Originally Posted by
ucfdad
Thanks. I am a new rider, so please excuse the stupid questions. I have a Bontrager floor pump. Should I trust the gauge on the pump or should I buy a separate gauge?
In reading the forums it appears that a loss of 10 lbs in a week is normal, so I need to get used to checking more frequently.
The pump gauge is fine. Pressure losses depend on the tube thickness and the tire pressure -- I assume higher pressure tires drop a little faster.
When you pull off the pump, there's a hiss of escaping air. That's from the hose, not the tire.
With 43 mm tires at your weight, I'd try about
70-75 psi rear, and
55-60 front. (At 170 pounds, I use 45 psi rear and 38 psi front on a 40 mm tire! So you still have room to experiment with even lower pressures.)
When I look down at the front tire while riding, I can see a slight bulge outwards at the road contact.
Too high pressure: it's a bumpy ride, and often not any faster. Rough roads send a lot of buzz and vibration to the rider.
Too low: there's a risk of a "pinch flat". The wheel hits a sharp edged hole or larger sized rock, and the tire is squashed flat against the rim. The tube is folded in the middle and gets one or a pair of small slits where the rim mashes into it. Pinch flats are more likely at faster speeds and on sharper, larger obstructions.
Too low: the ride feels mushy and the steering response is slowed.