M
Michael Press
Guest
In article <[email protected]>,
[email protected] (Jose) wrote:
> On Sat, 14 Jun 2008 11:29:58 -0700, Michael Press <[email protected]>
> wrote:
>
> Hi Michael,
>
> >A good 25 mm wide tire
> >can be built with 127 thread per inch casing. A 28 mm wide
> >is always built with 66 thread per inch casing.
>
> Vittoria Rubino Pro and Pro Tech, 700x28, 120 tpi, 70-115 psi, 230-250
> gr.
I am not saying that Vittoria does, but some companies
fudge the advertised thread per inch. The goal is to
make the sidewalls thin so as to decrease the power
dissipated flexing the sidewalls and the tread.
Some companies have count all the threads in a doubled up
ply and say they have a high tpi rating. But the tire
rides like a garden hose anyway.
The reason that wider tires need stronger thicker side
walls is that the required tensile strength increases
as the curvature decreases. The operative term is
`hoop stress.'
>
> The ContinentalUltraGatorSkin 700x28, and Panaracer Pasela 700x28 also
> come to mind. At the least the Continental has a hight thread count -
> as always...
>
>
> > This difference
> >alone will negate the advantage in width of the 28 mm wide tire.
>
> Not sure what you mean here. I've learned that lower tpi equals more
> confort but less performance. Am I missing something?
I have 25 mm tires on one bike, 28 mm on the other.
There is no discernible difference to me.
Both are good quality slicks with as supple a casing
as possible, but the 28 mm has a thicker casing
that eats up the advantage of the slightly lower
tire pressure.
Thinner side walls, casing, and tread equal more comfort
other things being equal. An honest 127 tpi tire will
deliver comfort and easier rolling because it will deliver
a thinner casing.
> Aramid vs steel bead: besides a slight weigh diference, what
> perceivable diferences do they have?
None that I know of. Aramid bead tires fold nicely
for carrying, but few people really need to carry
a spare tire. Some say the aramid bead will stretch
a bit to make mounting and unmounting easier.
Steel beads do not stretch, and if the tire is a
bear to mount it will remain so.
> >I find 25 mm wide tires to be comfortable.
> >If you want wide tires for comfort, then you need a new frame.
>
> No, I don't think I want a full suspension frame ;-)
I mean a frame with more space for tires.
You're having me on, aren't you?
Try the Avocet Fasgrip. Definitely go for slick tread.
--
Michael Press
[email protected] (Jose) wrote:
> On Sat, 14 Jun 2008 11:29:58 -0700, Michael Press <[email protected]>
> wrote:
>
> Hi Michael,
>
> >A good 25 mm wide tire
> >can be built with 127 thread per inch casing. A 28 mm wide
> >is always built with 66 thread per inch casing.
>
> Vittoria Rubino Pro and Pro Tech, 700x28, 120 tpi, 70-115 psi, 230-250
> gr.
I am not saying that Vittoria does, but some companies
fudge the advertised thread per inch. The goal is to
make the sidewalls thin so as to decrease the power
dissipated flexing the sidewalls and the tread.
Some companies have count all the threads in a doubled up
ply and say they have a high tpi rating. But the tire
rides like a garden hose anyway.
The reason that wider tires need stronger thicker side
walls is that the required tensile strength increases
as the curvature decreases. The operative term is
`hoop stress.'
>
> The ContinentalUltraGatorSkin 700x28, and Panaracer Pasela 700x28 also
> come to mind. At the least the Continental has a hight thread count -
> as always...
>
>
> > This difference
> >alone will negate the advantage in width of the 28 mm wide tire.
>
> Not sure what you mean here. I've learned that lower tpi equals more
> confort but less performance. Am I missing something?
I have 25 mm tires on one bike, 28 mm on the other.
There is no discernible difference to me.
Both are good quality slicks with as supple a casing
as possible, but the 28 mm has a thicker casing
that eats up the advantage of the slightly lower
tire pressure.
Thinner side walls, casing, and tread equal more comfort
other things being equal. An honest 127 tpi tire will
deliver comfort and easier rolling because it will deliver
a thinner casing.
> Aramid vs steel bead: besides a slight weigh diference, what
> perceivable diferences do they have?
None that I know of. Aramid bead tires fold nicely
for carrying, but few people really need to carry
a spare tire. Some say the aramid bead will stretch
a bit to make mounting and unmounting easier.
Steel beads do not stretch, and if the tire is a
bear to mount it will remain so.
> >I find 25 mm wide tires to be comfortable.
> >If you want wide tires for comfort, then you need a new frame.
>
> No, I don't think I want a full suspension frame ;-)
I mean a frame with more space for tires.
You're having me on, aren't you?
Try the Avocet Fasgrip. Definitely go for slick tread.
--
Michael Press