fabiocortez

I've lurked, I've researched and asked questions but anyways here goes.

I'm riding a giant 2016 giant escape 3 hybrid bike with 700X32c tires at a high psi and I seem to keep getting flats because my town is bumpy and has alot of gravely areas rough roads, rough sidewalks. 3 flats in about 230+ miles, I do check the psi before each ride.

I unweight the bike, I try to avoid these rough areas but I'm wondering if I switch to 700x38c tires at a lower psi, will I have as many problems with bumps and gravel, I'm mostly concerned about bumps and flats. Any help is appreciated, just want some advice before I drop some cash on this wheel/tube set.

I used to ride mountain bikes and I could go year in and out and never have to change tubes or refill the tires with air.

I prefer hybrids, the escape 3 is awesome, light and fast. No complaints other than the flats I get.

BobbyG

What kind of flats? Punctures? Pinch flats? Snake bites? Tears? At the stem base?
Are these slow leaks, or big blowouts?

It could be thorns, it could be faulty rim tape (you know to protect the inner tube from the spoke heads) It could be from using innertubes that are too big or too little?

Please describe the type of flats.

Viich

Also, what do you mean by high pressure? To different people that could be 40 - 120 psi.

fabiocortez

Um, I have no idea what kind of flats really, and I run about 75 psi. the tubes are 700x32

JanMM

Are there holes in the tire tread? That align with holes in the tube? Or just holes in the tube?
Manufacturer max pressure for 32mm tires can range from about 60-100psi.

MarcusT

Finding the cause of the flats would help a lot in offering you advice. Punctures or snake bites? If it is constant punctures, have you checked the interior of the tire to make sure the cause of the flat was removed?

TenSpeedV2

What is the max recommended psi on the tire on the bike currently? It will say on the sidewall. You may be running it too high, possibly causing the flats.

rumrunn6

flats aside, even tho 32 to 38 isn't a big jump, a higher volume tire will be more comfy

jgwilliams

You also don't say what the tyre is that you're riding. Tyres are not all created equal and some supplied as original equipment can be quite poor. I've been using Continental Grand Prix 4 Season for a while now and can count the number of punctures on one hand. I had Schwalbe Durano's on another bike that did 4000 miles before I got a puncture. This handy web site will give you details of not only rolling resistance but puncture resistance for a number of popular makes.

Then, as others have said, make sure that when you fix a puncture you remove the original cause. Little flints or thorns embedded in the casing can be very hard to spot but they will gradually poke through the inner tube and giving exactly the symptoms you describe. Also check that the rim tape, if fitted, is fitted correctly so that the spokes aren't poking into the inner tube.

At 75 psi I'd have thought you were unlikely to be getting pinch flats, though it's not impossible. I can't see that a bigger tyre at lower pressure would make much difference either way. I ride 23mm or 25mm tyres at 100 psi with hundreds, if not thousands of miles between punctures, riding over some pretty rough roads, though very few trails.

Hope that helps

John

jefnvk

I regularly ride 32s on rough pavement and gravel, and only once have had a puncture attributed to a piece of glass.

You should figure out what is causing the issue first, before looking at changing anything you need to know what isn't working.

wphamilton

Not enough information to say anything definite, but I can give you my personal experience with this. The short version is, it wasn't the tires.

Like you, I was riding on 700cx32 and getting flats, enough of them that it was a real issue. I looked for better tires, went with kevlar belted flat resistant, higher pressure, harder heavier tires and so on. It did help some, but I'd still get flats.

At some point my preferences changed, I wasn't getting as many flats, and I desired tires that didn't slow me down as much and weren't as heavy, so I abandoned the Kevlar belted tires. I still didn't see more than an occasional flat so I looked for more supple, higher TPI tires. Still, no flat problem. You can see where that's going.

So I'm using decent road tires with no thought at all for flat protection, and getting far fewer flats than when I was using big flat-resistant "commuter" tires - what changed? Some people don't even carry flat kits, because they literally never have a flat, what's different with them? My commute now is more or less the same now as my riding ten years ago, and almost the same route since 2010. Except, I used to have to exit the parking lot through a tree line up a little hill, then downhill over a dirt road. Rocks, ruts, etc for only a few hundred feet. Maybe some broken bottles, which I always avoided of course. All of that changed.

Also I noticed more flats during and after rains - it wasn't the water obviously, so it must have been whatever the water had scattered about. I'd just ride over it, through puddles, whatever. But that has changed also; I don't ride over anything, including twigs and acorns but certainly not sticks or anything I can't easily see.

So, from flats every month or sometimes much more frequently, to one or none per year (riding every day) the tires made a little difference but the real fix was in how I ride, and where I avoid riding. That may not be of much help, but look for even short sections where you might be riding over something. Glass and thorns especially; even the "clear" areas can have slivers that aren't necessarily visible.

Retro Grouch 

You need to figure that out. There are three types of flats:

For most people, the most common is a puncture. It reveals itself as a single hole in your inner tube. Outside of the inner tube = a thorn or wire or piece of glass. You need to make sure that whatever caused the hole is gone. 3 flats in 230 miles makes me think it might still be in there. Tiny wires from radial arm tires commonly cause such flats and can be hard to find and dig out. Many riders install their tires with the label aligned with the valve stem partly so they can see if they are getting repeated punctures in the same place relative to the tire. Sometimes the hole is on the inside circumference of the tube. If that's the case, look at the rim strip on your rim. It has to completely cover the spokes and every tiny little crescent of spoke hole in the rim.

The second type of flat is an impact flat, sometimes called a snake bite. It's mark is 2 tiny parallel slits in the inner tube. If your tires are under inflated and you hit a pot hole or a curb or something, your tire can collapse at that spot and pinch the inner tube against the rim. If you get a lot of snake bites, you should increase your tire air pressure.

The 3rd type is a star. That's what happens whey your inner tube finds a way to escape between the tire bead and your rim. You'll know it immediately when that happens. They are all too common and result from improper tire installation. You need to be careful that no part of the tube is caught between the tire bead and rim seat.

BlazingPedals

More likely, 75 psi is pretty low and he's getting pinch flats. What is the rated pressure printed on the sidewalls? First thing to do is pump it up to the max pressure. If flats go away, problem solved.

Pinch flats, aka 'snakebites' are characterized by two small holes in the tube, like from a snake's fangs. With a snakebite, there is usually no hole in the tire, just the two in the tube. They're caused by the tire bottoming out and the tube gets the holes bludgeoned in it by the rim.

tajar66

I found the tire Giant uses easily penetrated by stuff. I was getting a flat every ride, switched to Gatorskins and haven't had a flat in a while.

AlexCyclistRoch

When it comes to tires, there are 3 things you need to consider:

1) Price

2) Durability (and flat protection)

3) Ride/handling

Now, pick which 2 are most important, because you'll never get all 3. In your case, you seem to need durability. There are cheap tires that are durable, but are about as supple as a garden hos (cheap Chinese makers, like Kenda come to mind), and there are expensive tires with kevlar belts, but they cost $40/tire or more, but at least they ride well.

Viich

75psi is NOT low for 32mm wide tires, and I highly doubt these are pinch flats. I ran less in my 27x1 1/4 (=32mm) last year, and I run exactly 75psi as target pressure in 28s - and I don't top up every day. I average maybe a flat per wheel per year now. I'm only riding a few thousand km in a year, but still.

I'd guess an embedded object in the tire or a rough/sharp spot on the wheel itself are the most likely causes.

Wildwood 

Schwalbe Marathon Plus in a 32mm @100psi on my tandem that carries 350lbs of human - road and hard-packed offroad is OK too.

Scarbo

+1

This is key. You just have to ascertain exactly what kind of flat you are getting before anybody can begin to advise you properly.

jgwilliams

So, all of this proves that if you laid all the cyclists in the world end to end they still wouldn't reach a conclusion!

fabiocortez

LOL, the only people who could assure me that bigger lower psi tires would do better with impacts is same people who actually sell these tires but even they wouldn't give me a straight answer.

I love my bike, it's real fast, but it doesn't handle bumps well at all.

the punctures are caused by bumps, nothing sticking into or through the tire,

I'm trying slime, if that doesn't work I will upgrade to 38mm tires/tubes that run at a lower psi.

rm -rf

The first thing to do: determine the cause of the flats.

It helps to have the tire's label lined up with the valve. So, a hole in the tube can be matched up with the location on the tire itself, to look for an embedded piece of glass (which can be hard to see).

Alternatively, mark the valve location on the tire before you remove it, or just remove one bead, leaving the other bead on the rim.

The usual causes:

1. A loud bang, and a big slit in the side of the tube:
The tire bead came off the rim, allowing the tube to blow up like a balloon, and pop. It doesn't sound like what you had.

2. Glass, thorns, or sharp rocks. (or tiny pieces of wire from a truck tire, these often cause flats that very slowly lose pressure.)
The hole is on the outside of the tube. Pump up the tube, and hold it up to your face. You can either hear the air escaping, or feel the air on you cheek. Very tiny punctures can't be located this way, so submerge the inflated tube in the bathtub and look for small air bubbles escaping--wipe off each bubble, and see if it comes back on the same spot.

If it's a big cut in the tire, it will let the air out fast, and be kind of obvious even before you remove the tube to check it. But many punctures are small, from slivers of glass, thorns, or bits of metal.

A very small hole could leak air slowly, going flat at a slow rate.

You have to find the embedded sharp piece, or the hole in the tire that matches up with the tube puncture. You may need to poke into the hole or bend the tread to see if anything is still in there.

If you don't get it out, you'll get another puncture very soon.

3. Pinch flats.
The hole or pair of holes is usually a small slit, maybe a few mm long, and either on the side or the inside part of the tube.
Slamming into a pothole or big rock, the tire tread is flattened out against the rim, and the tube is pinched in between, making a slit.
The slit is usually big enough to make a hissing noise, and go flat quite quickly.
The tire itself is usually undamaged.

Avoid sharp edged potholes, and keep the tires inflated correctly.
Your 70 psi on a 32mm tire is fine, and could actually go a little lower.

4. Rim tape problems.
The rim tape or rim strip covers the spoke holes. If it shifts out of position, the tube is forced into the hole, causing a puncture. Even just an edge of a spoke hole peeking out can do this.
This is on the inside of the tube.

Are you hopping curbs or slamming into potholes or bigger rocks at speed?
Do the tires have damage, with frayed and cut threads?

It sounds like pinch flats -- see the pinch flat diagnosis above. The cuts are on the inside portion of the tube? A pair of slits side-by-side is most common, but sometimes there's only one.

Normally, a pinch flat starts hissing within a few seconds of hitting the object, so it's usually obvious what happened. Occasionally, the slam just makes a weak spot in the tube, and it doesn't start losing air right away.

But you mentioned you unweight the bike, so I'm surprised you get pinch flats at all. Mostly the back wheel? (It's easier to unweight the front wheel, so the back often gets slammed.) Hitting sharp edges, like a squared off rock, a manhole cover's edge, or a curb, are more likely to pinch flat than a rounded off pothole or a round rock.

Flip Flop Rider

replace the tires

the tires were set up correctly from the bike shop and they are flatting. You could do research and collect data for a while but the bottom line is the tires are flatting, change the tires!

Conti Gatorskin Hardshells and Schwalbe Marathon Plus..have 2 bikes with these tires on them and don't get flats

spending money on tires is a given, look for deals

fabiocortez

Thanks for the reply, I'm almost 100% sure these flats are caused by impacts and/or riding on rough terrain. I am not slamming the bike into bumps I'm as careful as I can be but there are still alot of smaller bumps that I do hit, I try best to avoid them. I do unweight the bike or I completely just get off the bike and walk it through some of these areas, or I find a shortcut.

For now, I'm trying tube sealant, if that doesn't work I will upgrade my tire and wheel set, and because of your advice I will try running a slightly lower psi. I rode 13 miles yesterday all over town with no problems, it was a pretty bumpy ride and tires are still holding air, I always check them before going on rides.

BlazingPedals

You seem to think that running lower pressure will be part of the solution. If you insist, then go for it. It seems you already have your heart set on fatter tires at lower pressure. And it may work. But just pumping your tires up to 90 psi would be FREE to try and might fix your problem.

fabiocortez

I'm keeping 75 psi and added some slime to the tubes, which seems to be working great. I am mostly sure my flats were just from hitting bumps too hard but either way things seem to be going well. If this keeps working I will stick with the 32mm tires.