ROCKBROSMini Bike Pump Portable Electric Bicycle Pump100PSI Tiny Bike Air Pump Tire Inflator Type-C Rechargeable Battery with Presta Schrader Valve, Cycling Gifts for Men Women

Just got this a few hours ago, charged it up, and completely deflated my 2.2" x 700c Continental Race Kings and kept reinflating to 24.5 psi until the battery was dead. I got two full inflations, and on the third inflation, the battery was dead once the tire hit 20.5 psi. That, in my opinion, is excellent value for the money. It weighs less than two CO2 cartridges and a mini-pump, and the form factor takes up less space than the aforementioned items.Some more details about the test parameters. Ambient temperature was 72ºF. This is significant as most batteries suffer from diminished performance in the winter. I'll have to put it in the refrigerator (typically around 38º F to 40ºF, which coincidentally is just above my low tolerance level for 20 miles of gravel riding) and see how it does under those conditions. My rims also measure 25 mm internal. A rim like the Zipp Firecrest XPLR has a 32 mm internal width, which actually increases the volume of air inside the tire (this is why rims with wider internal measurements can run lower tire pressures). Of course, rims with wider internal measurements can run lower tire pressures so... it might balance out.A note about use: It appears as if the air intake is around the USB-C charging port. The port is located in a position where you naturally put a finger right over it. If you do that, it will stall out. It happened twice, but I quickly realized what was happening. I would suggest a way to improve this product would be to move the intake if possible, though this may be limited by the design of the internal pump. Putting the intake on the back of the unit would probably be ideal.I considered giving this four stars, because it doesn't have a feature I want. In reality, this is a feature I'm willing to pay more for SO, for the price they're charging and the value this product delivers, this is absolutely a five-star product, no doubt. Okay, so what do I want? I like the size. In testing this pump I found that my "thumb tire pressure gauge" was calibrated to 20 psi. On several tires, my thumb thought the tire was up to pressure when it hit 20 PSI (so in the field I just have to keep pumping for about 25 seconds longer to hit 24.5, my target pressure for my rear wheel). I would pay more for a device that kept this form factor, but automatically cut off at the desired pressure. The interface to set that pressure would be via BlueTooth and an app. I'm not sure if this is technically feasible. Perhaps there's an indirect way to measure pressure through motor performance as the pressure increases (anecdotally, it sounds like the RPMs may decrease a little as the pressure increases, which might be an indirect proxy for pressure if it was found to be repeatable).So, what does this product mean for me? It means that on gravel rides in more populated areas, I will be leaving the CO2 and the mini pump behind. If I'm solo in a less populated area, I will still leave the CO2 behind, but I will bring a mini hand pump, just in case. Electronics fail, and Murphy is a jerk. Mini-pumps are a pain, but they're a simpler system that is less likely to fail. This is an AWESOME product. I was totally skeptical and thought I'd be sending it back. Well done, RockBros!

Rockbros stands behind their products. I had an issue with this mini-pump 4 months after the warranty date but a simple e-mail direct to Rockbros was replied to the next day and a new unit sent to me in just 2 days. Great service especially since I have a gravel ride event 2 days from now.

Electrics pumps sounds like a good idea but product breaks when you need it most.I charged this pump and tested it out when I first purchased it. It worked the first time. Over the next couple of months I made sure it was charged regularly. The first time I got a puncture on the road I went to use it but the device stopped a second later. It wouldn't restart. When I recharged it later the same behavior happened again.This is the 2nd electronic pump I've purchased and both have exhibited the same behavior. This tech needs to be improved.No option to return the device on Amazon. Vendor link is a site without English language support, so appears to be a dead-end.

Maybe I didn't read the entire pamphlet but I didn't know how to start the pump. I found out that I need to hold thepower switch for about 3 seconds to get started. I received the request to rate this product after owning it for a few hours. I don't think I know enough to rate it.

ExcelenteFuncionaMuy buenoTamaño pequeñoPortátilHasta más de120 psi totales

The media could not be loaded. Wow! I like it alot. I have used this at home to test it several times and wow! Easy to use, very portable and it pumps air in my 700cx24mm tire pretty darn fast. I carry a large battery pack that supplies power to my two Gopro 10 cameras so if I need to recharge this (that recharges itself in 5 minutes) I can do it fairly easy. If u dont have a extra power pack to recharge this make sure u change ur tube & tire right the 1st time. Always check for foreign objects stuck in the tire before u put it back on. ALWAYS!Update, although id rather not talk about it but I did get a flat! Darn it! I'd use stronger words but, anyway this was a freakin life saver. I fixed the flat and connected this and started it up. I left it alone and continued to clean up all my crap from fixing the flat and when I was almost the pump was done. I plugged it in again (I carry a large charger for my gopros) and recharged it as I continued to clean up. That's how fast this little bugger is. I'm soooo glad I bought this. Im ready to get another as a back up because some manufacturers only make so many then move on to something else and I'll never see this again. I'm pretty sure I'm buying another very soon. O!, good luck fixing ur future flat tires and remember, stay cool. I fix flats better & faster if ur not pissed off.

UPDATED 3/17/2024Did receive a replacement mini pump from RockBros. Charged it up and then used it to fully fill three 29" mountain bike tires to 22psi. I have charged it back up and will see how long it holds a charge retesting periodically. Updating rating from 1 star to 3 stars for now. Will update this review and possibly my rating after 2-3 month test to see if it holds a charge.Original-------------------------------------------------------------When I received it I charged it up and tested out. Was very impressed that it blew up 2 and almost a 3rd 29" mountain bike tire. I wrapped it in a ziplock and put it in my seat bag for use someday out on the trail. 3 months later was reorganizing my seat bag and tested it out. Guess what? No worky. So I charged it up, it went from red to green and tried it again..... no light and no pumping. Charged again, again from red to green, pushed the bottom a couple of times again and no pumping. Have tried to contact RockBros several times. First time they asked me for my order number, and I sent it. That was on 3/7. I have emailed them several times since then and have not received a response. Hoping a new one is in the mail. If this gets resolved, I will update this review. But for now I seem to be out $65.