Brooky

Hi,

I've just managed to find an immaculate second hand British Racing Green Dawes Galaxy for £320. Its a little large but I feel I can cope with that.

I've learnt my first lesson "Don't over inflate tyres!!"

The tyre said 70psi 5bar MAX. (Didn't see the max bit though! )

This blew the innertube arround the valve.

What would be an ideal tyre pressure for on the road? :confused:

ljbike

The pressure embossed on the tyre is the recommended pressure you should use. 70 to 75 pounds air pressure is not excessive for a touring road tire. Many tires are built for 90/100/110/120/150 pounds of pressure. The higher pressure tires are very hard and do not dampen road vibration. Good Touring tyres are in the 70/75 pound range. You could even go to tyres of 90 pounds, but again, the ride would be harsher.

Use quality BUTYL tubes, not latex. Laytex are made for light weight and racing. They're No good for touring or general road use.

Congrats on finding a bike.

VegasCyclist

well did you inflate it to 70 psi?, and does the rim have rim tape. if it is missing rim tape the inner tube could have simply cut itself on the metal at the high pressure. in which case applying rim tape to the rim may solve this problem and allow you to have a pressure of 70 psi. the tires I have on my road bike run at about 90 psi, and I have had no problems with inner tubes as of yet.

Brooky

Yes theres rim tape there and it looks brand new. I did inflate to 70 psi and ran into trouble when I took the pump off. (Probably tearing the innertube valve connection?!?)

The valve is Presta i think whatever that means and I tightened the bolt that sits on the wheel rim quite tight. It was quite loose before. I think this may have caused the problem. What do you think? :confused:

ljbike

Presta valves are skinny and more common in Europe. In the States the Shrader (fat valve) are the most common. That nut that holds the Presta valve shouldn't be tightened until the tyre and tube are inflated to the proper pressure.
Twisting the pump head straight on and straight off should not put any undo stress on the valve or the tube.

You might want to check the hole in the rim to see if it has any burrs which might cut the tube. If so, remove them.

Brooky

Righto thanks!! I'll do that.

John E

I think you are using a Presta valve in a Schraeder-drilled rim. Try putting a thin metal washer over the valve stem, to keep the tube from bulging through the rim. The inner diameter of the washer should just barely exceed the outer diameter of the valve stem, and of course the outer diameter should slightly exceed that of the hole in the rim.