Lowest rolling resistance of 27 inch tires?

[Scoosh]

MOD NOTE:
Stop the personal stuff, answer the question and try to help the new Member.

Thank you.

 

[Yellow Saddle]

i think there is plenty of independant tests out there that proves conti to be true.........best you go read them, unless you've got your own technical data available to prove otherwise. if the latter is to be true, then maybe you should provide a link to this data, rather than just calling people out as conforming to authority.

i look forward to reading your data and then forming my own opinion based on relevant data provided.

Jowwers, I've had a good look at the two links you provide. There is NO data in there relating to either puncture protection or rolling resistance.

Puncture protection should be quoted in Joules of energy applied to a given needle/blade dimension required to penetrate a certain thickness of said material.
Rolling resistance is quoted in Newtons of force.

I see lots of fancy graphs and marketing bumph but no data.

As contrary information I supply the following facts:

1)Rolling resistance is a function of tyre compound, casing construction and overall thickness. Thinner is better, silica is better than carbon black. I have already said what casing construction is optimal and what rubber compound is optimal.
2) Puncture resistance (assuming a given spike/blade) is dependent on: a) Material thickness, lubricity of the entry point (water on the road), thickness of the casing plies and compound of the rubber/puncture protection layers. The compound of such a layer must have a high toughness, thus high hysteresis and hence high rolling resistance. By definition it has to absorb energy. Whether it absorbs the spike's energy or rolling energy, it has to be energy hungry.

These two properties are in direct contrast with each other. More puncture protection causes higher rolling resistance and conversely. Making the matter even worse, the rubber with the lowest rolling resistance is a silica rubber (all coloured tyres have silica (sand) as a filler, even some black ones) displays the poorest durability and wet traction.

It is a matter of physics, not marketing that dictates these things.

I am sure where you live you can find a good library that can corroborate what I state here. No need to take my word for it.

 

[jowwy]

Jowwers, I've had a good look at the two links you provide. There is NO data in there relating to either puncture protection or rolling resistance.

Puncture protection should be quoted in Joules of energy applied to a given needle/blade dimension required to penetrate a certain thickness of said material.
Rolling resistance is quoted in Newtons of force.

I see lots of fancy graphs and marketing bumph but no data.

As contrary information I supply the following facts:

1)Rolling resistance is a function of tyre compound, casing construction and overall thickness. Thinner is better, silica is better than carbon black. I have already said what casing construction is optimal and what rubber compound is optimal.
2) Puncture resistance (assuming a given spike/blade) is dependent on: a) Material thickness, lubricity of the entry point (water on the road), thickness of the casing plies and compound of the rubber/puncture protection layers. The compound of such a layer must have a high toughness, thus high hysteresis and hence high rolling resistance. By definition it has to absorb energy. Whether it absorbs the spike's energy or rolling energy, it has to be energy hungry.

These two properties are in direct contrast with each other. More puncture protection causes higher rolling resistance and conversely. Making the matter even worse, the rubber with the lowest rolling resistance is a silica rubber (all coloured tyres have silica (sand) as a filler, even some black ones) displays the poorest durability and wet traction.

It is a matter of physics, not marketing that dictates these things.

I am sure where you live you can find a good library that can corroborate what I state here. No need to take my word for it.

i think i said independant data - not data within the links

again you provide nothing to back up what you call marketing bumph...............do some independant testing and then get back to us on whether you can have both or not....

conti say they have provided a tyre that has the lowest rolling resistance in independant tests, with the added puncture protection of the vectran braker. the vectran braker wasn't added after the resistance test were undertake, as the breaker was already incased in the tyre.

Therefore you can have a lightweight, low rolling resistance tyre with added puncture protection when using conti gp4000s II.

can you povide any data to prove that conti or the independant testers wrong?...........as for the mods, i have made no personal comments in my reply, i am only asking for clarification of his comments that you can't have both, therefore helping the OP

 

[Smokin Joe]

I've already got that covered with thicker tubes.

You haven't.

Tubes are only soft rubber and once the tyre has been penetrated the tube has no chance. A thicker tube might buy you a few yards, but nothing more.

 

[Ajax Bay]

Need to be light too, otherwise they won't be 'faster'. Light, fast, inexpensive, 32+mm.

 

[Ajax Bay]

@jowwy you've linked to GP4000S II but these tyres are not an option for the OP: "The new sizes of 23-571, 20-622 and 28-622 cover a broader range of customer requirements," - not broad enough for the OP who has specified 1 1/4" (ie 622-32). And that's the point: there are several candidate tyres at 28 but at 32 the light/fast options are very limited. What's your recommendation to the OP @jowwy ?

 

[Tim Hall]

@jowwy you've linked to GP4000S II but these tyres are not an option for the OP: "The new sizes of 23-571, 20-622 and 28-622 cover a broader range of customer requirements," - not broad enough for the OP who has specified 1 1/4" (ie 622-32). And that's the point: there are several candidate tyres at 28 but at 32 the light/fast options are very limited. What's your recommendation to the OP @jowwy ?

My reading of it was that she wants 27 inch x 11/4, rather than 700c, so 630-32, not 622-32, which limits her options even more.

 

[jowwy]

@jowwy you've linked to GP4000S II but these tyres are not an option for the OP: "The new sizes of 23-571, 20-622 and 28-622 cover a broader range of customer requirements," - not broad enough for the OP who has specified 1 1/4" (ie 622-32). And that's the point: there are several candidate tyres at 28 but at 32 the light/fast options are very limited. What's your recommendation to the OP @jowwy ?

Some 28s on wider rims come up in size.......my 28mm conti 4000s II size up to 30mm. So i would still say gp4000s II

 

[moongaze]

You haven't.

Tubes are only soft rubber and once the tyre has been penetrated the tube has no chance. A thicker tube might buy you a few yards, but nothing more.

Perhaps I should specify that I have thicker thorn resistant tubes. I used to get flats seemingly every other day till I switched to the more resistant tubes. Ive had 3 flats in the last 4 months on the thicker tubes. What you're saying does not match my experience. I ride everyday 8 hour shifts so I've got a lot of mileage on the different tubes

 

[moongaze]

My reading of it was that she wants 27 inch x 11/4, rather than 700c, so 630-32, not 622-32, which limits her options even more.

He. And yeah I'm considering switching to 700 because I've surfed online for a while now for better tires and the Continental ultra sport seem to be the only tires matching what I'm looking for

 

[moongaze]

TBF, he doesnt actually say 'he would even consider the more expensive one with puncture protection if it was faster'...he says 'BUT, They're higher priced but I think it's because of the added puncture protection'...he at no stage says puncture protection is a requirement or important to him, but does say speed is.
I interpret that to mean the puncture protection is a facet of a particular tyre that is there, but not neccessarily of importance to him.

Perhaps Moongaze can clarify. It seems quite clear to me...but i'll happily shut up if i'm wrong.

As a side issue....i agree, thicker tubes will give little or no extra puncture protection.

Thanks. I didn't think it was so hard to comprehend what I meant
.

 

[Ajax Bay]

I have thicker thorn resistant tubes.

What sort/make of inner tubes are they?
The Conti page for Ultra Sport suggests that while they make 630-32 you can't get 622 in any more than 28.

 

[Ajax Bay]

Some 28s on wider rims come up in size.......my 28mm conti 4000s II size up to 30mm. So i would still say gp4000s II

And from the rollingresistance site, testing these tyres in 23/25/28 flavour, "on a 17C rim and an air pressure of 100 psi, all versions of the GP4000S II are a bit wider than specified. With the 23C being 25 mm wide, 25C 27 mm wide and the 28C a whopping 31 mm wide."

Since these are 2+ watts lower rolling resistance than Ultra Sports (12.2 v 14.3) and lighter (260g v 340g), and if you get 28s they are nearly 1 1/4 (31mm on a 17mm rim) so suggest that's the best tyre to meet the OP's requirements (on a 700c wheel).

 

[Ajax Bay]

You did say you didn't want p***ture protection, didn't you @moongaze and your thicker inners will sort that for you? @jowwy 's recommendation is the Conti 4000S II but from a thread he's just started:

Yesterday my one ride old gp4000s II lost in a fight with a sharp object and sustained a cut all the way through to the tube....resulting in a blow-out.

He's going to chuck it and replace with a GP 4 Seasons (which have too high a rolling resistance to meet your criteria).

 

[jowwy]

You did say you didn't want p***ture protection, didn't you @moongaze and your thicker inners will sort that for you? @jowwy 's recommendation is the Conti 4000S II but from a thread he's just started:

He's going to chuck it and replace with a GP 4 Seasons (which have too high a rolling resistance to meet your criteria).

Im chucking it cause its ruined.......and its the first one ive ruined in 3years of commuting on them. The reason im using 4 seasons is because i have a set already in the shed. Gp4000s II will still be used at weekends on the best bike.

And in tests 4seasons are not that high in rolling resistance, but are higher than 4000s II