Switched from 23mm to 30mm tyres- bad move?

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  • jamesco
    jamesco Posts: 687
    ugo.santalucia wrote:
    Academic... 47 times means you have started timing yourself last summer, I suspect. As the temperature drops, two things happen:

    1) The air carries more moisture, which increases your aerodynamic drag significantly. Although water is lighter than other atmospheric gases in terms of molecular weight, unlike nitrogen and oxygen it travels in clusters (hence why it is a vapour and not a gas), which makes it more dense..
    No, colder air carries less moisture. It's why you get condensation on the inside of windows in winter. Colder air is denser, however.
    ugo.santalucia wrote:
    2) There is less kinetic energy in the air, which makes it harder to shift, hence increased aerodynamic drag.
    Kinetic energy in the air? What's that? Wind? Seems to blow the same way in winter & summer - i.e. always a headwind :)
  • meanredspider
    meanredspider Posts: 12,337
    jamesco wrote:
    ugo.santalucia wrote:
    Academic... 47 times means you have started timing yourself last summer, I suspect. As the temperature drops, two things happen:

    1) The air carries more moisture, which increases your aerodynamic drag significantly. Although water is lighter than other atmospheric gases in terms of molecular weight, unlike nitrogen and oxygen it travels in clusters (hence why it is a vapour and not a gas), which makes it more dense..
    No, colder air carries less moisture. It's why you get condensation on the inside of windows in winter. Colder air is denser, however.
    ugo.santalucia wrote:
    2) There is less kinetic energy in the air, which makes it harder to shift, hence increased aerodynamic drag.
    Kinetic energy in the air? What's that? Wind? Seems to blow the same way in winter & summer - i.e. always a headwind :)

    Yes - cold air is more dense and Bernoulli had something to say about that. "Less kinetic energy" [of the molecules] is the same thing as saying "more dense" in this case. Cold air definitely carries less water than warm air (it's why you get more issues with static electricity in very cold weather).

    All of that said, I'm sure the OP's times are mostly due to them being crap tyres. It doesn't help that I've always found the Rubino Pro to be a pretty fast tyre which will emphasise the difference.
    ROAD < Scott Foil HMX Di2, Volagi Liscio Di2, Jamis Renegade Elite Di2, Cube Reaction Race > ROUGH
  • itboffin
    itboffin Posts: 20,052
    just fitted these to my wifes hybrid the 26" version are massive compared with the conti sportcontact i took off, also her bike now feels very heavy handling even though the both tyre sets weigh the same, must be the difference in going from 1.3" to 1.5" i foresee complaints coming my way.
    Rule #5 // Harden The Feck Up.
    Rule #9 // If you are out riding in bad weather, it means you are a badass. Period.
    Rule #12 // The correct number of bikes to own is n+1.
    Rule #42 // A bike race shall never be preceded with a swim and/or followed by a run.
  • cookeeemonster
    cookeeemonster Posts: 1,991
    First ride review: Randonneur Pro 700x35 (that actually measure up as 32). Pressure 60 PSI front (60, WTF? is this a mountain bike?!?!?), 70 PSI back (max PSI)

    Weather: headwind of between 9-14mph depending on what weather app you use, temperature 4 degrees C.

    Traffic/lights: normal amount of start/stopping.

    Ok, these, despite being twice the weight of the 28mm 4seasons (and 6mm wider than the not really 28mm 4seasons which are actually more like 26mmm) felt very little different when pushing off...I'm sure they are slower...but they really didn't feel it. Felt sooooo much nicer than the 28mm marathon pluses I put on the other day which felt real sluggish...a world of difference in fact.

    Comfort wise...very noticeable. I still have a releatively bumpy ride - the CS3 is an utter rubbish surface before I get to inner london roads which are not great but are better than the cycle path...but it was definately a nicer expeience. Going home with a tailwind tonight is gonna be even better :)

    Grip and cornering seems good but to be honest, I rarely race around corners anyway...but these felt more stable in the short time I've ridden them so far...might be the placebo effect.

    So all positive at the moment...probably too soon for a proper review, but yeah, I'm happy so far. Looks like I'm riding a fatbike too ;)
  • cookeeemonster
    cookeeemonster Posts: 1,991
    also forgot to say...it's been 2 years+ since I've been able to get a tyre on as easily and quickly as that - getting a single marathon off took longer than putting 2 randonneurs on...thank f**k I didnt have to do that at the side of a road.
  • arthur_scrimshaw
    arthur_scrimshaw Posts: 2,596
    CookeeeMonster wrote:
    First ride review: Randonneur Pro 700x35 (that actually measure up as 32). Pressure 60 PSI front (60, WTF? is this a mountain bike?!?!?), 70 PSI back (max PSI)

    Weather: headwind of between 9-14mph depending on what weather app you use, temperature 4 degrees C.

    Traffic/lights: normal amount of start/stopping.

    Ok, these, despite being twice the weight of the 28mm 4seasons (and 6mm wider than the not really 28mm 4seasons which are actually more like 26mmm) felt very little different when pushing off...I'm sure they are slower...but they really didn't feel it. Felt sooooo much nicer than the 28mm marathon pluses I put on the other day which felt real sluggish...a world of difference in fact.

    Comfort wise...very noticeable. I still have a releatively bumpy ride - the CS3 is an utter rubbish surface before I get to inner london roads which are not great but are better than the cycle path...but it was definitely a nicer expeience. Going home with a tailwind tonight is gonna be even better :)

    Grip and cornering seems good but to be honest, I rarely race around corners anyway...but these felt more stable in the short time I've ridden them so far...might be the placebo effect.

    So all positive at the moment...probably too soon for a proper review, but yeah, I'm happy so far. Looks like I'm riding a fatbike too ;)

    I'm running these in a 32, this tme of year I run the front around 50, rear 55 - 60. They look a bit flat but run nicely. I'd try the 35 but probably need to chnage my mudguards as they are a bit snug atm!
  • roger_merriman
    roger_merriman Posts: 6,165
    CookeeeMonster wrote:
    So all positive at the moment...probably too soon for a proper review, but yeah, I'm happy so far. Looks like I'm riding a fatbike too ;)

    One things that mildly amused me is last year when commuting on the roadie/SS my wifes hybrid with it's 28mm Marathon plus looked, big wide tyres.

    Now my commute/around town bike is the old MTB, her bike's tires look so thin, which is not really surprising since the MTB tyres are around twice the size.

    My commute is mixed surfaces and was always a little rough in places on the roadie/ss but is plush at 40psi

    mildly irritating no slower in time taken even on the odd jawnt into central london, though the absolute top speed is slower.
  • cookeeemonster
    cookeeemonster Posts: 1,991
    Arthur Scrimshaw wrote:
    CookeeeMonster wrote:
    First ride review: Randonneur Pro 700x35 (that actually measure up as 32). Pressure 60 PSI front (60, WTF? is this a mountain bike?!?!?), 70 PSI back (max PSI)

    Weather: headwind of between 9-14mph depending on what weather app you use, temperature 4 degrees C.

    Traffic/lights: normal amount of start/stopping.

    Ok, these, despite being twice the weight of the 28mm 4seasons (and 6mm wider than the not really 28mm 4seasons which are actually more like 26mmm) felt very little different when pushing off...I'm sure they are slower...but they really didn't feel it. Felt sooooo much nicer than the 28mm marathon pluses I put on the other day which felt real sluggish...a world of difference in fact.

    Comfort wise...very noticeable. I still have a releatively bumpy ride - the CS3 is an utter rubbish surface before I get to inner london roads which are not great but are better than the cycle path...but it was definitely a nicer expeience. Going home with a tailwind tonight is gonna be even better :)

    Grip and cornering seems good but to be honest, I rarely race around corners anyway...but these felt more stable in the short time I've ridden them so far...might be the placebo effect.

    So all positive at the moment...probably too soon for a proper review, but yeah, I'm happy so far. Looks like I'm riding a fatbike too ;)

    I'm running these in a 32, this tme of year I run the front around 50, rear 55 - 60. They look a bit flat but run nicely. I'd try the 35 but probably need to chnage my mudguards as they are a bit snug atm!

    Yeah I had to adjust mine. They are Portland Design Works full metal fenders (actually fair bit lighter than the sks chromoplastics despite the 'metal') and they have easily adjustable stays thankfully.

    Having said that the back is making a noise...the sticky out bits of the tyre (what they called?) that normally wear off after a little while are hitting the bracket...should've cut them of with some scissors last night :)

    oh yeah average speed/time was pretty good today too :) (again, waaaaaaaay too early for this to be remotely meaningful)
  • ugo.santalucia
    ugo.santalucia Posts: 28,248
    CookeeeMonster wrote:
    First ride review: Randonneur Pro 700x35 (that actually measure up as 32). Pressure 60 PSI front (60, WTF? is this a mountain bike?!?!?), 70 PSI back (max PSI)

    Weather: headwind of between 9-14mph depending on what weather app you use, temperature 4 degrees C.

    Traffic/lights: normal amount of start/stopping.

    Ok, these, despite being twice the weight of the 28mm 4seasons (and 6mm wider than the not really 28mm 4seasons which are actually more like 26mmm) felt very little different when pushing off...I'm sure they are slower...but they really didn't feel it. Felt sooooo much nicer than the 28mm marathon pluses I put on the other day which felt real sluggish...a world of difference in fact.

    Comfort wise...very noticeable. I still have a releatively bumpy ride - the CS3 is an utter rubbish surface before I get to inner london roads which are not great but are better than the cycle path...but it was definitely a nicer expeience. Going home with a tailwind tonight is gonna be even better :)

    Grip and cornering seems good but to be honest, I rarely race around corners anyway...but these felt more stable in the short time I've ridden them so far...might be the placebo effect.

    So all positive at the moment...probably too soon for a proper review, but yeah, I'm happy so far. Looks like I'm riding a fatbike too ;)

    Sounds familiar...

    TBH I think you are running them too high... I run the smaller 32 mm size at 50-60 PSI, so yours should go 50 PSI tops
    left the forum March 2023
  • cookeeemonster
    cookeeemonster Posts: 1,991
    ugo.santalucia wrote:
    CookeeeMonster wrote:
    ...

    Sounds familiar...

    TBH I think you are running them too high... I run the smaller 32 mm size at 50-60 PSI, so yours should go 50 PSI tops

    I weigh around 14 stone, so thought that I should go near the limit for the back one at least (which is 70psi)
  • itboffin
    itboffin Posts: 20,052
    What am I missing here why do the 700 come up smaller? The 26" are spot on.
    Rule #5 // Harden The Feck Up.
    Rule #9 // If you are out riding in bad weather, it means you are a badass. Period.
    Rule #12 // The correct number of bikes to own is n+1.
    Rule #42 // A bike race shall never be preceded with a swim and/or followed by a run.
  • veronese68
    veronese68 Posts: 27,318
    If you take a short fat piece of rubber and stretch it what happens? It gets thinner. Not much of a boffin are you. :roll:
    Kinesis Pro6
    Marin Nail Trail
    Cotic Solaris
  • itboffin
    itboffin Posts: 20,052
    No you lot just can't measure right innit
    Rule #5 // Harden The Feck Up.
    Rule #9 // If you are out riding in bad weather, it means you are a badass. Period.
    Rule #12 // The correct number of bikes to own is n+1.
    Rule #42 // A bike race shall never be preceded with a swim and/or followed by a run.
  • RussAlf
    RussAlf Posts: 706
    edited December 2014
    Interesting reading this, i have 28mm GP4 seasons on my Tripster ATR but pretty unimpressed with how easily they cut, gone through 2 rears in the last 2 months.

    Are the 32mm randonneurs more like 28mm? I have 35mm chromoplastics so need to ideally fit them under these? Or i might get 45mm chromos and go to 35mm randonneurs.
  • ugo.santalucia
    ugo.santalucia Posts: 28,248
    RussAlf wrote:
    Are the 32mm randonneurs more like 28mm?

    They come at 29-30 depending on the rim.
    left the forum March 2023
  • tgotb
    tgotb Posts: 4,714
    jamesco wrote:
    ugo.santalucia wrote:
    Academic... 47 times means you have started timing yourself last summer, I suspect. As the temperature drops, two things happen:

    1) The air carries more moisture, which increases your aerodynamic drag significantly. Although water is lighter than other atmospheric gases in terms of molecular weight, unlike nitrogen and oxygen it travels in clusters (hence why it is a vapour and not a gas), which makes it more dense..
    No, colder air carries less moisture. It's why you get condensation on the inside of windows in winter. Colder air is denser, however.
    Being a tester, I know a bit about this. Air does get denser as it gets colder, but at a given temperature it gets *less* dense with increasing humidity. The fastest conditions tend to occur on warm, humid evenings.

    Curiously (and strictly anecdotally) rain doesn't seem to make much of a difference at all, though it does make the whole experience rather more miserable...
    Pannier, 120rpm.
  • itboffin
    itboffin Posts: 20,052
    anyone tried these tyres on a Ribble winter yet? i've run 25c conti hardshells with no problems but i dont know what a 28+ would look like.
    Rule #5 // Harden The Feck Up.
    Rule #9 // If you are out riding in bad weather, it means you are a badass. Period.
    Rule #12 // The correct number of bikes to own is n+1.
    Rule #42 // A bike race shall never be preceded with a swim and/or followed by a run.
  • dodgy
    dodgy Posts: 2,890
    Vittoria Voyager Hyper Folding Tyre £9.99 today only at PlanetX
    http://www.planetx.co.uk/i/q/TYVIVOHY/v ... lding-tyre

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