tincaman
Guru
- Location
- Chudleigh, South Devon
That's nuts, you should be around 90psi, assuming you don't weigh over 80kg. Greater contact patch, more grip, smoother ride, less rolling resistance (lower suspension loss)
Goodbye Duranos, you've served me well
- Thread starter annirak
- Start date
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bladesman73
Über Member
mate do yourself a favour and get then down to 90-100psi. 25mm tyres allow you to lower the pressure without losing speed
OP
OP
annirak
Veteran
- Location
- Cambridge, UK
I've never seen any evidence to suggest that lower tyre pressure comes with lower rolling resistance. Quite the opposite, in fact.
Contact patch is the same with wider tires, it's just a different shape, so rolling resistance is unchanged.
Comfort is increased, and the tyre will maintain contact with the road better, so you will go faster. Jan Heine of BQ goes into more detail.
Richard A Thackeray
Legendary Member
I specified my newly acquired Ribble CGR, with Durano Race-Guard (folders), in a '28'
I wonder how they'll last, as I'm not used to that model, & that width - not used anything that wide since I used to use Tioga City Slickers on my Pace Research back in the 90's (26 x 1.25)
That said, I am used to Schwalbe, as my 'blue' Ribble has Lugano tyres, & the (Ribble) Gran Fondo has 'One'
Both of these have them in a '23' though
I wonder how they'll last, as I'm not used to that model, & that width - not used anything that wide since I used to use Tioga City Slickers on my Pace Research back in the 90's (26 x 1.25)
That said, I am used to Schwalbe, as my 'blue' Ribble has Lugano tyres, & the (Ribble) Gran Fondo has 'One'
Both of these have them in a '23' though
Ajax Bay
Guru
- Location
- East Devon
You may think that, but that's just your perception. You connect 'skating' along and a 'hard' ride with speed. But just as driving with the window open seems faster that wound up, it's just perception. See Jan Heine's article Tire Pressure Take-Home and my extract pasted below.
"Recently, Velo-News confirmed our results: The performance of a hand-made tire with cotton casing did not change at different tire pressures.
"It can be hard to believe this, because higher pressure feels faster. Here is why: When you go faster, your bike hits more road irregularities per second: The road buzz increases in frequency. Most cyclists know: higher speed = higher frequency. Higher tire pressure cheats you into thinking that you are going faster, because it also increases the frequency of the vibrations: higher pressure = higher frequency. It’s natural to assume that this means: higher pressure = higher frequency = higher speed, but that is incorrect. Instead, you are looking at two different mechanisms that both increase the frequency of the road buzz. Even after years of riding supple, wide tires, this “placebo” effect sometimes plays tricks on me. A supple tire absorbs vibrations better, so it can feel slower – until you look at your speedometer."
FishFright
More wheels than sense
OP
OP
annirak
Veteran
- Location
- Cambridge, UK
Looks like more armchair analysis to me. You lost me when you said "feels." I'm going off my speedometer. And articles with measurements.
http://www.velonews.com/2014/12/bik...essure-width-affect-rolling-resistance_355085
The problem with quoting rolling resistance testing by machine is that it doesn't represent real world usage. If you'd read the analysis quoted by @Ajax Bay above then you'd know why.
tincaman
Guru
- Location
- Chudleigh, South Devon
That's a great article, but the bottom line is that on a beautiful smooth surface, your 145psi and a small contact patch may be a little bit faster, but in the real world out on our typically rough roads then fatter tyres (combined with lower pressures) cushion the ride, reducing hysteresis and suspension losses, these are losses in the tyres themselves and also those you take through your own body. There is more to it than just that and the BQ articles mentioned before make excellent reading
fossyant
Ride It Like You Stole It!
- Location
- South Manchester
145 PSI - have you got any teeth left ? 
Ajax Bay
Guru
- Location
- East Devon
OK I've read that article - thank you for sharing the link. What are your take-aways from the article? A stiffer tyre has greater rolling resistance. Two supple tyres of the same construction have essentially the same rolling resistance at the two testing pressures (112 and 84psi) - on a machine.
nickyboy
Norven Mankey
- Location
- You want hills? We got hills
A quote from your article
"On the road, there will be a point with every surface where, above a certain pressure, rolling resistance will increase."
None of the testing you quote was done at pressures even approaching 145psi so the article is not relevant to the discussion as to whether 145psi produces more or less rolling resistance than, say, 100psi. But your article does say that were one to graph rolling resistance and tyre pressure, the resistance would reduce as pressure increased, then there would be a point of inflexion where the rolling resistance increased again. Wanna bet 145psi is not past this point?
martint235
Dog on a bike
- Location
- Welling
You can run 23mm D+ at 145psi too. I love D+ and found them even more reliable than M+
Out of pedantry, isn't the DD an Ultremo rather than a Durano. I'm currently trying them out on the commute bike
Out of pedantry, isn't the DD an Ultremo rather than a Durano. I'm currently trying them out on the commute bike
