How slick is slick?

I have some quite narrow road tyres on my racer with about 1mm deep tread - I have seen similar
tyres sold as "road" tyres in shops - sometimes they are the only narrow 27" tyres on show (as they
are in the small bike store in Bristol Market).

Would I see a big reduction in rolling resistance if I swapped them for something totally slick?

RC

 

In a brief moment of lucidity CLogicRogerC scribbled:

> I have some quite narrow road tyres on my racer with about 1mm deep tread - I have seen similar
> tyres sold as "road" tyres in shops - sometimes they are the only narrow 27" tyres on show (as
> they are in the small bike store in Bristol Market).
>
> Would I see a big reduction in rolling resistance if I swapped them for something totally slick?
>
> RC

Unlikely .. There's more rubber on the road with a slick, the 'tread' is only used as a method of
displacing any water on the road surface.

--

My house is FOR SALE ... http://tinyurl.com/69r0

 

> In a brief moment of lucidity CLogicRogerC scribbled:
>
>>
>> Would I see a big reduction in rolling resistance if I swapped them for something totally slick?
>>
>> RC
>
> Unlikely .. There's more rubber on the road with a slick, the 'tread' is only used as a method of
> displacing any water on the road surface.

Is the wrong answer. Treaded tyres will normally have much higher rolling resistance than slicks -
see the rec.bicycles.tech FAQ on the subject at http://draco.acs.uci.edu/rbfaq/FAQ/8b.14.html. Tread
is unnecessary on bicycle tyres for water clearance - bicycle tyres cannot aquaplane and tread just
means less contact area. Treaded tyres are best reserved for off-road use -
http://www.sheldonbrown.com/tyres.html

Tony

--
http://www.raven-family.com

"I don't want any yes-men around me. I want everybody to tell me the truth even if it costs them
their job."

Samuel Goldwyn

 

On Sun, 16 Mar 2003 19:59:58 -0000, Tony Raven <[email protected]> wrote:

>
> > Unlikely .. There's more rubber on the road with a slick, the 'tread' is only used as a method
> > of displacing any water on the road surface.
>
> Is the wrong answer. Treaded tyres will normally have much higher rolling resistance than slicks
> - see the rec.bicycles.tech FAQ on the subject at http://draco.acs.uci.edu/rbfaq/FAQ/8b.14.html.
> Tread is unnecessary on bicycle tyres for water clearance - bicycle tyres cannot aquaplane

Well, they _could_ aquaplane, if you were going fast enough.

regards, Ian SMith
--
|\ /| no .sig
|o o|
|/ \|

 

On Sun, 16 Mar 2003 21:38:08 +0000 (UTC), Ian Smith <[email protected]> was popularly supposed
to have said:

>On Sun, 16 Mar 2003 19:59:58 -0000, Tony Raven <[email protected]> wrote:

>>
>> > Unlikely .. There's more rubber on the road with a slick, the 'tread' is only used as a method
>> > of displacing any water on the road surface.
>>
>> Is the wrong answer. Treaded tyres will normally have much higher rolling resistance than slicks
>> - see the rec.bicycles.tech FAQ on the subject at http://draco.acs.uci.edu/rbfaq/FAQ/8b.14.html.
>> Tread is unnecessary on bicycle tyres for water clearance - bicycle tyres cannot aquaplane
>
>Well, they _could_ aquaplane, if you were going fast enough.

"Fast enough" being about 200 MPH, if memory serves.

Anyone got any JATO rockets handy? I think someone here wants to reprise an urban legend...

--
Dan Holdsworth PhD [email protected] By caffeine alone I set my mind in motion, By the
beans of Java do thoughts acquire speed, hands acquire shaking, the shaking becomes a warning, By
caffeine alone do I set my mind in motion

 

In a brief moment of lucidity Tony Raven scribbled:

>> In a brief moment of lucidity CLogicRogerC scribbled:
>>
>>>
>>> Would I see a big reduction in rolling resistance if I swapped them for something totally slick?
>>>
>>> RC
>>
>> Unlikely .. There's more rubber on the road with a slick, the 'tread' is only used as a method of
>> displacing any water on the road surface.
>
> Is the wrong answer. Treaded tyres will normally have much higher rolling resistance than slicks -
> see the rec.bicycles.tech FAQ on the subject at http://draco.acs.uci.edu/rbfaq/FAQ/8b.14.html.
> Tread is unnecessary on bicycle tyres for water clearance - bicycle tyres cannot aquaplane and
> tread just means less contact area. Treaded tyres are best reserved for off-road use -
> http://www.sheldonbrown.com/tyres.html
>
> Tony

That also depends on how treaded they are though ..

--

My house is FOR SALE ... http://tinyurl.com/69r0

 

"Dan Holdsworth" <[email protected]> wrote in message
news:[email protected]nd.ntl. com...
> On Sun, 16 Mar 2003 21:38:08 +0000 (UTC), Ian Smith <[email protected]> was popularly supposed
> to have said:
>
> >
> >Well, they _could_ aquaplane, if you were going fast enough.
>
> "Fast enough" being about 200 MPH, if memory serves.

Don't worry, Dan; Ian seems to like picking nits.

 

"Tony Raven" <[email protected]> wrote in message
news:<[email protected]>...

> > In a brief moment of lucidity CLogicRogerC scribbled:
> >
> >>
> >> Would I see a big reduction in rolling resistance if I swapped them for something totally
> >> slick?
> >>
> >> RC
> >
> > Unlikely .. There's more rubber on the road with a slick, the 'tread' is only used as a method
> > of displacing any water on the road surface.
>
> Is the wrong answer. Treaded tyres will normally have much higher rolling resistance than slicks -
> see the rec.bicycles.tech FAQ on the subject at http://draco.acs.uci.edu/rbfaq/FAQ/8b.14.html.

Given that the OP is already talking about road tyres with a minimal tread, 'much higher rolling
resistance' seems improbable. Sure, the tread doesn't do any good, but I can't see it doing much
harm either.

James

 

[email protected] (CLogicRogerC) wrote in message
news:<[email protected]>...
> I have some quite narrow road tyres on my racer with about 1mm deep tread - I have seen similar
> tyres sold as "road" tyres in shops - sometimes they are the only narrow 27" tyres on show (as
> they are in the small bike store in Bristol Market).
>
> Would I see a big reduction in rolling resistance if I swapped them for something totally slick?
>
> RC

Rolling resistance is a complex area, but rubber thickness and carcass construction play a major
part. You want a tyre with a high Threads per Inch (TPI. Made of cotton something like 280+. Then a
smooth or virtually smooth tread, which is thin.

Of course the downside of a thin rubber tread is the tyre will puncture more.

Then you need to think about the width of the tyre. A 23c tyre will roll a bit better than a 20c,
all other things being equal, this is because the shape of the contact patch.

If you are considering changing tyres firstly, dont expect a massive difference. Secondly, expect a
few more punctures.

Good Luck

 

"James Annan" <[email protected]> wrote in message
news:[email protected]...
> "Tony Raven" <[email protected]> wrote in message
news:<[email protected]>...
>
> Given that the OP is already talking about road tyres with a minimal tread, 'much higher rolling
> resistance' seems improbable. Sure, the tread doesn't do any good, but I can't see it doing much
> harm either.
>

Yes it was interesting to see how *measurably increase rolling resistance* of the quoted URL became
*much higher*. Do we have figures, it would also be nice to see figures for pressure because I'm
pretty sure that low pressure does lead to much higher rolling resistance.

 

Tony Raven wrote:

[snip]

> Is the wrong answer. Treaded tyres will normally have much higher rolling resistance than slicks -
> see the rec.bicycles.tech FAQ on the subject at http://draco.acs.uci.edu/rbfaq/FAQ/8b.14.html.
> Tread is unnecessary on bicycle tyres for water clearance - bicycle tyres cannot aquaplane and
> tread just means less contact area. Treaded tyres are best reserved for off-road use -
> http://www.sheldonbrown.com/tyres.html

Is this /really/ true, in all circumstances ? As a teenager, I used to come off my (Holdsworth) bike
rather too often for comfort in the wet, with the bike sliding away underneath me on the reverse
camber of roundabouts. I then changed to John Bull Road Sprint at the front, and John Bull Safety
Speed at the rear, both of which had a nice diamond pattern on the off-centre part of the tread.
This seemed to do the trick, because after that I never came off in the wet again. The tyres were at
110 and 90 psi, rear and front, respectively.

Philip Taylor

 

[email protected] (Dan Holdsworth) wrote in message
news:<[email protected]nd.ntl.com>...
>
> >> Is the wrong answer. Treaded tyres will normally have much higher rolling resistance than
> >> slicks - see the rec.bicycles.tech FAQ on the subject at
> >> http://draco.acs.uci.edu/rbfaq/FAQ/8b.14.html. Tread is unnecessary on bicycle tyres for water
> >> clearance - bicycle tyres cannot aquaplane
> >
> >Well, they _could_ aquaplane, if you were going fast enough.
>
> "Fast enough" being about 200 MPH, if memory serves.
>

Indeed - the Michelin research team at Clermont-Ferrand did some tests during the development of
Axial Pros, and the speed at which aquaplaning set in was ridiculously high!

David E. Belcher

Dept. of Chemistry, University of York

 

"Philip TAYLOR [PC336/H-XP]" <[email protected]> wrote in message
news:<[email protected]>...

> I then changed to John Bull Road Sprint at the front, and John Bull Safety Speed at the rear, both
> of which had a nice diamond pattern on the off-centre part of the tread. This seemed to do the
> trick, because after that I never came off in the wet again.

It was probably the change of compound rather than tread pattern that made the difference. Some
tyres are poor in the wet regardless of the tread pattern or lack of it.

--
Dave...