new tyre and inner tube but flat when riding
hi all, new to the forum hope someone can help. ive got a shimano mountain bike ive just put a new inner tube and new rear tyre on my bike, it fits well and pumps up hard to the touch with not much give, im 12 stone 12lb but when i ride on my bike the tyre looks pretty well flat. when i get off the tyre still feels hard. i havent got a pump with a pressure guage just a ordinary one, any idea whats happening or am i just a fat so and so and need to lose weight.