K
Ken
Guest
<[email protected]> wrote in message
news:[email protected]...
> Hi everyone,
>
> Around here the roads have a very coarse texture that causes a lot of
> drag. Occasionally I happen across a new section of asphalt, and the
> difference is very noticable. The coarseness is hard to describe but
> I'd say the trough-to-valleys of the road "chunks" is between 5mm-10mm
> and the depth of the valleys is 5mm-10mm as well more or less
> constantly. In the middle of the road where the car tires (studded in
> winter) don't spend as much time it is much smoother, but riding in the
> middle of the road isn't such a good idea...
>
> I've read numerous sites and articles about rolling resistance and
> tires pressures, but none make any mention of effects of varying
> degrees of road surface roughness. The rough roads I'm thinking about
> cause the whole bike to vibrate quite a bit. It is difficult for me to
> read my HR monitor due to the shaking. It feels like the bike is
> bumping up and down over every little pebble embedded in the asphalt.
> In this sense, rolling resistance isn't just the deforamtion of the
> tire, but the displacement (upward) of the whole bike and the force
> needed to plow over this surface.
>
> Would less tire pressure perhaps make more sense under these
> conditions? Such that the tire deforms more around the texture. In
> other words, what is worse, resistance form deforming tires, or
> resistance for bumping up and down 10mm every 10mm ridden? I am over
> 100kg so I am also interested in how this may affect things. Comfort
> and pinch flats is a whole different issue, as is large air chambers
> from tubulars vs smaller for clichers. I'm concerned with clichers for
> now.
>
> Anyone have any suggestions or info/links on how pressue and rough
> surface work togther?
>
> Thanks!
>
> Joseph
>
Ah sounds like the same type of roads I ride on. Here I believe the roads
are made of a mixture of asphalt and broken sea shells, and this makes for a
very rough ride. You are right about riding where the cars drive and being
smoother. But riding tthere is not safe. But I have tried different
pressures in my tire and it seems to me that lower the pressure will only
increase the rolling resistance, therefore this makes little sense.
Ken
news:[email protected]...
> Hi everyone,
>
> Around here the roads have a very coarse texture that causes a lot of
> drag. Occasionally I happen across a new section of asphalt, and the
> difference is very noticable. The coarseness is hard to describe but
> I'd say the trough-to-valleys of the road "chunks" is between 5mm-10mm
> and the depth of the valleys is 5mm-10mm as well more or less
> constantly. In the middle of the road where the car tires (studded in
> winter) don't spend as much time it is much smoother, but riding in the
> middle of the road isn't such a good idea...
>
> I've read numerous sites and articles about rolling resistance and
> tires pressures, but none make any mention of effects of varying
> degrees of road surface roughness. The rough roads I'm thinking about
> cause the whole bike to vibrate quite a bit. It is difficult for me to
> read my HR monitor due to the shaking. It feels like the bike is
> bumping up and down over every little pebble embedded in the asphalt.
> In this sense, rolling resistance isn't just the deforamtion of the
> tire, but the displacement (upward) of the whole bike and the force
> needed to plow over this surface.
>
> Would less tire pressure perhaps make more sense under these
> conditions? Such that the tire deforms more around the texture. In
> other words, what is worse, resistance form deforming tires, or
> resistance for bumping up and down 10mm every 10mm ridden? I am over
> 100kg so I am also interested in how this may affect things. Comfort
> and pinch flats is a whole different issue, as is large air chambers
> from tubulars vs smaller for clichers. I'm concerned with clichers for
> now.
>
> Anyone have any suggestions or info/links on how pressue and rough
> surface work togther?
>
> Thanks!
>
> Joseph
>
Ah sounds like the same type of roads I ride on. Here I believe the roads
are made of a mixture of asphalt and broken sea shells, and this makes for a
very rough ride. You are right about riding where the cars drive and being
smoother. But riding tthere is not safe. But I have tried different
pressures in my tire and it seems to me that lower the pressure will only
increase the rolling resistance, therefore this makes little sense.
Ken