Quick help - MTB Tyre pressure for a newbie


I borrowed my father mountain bike and I’m off to countryside to social distancing.
I have little experience but I kind have general bike skills.

Question is: how much tyre pressure should I run on a 29" x 2.35 (I think axle is 12 x 142mm) for single track and open dirt roads? For reference, I’m 170cm, 65kg and 285w FTP.

Thank you

Tire pressure really takes some experimentation. It depends on trail condition, riding style and the tire itself. For a 2.35 tire at your weight I’d probably start somewhere in the vicinity of 20-22psi and adjust from there. If you feel the tire folding or feeling really squishy in turns, put in more air. If it’s bouncy, take some out. For comparison, I have 2.4 tires and weigh 83kg and I usually use 23-24psi



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And it’s advisable to run more PSI in rear versus front. 73 kg - I’ve settled on 24 PSI rear, 19-21 PSI front. I used to laugh at the guys messing with digital gauges, now I’d recommend one. My floor pump gauge is off by 10 PSI and I was over inflating. But the recommendations here are good and will get you started.

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Thank you guys!!!

This is the bike, fwiw,

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Thanks for reminding me, I’ve been meaning to get a digital pressure gauge. Just picked up the Topeak option on Amazon, seems to be a go-to for cyclists.

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You don’t say if you are running tubeless or not. If so then the Stans formula is: weight in pounds divided by seven gives your base PSI then plus one psi for the rear, minus one for the front. Use that as your starting point. If you are bouncing off things then let a bit out, if your tyres are squirming or you ding the rim then add some more. Different tyres can also have different optimal pressures.

Once you’ve hit a suitable pressure for you then you don’t need an accurate gauge on your pump, it just needs to be consistent. Even better is being able to squeeze the tyre and feel the resistance so you don’t rely on the gauge.


Yes, I’m running tubes.

Maybe a few more psi then, just in case. Say 24f and a bit more in the rear.

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Silca has a new “professional” tire pressure calculator. Putting in my numbers for road, gravel, and MTB gives me plausible results.