primo comet tyre in uk?

[Kell]

It was only a year or so ago that I first read (think it was a GCN article) that bike tryes (for the city) don't actually benefit from from having tread in any useful way.

Seems counter-intuitive, but the evidence is all there.

 

[Kell]

Tyres grip smooth surfaces, like tarmac, because of the way the rubber interacts with the road at a microscopic level. Unlike car tyres, road bike tyres don’t need patterned tread because a bike never goes fast enough to build up a layer of water under the tyre and skid. The best tyres for road use, therefore, have no pattern on the tread, or only a very light pattern.

From this article: https://totalwomenscycling.com/road...ifier-everything-you-need-to-know-about-tyres

90%+ of the tyres sold to us cycle tourists have utterly useless and counterproductive tread moulded into them.

From this article: https://www.bretonbikes.com/homepag...he-importance-of-tread-pattern-on-cycle-tyres

 

[berlinonaut]

I cant imagine why anyone would run bald tyres out of choice on a bike meant to be used in a city?

I do run Kojaks on my city-Brompton 98% of the year. Fast (for a Brompton tire) and comfy at high pressure. No need for thread in the city. I even use them for touring. The occassional flats are fixed very quickly. I only use other tires when the streets become really dirty or snowy in winter or for touring off the beaten track.

 

[ukoldschool]

I find this all very odd, perhaps I am the only person that encounters mud, leaf debris etc on a seemingly daily basis?
Having just swapped a bald front Marathon racer for a new treaded Marathon plus I can absolutely dispute the idea that a bald tyre feels in any way safer to a treaded one to me.

Also the point about a bald tyre being faster is surely also counter intuitive? a treaded tyre will surely have a smaller contact area with the road that a tyre with no tread whatsoever, and therefore rolling resistance is less with tread (the gaps in the tread must accoutn for 5% or 10%??) all guess work but I know that on my commute across a park and along a cycle path where dogwalkers and tree cover means there is debris everywhere (inclusing bunny hopping unexpected stray tree branches last night in the dark thanks to storm brendon...) and I wouldnt dream of specifically buying a bald tyre for my ride. Perhaps Im insane?

 

[Tenkaykev]

I find this all very odd, perhaps I am the only person that encounters mud, leaf debris etc on a seemingly daily basis?
Having just swapped a bald front Marathon racer for a new treaded Marathon plus I can absolutely dispute the idea that a bald tyre feels in any way safer to a treaded one to me.

Also the point about a bald tyre being faster is surely also counter intuitive? a treaded tyre will surely have a smaller contact area with the road that a tyre with no tread whatsoever, and therefore rolling resistance is less with tread (the gaps in the tread must accoutn for 5% or 10%??) all guess work but I know that on my commute across a park and along a cycle path where dogwalkers and tree cover means there is debris everywhere (inclusing bunny hopping unexpected stray tree branches last night in the dark thanks to storm brendon...) and I wouldnt dream of specifically buying a bald tyre for my ride. Perhaps Im insane?

Yes, it seemed counter intuitive to me.
When I visited the Schwalbe Web site one part of the technical data mentioned that the treads were for decorative purposes, though that may have been referring to a specific model of tyre.

 

[Kell]

When I didn't need to worry about trains, I used to commute by MTB. At first I used the tyres that came with it, and they clearly had a noticeable 'thrum' due to the tread blocks. You could feel them squirming sideways and moving about. And the tread meant that the ride was bumpier and therefore slower than the same bike when I moved to something like a Specialised Nimbus (even though that had some tread pattern).

Obviously, the effects are reduced by less aggressive tread patterns, but all the issues will still affect a city-biased treaded tyre to a lesser degree.

Finally, the point about the contact area - there's been a big shift in thinking about this in pactice on the road.

Maybe in a smooth velodrome, it's correct to think that a hard, thin tyre is fastest, but what actually slows bikes down are the lumps and bumps in the road surface. So just like running knobbly tyres, but the knobbles are on the road, not the tyre. It's this road vibration that slows bikes down

Many road racers have found that moving from a 23mm tyre to a 25mm or even 28mm tyre (at a lower pressure) will offer significantly better (i.e. less) rolling resistance, greater comfort and reduced fatigue.

The attached video explians it far better than I can.


View: https://www.youtube.com/watch?v=yrHxQg1OW0A

 

[Ridgeway]

I find this all very odd, perhaps I am the only person that encounters mud, leaf debris etc on a seemingly daily basis?
Having just swapped a bald front Marathon racer for a new treaded Marathon plus I can absolutely dispute the idea that a bald tyre feels in any way safer to a treaded one to me.

A worn out tyre with a now bald pattern is very different vs a slick tyre that was intended to be slick.

I have Kojak's on my Brompton and find them remarkably grippy, if however i used them in any mud or snow then they'd be useless, a treaded tyre would slightly better than useless but nether the less not practical either.

Old worn out tyres will have a hard rubber compound that will be very unforgiving vs a sticky/soft slick like a Kojak.

My Bromy came with Kojaks and i intended to change them as i thought they wouldn't fit my general purpose needs, however they do and they work very well.

 

[Kell]

I find this all very odd, perhaps I am the only person that encounters mud, leaf debris etc on a seemingly daily basis?
Having just swapped a bald front Marathon racer for a new treaded Marathon plus I can absolutely dispute the idea that a bald tyre feels in any way safer to a treaded one to me.

Mud and leaves are very different.

On mud, you lose grip because your tyre slips on the mud. Therefore a tread would help dig in to the mud and provide grip.

With leaves, you lose grip because the leaves are slippy. This works in two ways against you. One is that in some instances your tyre loses grip with the leaves, but in my experience, it's more often than not that your tyres grip on the leaves, but the leaves lose grip on the road surface. Therefore bald or treaded tyres make no difference.

Tread will help if you need to penetrate the substrate (mud, sand) but in all other instances slicks would be better.

Having said all that... will I buy total slicks next time around? Unsure.

 

[roley poley]

is the solution a wide enough slick centre to allow for banking over on the roads and knobbles on the side walls that only come into play as the tyre presses into squish? That must have been done I am sure I have seen stuff like this or is such a combo poo at both.?

 

[Kell]

is the solution a wide enough slick centre to allow for banking over on the roads and knobbles on the side walls that only come into play as the tyre presses into squish? That must have been done I am sure I have seen stuff like this or is such a combo poo at both.?

Many hybrid tyres have a similar design. A high central ridge that is slick for upright riding in town, with tread patterns around the side.

This isn't the best example I've seen, but illustrates the point.

https://bicycle.kendatire.com/en-us/find-a-tire/bicycle/legacy/kwick-tendril/

 

[berlinonaut]

a treaded tyre will surely have a smaller contact area with the road that a tyre with no tread whatsoever, and therefore rolling resistance is less with tread (the gaps in the tread must accoutn for 5% or 10%??)

eh, no. 😊 Thread doesn't overrule physics. I'd recommend to read the short FAQs on the Schwalbe webpage for the basics of the basics: https://www.schwalbetires.com/tech_info/rolling_resistance It is a complex topic and it is counterinuitive in some aspects.

Perhaps Im insane?

That's for sure!

 

[Tenkaykev]

I'd recommend to read the short FAQs on the Schwalbe webpage for the basics of the basics: https://www.schwalbetires.com/tech_info/rolling_resistance It is a complex topic and it is counterinuitive in some aspects.

That's a very helpful link, I've bookmarked it now so I don't lose it again.