Road bike tyres losing small amount of pressure

[Elybazza61]

I have the same bike, I don't know your weight but at 80kg, I find 90 rear and 80 front is plenty for that size of tyre. I should think 120 feels like the tyres are made of stone

I thought the same;don't have any tyres pumped up that high,maybe 93 max and that's on some 23's on old narrow rims.

The pressure written on the sidewalls is just the max a tyre can take usually;I'd give them a go at 85-90;less risk of pinch flats at lower pressures too(supposedly).

 

[Elybazza61]

Surely it's the type of tubes you are using that dictate whether you get a slow pressure loss; not the tyres?

Don't think standard tubes should go down much in a day;latex ones always go down when not in use,they are lovely to ride on though,,,

 

[e-rider]

I try to ride everyday or failing that every other day & before each ride I always pump my tyres up , I've found that 120 psi works well for me , feels comfortable & the bike rolls well on that pressure

The reason that I ask though is every time I check them they're never still at 120 psi , more like 100-110 psi after say a 50/60 Mile ride , is this normal for tyres to loose a small amount of pressure after each ride ?

yes if the weather is hot - I lose about 5psi per day on a hot summers day. In the winter I lose about 5 psi per week

 

[User269]

........................................ risk of pinch flats at lower pressures too(supposedly).

No. Risk of pinch flats reduced at higher pressure, that is, minimum recommended pressure for the tyre and above, depending on rider weight, comfort and so on.

 

[Lonestar]

Surely it's the type of tubes you are using that dictate whether you get a slow pressure loss; not the tyres?

Both.

 

[Tim Hall]

Surely it's the type of tubes you are using that dictate whether you get a slow pressure loss; not the tyres?

Both.

I can't envisage a mechanism where the type of tyre will affect pressure loss.

 

[Globalti]

Er... latex inners lose pressure at about 5-10 lbs a day. Even lightweight butyl loses some pressure. It's due to the air molecules passing though the molecular matrix of the rubber.

I weigh 76 kilos and I find the best pressure to be around 90 lbs. Above that my hands begin to tingle thanks to our crappy roads.

 

[mjr]

I can't envisage a mechanism where the type of tyre will affect pressure loss.

Different tyres deform differently and so squeeze the tubes more or less?

 

[T4tomo]

I can't envisage a mechanism where the type of tyre will affect pressure loss.

Me neither!

 

[burndust]

i have mine set at 100psi and pump to 105psi to allow for leakage when pump removed, top up every few days and always before and after a big ride, interestingly not a single puncture in about 2000 miles and i've been on some shitty roads

 

[Lonestar]

I can't envisage a mechanism where the type of tyre will affect pressure loss.

Oh well.Our opinions differ then.

Different tyres deform differently and so squeeze the tubes more or less?

You know what I mean and where I'm coming from?

 

[Tiny01]

I'd say you don't lose any air from the tyre when you remove the chuck. The valve gets forced open by the higher pressure in the pump. You stop pumping when the (wildly inaccurate) gauge gets to 100psi. The valve closes, but there's still air in the connector above atmospheric pressure. You take the chuck off and it's this air you can hear escaping.

Yep exactly that Tim & yes I'm just taking the reading from my Revolution track pump & yes I'd imagine that's not very accurate , are you able to advise me on a reasonable accurate tyre pressure gauge that I could then double check the pressures please ?

 

[Tiny01]

I have the same bike, I don't know your weight but at 80kg, I find 90 rear and 80 front is plenty for that size of tyre. I should think 120 feels like the tyres are made of stone

I'm 99kg currently , if I tried to run on those pressures the bike would feel like I'm cycling through sand !

Feels comfortable with 120 psi reading taken from my track pump