Hi guys, new member here. I have a "Teromas" brand portable air compressor I ordered on eBay. It has three settings: psi, bar and Kg/cm2. I like it because it has an adapter to use on a home outlet (110 v) as well as a 12v DC adapter to use in your car's cigarette lighter. I've been weary about using one of these things in the car's cigarette lighter after I blew a car fuse out using another portable air compressor several years ago.

Anyway, I have an old 1974 Schwinn Continental. I bought new tires for it a couple of years ago and the guy at the bike shop said the recommended tire pressure was 90 psi. When I tried to use the psi setting on the compressor, the tire became really full when the digital readout was nowhere near that. I was afraid I'd blow out a tube, so I unplugged it. Then I tried using the bar setting. According to a conversion chart I found, the correct bar setting to use for 90 psi is 6.21. However the lowest bar setting possible on the compressor is 10.00!

Any thoughts? Is there any way to use this without using the old "that feels about right" thumb method on the tire? Maybe this compressor is geared more toward auto tires than bike tires.

Automobile tires in general run much lower pressure than narrow road bike tires. The tires on my car are supposed to need 38 psi while the tires on my road bike need a minimum of 80 psi

Sure you haven't missed a decimal point?
What's the lowest PSI setting?

https://www.onlineconversion.com/pressure.htm

The Teromas manual says:
That doesn't sound like you set the Inflator to 90psi. You set it to whatever is above 90, and then you watch the gauge climb. When it hits 90, you turn it off.

Few compressors have the capability to run off 12vdc as well as 110vac because the wiring is different. That is a cool feature. I would be wary of the 12v capability, however. Some cars need the engine running to use the cigarette lighter. Many cars nowadays don't even have a lighter at all and instead have USB power or 110v outlets.

The obvious solution to the problem of not trusting your pump's pressure readout is to buy a separate gauge that reads up to 90psi.

I have no guess about the 10 bar minimum on the compressor.

A digital display doesn't mean the reading is more accurate. it still takes electronics to convert pressure to voltage to display.
Measure with a good hand held gauge to confirm the accuracy.
For about $40, you're not getting top notch accuracy.
I think you'll find yourself setting it to the pressure that seems right in the tire and then using whatever the gauge displays for reference.

Just get a proper pump and solve the issue. I find compressors to be handy for a high volume of inflations at the shop or seating tubeless but for my regular pumping a simple bike pump of good quality is way better. If I pump regularly I don't have to pump much and don't have to worry about overinflation unless I decide to over inflate them for some reason.

I haven't seen or heard of that brand and being it is from a random website who knows but it sounds like it wasn't designed around bicycles. Plus with an old bike like that I would want to be very careful pressure wise.

When it comes to inflating bicycle tires the Floor Pump rules.

I recently purchased a Bell Zephyr Bicycle Floor Pump (30+ USD) and for its price have been quite pleased with its performance. It has a large gauge on it that accommodates my poor vision...


Bell Zephyr Bicycle Floor Pump 30+ USD

> Sure you haven't missed a decimal point?
> What's the lowest PSI setting?

I used a chart which had the bar for psi 100 at 6.90 so that's pretty close.

I guess I'll just buy a tire gauge and measure it that way instead of risking overinflation and having to buy a new tube. Sometimes you can't tell it's overinflated until you sit on the bike and pedal for a few seconds and find out the hard way.

Maybe I didn't set the compressor correctly at the start, I could have started with the setting too high to begin with.

I bought a Bell manual pump a few years back and I never could get the thing to work correctly so I threw it away and thought I'd try an electric compressor this time.

Thanks everyone for your input.

Bell doesn't make pumps, they are a helmet company, that is probably your issue. A wally-mart product labeled Bell is not going to be of much quality. A nice Joe Blow from Topeak or Specialized Air Tool Comp or similar quality pump from your bike shop will be easy to use.

Joe Blow track pump recommendation seconded.Ideally with a metal base. I also am expecting one of these delivered soon which has an ingenious valve connector design
https://www.kickstarter.com/projects...ne/description

Having said that, I’ve got a 12V only portable compressor for the cars which cost about $40 and while it’s as noisy as hell, it does work well up to the 42psi I’ve used that for.

I’m sure the lowest bar pressure on this one must have been 1.0
10.0 is huge.

Does the inflator not show current pressure on its display?

Well they made this one, "Bell Air Glide 880 160 psi Foot Pump For Bicycle Tires." It looks like the one Bill posted except it was orange. It's still in my eBay purchase history.

The thing wouldn't even work correctly, you'd raise the handle and it wouldn't go back down, also the gauge didn't work. A total lemon. The guy wound up giving me a refund. At least it had a hand pump with it that seems to work.

Kontact: No I don't believe it does. Which one would think would be essential.

So when it is in the act of filling the tire, what does it display?

you don’t believe it does? Were you not looking at it when you used it?

So it’s not this one then? Because this one does.

Yep that looks like the one I have. I've only used it one time. When I first turned it on and hooked it up I don't remember it showing whatever pressure was in the tire (which was pretty low since I haven't taken the bike out in a year). I remember the digital readout getting up to about 30 psi, I felt the tire and it was really tight so I turned it off immediately instead of letting it get all the way up to 90 psi.

It was a nice day so I rode the bike around the city for a few hours without any problems though, using the "thumb" method for the tire pressure (lol).

Maybe I'm not using the compressor correctly but I don't want to experiment around with it and have to shell out a lot of money to have someone replace a tube if it blows out (I don't really have the desire/expertise to hassle with that myself).

Might just be a faulty unit

The digital readout might not have shown pressure because after a year, there would have been very low pressure in the tires.

The wheels of an early '70's Schwinn Continental usually can't be relied on to retain tires reliably at pressures much above 70 psi, even if the tire labels indicate that they can take a higher maximum pressure.

Riding at 30 psi might feel OK but runs the risk of damaging the tires or rims or both from hitting a pothole.

You should keep the pressure at around 65 or 70 psi.

Experiment on the car

Sounded like he was running it way higher than 30 but the unit reported the wrong pressure.

According to this video, you are reading it or setting it wrong:
https://www.amazon.com/live/video/07...181aeb98379170

I keep a little cheap compressor in the car, it runs fine from the lighter socket and easily gets skinny wheelchair tyres to 90 psi. If you're worried about yours blowing fuses you can get clamp-on connectors for the battery posts to run it full power and unprotected (or just carry spare fuses). One Bar is 14.5 psi, 15 psi is near enough and makes it easy to convert in your head. The 90 psi your shop person suggested could be too high, search online for "bicycle tyre pressure calculator" (without the quotes) for calculators from various manufacturers - these use your weight and the type of riding you do as well as tyre size to calculate your optimum pressure for comfort and efficiency. Try a few, they don't all work the same, but will give you a good starting point for tuning your ride. As for setting your pressure on the pump - 10 Bar is too much for any automotive application, even some 18 wheelers, so you should check how to set the pressure, and what the display is indicating. I also keep a pencil tyre gauge in the car, these are cheap and reliable.

Floor pump is much quicker to deal with bicycle tires with. I have several air compressors in the shop. I always grab the floor pump for my bicycle tires.

I'm going to guess that with your Bell Floor pump, you didn't have the air chuck set for the type of valve stem your tubes had. Schrader or presta. Or there was some misunderstanding about how something worked or what it actually did. Air chucks on all floor pumps are getting cheaper made and are crappy. Depending on how old your Bell floor pump was, it might be too new and crappy to work well for long.

I've got a Zefal floor pump from Walmart that was less than $10.00. Probably about the same quality as the Bell. I put a new and better air chuck on it for 5 bucks when it was 5 - 7 years old. And 20 years later on the pump itself, it's still pumping my tires up for most every ride.

90 PSI probably is a lot of air in those 27" x 1¼" tires that are on your Continental. If they are wider tires, then definitely too much. If you have the same hookless rims I had on my Schwinn's, then 70 PSI is probably the max you should go.

The point is they don't make pumps, yes there is a logo from Bell on those things but the quality of Bell isn't there. It is cheap stuff sold at places like Wally-Mart to make you think quality because they use a logo from a known quantity and quality. I am guessing likely Bell or whatever their parent company is had the idea to sell this stuff as an easy money maker. Sell a cheap pump or a cheap "lock" with a known logo and it will go easily. People don't know Woohgila or Nobkoa or whatever made up name some of this stuff has but Bell, yeah Bell is well known. Steve McQueen used Bell helmets and people love him.

It is a smart move, use your cache to sell low initial cost stuff at a place that won't interfere with your main brand and make more profits. The people buying the low initial cost stuff probably won't be buying main brand stuff and the main brand folks probably aren't going to pay attention to the low initial cost stuff any may not know it exists or probably won't touch it.

A quality bike pump shouldn't have problems at least not for a large number of years.