Mildenhall today.

Simon Brooke said:

Quoted message said:

I can understand that a single thing might be stronger than two
slimmer ones, but what I don't understand is how the bit where the
horizontal hub meets the vertical blade could possibly be stronger
when there's one blade than two.

In the case of one, there's a lever trying its best to snap the tip
off the blade.

Just like there is on all four wheels of your car. Quick! You need to go
out and weld extra struts down the outside of each wheel before they
snap off!

I'm not denying it works - obviously it does. My Vespa had one-sided
hubs, and so does my C1, but they're all made of thick metal. I just
don't understand how. I can easily make something that looks a bit like
a traditional bike fork - from Lego, from a couple of bits of wood, or
even from some metal if I happened to have some suitable bits lying
around and didn't mind getting blood on my shirt - and in each case I'd
be able to build a strong one much more easily the traditional way than
the monoblade way.

Daniele
--
Apple Juice Ltd
Chapter Arts Centre
Market Road www.apple-juice.co.uk
Cardiff CF5 1QE 029 2019 0140

"James Annan" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Mark South said:

It's not linear. It's diameter^4.

Since I've already corrected this error it is odd that you are so
determined to repeat it.

We were talking about the resistance of a tube to bending. The deflection per
applied load scales inversely with the quartic of the outside diameter.
--
Mark South, Super Genius: World Citizen, Net Denizen

Mark South said:

We were talking about the resistance of a tube to bending. The deflection per
applied load scales inversely with the quartic of the outside diameter.

I think you need a better advanced physics textbook (or even a rather
elementary one).

James
PS Quartic is for a solid tube, cubic for a hollow one (of fixed wall
thickness).
--
If I have seen further than others, it is
by treading on the toes of giants.
http://www.ne.jp/asahi/julesandjames/home/

Simon Brooke said:

in message
<[email hidden]>,

D.M. Procida (') said:

I can understand that a single thing might be stronger than two
slimmer ones, but what I don't understand is how the bit where the
horizontal hub meets the vertical blade could possibly be stronger
when there's one blade than two.

In the case of one, there's a lever trying its best to snap the tip
off the blade.

Just like there is on all four wheels of your car. Quick! You need to go
out and weld extra struts down the outside of each wheel before they
snap off!

Seems to me that Daniele was asking a serious question. It also seems to
me that you'd rather mock him than answer him, which is a shame.

--
Keith Willoughby http://flat222.org/keith/
Michael, they have taken you away

Alan Braggins [email hidden] opined the following...

Quoted message said:

Do you mean "not racing uprights" or "not high speed uprights" or something
similar? (Do UCI rules require conventional two-sided supports for wheels?)

I do indeed. I would have expected to see it migrate to conventional
bikes (ie. not odd MB freight thingies ;-0 ) but it doesn't appear to be
as useful from the manufacturing POV. I think that there might be an
issue WRT components, and ease of sourcing them.

Quoted message said:

Why would an upright with an offset rear wheel suffer from high speed
cornering problems if a recumbent like the Ratcatcher doesn't?
(Assuming it doesn't - I haven't seen one cornering at speed, but I believe
it does - I suppose that could be the skill of the rider overcoming problems
that make it generally unusable though.)

Not sure actually. It's possible that the lower CoG of the recumbents
might make life easier, but I guess that it's easier to move the CoG
around on an upright. It's basically a gut feeling, but without breaking
out the welder I'm not sure that I can test it.

Jon

the.Mark [email hidden] opined the following...

Quoted message said:

I used to have a folding bike about 30 years ago that I would ride with the
hinge loose. It was rideable with the front wheel up to about 4 or 5 inches
out from the centre without much difficulty. I think it was a Polish make.

Now I think about it, I've ridden Wobbly John's wobbly bike which can be
ridden with the rear wheel tracking at least a foot to either the left
or right of the front (I can't ride it that well, but did manage to ride
it and steer which impressed me!).

Jon

Peter Clinch [email hidden] opined the following...

Quoted message said:

I'm less interested in the formulae than looking at examples and /seeing
them work in actuality/. I understand the technology of mechanical
watches much better than cesium clocks, but that doesn't prevent me from
realising that properly implemented a cesium clock actually tells the
right time!

This is fine, but those of us who display a mildly cynical nature prefer
to understand, rather than simply accept. Thus I admire Mike Burrow's
innovative designs and eloquent justifications, but still question the
advantages.

Mike's retort to the question "why monoblades?" is "why not
monoblades?". This is entertaining, but doesn't offer a very good
starting point. If you can argue for them from the assumption that they
are a good thing, you're doing the same as arguing in favour of forks
from the same basis.

It'd be better to say: "These are an intrinsically better design because
of X".

Jon

Simon Brooke [email hidden] opined the following...

Quoted message said:

Yes, but you don't win race after race after race against the best
competition in the world by marketing.

No. You win them by making sure that you get to supply bikes for the
best riders!

Quoted message said:

Why on earth should it prefer to turn in either direction? My Cannondale
has no bias. Why should it have?

I think Mark misunderstands the lefty here, unlike the rear mounts on
beasts like the Ratcatcher, it is not off centre.

Jon

[email hidden] (D.M. Procida) wrote in message news:<[email hidden]>...

Quoted message said:

I can understand that a single thing might be stronger than two slimmer
ones, but what I don't understand is how the bit where the horizontal
hub meets the vertical blade could possibly be stronger when there's one
blade than two.

It isn't.

The wheel axle is cantilevered out from the fork, this is intrinsically a
weaker design than supporting it at both ends. But this is (apparently) not
an important weakness in the overall system. The monoblade is better at
resisting fore-aft bending moments and this is (probably, I can't claim
any particular expertise) the major loading that determines the design.

For torsion, side loading, and the bending moment on the axle which you
highlight above, the monoblade is generally worse, but these don't matter
too much.

James

Jon Senior said:

No. You win them by making sure that you get to supply bikes for the
best riders!

Though with MTBs there is actually far more tangible difference between
individual bikes than is the case with UCI road racers, where the whole
/point/ of all the baroque regulations is to ensure that the machinery
is more or less the same.

And why would the best riders want to ride anything that dented their
chances of competing as well as possible? The best riders should have
their pick of rides, because they'll want to win.

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/

Mark South said:

If you persist in caricaturing my questions that's your choice.

If you persist in blaming the messengers for pointing out your
dismissals of real life examples are dopey and/or straw men, that's yours...

Being an aggressive arguer it's not entirely unusual that I have to take
stock and issue an apology for tone, but in this case we're very, very
far out in "pot calling kettle black" territory!

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/

Jon Senior said:

This is fine, but those of us who display a mildly cynical nature prefer
to understand, rather than simply accept. Thus I admire Mike Burrow's
innovative designs and eloquent justifications, but still question the
advantages.

Quite so, but writing things off because they don't "seem right", or you
can't find the Magic Factor X during a non-expert chat is only part of
the story, especially when people are riding around on the things in
question. Mark was dismissing working examples as irrelevant to showing
they actually do work, which is what I was taking issue with.

Burrows isn't the /only/ person making monoblades, and the question may
actually be put better to scooter and m/cycle engineers who've been
using them for years, one presumes with some sort of reasoning.

Quoted message said:

Mike's retort to the question "why monoblades?" is "why not
monoblades?". This is entertaining, but doesn't offer a very good
starting point.

Actually, I think it may... If examples aren't enough, then all the
working examples of "normal" forks don't count either! In other words,
we know that both sorts actually can be made in practice, so can you
justify the use of stereo forks over monoblades?

Quoted message said:

If you can argue for them from the assumption that they
are a good thing, you're doing the same as arguing in favour of forks
from the same basis.

It'd be better to say: "These are an intrinsically better design because
of X".

Yes, so why are stereo forks intrinsically better, aside from
availability? Easier to support the wheel though not as strong, but I
get there by just inverting the monoblade arguments...

I'm not convinced they are a Clear Win, but I am convinced, through
actual examples, that they are viable and work in the implementations
I've seen. Yesterday Mark was arguing against even that.

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/

Simon Brooke said:

in message <[email hidden]>, Dave Larrington

Quoted message said:

Quoted message said:

See also here:

<URL:

legslarry.beerdrinkers.co.ukbucher.jpg>Open ↗

Quoted message said:

Stereo fork but the rear swing-arm is offset and the wheels in line

Now is that nice or is that nice?

What is it, and how many grandmothers does one have to push over
cliffs to get one?

'tis a homebuilt by a German chap, one Clemens Bucher. Carbon main frame
member, ally swing arm, fully-enclosed transmission with Sachs 3x7 at the
crossover. Photo taken in 1997 at the Worlds in Cologne.

--

Dave Larrington - http://www.legslarry.beerdrinkers.co.uk/
===========================================================
Editor - British Human Power Club Newsletter
http://www.bhpc.org.uk/
===========================================================

In article said:

as useful from the manufacturing POV. I think that there might be an
issue WRT components, and ease of sourcing them.

Absolutely, as mentioned earlier. They won't be really widely used until
they are cheap, and they won't be really cheap until they are widely used.
But they might get gradually cheaper and more widely used together.

Alan Braggins said:

Absolutely, as mentioned earlier. They won't be really widely used until
they are cheap, and they won't be really cheap until they are widely used.
But they might get gradually cheaper and more widely used together.

Quite possibly. c.f. recumbent cycles, hydraulic disc brakes, superhub
gearing, high quality lighting, and in the past, alloy wheels,
derailleur gears, aluminium frames, etc. etc.

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/

in message <[email hidden]>, Jon Senior

jon_AT_restlesslemon_DOTco_DOT_uk ('') said:

Mike's retort to the question "why monoblades?" is "why not
monoblades?". This is entertaining, but doesn't offer a very good
starting point. If you can argue for them from the assumption that
they are a good thing, you're doing the same as arguing in favour of
forks from the same basis.

It'd be better to say: "These are an intrinsically better design
because of X".

All engineering is compromise. The compromise in fork design is between
larger stansions (stronger), support at both ends (removes torsional
stresses at the tip), aerodynamic drag, and weight.

The monoblade allows you to have a larger, stronger stansion and thus
less weight, but at the cost of requiring you to cope with torsional
loading at the tip. Provided you do this adequately it's a good
compromise, and can also contribute to reducing aerodynamic drag.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/
;; If God does not write LISP, God writes some code so similar to
;; LISP as to make no difference.

in message <[email hidden]>, Keith Willoughby

(') said:

Simon Brooke said:

in message

<[email hidden]>,

Quoted message said:

Quoted message said:

D.M. Procida (') said:

I can understand that a single thing might be stronger than two
slimmer ones, but what I don't understand is how the bit where the
horizontal hub meets the vertical blade could possibly be stronger
when there's one blade than two.

In the case of one, there's a lever trying its best to snap the tip
off the blade.

Just like there is on all four wheels of your car. Quick! You need to
go out and weld extra struts down the outside of each wheel before
they snap off!

Seems to me that Daniele was asking a serious question. It also seems
to me that you'd rather mock him than answer him, which is a shame.

It's a perfectly serious answer. The engineering of the stub axle on a
monoblade is very much the same as the engineering of the stub axle on
a car - no more complex and no weaker. There's a good, clear structural
diagram here:
<URL:http://www.cannondale.com/bikes/innovation/archive/leftyjake.html#structure>

This is of course a suspension monoblade, which is inevitably much more
complex than one without suspension.

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

;; how did we conclude that a [censored] cartoon mouse is deserving
;; of 90+ years of protection, but a cure for cancer, only 14?
-- user 'Tackhead', in /. discussion of copyright law, 22/05/02

Simon Brooke said:

in message <[email hidden]>, Keith Willoughby

(') said:

Simon Brooke said:

in message
> In the case of one, there's a lever trying its best to snap the tip
> off the blade.

Just like there is on all four wheels of your car. Quick! You need to
go out and weld extra struts down the outside of each wheel before
they snap off!

Seems to me that Daniele was asking a serious question. It also seems
to me that you'd rather mock him than answer him, which is a shame.

It's a perfectly serious answer.

No. It was a perfectly mocking answer to a straw man. (Daniele didn't
seem to be claiming that a monofork was weaker; he just wanted to know
how it wasn't.)

Quoted message said:

The engineering of the stub axle on a monoblade is very much the same
as the engineering of the stub axle on a car - no more complex and no
weaker.

So, how does that work then?

Quoted message said:

There's a good, clear structural diagram here:
<URL:http://www.cannondale.com/bikes/innovation/archive/leftyjake.html#structure>
complex than one without suspension.

Looks like the answer is a much thicker hub at the point it joins to the
fork. Thanks.

--
Keith Willoughby http://flat222.org/keith/
Oh. Dog and a beer.

Keith Willoughby said:

Looks like the answer is a much thicker hub at the point it joins to
the fork. Thanks.

Thicker axle in the case of the monoblade on Cosimo. It's about a 20 mm
diameter tube, relatively thin walls compared with a standard axle.

--

Dave Larrington - http://www.legslarry.beerdrinkers.co.uk/
===========================================================
Editor - British Human Power Club Newsletter
http://www.bhpc.org.uk/
===========================================================