Bicycle Mechanics - Tire won't inflate to a minimum amount

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Scheherezade
08-01-08, 07:44 PM
I know it's probably uncouth and greedy of me, but my first post on these forums shall be in request.
I've been slowly getting into bicycling this past year after bringing up an old bike to college to save on gas. Well, that bike ended up getting stolen this spring, so I wanted a decent cheapo that I could ride for a couple more years before I graduate. I ended up with this Wal-Mart bike, http://www.walmart.com/catalog/product.do?product_id=8399245 I wanted to go with something that I could be ok with leaving outside at all times (not an option to keep a bike indoors where I live), and being partially exposed to Minnesota winter elements. I definitely plan on looking into a more quality bike when I have permanent housing.
Anyway, my tire got slashed this past week, so I ended up going on www.biketiresdirect.com and buying some new tires and tubes (they didn't have big enough tires at department stores, so I choose to order online). Anyway, I got these tires ( Michelin Dynamic Tire Black 700x28) with these tubes (Quality 700c Schrader Valve Tube 700x28/32mm). They are more narrow tires than my old ones, but they seem to fit on the rims fine. The recommended PSI on the tires is 58-87 PSI. However, I was only able to inflate the tires to about 56 PSI with either a pump or an air hose. I assume that something is wrong with the sizing of the stuff I bought, but I'm not really sure because I'm new to this.
Where did I go wrong?
DieselDan
08-01-08, 07:53 PM
Where did I go wrong?
Asking something this absurd in this forum.
The nut behind the wheel is loose. Tighten it then pump your tire up. If you need to, turn up the regulator.:notamused:
Scheherezade
08-01-08, 08:41 PM
I had hoped I wouldn't get this sort of reaction, but I guess I'm too much of an optimist. I am sorry to be ignorant of how to fix this problem, I'm sorry that I couldn't find a quick answer after reviewing some of the reference materials given on this site, and I'm sorry that my bike tire won't accept anymore air in the tube. But, I don't think any of that justifies rudeness to the level I received.
Ex Pres
08-01-08, 08:45 PM
You didn't say what kind of pump you are using.
Scheherezade
08-01-08, 08:52 PM
I used a small portable handpump (generic wal-mart brand) a larger floor pump (also generic wal-mart brand), and a air hose at a gas station. None of these allowed me to put more than 56 PSI in the tire.
crackerdog
08-01-08, 09:00 PM
or type of air pressure guage.
socalboomer
08-01-08, 09:22 PM
Most of those are meant for lower pressure type things - you might need to get a higher-pressure pump. I would head to your local bike shop to have them give some hands-on advice for it. . .
and ignore the peanut gallery! :lol:
ShadowGray
08-01-08, 09:25 PM
http://www.performancebike.com/shop/Profile.cfm?SKU=18239&item=40-1872&slitrk=search&slisearch=true
Takes me to 150 easy. (and usually on sale for 25 or less)
Bill Kapaun
08-02-08, 12:14 AM
A gas station air pump should be capable.
I'd try a different gas station.
The cheaper hand pumps you describe just won't do the job. Been there!
Since you seem to be able to measure all of them, I assume you have a hand pressure gauge? Mine doesn't physically read above about 54 PSI. I would check it against a different gauge.
DannoXYZ
08-02-08, 02:55 AM
Don't use hand pumps, floor pumps only.
Widsith
08-02-08, 07:19 AM
I used a small portable handpump (generic wal-mart brand) a larger floor pump (also generic wal-mart brand), and a air hose at a gas station. None of these allowed me to put more than 56 PSI in the tire.
I haven't used a gas-station air hose on a bike tire in many years, but I've been told that these days most of them only go up to 50 or 60 psi at best. I recently bought a Bell floor pump from Wal-Mart for $14.99 but it wasn't much good. At about 40 psi it started leaking air where it clamped around the valve stem, and around 60 or 70 it was leaking from the pump body (I'd feel a breeze blow up along the pump handle on each downstroke). By the time it got to 80 psi it wouldn't put any more in the tire. I tried it on two different brand-new tires and tubes, and 80 was the maximum I could get on either. So I took it back and bought a Specialized Air Tool Comp Floor Pump (http://www.specialized.com/bc/SBCEqProduct.jsp?spid=25945) for $43 from my LBS. It easily takes my tires up to my usual pressure (95 psi) and feels like it would be good for much more than that. The owner of the LBS told me that the less expensive ($30) Air Tool Sport Floor Pump (http://www.specialized.com/bc/SBCEqProduct.jsp?spid=25947) should work just as well up to about 130 psi, but I chose the more expensive one because I thought the alloy body and steel base of the Air Tool Comp would last a lot longer than the composite construction of the Air Tool Sport.
I recently bought a Bell floor pump from Wal-Mart for $14.99 but it wasn't much good. ... By the time it got to 80 psi it wouldn't put any more in the tire.
I bought one of these; it had a pressure guage for up to 120 psi and I thought cool, this might give me the 100psi I need! NOT! 80 psi at best.
Scheherezade: Also, make sure you're flipping the lever the right way on the fitting that attaches to the valve. Some flip UP to tighten, some the opposite.
Scheherezade
08-02-08, 09:56 AM
Well, I went to a bike shop and got a better pump for the job, and it worked like a charm.
For clarification, I used both pressure gauges in both the pumps and with a handheld car tire pressure gauge, and they all seemed to read about the same before I used the better pump.
Thanks to all for the help, =)
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