

22
25
28
32
37
42
47
54
61
70
79
90
102
116

Just for comparison, here are the gear inches for the 14 gears of the
Rohloff with a more reasonable, and possibly permitted (I've seen it
several times), 42-16 setup. Still a very respectable spread, and
probably more pleasurable to use:

20
23
26
29
33
38
43
49
56
64
72
82
93
106

Adding the Schlumpf Speed Drive to a Rohloff Speed Hub seems
unnecessary: it will add only four useful gears at most, the rest
being duplicated.

Okay, let's look at the Shimano Nexus 8-speed hub.

With a 37-622 tyre and the same 46-16 gears as inour first example,
but in this case even more abusive, the Shimano Nexus 8-speed hub
combined with the Schlumpf Mountain Drive would give an even wider
useful spread, 14 unique gears out of 16 covering from a Himalayan low
gear to 127in to pose with in cafe society. (This covers the entirely
unreasonable 18 to 123in someone asked for in a concurrent thread, and
a bit more.)

Gear Direct SMD
1 42 17
2 51 20
3 59 24
4 67 27
5 79 32
6 97 39
7 112 45
8 127 51

I was speaking to a guy in the parts department at Volvo in Gothenburg
a few years ago, and when he heard I planted a Chevy mouse motor in
one of their estates and was now supercharging it and looking to use a
few gennie Volvo parts, he said thickly, "Doncha tell Warranty. Inna
flash Warranty turn your ash to grash." (On a tip from this colourful
fellow I ordered the parts I wanted a lot cheaper from Rolls-Royce
than from Volvo; they bought them the same place but the Volvo markup
was higher...) I imagine Shimano will turn one's warranty, and one's
ass, to grass in a flash if they hear about a 46-16 FR tooth ratio on
one of their Nexus hubs, when they went to the trouble of printing the
ratio warning on the cover of the spec sheet.

So let's try 38-18, which at 2.11 recurring is arguably within the
permitted ratio, and can be built with Shimano's goodlooking and
reasonably priced own-brand parts intended for the hub gear bikes.
With the Schlumpf Mountain Drive, that gives 14 unique gears that
covers everything from loaded goatherding to pretty fast touring:

31 12
37 15
43 17
49 20
58 23
71 28
82 33
94 37

It does look like iconoclasm and scoffjawing the warranty is
unnecessary. With either the Rohloff or the Nexus/Schlumpf combination
you can get nicely spaced gear ratios over a very wide operating band.
The designers of those hubs and geared bottom bracket got it right.

In fact, riding daily in the low rolling hills of West Cork, I find
38-19 sets of teeth just right on the Nexus gear hub without the need
for the Schlumpf geared bottom bracket; it gives me the following gear
inch development for the 8 gears, perfect for day rides on my
particular countryside without ever having to push:

29
35
41
47
55
67
78
89

Sprockets with any number of teeth you can want are readily available,
so for another use, say loaded alpine touring, I would not hesitate to
change the sprocket to give a ratio that is not permitted. I think the
Nexus hub is a lot sturdier than Shimano lets on, and it is widely
known that the Rohloff hub is panzer.

Andre Jute
Libertarian: a conservative who talks up a good liberal line.

"Andre Jute" wrote in message
...

So, the 46/16 you claim is not permissible is in fact entirely legit -
it's
rather easier on the hub than the minimum permissible gearing.

Certainly to the engineer it is legitimate, but to the manufacturer it
is not permissible because he has stated both an upper and a lower
range. I say again, check the viewpoint from which I make a particular
statement.

That'll be the viewpoint which completely ignores what the manufacturer
says, would it? Rohloff don't specify maximum gearing.

You screwed up, admit it, move on.

clive

Former Normal person " wrote:
On Jan 31, 1:18 am, Tom Sherman
wrote:

However, for a recumbent bicycle, that wide gearing range is not at all
unreasonable, but nearer to a necessity.

Bents and climbing don't mix well, in other words.

Ever seen a state of the are recumbent with a properly trained rider?
(The answer is almost certainly not.) Do not compare apples to oranges.

The proper climbing technique
on a recumbent bicycle is unlike that for an upright bicycle, where the
preferred climbing technique of many is to stand and pedal at a
relatively low cadence, while pulling on the handlebars to increase
one's "effective" weight.

Nice try. Upright riders can sit or stand and easily switch back and
forth. Bent riders can't.

Where was the claim otherwise stated up-thread?

The (performance oriented) recumbent will also descend faster (snip)

"Also"? Where did "also" come from? 120rpm in a 15" gear? Isn't that
right about stall speed for you guys?

"Also" in comparison to climbing on a recumbent, not to upright
bicycles. That should have been obvious from the context

(where
tight corners or rough surfaces do not limit speed too severely) than
the upright.

I agree that in the real world, on real streets with potholes and
tight corners, uprights are safer to ride than bents (just sending a
little rhetoric back at you, there).

Except that major injury is much more likely in a minor fall from an
upright than from a recumbent, since there is little change of landing
on one's head or shoulder with much force while crashing a recumbent,
unlike the upright.

In particular, on a frontally or fully faired recumbent,
the rider can pedal without increasing drag, so a very high gear can be
used while going downhill.

The proselytizing gets old, Tom.

If you think this was intended to proselytize, your comprehension is off.

"dustoyevsky" is the one trying to start a flame war here, not me. I was
merely commenting on a technical point made by Andre Jute in regards to
usable gearing range.

We all know about wind resistance and bents and all that stuff. OK?
Oh, and "comfort". Well, I've tried a bent, I didn't feel very
comfortable g. Sure enough, the next guy had to go around the
parking lot a little faster to show me up, and he crashed. Whoops!
Truth be told, that was on a short-wheelbase prototype (lots of
prototypes in the bent world, from my brief lookings, btw).

Who brought up comfort? Was not me.

We had a semi-regular bent rider on the Wednesday night "Tour of the
Inner Loop" in Houston (Planetary Bicycles, 6:00) and two or three
others who were occasionals. No problems here, but no thanks, either.
Not for riding on real roads, anyhow.

BTW, from what I've seen, the problem with mixing bents and bicycles
isn't wheelbase or profile (or slowing down on hills), it wobbling.
Does everyone wobble, or just the three or four guys I've ridden with?

Probably just the guys you ride with. Lots of upright riders wobble also.

(Don't get me wrong dept.): If you haven't "heard" me say before,
"there's a bent in everyone's future"-- kind of a parallel to your
"failure" thing in your sig. But, at 58-1/2 (three quarters,
actually), with a bad back, arthritis in the hands, and a difficulty
with one of the saddle contact areas (doing much better, thanks), I'm
not there yet.

You must be confusing me with Doug Cimper.

Few bents are seen here in Austin, compared to bicycles. As in, you go
to a larger group ride, non-racer groups such as the esteemed ACA
weekend rides, you don't see a bent very often at all.

Chalo Colina is sure to get a recumbent any day! [rec.bicycles.tech
inside joke]

Well... Houston is flat, Austin is hilly. Bingo! --D-y

What was the prize?

--
Tom Sherman - Holstein-Friesland Bovinia
"And never forget, life ultimately makes failures of all people."
- A. Derleth

Edward Dolan wrote:
wrote in message
...
On Jan 31, 1:18 am, Tom Sherman
wrote:

[Quotation marks are messed up, so I will supply my own.]

"dustoyevsky's" post is fine. It is Ed Dolan's Microsoft Windows Mail
6.0 that has been mucking up posts recently.

However, for a recumbent bicycle, that wide gearing range is not at all
unreasonable, but nearer to a necessity.

Bents and climbing don't mix well, in other words.

Dust has really get that part right!

The proper climbing technique
on a recumbent bicycle is unlike that for an upright bicycle, where the
preferred climbing technique of many is to stand and pedal at a
relatively low cadence, while pulling on the handlebars to increase
one's "effective" weight.

Nice try. Upright riders can sit or stand and easily switch back and
forth. Bent riders can't.

Bent riders are like potted plants.

The (performance oriented) recumbent will also descend faster (snip)

"Also"? Where did "also" come from? 120rpm in a 15" gear? Isn't that
right about stall speed for you guys?

Many bent riders go downhill too fast and suffer the consequences.

(where
tight corners or rough surfaces do not limit speed too severely) than
the upright.

I agree that in the real world, on real streets with potholes and
tight corners, uprights are safer to ride than bents (just sending a
little rhetoric back at you, there).

Bent riders need to slow down when the road gets rough.

In particular, on a frontally or fully faired recumbent,
the rider can pedal without increasing drag, so a very high gear can be
used while going downhill.

The proselytizing gets old, Tom.

We all know about wind resistance and bents and all that stuff. OK?
Oh, and "comfort". Well, I've tried a bent, I didn't feel very
comfortable g. Sure enough, the next guy had to go around the
parking lot a little faster to show me up, and he crashed. Whoops!
Truth be told, that was on a short-wheelbase prototype (lots of
prototypes in the bent world, from my brief lookings, btw).

Fully faired recumbents are a pain in the neck. Mostly they don't work
very well.

We had a semi-regular bent rider on the Wednesday night "Tour of the
Inner Loop" in Houston (Planetary Bicycles, 6:00) and two or three
others who were occasionals. No problems here, but no thanks, either.
Not for riding on real roads, anyhow.

"Bent riders need to slow down when the road gets rough." - Ed Dolan

BTW, from what I've seen, the problem with mixing bents and bicycles
isn't wheelbase or profile (or slowing down on hills), it wobbling.
Does everyone wobble, or just the three or four guys I've ridden with?

The slower you go on any bike, the more you wobble.

(Don't get me wrong dept.): If you haven't "heard" me say before,
"there's a bent in everyone's future"-- kind of a parallel to your
"failure" thing in your sig. But, at 58-1/2 (three quarters,
actually), with a bad back, arthritis in the hands, and a difficulty
with one of the saddle contact areas (doing much better, thanks), I'm
not there yet.

Hang in there Dust - you will end up on a recumbent yet with all your
ailments.

Few bents are seen here in Austin, compared to bicycles. As in, you go
to a larger group ride, non-racer groups such as the esteemed ACA
weekend rides, you don't see a bent very often at all.

The largest group ride that I know of is RAGBRAI (Iowa). There are always
lots of recumbents on that ride.

Well... Houston is flat, Austin is hilly. Bingo! --D-y

"Bents and climbing don't mix well, in other words." - Dust

For the love of both Tullio Campagnolo and Shozo Shimano, get a real
newsreader, Ed!!!

--
Tom Sherman - Holstein-Friesland Bovinia
"And never forget, life ultimately makes failures of all people."
- A. Derleth

"Andre Jute" wrote in message
...

Never mind the gear, how do you keep your balance going up a 25% grade
with a loaded bike?

Same way as at higher speed, only potentially with rather larger movements.

On Feb 1, 12:45*am, Tom Sherman
wrote:
Edward Dolan wrote:
wrote in message
...
On Jan 31, 1:18 am, Tom Sherman
wrote:

[Quotation marks are messed up, so I will supply my own.]

*
"dustoyevsky's" post is fine. It is Ed Dolan's Microsoft Windows Mail
6.0 that has been mucking up posts recently.



However, for a recumbent bicycle, that wide gearing range is not at all
unreasonable, but nearer to a necessity.

Bents and climbing don't mix well, in other words.

Dust has really get that part right!

The proper climbing technique
on a recumbent bicycle is unlike that for an upright bicycle, where the
preferred climbing technique of many is to stand and pedal at a
relatively low cadence, while pulling on the handlebars to increase
one's "effective" weight.

Nice try. Upright riders can sit or stand and easily switch back and
forth. Bent riders can't.

Bent riders are like potted plants.

The (performance oriented) recumbent will also descend faster (snip)

"Also"? Where did "also" come from? 120rpm in a 15" gear? Isn't that
right about stall speed for you guys?

Many bent riders go downhill too fast and suffer the consequences.

(where
tight corners or rough surfaces do not limit speed too severely) than
the upright.

I agree that in the real world, on real streets with potholes and
tight corners, uprights are safer to ride than bents (just sending a
little rhetoric back at you, there).

Bent riders need to slow down when the road gets rough.

In particular, on a frontally or fully faired recumbent,
the rider can pedal without increasing drag, so a very high gear can be
used while going downhill.

The proselytizing gets old, Tom.

We all know about wind resistance and bents and all that stuff. OK?
Oh, and "comfort". Well, I've tried a bent, I didn't feel very
comfortable g. Sure enough, the next guy had to go around the
parking lot a little faster to show me up, and he crashed. Whoops!
Truth be told, that was on a short-wheelbase prototype (lots of
prototypes in the bent world, from my brief lookings, btw).

Fully faired recumbents are a pain in the neck. Mostly they don't work
very well.

We had a semi-regular bent rider on the Wednesday night "Tour of the
Inner Loop" in Houston (Planetary Bicycles, 6:00) and two or three
others who were occasionals. No problems here, but no thanks, either.
Not for riding on real roads, anyhow.

"Bent riders need to slow down when the road gets rough." - Ed Dolan

BTW, from what I've seen, the problem with mixing bents and bicycles
isn't wheelbase or profile (or slowing down on hills), it wobbling.
Does everyone wobble, or just the three or four guys I've ridden with?

The slower you go on any bike, the more you wobble.

(Don't get me wrong dept.): If you haven't "heard" me say before,
"there's a bent in everyone's future"-- kind of a parallel to your
"failure" thing in your sig. But, at 58-1/2 (three quarters,
actually), with a bad back, arthritis in the hands, and a difficulty
with one of the saddle contact areas (doing much better, thanks), I'm
not there yet.

Hang in there Dust - you will end up on a recumbent yet with all your
ailments.

Few bents are seen here in Austin, compared to bicycles. As in, you go
to a larger group ride, non-racer groups such as the esteemed ACA
weekend rides, you don't see a bent very often at all.

The largest group ride that I know of is RAGBRAI (Iowa). There are always
lots of recumbents on that ride.

Well... Houston is flat, Austin is hilly. Bingo! *--D-y

* "Bents and climbing don't mix well, in other words." - Dust

For the love of both Tullio Campagnolo and Shozo Shimano, get a real
newsreader, Ed!!!

Or we shall withdraw the benefice of John Boyd Dunlop from you. See
how you like riding on solid tyres. -- Andre Jute

--
Tom Sherman - Holstein-Friesland Bovinia
"And never forget, life ultimately makes failures of all people."
- A. Derleth

Andre Jute wrote:
Tom Sherman wrote:

Andre Jute wrote:
...
Okay, let's look at the Shimano Nexus 8-speed hub.

With a 37-622 tyre and the same 46-16 gears as in our first example,
but in this case even more abusive, the Shimano Nexus 8-speed hub
combined with the Schlumpf Mountain Drive would give an even wider
useful spread, 14 unique gears out of 16 covering from a Himalayan low
gear to 127in to pose with in cafe society. (This covers the entirely
unreasonable 18 to 123in someone asked for in a concurrent thread, and
a bit more.)

Unreasonable for an upright bicycle, yes.

See what I replied to Clive George about viewpoints in my original
post. I hadn't thought of recumbents... Okay, add recumbents and
stipulate that a bent rider might find 16-127 gear inches on the road
useful.

I have approximately that range on a recumbent bicycle, and have found
both the highest and lowest gear useful (on different sides of the same
hill on several occasions).

However, for a recumbent bicycle, that wide gearing range is not at all
unreasonable, but nearer to a necessity. The proper climbing technique
on a recumbent bicycle is unlike that for an upright bicycle, where the
preferred climbing technique of many is to stand and pedal at a
relatively low cadence, while pulling on the handlebars to increase
one's "effective" weight.

Conversely, the proper climbing technique on a recumbent is to use a
very high cadence (e.g. 120 RPM) and to pull back [2] as much as
possible. Trying to use the upright climbing technique will result in
excess lactic acid buildup with the rider then needing to stop or slow
severely to recover.

Those of high blood pressure, a tendency to foam at the mouth. an
inability to think for themselves or outside the box, or who have ever
been insulted by Edward de Bono, should skip this paragraph. Now! Are
you gone?
Okay. //////////////////////////////////////////////////////////////////////
I don't bother with cadence, Tom. That's stuff for athletes, nothing
to do with me. My purpose in cycling is different. I get my heart rate
up to 80 per cent of max and then pedal slower or faster to keep it
there, counting on my Shimano Cyber Nexus automatic gearbox to keep
the box in the optimum gear for the road inclination. It works a
treat. Your friends on the recumbent newsgroup to which you
crossposted this can see my automatic hub gears and adaptive
suspension and the associated computerized control elements at:
http://members.lycos.co.uk/fiultra/B...%20Smover.html
May The Force be with the recumbent riders too.

I do not have a fixation on cadence by any means, but I believe that
much of the poor climbing reputation recumbent have is due to three factors:
1 - Non-optimum bicycle design. The DF upright frame has been optimized
since WW1, with the only real improvements coming from better materials.
Conversely, the recumbent is still in an evolutionary stage towards
improved designs.

2 - Trying to climb like an upright rider, using relatively high gears
and low cadence and mashing more than pulling on the pedals. Most stock
recumbents (and many stock uprights for that matter) are geared too high
overall for most riders.

3 - Most recumbents are being ridden by older and/or less fit riders. On
invitational rides, upright riders walking the steeper uphill sections
is not too uncommon of a sight, but in that case observers judge the
riders to be unfit and do not condemn the bicycle design. Instead, the
upright's climbing ability is judged by those ridden by racers and very
fit riders.

The (performance oriented) recumbent will also descend faster (where
tight corners or rough surfaces do not limit speed too severely) than
the upright. In particular, on a frontally or fully faired recumbent,
the rider can pedal without increasing drag, so a very high gear can be
used while going downhill.

We might when we exhaust this topic discuss aerodynamics and their
quantification.

On my un-faired recumbents, a noticeable speed decrease occurs when
descending if I switch from coasting to pedaling either backwards or
forwards too slowly to apply power to the wheel.

I have a couple of lowracer bicycles with gear inch range of 19-120
(achieved with a step-up jack-shaft) and a "bodysock" faired long wheel
base recumbent with a range of 15-125 gear inches (achieved with a
triple crank and 3x7 hub). I have found both the lowest and highest gear
ratios on these bicycles useful.

But is it also true that most recumbent riders do not have such
extreme requirements? Or are you making a case that 15-125 should be a
norm for recumbents?

On an un-faired recumbent, the higher gears could be sacrificed with
little loss, but the lower ones should not be.

...
In fact, riding daily in the low rolling hills of West Cork, I find
38-19 sets of teeth just right on the Nexus gear hub without the need
for the Schlumpf geared bottom bracket; it gives me the following gear
inch development for the 8 gears, perfect for day rides on my
particular countryside without ever having to push:

29
35
41
47
55
67
78
89

Would not a higher gear be useful when drafting trucks downhill?

You're wicked, Tom. Even better than drafting and pedalling like mad
is being towed and not pedalling at all.

It never hurts to stir the pot.

...
[3] http://www.trisled.com.au/nitro.html.

I wouldn't go on a public road in a Nitro without first arranging
blocking cars front and rear with big signs reading "SLOW! Madman on
the road." That thing makes you invisible to housewives in big SUVs
who are a danger even to fluorescently visible cyclists.

I have ridden a bicycle that low in Chicago traffic, and some in Chicago
ride even lower bicycles:
http://www.wisil.recumbents.com/home.asp?URL=wisil/main.asp. I have
seen these bicycles being ridden on public roads. (As an aside, I
purchased a bicycle from Barb, which can be adjusted to fit both of us,
despite my being 0.3 meter taller than her.)

--
Tom Sherman - Holstein-Friesland Bovinia
"And never forget, life ultimately makes failures of all people."
- A. Derleth