Kit 2 convert front of upright bike to 2 wheels?

I know there's a kit to convert the rear of an upright bike to two wheels and wonder if tthere's one to convert the front to two wheels as the two front wheels trikes are said to be a lot more stable tthan tthe two rear wheels trikes are. Anyone know of a two wheels front conversion?

Cheers

On Sunday, April 19, 2015 at 7:46:56 PM UTC-4, Sir Ridesalot wrote:
I know there's a kit to convert the rear of an upright bike to two wheels and wonder if tthere's one to convert the front to two wheels as the two front wheels trikes are said to be a lot more stable tthan tthe two rear wheels trikes are. Anyone know of a two wheels front conversion?

Cheers

http://goo.gl/5lBw5i

a larger front tire than rear ....

On Sun, 19 Apr 2015 16:46:54 -0700 (PDT), Sir Ridesalot
wrote:

I know there's a kit to convert the rear of an upright bike to two wheels
and wonder if tthere's one to convert the front to two wheels as the
two front wheels trikes are said to be a lot more stable tthan tthe
two rear wheels trikes are. Anyone know of a two wheels front conversion?

http://www.core77.com/posts/18082/triblean-retrofit-kit-makes-tricycles-for-grown-ups-18082
A variation of the design was sold by Onya Cycles of San Francisco as
a cargo bike, but that seems to have disappeared.

I don't believe that such an reversed tricycle derangement is more
stable. The problem is keeping all 3 wheels on the ground. If you
loose traction on a conventional tricycle, on one of the rear drive
wheels, you still travel in roughly the forward direction. However,
if you lift one of the two articulated steering wheels on a reverse
tricycle, the handlebars are going to turn inward, pivoting on the
wheel still on the ground, and you'll either crash or loose control.
That's why the Triblean retrofit kit needed the kinematic nightmare in
order to be usable.

If you really want "stability", perhaps a gyroscope might be more
appropriate:
https://www.kickstarter.com/projects/529668138/jyrobike-auto-balance-bicycle
http://shop-us.jyrobike.com
or maybe a retrofit:
https://grabcad.com/library/gyroscopic-bike-stabilizer

This replacement wheel appears to be defunct, but might be raised from
the dead:
http://www.singletracks.com/blog/mtb-gear/gyroscopic-bike-wheel-wont-let-you-fall/

This isn't exactly a gyro stabilizer, but can probably be modified to
provide some stabilization:
http://www.gizmag.com/flywheel-bicycle-regenerative-braking/19532/

Or, just buy an ErockIT:
http://techcrunch.com/2011/02/11/segway-2-0-german-bicycle-on-steriods-comes-to-the-us/
http://www.gizmag.com/the-erockit--50-mph-pedal-electric-hybrid-motorcycle/9528/
Notice that the riders feet never hit the ground, which suggests that
it might be gyro stabilized, but I'm not sure. The domain seems to
have expired, so who knows if this one will ever hit the market.



--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On 4/19/2015 10:18 PM, Jeff Liebermann wrote:
On Sun, 19 Apr 2015 16:46:54 -0700 (PDT), Sir Ridesalot
wrote:

I know there's a kit to convert the rear of an upright bike to two wheels
and wonder if tthere's one to convert the front to two wheels as the
two front wheels trikes are said to be a lot more stable tthan tthe
two rear wheels trikes are. Anyone know of a two wheels front conversion?

http://www.core77.com/posts/18082/triblean-retrofit-kit-makes-tricycles-for-grown-ups-18082
A variation of the design was sold by Onya Cycles of San Francisco as
a cargo bike, but that seems to have disappeared.

I don't believe that such an reversed tricycle derangement is more
stable. The problem is keeping all 3 wheels on the ground. If you
loose traction on a conventional tricycle, on one of the rear drive
wheels, you still travel in roughly the forward direction. However,
if you lift one of the two articulated steering wheels on a reverse
tricycle, the handlebars are going to turn inward, pivoting on the
wheel still on the ground, and you'll either crash or loose control.
That's why the Triblean retrofit kit needed the kinematic nightmare in
order to be usable.

I'm pretty sure that a trike with two front wheels (i.e. a tadpole
trike) is much more stable than a single front wheel trike (i.e. a delta
trike). The big difference comes when a person "overcooks a turn,"
entering it too fast. The natural response is to brake, which (in
common parlance) throws the rider's weight forward and toward the
outside of the turn. A tadpole trike has a front wheel in a position to
resist the resultant tipping; a delta trike does not.

Regarding the kinematic nightmare in the triblean, my guess is that it's
needed only to allow leaning into the curve. That's probably necessary
for sporting riding, but perhaps not for slow puttering. I doubt it has
anything to do with handlebar reaction torques, which is what I think
you're describing with "handlebars turn inward." I'd think that aspect
could be controlled by the proper choice of steering trail and other
geometry.

Anybody got a link to the details of the tilting front suspension as
used on things like Piaggio scooters? Those seem to work quite well,
although I've never had a chance to test one.


--
- Frank Krygowski

On Mon, 20 Apr 2015 10:52:09 -0400, Frank Krygowski
wrote:

I'm pretty sure that a trike with two front wheels (i.e. a tadpole
trike) is much more stable than a single front wheel trike (i.e. a delta
trike). The big difference comes when a person "overcooks a turn,"
entering it too fast. The natural response is to brake, which (in
common parlance) throws the rider's weight forward and toward the
outside of the turn. A tadpole trike has a front wheel in a position to
resist the resultant tipping; a delta trike does not.

On thinking it over again, I have to admit that you're correct.

I happen to be currently looking for a tricycle or tricycle conversion
for a friend who has balance problems. Stability is a major concern
so I did some test rides on prospective used bicycles to see how they
feel. I haven't ridden a tricycle for many years and had no idea how
it would ride. I certainly had problems in a turn, especially on
non-level ground as you describe and agree that reversing the wheel
arrangement would help. This also agrees with the conventional
wisdom:
http://auto.howstuffworks.com/three-wheel-car4.htm
It's probably similar to blowing a tire on a automobile. If I lose a
rear tire, the car will skid somewhat. If the engine is still
running, some control can be maintained using the front wheels.
However, if a front tire blows, the car will turn in the direction of
the blown tire, and possibly roll by tripping over the blown tire.

However, I'm worried about how a tadpole arrangement would work on a
downhill run. With most of the weight towards the front, I suspect
that it might cause both wheels to swing in the direction of the turn,
and then pitch pole forward. The area where we live doesn't have any
flat terrain. The only way I can be sure is to try it. I don't have
such a machine, so this is only a guess(tm).

Also, I'm worried about what a tadpole arrangement might do without
the articulated arrangement, where one wheel might lift off the
ground. Again, I would need to try it.

Regarding the kinematic nightmare in the triblean, my guess is that it's
needed only to allow leaning into the curve. That's probably necessary
for sporting riding, but perhaps not for slow puttering.

Agreed, although I think the kinematic nightmare might have steering
and control benefits by keeping all 3 wheels on the ground on rough
and uneven roads.

I doubt it has
anything to do with handlebar reaction torques, which is what I think
you're describing with "handlebars turn inward."

Yep. Part of stability is control. It's difficult to tell from the
photos, but it looks like the equivalent of the head tube angle might
be more vertical than the usual 65 to 75 degrees:
http://www.core77.com/posts/18082/triblean-retrofit-kit-makes-tricycles-for-grown-ups-18082
With no hands on the handlebars, my guess(tm) is that it won't go in a
straight line. However, with the different turning radii of the two
front wheels, I don't have a clue what it might do in a sharp turn.

I'd think that aspect
could be controlled by the proper choice of steering trail and other
geometry.

Certainly. A very relaxed 65 degree head tube angle and large front
fork offset (rake) would certainly help. However, too much of these
will make the machine difficult to turn, with the turning resistance
being twice that of a conventional 2 wheel bicycle because one has to
turn two wheels.

Anybody got a link to the details of the tilting front suspension as
used on things like Piaggio scooters? Those seem to work quite well,
although I've never had a chance to test one.

Not me, but there might be something on 3 wheel motorcycle
conversions.



--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On 4/20/2015 1:35 PM, Jeff Liebermann wrote:
On Mon, 20 Apr 2015 10:52:09 -0400, Frank Krygowski
wrote:

I'm pretty sure that a trike with two front wheels (i.e. a tadpole
trike) is much more stable than a single front wheel trike (i.e. a delta
trike). The big difference comes when a person "overcooks a turn,"
entering it too fast. The natural response is to brake, which (in
common parlance) throws the rider's weight forward and toward the
outside of the turn. A tadpole trike has a front wheel in a position to
resist the resultant tipping; a delta trike does not.

On thinking it over again, I have to admit that you're correct.

I happen to be currently looking for a tricycle or tricycle conversion
for a friend who has balance problems. Stability is a major concern
so I did some test rides on prospective used bicycles to see how they
feel. I haven't ridden a tricycle for many years and had no idea how
it would ride. I certainly had problems in a turn, especially on
non-level ground as you describe and agree that reversing the wheel
arrangement would help. This also agrees with the conventional
wisdom:
http://auto.howstuffworks.com/three-wheel-car4.htm
It's probably similar to blowing a tire on a automobile. If I lose a
rear tire, the car will skid somewhat. If the engine is still
running, some control can be maintained using the front wheels.
However, if a front tire blows, the car will turn in the direction of
the blown tire, and possibly roll by tripping over the blown tire.

However, I'm worried about how a tadpole arrangement would work on a
downhill run. With most of the weight towards the front, I suspect
that it might cause both wheels to swing in the direction of the turn,
and then pitch pole forward. The area where we live doesn't have any
flat terrain. The only way I can be sure is to try it. I don't have
such a machine, so this is only a guess(tm).

Also, I'm worried about what a tadpole arrangement might do without
the articulated arrangement, where one wheel might lift off the
ground. Again, I would need to try it.

Regarding the kinematic nightmare in the triblean, my guess is that it's
needed only to allow leaning into the curve. That's probably necessary
for sporting riding, but perhaps not for slow puttering.

Agreed, although I think the kinematic nightmare might have steering
and control benefits by keeping all 3 wheels on the ground on rough
and uneven roads.

I doubt it has
anything to do with handlebar reaction torques, which is what I think
you're describing with "handlebars turn inward."

Yep. Part of stability is control. It's difficult to tell from the
photos, but it looks like the equivalent of the head tube angle might
be more vertical than the usual 65 to 75 degrees:
http://www.core77.com/posts/18082/triblean-retrofit-kit-makes-tricycles-for-grown-ups-18082
With no hands on the handlebars, my guess(tm) is that it won't go in a
straight line. However, with the different turning radii of the two
front wheels, I don't have a clue what it might do in a sharp turn.

I'd think that aspect
could be controlled by the proper choice of steering trail and other
geometry.

Certainly. A very relaxed 65 degree head tube angle and large front
fork offset (rake) would certainly help. However, too much of these
will make the machine difficult to turn, with the turning resistance
being twice that of a conventional 2 wheel bicycle because one has to
turn two wheels.

Anybody got a link to the details of the tilting front suspension as
used on things like Piaggio scooters? Those seem to work quite well,
although I've never had a chance to test one.

Not me, but there might be something on 3 wheel motorcycle
conversions.

As long as we're discussing these things, another disadvantage to 3
wheelers is the need to find not one, not two, but three separate and
properly spaced smooth tracks between the potholes. With the record
crop of potholes in our area, that's no small task.

On a club ride last week, a new guy came along riding his super-low
recumbent trike. It did fine on smooth roads, particularly if they were
downhill. But on one potholey downhill, he screeched to a stop to
recover a taillight that had knocked loose when he couldn't avoid some
bad bumps.

We've got enough potholes that finding one track through, for a
two-wheeler, is sometimes an impossible task. And if that situation
occurs, I can at least stand up, and perhaps jump the bike over a hole.
He had no such defense.

But I can certainly see an upright trike making sense for a person with
balance problems. Heck, I may be in that situation myself, some day.

--
- Frank Krygowski

On 21/04/15 03:35, Jeff Liebermann wrote:
On Mon, 20 Apr 2015 10:52:09 -0400, Frank Krygowski
wrote:


I'd think that aspect
could be controlled by the proper choice of steering trail and other
geometry.

Certainly. A very relaxed 65 degree head tube angle and large front
fork offset (rake) would certainly help. However, too much of these
will make the machine difficult to turn, with the turning resistance
being twice that of a conventional 2 wheel bicycle because one has to
turn two wheels.


ISTM, more rake reduces trail and in fact makes for a less stable
steering geometry. Forks with less rake increases trail because they
put the contact patch further behind the steering axis, rather than
closer to it. There is a small range of trail that, from what I
understand, can provide everything from slow and stable steering to
twitchy and a feeling of instability. Beyond this range may produce
undesirable handling for anyone.

http://www.bikeforums.net/framebuild...-handling.html

--
JS

On Monday, April 20, 2015 at 11:02:33 PM UTC+1, James wrote:
On 21/04/15 03:35, Jeff Liebermann wrote:
On Mon, 20 Apr 2015 10:52:09 -0400, Frank Krygowski
wrote:


I'd think that aspect
could be controlled by the proper choice of steering trail and other
geometry.

Certainly. A very relaxed 65 degree head tube angle and large front
fork offset (rake) would certainly help. However, too much of these
will make the machine difficult to turn, with the turning resistance
being twice that of a conventional 2 wheel bicycle because one has to
turn two wheels.


ISTM, more rake reduces trail and in fact makes for a less stable
steering geometry. Forks with less rake increases trail because they
put the contact patch further behind the steering axis, rather than
closer to it. There is a small range of trail that, from what I
understand, can provide everything from slow and stable steering to
twitchy and a feeling of instability. Beyond this range may produce
undesirable handling for anyone.

http://www.bikeforums.net/framebuild...-handling.html

--
JS

A good test is turning the fork around to face backwards. It is amazing on how many forks, including some touted "scientific" ones, operating the fork rearwards makes no difference to the stability of the bike.

On Monday, April 20, 2015 at 6:23:58 PM UTC-4, Andre Jute wrote:
On Monday, April 20, 2015 at 11:02:33 PM UTC+1, James wrote:
On 21/04/15 03:35, Jeff Liebermann wrote:
On Mon, 20 Apr 2015 10:52:09 -0400, Frank Krygowski
wrote:


I'd think that aspect
could be controlled by the proper choice of steering trail and other
geometry.

Certainly. A very relaxed 65 degree head tube angle and large front
fork offset (rake) would certainly help. However, too much of these
will make the machine difficult to turn, with the turning resistance
being twice that of a conventional 2 wheel bicycle because one has to
turn two wheels.


ISTM, more rake reduces trail and in fact makes for a less stable
steering geometry. Forks with less rake increases trail because they
put the contact patch further behind the steering axis, rather than
closer to it. There is a small range of trail that, from what I
understand, can provide everything from slow and stable steering to
twitchy and a feeling of instability. Beyond this range may produce
undesirable handling for anyone.

http://www.bikeforums.net/framebuild...-handling.html

--
JS

A good test is turning the fork around to face backwards. It is amazing on how many forks, including some touted "scientific" ones, operating the fork rearwards makes no difference to the stability of the bike.

A lot of times turning the fork around means that you can't steer because the wheel now hits the downtube.

Cheers

On Tuesday, April 21, 2015 at 12:02:40 AM UTC+1, Sir Ridesalot wrote:
On Monday, April 20, 2015 at 6:23:58 PM UTC-4, Andre Jute wrote:
On Monday, April 20, 2015 at 11:02:33 PM UTC+1, James wrote:
On 21/04/15 03:35, Jeff Liebermann wrote:
On Mon, 20 Apr 2015 10:52:09 -0400, Frank Krygowski
wrote:


I'd think that aspect
could be controlled by the proper choice of steering trail and other
geometry.

Certainly. A very relaxed 65 degree head tube angle and large front
fork offset (rake) would certainly help. However, too much of these
will make the machine difficult to turn, with the turning resistance
being twice that of a conventional 2 wheel bicycle because one has to
turn two wheels.


ISTM, more rake reduces trail and in fact makes for a less stable
steering geometry. Forks with less rake increases trail because they
put the contact patch further behind the steering axis, rather than
closer to it. There is a small range of trail that, from what I
understand, can provide everything from slow and stable steering to
twitchy and a feeling of instability. Beyond this range may produce
undesirable handling for anyone.

http://www.bikeforums.net/framebuild...-handling.html

--
JS

A good test is turning the fork around to face backwards. It is amazing on how many forks, including some touted "scientific" ones, operating the fork rearwards makes no difference to the stability of the bike.

A lot of times turning the fork around means that you can't steer because the wheel now hits the downtube.

Cheers

That too.

Andre jute