You need a new pump. 50psi is definitely insufficient for such a narrow tire - I’d be surprised if you didn’t get a flat, even with kevlar tires and tire liners. (Wider tires can get away with low pressure because they can squash quite a bit before the tube is actually pinched.) Just go to any bike shop and get a pump with a built-in gauge.
I don’t think gas station pumps can go up to 90 psi. They are usually limited (on purpose) to pressures typically used by automobiles. Also, I would guess your tire can take quite a bit more than 90 psi. I always run the tires on my commuting bike at 120 psi, and top it off every other day.
You might blow a heart valve, but you aren’t likely to damage the pump or the tire. Skinny little tires have to be so hard you can put all your weight on your thumb and it doesn’t move. If you can’t get it that hard, get another pump, which shouldn’t cost you more than $20-30.
I know that many dopers are irritably scanning various threads and thinking: “Big deal, braless women, what about Evil Captor’s flat bike tires?” So I thought I’d update.
I had one flat this week, that was on FRONT wheel of my bike, happened on Wednesday and no flats since. I’m pretty sure what happened there – when I got the Kevlar-lined tire for my rear wheel, I upgraded the front wheel by moving the much newer (just bought a few weeks ago) rear tire to the front. When I was removing the inner tube I noticed it seemed like original equipment – I bought the bike, an old Ross touring bike – used, so the tire coulda been 10 or 15 years old. I mean, it had old-style brakes and an old-style derailleur without indexed shifting, so it was probably quite an elderly inner tube.
But it wasn’t broke so I didn’t fix it, and wound up having to swap it out when I found the tire flat at lunchtime on Wednesday. The new inner tube has worked just fine.
So, Kevlar tires, Slim filler, and more inflated tires though I haven’t gotten around to getting them up to 90 lbs yet. I guess it’s because I’ve frequently had the experience that, when I really push on somethning that’s resisting, it (whatever it might be) tends to break. Thing is, it’s a floor pump (The Judge by Bell) and seems quiite sturdy, I find it hard to believe I’ll improve things much by getting a new floor pump.
Sorry to be repeating myself, but if you want to ride on 1-1/8" wide tires, you’ve got to figure out a way to inflate it properly. You mentioned earlier that there is hissing noise when you go above 50 psi. It seems likely that the rubber seal on the pump head is degraded. That’s why I suggested a new pump. It’s also possible that you’re attaching it to the valve incorrectly, but a new pump may fix that as well (hopefully it has a newer better design, if not at least it’ll come with instructions.)
And if you need reassurance that the tire can take 90 psi, just read the markings on the tire. The max pressure should be listed.
4 flats in one day + a 1 mile bike carry, a 3 mile bike carry, $$$$$ & 14 gallons of sweat = loading that narrow wheeled tiny seated 10 speed and a few others I had into my favorite bike shop and said, “Here, I am trading all this pain in for THAT”. I was pointing at a mid high class 21 speed mountain bike. I had a ‘huge’ seat added. I am old so I swapped out the front bars for some dirt bike bars I had so I could sit up straight. Had “K” heavy duty tires, a Kelvar belt and ‘thorn’ tubes ( the bottom half of the tube is double thick) put on both ends. It has been 14 years and I have never had another flat, (worn out tires do get replaced) and since I ride on any and all surfaces and am now 64 and on the wrong side of 300 #'s (6’4" and big frame) I would say that for me, that was the ‘no more flat solution.’
Yeah, bigger tires are definitely the way to go, and if my bike’s frame would accomodate them, I’d get them in a flash. But it won’t. For the time, being, no more flats, so that’s all to the good. Fourteen years and no flats DOES sound enticing. But I do like the way my old Ross road bike handles.
I do think that overall, the skinny tires on “road bikes” are suitable for tracks only. I don’t know why they call them “road” bikes. My son has had no problems whatsoever with his mountain bike tires.
I bought a foot pump with a built in pressure gauge that went up to 100 psi, but it was a POS. It wouldn’t get my tires over 30-40 psi – any more than that, and the pump jammed either in the up or down position. So I had a really good idea of how much pressure the pump wouldn’t put in my tire. Went back to the floor pump and had much better results.
For half a year I commuted on 25mm-wide tires, pumped to 120 psi. About 12 miles per day, including some rough pavement (poorly filled potholes, etc). I did not get a single flat during that time. IMO, for road use, the only problem with skinny tires is the harsh ride.
They call them that, because people ride them on roads.
I do a little over 1,000 miles a year on my road bike, and using 700X21 (very skinny assed) tires I only get about 1 flat a year.