trouble airing up tires on Trek 850
I just bought a used Trek 850 and I'm a newbie to mountain bikes. I can't figure out how to air up the tires. I bought a normal bike pump and cannot get it to fit on the tire. I know this seems like a dumb question, but if you can help, I'd really appreciate it.
There are 2 kinds of valve stems on tubes.
1. Schrader (like on auto tire). An internal little nipple in valve surpresses when proper pump head is used to inflate.
2. Presta (a Euro valve). This type of valve, you have unscrew part of the external valve to allow air to enter the tube.
Make sure your pump head can do both Presta and Schrader valves; one size does not fit all valve stems.
Hope this helps.
That usually involves rearranging parts in the pump head, assuming it's a type that swings both ways as most bike pumps are.
Originally Posted by zonatandem