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On the commuter, it has 700x35c tyres. I pumped them up to 80psi the other day, but today they feel a bit squirrelly, so I'm wondering if I've given them too much puff.
Admittedly, this could be because I came off pretty hard on black ice on Monday and today was the first day back on the bike, and I was probably a bit nervous and over-sensitive to such things.
Anyhoo, what do folks reckon is a sensible psi for that size tyre, for general commuting with a pannier by a 85kg gentleman?
Im using 700x33 tyres and go for 45 front and 40 rear although my commute is 50/50 road/off road on a cx bike. Im 85kg too but without panniers.
Maybe 50-60 psi?
I run mine (knobbly) at 60psi
easy,
(TPI + bodyweight (kg)-50) x (tyre width / rim width (internal))^2
+ 20% if dry, - 10% if wet
f= 1.1 if tubeless, 1.05 if latex tubes
with my G-Ones @ 35mm I use 50psi ish
(TPI + bodyweight (kg)-50) x (tyre width / rim width (internal))^2
(120+85-50) x (38/17)sq
= 155 x 4.9965
= 774.463psi
Might need a new track pump.
i run my Roubaix 30c tubeless tyres at 50psi, I don't run tyres at more than 75psi even 25c, you'll go no faster all expel less energy having them at 80psi!!
Corsa G Plus at 320TPI:
(320 + 73 - 50) * (35/17^2) = 42
Unfortunately I got one of the brackets in the wrong place and inflated my tyre to 1,454psi. THANKS SCAREDYPANTS.
If you're getting pinch punctures or cornering is like jelly then put more air in. If you're shaking your teeth out or it's skittish in corners let some out. Once you've found those lower and upper limits you can play with the bit in the middle to suss out what feels fastest.
When you've done that, measure it, and that's your answer.
It takes a few rides to get it right but it works without having to know what tyres or tubes you have, what roads you ride on, how heavy you are, how fast you ride, how much luggage you have or whether you like your bike to feel smoother or more lively—and without having to compare all those with anyone on the internet who suggests a number that works for them.
42! Now what was the question?
I run my tubeless 28mm g-one at 80 psi on the rear and weigh a bit more than 85kg.
maybe it's rim width / tyre width
or something
I am a similar weight and have 35mm Gravelking SKs at ~45 psi (tubeless).
Fast, comfy, don't burp
I run 40mm G-Ones at 50ish psi tubeless.
35mm Xplor USH at 55-60psi
WTB Nanos (40mm) at 45-55 with tubes.
I weight about 100kg.
73kgs 45 rear 40 front and very happy on rough gravel, concrete panel cycle paths and tarmac no black ice though - lower than i've used on 32mm wide (widest run previously) convinced by the reduce by 5psi until it doesn't feel right argument - having always been up at the 75-100psi for 700c tyres in the past I've been enlightened
edit with tubes
and
bainbrge - Member
Corsa G Plus at 320TPI:(320 + 73 - 50) * (35/17^2) = 42
Unfortunately I got one of the brackets in the wrong place and inflated my tyre to 1,454psi. THANKS SCAREDYPANTS.
pretty sure someone will be along to ask what ghetto inflate system you used
pretty sure someone will be along to ask what ghetto inflate system you used
What ghetto inflate system do you use ?
80 kg fully kitted up. Croix De Fer with tubes and 35mm Conti CrossSpeeds. For road use 65 and off road about 55 works for me
On the road I tend to run them at 85psi - but mine come up quite small.
Off road I'd run a lot lower. Probably 50 or so.
What Bez sed.
What Bez sed.
except
isn't always fastest. maybe not even often. Side issue that, though.what feels fastest.
I pump my commuter's 28s on wide touring rims up to 65/75 or 70/80 depending on I don't know what.
I pump them up again every month or two when they start to feel squodgy in corners, or I feel the rim bumping up a curb when I think I probably shouldn't have.
They tend to be in the 40's when I stick the pump on.
So sort of what bez sed, but pump to the upper limit, then when they go down to the bottom end, whack 'em back up to the top again. You don't want to faff with the pressure gauge every day with a commuter!
In the recent cold snap, maybe ~80PSI was squirelly because of the reduced contact patch combined with frost/ice.
I've been running my 38mm Gravdal studded tyres at ~50/75PSI for the last week or so.
~94Kg for me in winter work kit on Wazoo, after getting some new digital bathroom scales yesterday, which boosted my weight by ~3Kg over the old analogue ones!