wheel sizes on trailers

[Emanuel Berg]

I have four bicycle trailers. But I have
modified them so it is not possible to connect
them to bikes anymore, at least not the way it
was intended, as I have cut that part of the
front tube. This makes it easier to pull and
also when you have them all around moving
around and between them is easier without this
protruding/annoying part.

The trailers are very good for pulling.
For example, in one trailer one can pack 40-50
pieces of firewood!

Here [1] is what they look like.

Anyway, today I examined the tire sizes.
They are

2* 47-305 (16x1.75x2)
44-305 (16x1.75)
2 - 19 3/4 (24x2) (50-507?)

Here, we remember the interesting formula

roll-out = chainring/sprocket * wheel

However having neither chainring or sprocket,
what impact does the bicycle trailer wheel size
has, and how does that work? Impact not on the
bike but in general, I mean?

[1] http://user.it.uu.se/~embe8573/work-photos/supertramp-1.jpg
http://user.it.uu.se/~embe8573/work-photos/moasen-wood.jpg

--
underground experts united
http://user.it.uu.se/~embe8573

[James]

On 08/01/18 09:31, Emanuel Berg wrote:
>
> However having neither chainring or sprocket,
> what impact does the bicycle trailer wheel size
> has, and how does that work? Impact not on the
> bike but in general, I mean?
>
> [1] http://user.it.uu.se/~embe8573/work-photos/supertramp-1.jpg
> http://user.it.uu.se/~embe8573/work-photos/moasen-wood.jpg
>

The smaller the wheel the less easily it will be to pull it over a hard
bump. Imagine the wheel was the same radius as a brick. If you pull
the trailer and the wheel strikes a brick it will not naturally lift up
and over the brick. Now imagine the wheel radius is many times that of
the height of the brick. If you pull the trailer and the bigger wheel
hits a brick it will naturally ride up and over the brick.

Bearing friction is hardly a factor.

"For pneumatic tires on hard pavement, it is reported that the effect of
diameter on rolling resistance is negligible (within a practical range
of diameters).[33][34]"

https://en.wikipedia.org/wiki/Rolling_resistance

--
JS

[Emanuel Berg]

James wrote:

> The smaller the wheel the less easily it will
> be to pull it over a hard bump. Imagine the
> wheel was the same radius as a brick. If you
> pull the trailer and the wheel strikes
> a brick it will not naturally lift up and
> over the brick. Now imagine the wheel radius
> is many times that of the height of the
> brick. If you pull the trailer and the bigger
> wheel hits a brick it will naturally ride up
> and over the brick.
>
> Bearing friction is hardly a factor.
>
> "For pneumatic tires on hard pavement, it is
> reported that the effect of diameter on
> rolling resistance is negligible (within
> a practical range of diameters)."

OK, great.