Since i have had my diablo rosso corsa's fitted 3 weeks ago i have noticed that they are not keeping the required pressure in them, i am quite anal about tyre pressure and i check them every time i go out, i inflated them to 34psi front and 38psi rear and off i went with no issues, checked them 2 days later when i went out again only to find they had dropped to 26psi front and 32psi rear and have done so on 4 occasions now, it doesnt matter if they are left for 1 day or 1 week they settle at these pressures, there are no signs of tyre damage at all and they are performing very well, the valves on the tyres appear fine also Anybody any ideas as to why they would be loosing pressure like this ??
Have you check the valves are seated correctly ? leave the dust caps off - and see if they loose more presure
Soapy water should show any leaks mate, get it on a stand and have close look, the valves can perish so pull them hard over to the side and look for cracks, if they did not clean the rim of the wheel round the inside of the bead this can also leak, worse case would be they caught the bead of the tyre with the machine and it has a small tear in.. One or two psi from day to day is normal but the front sounds suss, if your going back get some bridgeport valves fitted they last for years and are easy to adjust pressure.
tyre pressure is all down to what the rider wants. you are correct that 36 and 42 are the suggested pressures. But the lower the pressure the larger contact patch will have with the road which gives more grip but also lower pressure makes to tyre wear faster so its all about what you want and what pressures make the bike feel better for you. chances are what makes the bike feel at its best for me other people might hate
us honda owners need the 11.3mm ones. I have some waiting for my next tyre change. You need a skinny walled socket to fit in the resess of the wheel to do them up though.
Just as a point of interest, I saw some tyre pressure indicators that you screw on to the top of the valve in place of the dustcap. If the pressure is correct they show green and red if there's a drop in pressure. Not much bigger than the dustcap and can be left on while riding the bike. Company is called Bike-It from Longton near Preston and they sell all sorts of accessories on Ebay.
That might be an idea then i can keep a closer eye on them without nipping to the nearest air pump everytime i go out
The gauges at petrol stations are not reliable. Think of th thousands of different people using them and just chucking them about. Your best bet is to buy a digital tyre pressure gauge and keep it in your pocket or under your seat wrapped up in an old rag.
This is a good point when i inflated the front back to 34 it felt like it was made of stone so i wonder if i am maybe over inflating them. i struggled to get lots of heat in them even when riding quite hard. is this a sign the pressure is too high ?
Don't underestimate the importance of a decent, tight dust cap in this thread either? They are the main non mechanical barrier against leaks on your tyres. Most valves will let air past gradually, especially if they're used a lot or getting old. It's a mechanism, designed to let air in or out, so wear and grit can degraded its efficiency quickly. The dust cap doesn't let air in or out without being removed physically so it's value can't be over stressed. Watch out for metal ones too, I've seen them react with the metal of the valve. And replace them immediately if you cross thread them, even once.
I have plastic dustcaps and have never had the issue of loosing pressure before so i doubt i have forgot how to tighten up a dustcap properly. but you never know i could have lol. I am going out again today so will give an update later on what they were like today. will try a different pressure guage aswell
