I bought this and can't get the Presta side to seal. It sealed once; figured I got it and put it in the bag. It's now sitting around collecting dust because I can't get a good seal. I have loosed the valve on the tire, screwed this down as far as it would go on the valve stem. Nothing. Doesn't inflate worth a darn. I have yet tried to use a Schrader adapter; that will be my next attempt. There has to be better out there. Will be contacting my local bike shop to see if they can figure it out.

I tried multiple times and have yet to be able to use this pump every time on a trail. I need to borrow one from somebody else.

Tried multiple times to use, never worked. Had to borrow one from a friend to do the job.

This does not get a good seal and is too complicated not worth the hassle. Leaks air from the opposite side and hard to maneuver. Had to walk my bike home

Don’t buy this pump unless you like being stranded.

The presta does not seal. Leaks air to the point you can't get any usable pressure. The hose seized and will not extend. Left me stranded.

I have this pump & successfully attached it to the tire, inflated the tire with no issues, but when I go to remove the pump from the tire ... it takes the entire Presta stem off with it & deflates the tire entirely. I've been jackin' around with this for over 2 hours & about ready to throw this pump right into the garbage. I noticed a couple folks managed to inflate the tire successfully, but I can't find ANYONE who knows how to disconnect the pump without removing the valve. If you know how to do it ... please educate the rest of us.

Awful pump, poor seal on a presta valve after 15 minutes of pumping, could not reinflate by 700cx43 gravel tire. Did no better gripping the valve stem of an inner tube with air leaking around the valve and noty being able to get any of the "30cc" per pump into the tire. Extremely dissapointed in a company like Specialized putting their name on an unreliable and poorly designed piece of critical equipment. Being stranded on the side of the road because you thought you had the right equipment is the worst feeling. Shame on you Specialized.

Pulleds our a valve, and couldn't get any air in the tube

good

Specialized pump on practically brand new specialized tires on a specialized bike and this thing won't get an air tight seal until it's also got a death grip on the valve body threads. So when I unscrew it to get the damn thing off it also unscrews the valve bodies and causes all the air in the tube -- all of it -- to come rushing out because there's no valve body in the thing any more. I'd return this pump for a refund if I could. If it didn't do this I'd give it full marks. I was happy with this pump until it started doing this. But a pump that does this is not a pump anymore.

A hose is the first requirement for me. Check. Next is a valve attachment that seals tigh but doesn’t remove my valve core when I’m done pumping. Check. Finally, for a mtb or gravel tire, you don’t need high pressure, so “low gearing” ie a high volume per stroke is great. I am impatient though, so I will move this too my gravel bike, and try the Big Bore mini pump for my mtb.

Out on Honeymoon Island's Pelican Trail, I had adjusted my fat tires down to 5 PSI for a deep sandy section, and was using my Specialized pump, trying to firm them back up to 8 or 9 PSI for the hard-packed bits. Hundreds of pump strokes later, I had managed to LOWER the pressure down to 4 PSI. Air bled out faster than I could pump it in due to the failure of the nozzle to seal onto the valve stem. I was about to throw this pump away and complain to my bike shop, but searched ""Specialized 30cc bike pump won't seal"", just in case someone else had solved my problem. One or two negative reviews here pointed out that the pump SCREWS SECURELY ONTO YOUR VALVUE STEM. Why didn't I know this? DOH! Testing back at home proved that the valve core stayed in stem. So, I am keeping this little guy! Do not expect speed with a 30cc barrel, but this pump is Solidly Built, fits in my saddle bag, and gets the job done. I might try the MTB version if this one wears out, but I like the short retractable hose on this model, which provides just enough slack to prevent back-and-forth stem movement. The best pump is the one you have with you, and the Air Tool Flex Pump, at 9"" x 1"", travels very easily.

Works well so far. I really like that the side-mount fits behind my water-bottle carrier. Pumps seem to come in for a lot of bad reviews - I once had a Silca in the 1970s, a work of art, that shattered - but this does look really well made, works smoothly, nothing leaks or rattles. If flats are a way of life, strap a floor pump to your bike - we had a Warm Showers guest who did that!