Smooth Mover: bicycle with electronic gearchange and adaptive suspension
 

On Sat, 08 Sep 2007 10:06:09 +0100, Roy roy@somedomainsomewhere
wrote:

Andre Jute wrote:
Techieporn for you.

My Trek Navigator L700 "Smover"
Bicycle with Automatic Gearchange and Electronic Adaptive Suspension
delivered by Shimano Di2 Cyber Nexus Groupset

a photo essay by André Jute

http://members.lycos.co.uk/fiultra/B...%20Smover.html


Much too messy.

Proper bike:

http://www.on-one.co.uk/index.php?mo... &PAGE_id=131

Roy.

A step too far for me. I need my gears, and I need a freewheel.
Comfort comes first.

d

--
Pearce Consulting
http://www.pearce.uk.com

Smooth Mover: bicycle with electronic gearchange and adaptive suspension
 

"Ian Iveson" wrote in message
. uk...
I can scoot down that ramp backwards and turn the bike with only a
couple of dabs with my right foot, but that was the first time my
son had been on a bike in a couple of years!

Then you shall be my inspiration. Can't be outdone by a uk.rec.audio
stripling. Hang on a mo....

Hmm...bugger. Nearly cost me two indicators and a mirror. I blame the
Metzlers. All the same I have discovered the perfect manoevre that
works even in confined spaces. You start off like you are going to
freewheel in an arc feet up, but as soon as you gather a bit of speed
and start to turn you grab the front brake, as if in panic, whereupon
the anti-dive (GPZ900) flings the front end up so the bike pivots
about the footrests and applies the rear brake to sustain the skewed
reverse stoppie. Now you can use the momentum in the desired direction
of travel to pirouette a half turn, putting you in the perfect
position to wheelie off down the street to the envious amazement of
your puny neighbours. It all looks very Lone Ranger.


Sounds a bit more like 'Tonto' to me...

If you need to get a bike to face the other way in a *cool* fashion and
it has a centre stand, pull the bike over toward you 'til it's balanced
and spin it round with the right amounts of push on the back end and
pull on the handlebars - only works on the flat and only if the bike
*lends itself* to such a manoeuvre. Do it in a controlled manner and
*rehearse* it before you go public...



Didn't quite make the half-twist this time. The several dozen
Slovakians that live next door are still jeering.


You'll be in the UK then....


I remember a film...Buster Keeton or Keystone Cops I guess, where a
policeman reverses a motorcycle...an Indian maybe...so naturally like
you might not notice anything peculiar. I believe reverse gears were
quite common for sidecar duty.


Yep. Still available on the Russian combos, I gather...


If you've never tried a combo, BTW, you should. Not with linked
sidecar brake, which ruins all the fun. Turns those wet autumn leaves
into total entertainment.


All the bikes I had (that I can remember) over the years are he

http://www.apah69.dsl.pipex.com/mybikes/mybikes.htm


The Matchless (4th from the bottom) was a combo when I got it - great
fun!

Actually, I was considering a combo earlier this year but the *not
inconsiderable* prices added to the total impracticability (and space
constraints) pushed that one onto the back burner for the forseeable...

Smooth Mover: bicycle with electronic gearchange and adaptivesuspension
 

Don Pearce wrote:
On Sat, 08 Sep 2007 08:42:58 +0100, Eiron wrote:

Andre Jute wrote:

Those brakes aren't dodgy, Don, they're hyper-competent; what I forgot
to add is that they have a built-in modulator. They stop the one-
eighth of a ton of me and the bike and light touring gear from thirty
kph in 11 feet. I know, because I chewed up a pair of tyres while I
practiced that one to perfection. But I agree with you, for casual use
those roller brakes are overkill.
A fat man on a granny bike braking at over 1g!
Don't the laws of physics apply in Eire these days?

Quite so. That comes out at 1.05g. Centre of mass combined with
wheelbase tell us that he performed the last 8 feet of that stop flat
on his face in the road. But that is a perfectly legitimate way of
stopping your bike.

I just tried a normal stop from 20mph on decent tarmac. It took 12 yards
which averages 0.37g, and the back wheel was hopping about. I expect 0.5g
would be a reasonable maximum if I moved down and back, or a bit more if
I wasn't so fat. Perhaps André meant 11 yards, or perhaps he's just won
another thousand euros after betting that someone would point out the
deliberate error. :-)

--
Eiron.

Smooth Mover: bicycle with electronic gearchange and adaptive suspension
 

On Sat, 08 Sep 2007 13:10:34 +0100, Eiron wrote:

Don Pearce wrote:
On Sat, 08 Sep 2007 08:42:58 +0100, Eiron wrote:

Andre Jute wrote:

Those brakes aren't dodgy, Don, they're hyper-competent; what I forgot
to add is that they have a built-in modulator. They stop the one-
eighth of a ton of me and the bike and light touring gear from thirty
kph in 11 feet. I know, because I chewed up a pair of tyres while I
practiced that one to perfection. But I agree with you, for casual use
those roller brakes are overkill.
A fat man on a granny bike braking at over 1g!
Don't the laws of physics apply in Eire these days?

Quite so. That comes out at 1.05g. Centre of mass combined with
wheelbase tell us that he performed the last 8 feet of that stop flat
on his face in the road. But that is a perfectly legitimate way of
stopping your bike.

I just tried a normal stop from 20mph on decent tarmac. It took 12 yards
which averages 0.37g, and the back wheel was hopping about. I expect 0.5g
would be a reasonable maximum if I moved down and back, or a bit more if
I wasn't so fat. Perhaps André meant 11 yards, or perhaps he's just won
another thousand euros after betting that someone would point out the
deliberate error. :-)

I'd be very surprised if you could ever reach 0.5g on a pushbike,
unless it is a recumbent. You just sit too tall with respect to the
front wheel position. If your back wheel was hopping, you had reached
the limit, and it is really difficult to do anything but move your
body forwards under braking - there is nothing to brace against.

So maybe he did mean 11 yards, but that would be a shame because it
would mean those fancy brakes couldn't actually match a normal set.

d

--
Pearce Consulting
http://www.pearce.uk.com

Smooth Mover: bicycle with electronic gearchange and adaptive suspension
 

On Sep 6, 8:09 pm, Andre Jute wrote:
On Sep 6, 7:27 pm, (Don Pearce) wrote:



On Thu, 06 Sep 2007 16:27:41 -0700, Andre Jute
wrote:

Techieporn for you.

My Trek Navigator L700 "Smover"
Bicycle with Automatic Gearchange and Electronic Adaptive Suspension
delivered by Shimano Di2 Cyber Nexus Groupset

a photo essay by André Jute

http://members.lycos.co.uk/fiultra/B...igator%20L700%....

My Trek is the 3400 - nice sensible road bike. Looks very similar to
that, but without the chain guard. Doesn't have all that dodgy brake
stuff, either. A reasonably heavy stop (say from 20mph in 5 seconds)
only needs to dissipate 3kJ at 600W, which is no problem at all to
dissipate in a pair of wheel rims.

d

--
Pearce Consultinghttp://www.pearce.uk.com

Those brakes aren't dodgy, Don, they're hyper-competent; what I forgot
to add is that they have a built-in modulator. They stop the one-
eighth of a ton of me and the bike and light touring gear from thirty
kph in 11 feet. I know, because I chewed up a pair of tyres while I
practiced that one to perfection. But I agree with you, for casual use
those roller brakes are overkill.

Oops, clearly a typo. My file copy says "24 (!!) feet". Can't account
for what happened to turn the two exclamations into the main
message...

Anyhow, 24 feet from thirty klicks is still very impressive, about a
third better than any rim braked bike would manage, and about a fifth
better than a bike with disc brakes would manage under the same
circumstances . It is all down to the modulator in the roller brake,
which works like ABS on cars, relaxing the brake just before the wheel
starts skidding.

For those of you who want to know the science, here is a reliable
authority on the subject:

"The maximum braking force that can be applied to a vehicle through
its wheels -- the mass of air having its own retarding force -- is
limited by the friction between the tire and the road, and is equal to
the weight of the vehicle multiplied by the coefficient of friction.
On a dry pavement, this coefficient could be as high as 1; with a
coefficient of unity, retardation would be 1g or 32.2ft/s^2 and the
stopping distance in feet would be V^2/29.9 where V is the speed in
mph. I must stress though that this is on an ideal surface such as
does not exist outside a test facility..."
(p98, Designing and Building Special Cars, by Andre Jute, Batsford,
London 1985)

For those without the math, the formula transforms as follows to
permit us to calculate average retardation in fractions of one gravity
when we know the entry speed and the stopping distance:

V^2/(29.9*D)

where V is speed in mph and D is stopping distance in feet. Taking my
example of 24ft from 30kph, we need first to convert 30kph to mph,
which is 18.64mph. So (18.64*18.64)/(29.9*24) gives us an average
retardation for the roller brakes, aided by the anti-skid modulation,
of 0.484g. This may be compared, as above, to around 0.4g achievable
with disc brakes and around 3.5g with the sort of rim brakes usually
fitted to racing bikes.

Going upmarket clearly doesn't mean less efficiency -- quite the
contrary: it means extraordinary efficiency. Those of greater
discrimination, who furthermore spend more money, believe they have a
right to a more pleasing product, In this case I have received
excellent value for my money!

Andre Jute
The trouble with most people is not what they don't know, but what
they know for certain that isn't true. ---Mark Twain

Visit Jute on Amps at http://members.lycos.co.uk/fiultra/


However, you missed the point of the chain guard and the roller
brakes: it isn't just that the brakes are better, and the chain guard
civilized; what matters is that the totally enclosed brakes and the
totally enclosed chain guard make it an allweather bike -- or that
they are put on there because the specification is for an all-weather
bike. Unlike rim brakes, roller brakes are immune to rain.

Of course, a bike like that, in its primary market, The Netherlands,
is intended and taken into one's family as a permanent fixtu it is
not supposed to wear out. Rim brakes in the sort of daily commuter use
a Dutch city bike gets will wear out a pair of rims every second
year, a dangerous business because it isn't always possible to tell
when the rim is worn so thin by the brake blocks that it collapses the
next time you hit a bump in the road.

Finally, rim blocks are dirty and throw off black stuff, not much chop
on a daily commuter bike (which is what my Trek "Smover" pretends to
be whenever the designers glance at the marketing brief).

So, you see, my Smover's specification is quite consistent with the
bike's supposed purpose, and even more so after I patched up overly
sporting ergonomics. I bet your 3400 was sold to you as a "leisure"
bike. I don't suppose either of us uses a bike as heavily as your
median Dutch officeworker.

Andre Jute
Impedance is futile, you will be simulated into the triode of the
Borg. -- Robert Casey

Smooth Mover: bicycle with electronic gearchange and adaptive suspension
 

On Sep 7, 4:02 pm, wrote:
On Thu, 06 Sep 2007 16:27:41 -0700, Andre Jute
wrote:

Techieporn for you.

My Trek Navigator L700 "Smover"
Bicycle with Automatic Gearchange and Electronic Adaptive Suspension
delivered by Shimano Di2 Cyber Nexus Groupset

a photo essay by André Jute

http://members.lycos.co.uk/fiultra/B...igator%20L700%...

Probably could buy a car for what that costs...

Not a new car, MMM.

The quality of the bike will please long after the price is forgotten.

Andre Jute
No real corpses were harmed in the assembly of my golem Worthless
Wieckless. I made him by stuffing a cow's bladder with pig offal. --
CE Statement of Conformity

Smooth Mover: bicycle with electronic gearchange and adaptive suspension
 

On Sep 8, 12:42 am, Eiron wrote:
Andre Jute wrote:
Those brakes aren't dodgy, Don, they're hyper-competent; what I forgot
to add is that they have a built-in modulator. They stop the one-
eighth of a ton of me and the bike and light touring gear from thirty
kph in 11 feet. I know, because I chewed up a pair of tyres while I
practiced that one to perfection. But I agree with you, for casual use
those roller brakes are overkill.

A fat man on a granny bike braking at over 1g!

Find the fat on my pic overlooking Dunworly Bay, several places on my
bike pages, and I won't put you in hospital when I run into you. You
mean an opa bike, not an oma bike (or granny bike as you ignorantly
have it). You wouldn't know either if you saw them, sonny.

Don't the laws of physics apply in Eire these days?

Same as everywhere else. Here is a reliable authority on the subject:

"The maximum braking force that can be applied to a vehicle through
its wheels -- the mass of air having its own retarding force -- is
limited by the friction between the tire and the road, and is equal to
the weight of the vehicle multiplied by the coefficient of friction.
On a dry pavement, this coefficient could be as high as 1; with a
coefficient of unity, retardation would be 1g or 32.2ft/s^2 and the
stopping distance in feet would be V^2/29.9 where V is the speed in
mph. I must stress though that this is on an ideal surface such as
does not exist outside a test facility..."
(p98, Designing and Building Special Cars, by Andre Jute, Batsford,
London 1985)

The math is developed elsewhere, where you can go find it.

--
Eiron.

Do come again, Eiron. It is always a giggle when you take yourself
seriously.

Andre Jute
Impedance is futile, you will be simulated into the triode of the
Borg. -- Robert Casey

Smooth Mover: bicycle with electronic gearchange and adaptive suspension
 

On Sep 8, 1:22 am, (Don Pearce) wrote:
On Sat, 08 Sep 2007 08:42:58 +0100, Eiron wrote:
Andre Jute wrote:

Those brakes aren't dodgy, Don, they're hyper-competent; what I forgot
to add is that they have a built-in modulator. They stop the one-
eighth of a ton of me and the bike and light touring gear from thirty
kph in 11 feet. I know, because I chewed up a pair of tyres while I
practiced that one to perfection. But I agree with you, for casual use
those roller brakes are overkill.

A fat man on a granny bike braking at over 1g!
Don't the laws of physics apply in Eire these days?

Quite so. That comes out at 1.05g. Centre of mass combined with
wheelbase tell us that he performed the last 8 feet of that stop flat
on his face in the road. But that is a perfectly legitimate way of
stopping your bike.

Anyone who wants to do the sum the easy way just pop this

(30 kph)^2 / (2 * 11 ft) in g

What's this nonsense, Don, a wiki written by you and the equally
useless Eiron? Didn't they teach you in tech school to use compatible
units? You're mixing Imperial and Metric measures hand over orange.
Here is a reliable authority on the subject:

"The maximum braking force that can be applied to a vehicle through
its wheels -- the mass of air having its own retarding force -- is
limited by the friction between the tire and the road, and is equal to
the weight of the vehicle multiplied by the coefficient of friction.
On a dry pavement, this coefficient could be as high as 1; with a
coefficient of unity, retardation would be 1g or 32.2ft/s^2 and the
stopping distance in feet would be V^2/29.9 where V is the speed in
mph. I must stress though that this is on an ideal surface such as
does not exist outside a test facility..."
(p98, Designing and Building Special Cars, by Andre Jute, Batsford,
London 1985)

That math is properly and correctly developed elsewhere in this
thread, where you can go find it.

into Google. I rarely use an other calculator these days.

You should learn how and you won't perpetrae further ****ups like in
this post.

Andre Jute
Our legislators managed to criminalize fox-hunting and smoking; when
they will get off their collective fat backside and criminalize
negative feedback? It is clearly consumed only by thickoes.

Smooth Mover: bicycle with electronic gearchange and adaptive suspension
 

On Sat, 08 Sep 2007 17:44:24 -0700, Andre Jute
wrote:

On Sep 8, 1:22 am, (Don Pearce) wrote:
On Sat, 08 Sep 2007 08:42:58 +0100, Eiron wrote:
Andre Jute wrote:

Those brakes aren't dodgy, Don, they're hyper-competent; what I forgot
to add is that they have a built-in modulator. They stop the one-
eighth of a ton of me and the bike and light touring gear from thirty
kph in 11 feet. I know, because I chewed up a pair of tyres while I
practiced that one to perfection. But I agree with you, for casual use
those roller brakes are overkill.

A fat man on a granny bike braking at over 1g!
Don't the laws of physics apply in Eire these days?

Quite so. That comes out at 1.05g. Centre of mass combined with
wheelbase tell us that he performed the last 8 feet of that stop flat
on his face in the road. But that is a perfectly legitimate way of
stopping your bike.

Anyone who wants to do the sum the easy way just pop this

(30 kph)^2 / (2 * 11 ft) in g

What's this nonsense, Don, a wiki written by you and the equally
useless Eiron? Didn't they teach you in tech school to use compatible
units? You're mixing Imperial and Metric measures hand over orange.
Here is a reliable authority on the subject:

"The maximum braking force that can be applied to a vehicle through
its wheels -- the mass of air having its own retarding force -- is
limited by the friction between the tire and the road, and is equal to
the weight of the vehicle multiplied by the coefficient of friction.
On a dry pavement, this coefficient could be as high as 1; with a
coefficient of unity, retardation would be 1g or 32.2ft/s^2 and the
stopping distance in feet would be V^2/29.9 where V is the speed in
mph. I must stress though that this is on an ideal surface such as
does not exist outside a test facility..."
(p98, Designing and Building Special Cars, by Andre Jute, Batsford,
London 1985)

That math is properly and correctly developed elsewhere in this
thread, where you can go find it.

into Google. I rarely use an other calculator these days.

You should learn how and you won't perpetrae further ****ups like in
this post.

Andre Jute
Our legislators managed to criminalize fox-hunting and smoking; when
they will get off their collective fat backside and criminalize
negative feedback? It is clearly consumed only by thickoes.


Google handles mixed units perfectly happily. That is one of its
biggest joys. The calculation works BECAUSE I included the units;
without them it would have assumed they were dimensionless numbers,
and failed. Try it before you condemn through ignorance.

While what you quote about the maximum braking force above is all fine
and dandy as far as it goes, it ignores the fact that a bike is tall
with respect to its wheelbase, and any attempt to approach that
maximum will result in it toppling. As I said, at 1g, you will be face
down in the road. Eiron actually tried the experiment and found an
empirical limit at about 0.35g, and my back-of-an-envelope
calculations show him to be pretty much spot on.

d

--
Pearce Consulting
http://www.pearce.uk.com

Smooth Mover: bicycle with electronic gearchange and adaptive suspension
 

On Sat, 08 Sep 2007 17:39:11 -0700, Andre Jute
wrote:

On Sep 8, 12:42 am, Eiron wrote:
Andre Jute wrote:
Those brakes aren't dodgy, Don, they're hyper-competent; what I forgot
to add is that they have a built-in modulator. They stop the one-
eighth of a ton of me and the bike and light touring gear from thirty
kph in 11 feet. I know, because I chewed up a pair of tyres while I
practiced that one to perfection. But I agree with you, for casual use
those roller brakes are overkill.

A fat man on a granny bike braking at over 1g!

Find the fat on my pic overlooking Dunworly Bay, several places on my
bike pages, and I won't put you in hospital when I run into you. You
mean an opa bike, not an oma bike (or granny bike as you ignorantly
have it). You wouldn't know either if you saw them, sonny.

Don't the laws of physics apply in Eire these days?

Same as everywhere else. Here is a reliable authority on the subject:

"The maximum braking force that can be applied to a vehicle through
its wheels -- the mass of air having its own retarding force -- is
limited by the friction between the tire and the road, and is equal to
the weight of the vehicle multiplied by the coefficient of friction.
On a dry pavement, this coefficient could be as high as 1; with a
coefficient of unity, retardation would be 1g or 32.2ft/s^2 and the
stopping distance in feet would be V^2/29.9 where V is the speed in
mph. I must stress though that this is on an ideal surface such as
does not exist outside a test facility..."
(p98, Designing and Building Special Cars, by Andre Jute, Batsford,
London 1985)

The math is developed elsewhere, where you can go find it.


Go and ask your driver. He will put you straight about braking.

d

--
Pearce Consulting
http://www.pearce.uk.com