tyre pressure new nike

[anonymous-user]

I've bought a new bike, a Carrera Virtuoso Road Bike, but unsure of tyre psi. They are 700 x 25c but looking on net says 100 psi but pumped to 50 psi and just seems that is too much, any help?

i'm about 108 kilos..

Edited by Thesprucegoose on Saturday 29th June 21:43

[mikecassie]

I run tubed tyres of the same size at 70psi front, 75psi rear and I'm 70kgs including the bike, water bottles etc. I'd find 50psi too soft for me but give it a go and see how you fare.

[frisbee]

You want to be up around 90-100psi. It roll better and there is less chance of pinch punctures (when you hit the edge of something and the tyre gets completely flattened against the rim.

It does feel like a lot of pressure when you are pumping them up and the tyres will feel rock solid to the touch.

[Randy Winkman]

Are people's tyre gauges/pumps showing the right numbers? 100 or so seems right for me for a 700x25 tyre. Back in the days of 700x20 it was even more than that. More like 120!

[mikecassie]

I've used a couple different pumps and find 70-75 about right for me. Last year I used a hotel pump when travelling and it read low. I ended up with 85-90psi in my rear tyre, I knew in the first descent something was wrong.
There's a few articles on velonews.com regarding tyre pressure vs tyre size.

[yellowjack]

Randy Winkman said:

Are people's tyre gauges/pumps showing the right numbers? 100 or so seems right for me for a 700x25 tyre. Back in the days of 700x20 it was even more than that. More like 120!

Similar here. Conti GP 4000SII 700 x 25c, run at c.85psi (f) and 90psi (r). In the "olden days" when 23c tyres were considered fat, we would run them at higher pressures "because rolling resistance". and "because pro". Happily, science and engineering have combined to suggest that wider tyres with less pressure in them are just as/more effective/efficient than narrow tyres pumped up until the pump overheats.

OP? If it's a road bike on 25c tyres I'd start around 65 psi and adjust up/down as necessary until you find the sweet spot for you. You'll know you're too low if your tyres start to squirm on the rims when cornering and/or you get pinch punctures. You'll know you're too high (for you) because your buttocks will tell you as much...

Oh, and inspect the tyre sidewall closely, as most tyres will have the recommended maximum and minimum inflation pressures moulded into the sidewall. Sometimes it can be difficult to find/read, especially if logos, etc are printed over the moulded info (a typical annoyance that otherwise excellent Continental tyres often have). Anything above the lower limit is usually good, with more pressure added the heavier you are. Ultimately the bottom of the tyre (contact patch) should flatten and bulge a little to give compliance, but not too much. Very few riders ought to need maximum pressure though, so don't think of this as a target - whatever suits you and works is best in the end.

Edited by yellowjack on Sunday 30th June 11:48

[Sparkov]

Optimum for OP's weight will be 125 psi at the back, 105 psi at the front. Reduce to 105/90 if riding on rough roads or off road.

[ChrisMCoupe]

At 108Kg you are certainly going to be at the higher end of the PSI range for a 25mm. Some people can happily get away with as little as 75 PSI on a 25 but I would certainly be north of 100 front and back and see how you get on, if you don't get any pinch flats you may be able to run a little less.

A good option as you aren't the most svelte of riders would be to run 28's if your frame allows, this means you can run slightly lower pressures and get added comfort without really sacrificing any real world speed gains.