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bike pump

Started by rama_nichana@yahoo.com, February 05, 2022, 02:19:09 PM

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rama_nichana@yahoo.com

https://amzn.to/3rQP0JE

got that.

but, would it work for the radmini ST 2 ?

pls share thoughts.

JimInPT

#1
When I was looking for a high-volume, low-pressure pump for my MiniST2, I ruled out any pumps with a max of over 100psi because I was concerned about accuracy in the low range and low volume per pump stroke.  Pumps in the range of 50psi and below are surprisingly hard to find, but I finally found a Specialized MTB floor pump for mountain bikes.  It's very well made, pumps a lot of air into fat tires with each stroke, has a huge easy-to-read dial with an adjustable ring to put a big red arrow on your desired pressure and maxes out at 40psi, so it's easy to read pressures in the 30psi range.

There is one significant problem with it and similar pumps - the large fitting and lever to clamp it to the valve stem makes it awkward to connect to the tires because of the small 20" wheel diameter, especially the rear where the motor housing also gets in the way.  But it fits and will work; you just have to figure out the process and angles to clamp it on.

Unfortunately, it's still hard to find for some reason and can be expensive ( https://www.jensonusa.com/Specialized-Air-Tool-MTB-Floor-Pump ), but I found one brand-new on eBay for $57 a few months ago - with a little luck and patience you might get a pretty good deal as well.

It works great and I can highly recommend it.
Shucks Ma'am, I'm no "Hero Member", I just like to wear this cape.

rama_nichana@yahoo.com

thanks for educating.  will hunt to grab the one that's preferred.  for now i need to have something that keeps me going.

curious, what kind valve does this radmini ST use ? schrader or presta.  i don't mention of it in bike specs. maybe i missed :)

JimInPT

All Rads have Schrader valves.
Shucks Ma'am, I'm no "Hero Member", I just like to wear this cape.

Eric7

#4
Trying to save you some money.  Calibrate your high pressure pump with your best pressure gauge.  Then just use a marker and mark the points.  That's how we calibrate things.  Then you can continue to use your high pressure pump.  It is not beautiful - there are some marks on the pump - but that's the most accurate way assuming you have an accurate pressure gauge.  I used to build scientific experimental instruments and that's how we did things.  A gauge that is inaccurate but repeatable can be fixed by some calibration marks.

Another tip, don't measure tire pressure with your expensive reference gauge if you have tire slime.  Tire slime will ruin your reference pressure guage.

rama_nichana@yahoo.com

thanks for the advise.

but calibration needs another gauge, but  :'( don't have. my earlier mountain bike, pump, all got stolen once i  moved from ID to CA.  back 11 years ago. now this radmini ST is my next bike since then. ID had lot of bike trails.


Veggyhed

#6
I probably should buy a floor pump but all I use is a topeak  mini pump for road bikes. I also use it topeak digital tire pressure gauge.
Considering the mini pump is for high pressure road bike tires the lower pressures on the pump gauge is off by about 7 to 8 psi when compared to the separate digital tire gauge. I  know I need 6 to 7 pumps per tire to maintain 20 to 23 psi so I just go about 5psi over what the gauge says on the mini pump.

Sent from my Pixel 3a using Tapatalk

JimInPT

#7
Quote from: rama_nichana@yahoo.com on February 09, 2022, 08:16:33 AMbut calibration needs another gauge, but  :'( don't have.

This is a very good and accurate pencil gauge for not a lot of money and quality-made in the USA; fits well in my bike's tool bag and I bought another one that clips to the pump for quick access to check pressure in the garage:
https://amzn.to/3heJ2fc

I've bought this same gauge for years to put into the door pockets of various vehicles; they're pretty good. 
Shucks Ma'am, I'm no "Hero Member", I just like to wear this cape.

Mooree

#8
Cycling outdoors is a great activity, especially on isolated, natural terrain, but there's no place nearby to inflate my bike's tires when they have problems or deflate them. Equipping yourself with how to inflate a bike tire without a pump is an important secret for natural enthusiasts. This method is the most popular among cycling enthusiasts due to its simplicity.