Tyre PSI questions.

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callummac

Regular
Location
Glasgow
Hi Guys,
Looking for some tyre pressure advice.

My tires have a PSI range on them from 50-85psi. I mainly do road cycling and some cyclepath cycling. I weigh 115kg. I am unsure how much pressure I should be putting into my tyres.

My tyres are Schwalbe Marathon Plus and I am planning very soon on purchasing some Schwalbe Marathon Deluxes (thanks to all who advised me on this)

Cheers.
 

Globalti

Legendary Member
"Whatever feels comfortable" is the answer and not so low that you risk pinch punctures from the rim bottoming out.
 

Ajax Bay

Guru
Location
East Devon
Bear in mind the tyres don't have to be pumped up to the max. Depends on the tyre width and your (you + bike) mass (say 115kg + 12kg) and a rough 55%/45% rear/front split of weight borne, for 37mm tyres (1 1/2") have the rear at ~69psi and your front tyre needs to be ~15psi less than the rear one. But see the attachment which imho is worth reading. I have a Schwalbe M+ and use this.
 

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Last edited:
Bear in mind the tyres don't have to be pumped up to the max. Depends on the tyre width and your (you + bike) mass, so for 37mm tyres (1 1/2") have the rear at 69psi and tyour front tyre needs to be ~15psi less than the rear one. But see the attachment which imho is worth reading. I have a Schwalbe M+ and use this.

I like that reference and use it as a guideline.
 

Ajax Bay

Guru
Location
East Devon
https://www.cyclechat.net/threads/looking-for-new-tyres-help-please.195714

35mm ish - I'm assuming from OP's other recent thread ^^^^. "Tyres are Schwalbe Marathon Plus [to be replaced by] Schwalbe Marathon Deluxes."
I mainly do road cycling and some cyclepath cycling. I weigh 115kg.
So he doesn't need to run them at low pressure for comfort and doing so (especially given all up weight of 127kg) risks snakebites.
@callummac - I would measure the actual width of the tyre pumped to 70psi to make sure that it matches what it says on the sidewall eg 622-38. Is it 38mm? Then use the chart.
 
I press the tyre with my thumb, if I can hardly dent it then it's hard enough.^_^

Sit on the bike and look at the back tyre, see how much it squashes out to the sides; too much squashing is too soft, you'll feel every bump. Not very scientific I know, but it seems to work.
 

Cubist

Still wavin'
Location
Ovver 'thill
Hi Guys,
Looking for some tyre pressure advice.

My tires have a PSI range on them from 50-85psi. I mainly do road cycling and some cyclepath cycling. I weigh 115kg. I am unsure how much pressure I should be putting into my tyres.

My tyres are Schwalbe Marathon Plus and I am planning very soon on purchasing some Schwalbe Marathon Deluxes (thanks to all who advised me on this)

Cheers.
If you ride on cyclepaths as well as the road, you need to be up towards the top end of the range you quote. 115 kg means that the tyres will benefit from higher pressures to avoid pinchflats. Try them at the full 80psi, and go ride your normal route. If they start skittering on any loose stuff back them off a few PSI at a time, but higher pressures will feel better on smooth tarmac.
 

Drago

Legendary Member
I weigh the same as you Callum and run about 40 on the MTB, about 35 on the rigid MTB when off road. I slip 110 into my road bikes with makes them harsh but much less has the rim in contact with the road on bad bumps, so I just have to lump it really.
 
OP
OP
callummac

callummac

Regular
Location
Glasgow
Sorry guys, noticed I had missed off what kit I am using.

Pinnicle Arkose 3 2015 cyclocross bike
700x38 Schwalbe Marathon Plus tyres.

Cheers
 

Kajjal

Guru
Location
Wheely World
Check the sidewall of the tyres for the psi range. Due to your weight pump to near the maximum and see how you get on. Harder tyres go faster on road and very smooth trails with less pinch punctures unless you over inflate them. Softer tyres are slower on smooth surfaces but grip better. See what suits you. I weigh 100 kg and my mountain bikes tyres are about 40psi and my 25/28mm gravel bikes tyres are at 90psi. As long a the tyres stay on the rims and you don't get alot of punctures go for whatever suits you best.
 
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