Yesterday morning I flatted not once, but TWICE (was only carrying one spare tube)! In general, I sure have been flatting a lot, especially recently and wanted to see what you all thought of Specialized Mondo Pro II Tires? They're almost new and I don't have any impression of them either positive or negative other than I keep getting flats. Rear tire every time, never the front. Several times I could not find any puncture through the tire itself. A few times though I had sharp rock / gravel that punctured through the tire. Could be the other times this is also what happened but the offending debris fell out before I found it. Or maybe I'm getting pinch flats? I have no idea. I generally don't waste time inspecting the old tube, rather focusing on the tire and making sure nothing is left that is going to puncture the new tube. I inflate to 125 psi rear 120 psi front. Is this not a good tire? Are there other tires that are significantly tougher? Why do I always flat on the rear and never on the front? My guess is because the rear is carrying more of the load?

I got that tire as stock on my Tarmac. I weigh 145lbs and they worked fine for me. After about a year of riding colored sidewall part of the tire was all cut up, but it didn't cause any flats. I think I got three flats in the year that I rode them.


I'll warn you that I did replace them because a bubble formed in the center of the tire mid ride and then about 10 minutes later the tire ripped and the tube experienced some explosive decompression. I almost went down. This was after about 1200 miles on them.


And I run them around 95-105 psi, so unless you're way over 200 lbs, you're probably running too high of pressure

here's a good read about your problem

https://18milesperhour.tumblr.com/pos...-flats-come-in

it pretty much sums up everyones frustration

Flats come in bunches. I went through a month where I probably got 8 flats. Then recently, none for the past four weeks or so (I have been averaging over 300 miles weekly all through July/August).

Then sometimes there's a persistent cause you are missing. Could be a rough spot on your rim strip. Could be a microscopic piece of glass or wire that you failed to locate and extract from the tire casing after a recent puncture (they can be hard to locate and find, sometimes you have to look in small cuts in the tread and dig them out). For me it sometimes tends to be tires that may not look so bad at first glance, but they are really worn. Worn out tires create flats several ways: small cuts in the sidewall and casing that abrade inner tubes, and more pinch flat because the kevlar tire beads are old and limp and don't seat as predictably when you mount a new tube. This latter phenomena is greatly exacerbated if you ride deep dish carbon wheels (anything from 38 mm and deeper).

When in doubt replace the tire. After that replace the rim strip. If all that fails, consider it a perfect excuse to buy new Zipps.

Carry a patch kit.

1) Make sure your tires aren't worn so thin that every sharp object goes through them.
2) Start adjusting your tire pressure. For me, flats got very seldom after I started running 95 front, 105 rear.
3) Stop riding through debris.

Have you checked the sidewalls of your tires for cuts? Even a tiny hole not larger than a pin prick will cause a flat over and over again until you use a tire boot. I would take the tire off, swab the inside with rubbing alcohol, and look for a cut that a light can shine through.

It's just a guess, but in my experience, when you are having lots of flats in a short time frame, they are all caused by the same thing rather than just puncturing in a different place each time.

I recently went from carrying no spare tubes, co2, etc (i ride a regular out and back close to home and figure I can always call the wife for a ride...never wanted to be changing flats on the side of the road) to carrying a spare tube and co2, to now considering getting a bigger seat bag so I can fit in two tubes and two co2 cartridges!

1] My tires are practically new
2] I always thought higher pressure was better...will think about it
3] I ride a pretty nice road with not much debris

I think everyone who has a lot of miles behind them has had your problem. I have replaced tires to solve the problem. Sometimes you will eventually find a cause. Try to always mount the first letter of the tire Name even with the valve.
Remove the tube and find the hole.
Then without removing the tire, lay the tube on the tire, valve by the first letter of the name and you can see where the puncture was made in the tire. That will be a clue for future flats. Good luck.

Yeah I was thinking that too...that they must all be related but I run my fingers up and down over and over inside my tires to feel for anything until I'm sure there's nothing. Then I visually inspect the outside to see if there's anything stuck in that I couldn't feel from the inside. Not saying that I'm not missing something, but I am trying to make sure this is not the case.

The tires that come on the tarmac are terrible. All of specialized's tires are pretty bad imho. I had about 6 flats in the first week with my new tarmac. Replaced tires, and it hasnt been an issue since.

I'm about 160-165 lbs so maybe I could drop tire pressure a little?

use tire sealant. I got a puncture a few weeks ago and didn't even notice it till I got home.. where I comfortably repaired it in my chair...

It also depends on the size and model of the tire, but 95/105 worked for me on most tires when I weighed 150-160 lb. 100/110 after I ballooned up to 180.

I used to think the higher the better, but that's not true for a variety of reasons. It's actually slower, rougher, and apparently can push more against sharp objects to help them penetrate the casing. You just also don't want to go too low, or you start getting pinch flats.

Next time you mount a tire, make sure you line up the tire badge with the valve hole. That way, next time you flat, and the cause is not obvious, you can find the puncture in the tube, and line it up with the matching spot on the tire, and then see if there's a tiny wire or piece of glass or whatever. This has helped me several times.

You'll know if you're pinch flatting, because the puncture is always a snake-bite pattern of two holes where the tube was pinched.

It is possible to have crap in your tires (usually tiny shards of glass or wires picked up from the road) that you can't feel or see, but that are still in there. Are you flatting in different places on the tube/tire? If so, you're just experiencing bad luck. If you don't know, you should always keep track of where the leak is by paying attention to the orientation of the tire and the tube.

Also remember to visually inspect the tire before running your finger inside it. I recall a thread where someone found part of a hypodermic needle in his tire, and was glad he saw instead of felt it.

I had a real bad string of flats - I've had about 9 since I first got my road bike in March - about 1500 miles. The first one was a pinch flat - about 2 weeks into owning my bike I realized I didn't have a gauge that went past 50 and I was riding with too low pressure. After I finally bought a pump, I had another flat the first day I pumped it full. That one I patched, and then 3 days later I had another flat. It was when I saw the green "scab" pushing through the sidewall of the tire I realized what that problem was. This was an conti ultra sport. I got a 4000 to replace it, but was still getting lots of thorns, glass, flints, etc.

Finally, a few weeks ago a buddy of mine says "You need to look into Mr. Tuffy liners or something". So, $16 and several hundred miles later and I haven't had a flat since.

Just yesterday, I was riding back from about 30 miles and I was thinking "I sure don't remember this road being this rough" and when I got home I inspected the tire and saw this little guy poking out:



You can't see it from this picture, but the head of the nail was worn completely off - I'd probably ridden that way at least 2 miles.

[edit]Rode another 40 miles this morning on the same tire without any issues. I went to top it off with air before I left and it didn't even need it[/edit]

Yesterday, I was towing the little guy in the trailer and thought he was squirming around a little more than usual, but every time I looked back, he was sitting still. It wasn't until I got to a quieter area that I realized the trailer had gotten a flat. 2 thorns had been picked up about 2-4 miles back.

I hate that - I was hauling my son in the trailer last weekend and the same thing happened. I don't usually move my patch/repair kit over to the commuter bike when I use it, and I didn't carry a frame pump on it either. Fortunately, it was a slow leak and I made it home without too much of a struggle. But the lesson was learned and that bike/trailer does not leave the garage without tools.

1. check the tire very throughly for debris, cuts, and whatnot. take the tire off the wheel and turn it inside out for this.
2. check your rim tape for something under it or a spoke nipple protusion. if neccesary replace it.
3. if your using tire valvestem nuts, do not tighten them down all the way. the valve will get sliced on the edge of the rim.
4. bring your wheel to your lbs and have them retension, dish, and true your wheel.

Putting tire liners in good racing tires is a total waste. If you're willing to use tire liners, you're better off starting with flat resistant tires as they'll be much cheaper, easier to use, more flat resistant (with tire liners, you're not getting any sidecut protection), and you'll get far more miles out of them.

The whole point of inspecting the tube is to know what caused the flat. Until you know, you can never be sure the same exact thing won't cause another flat.

So true.

We've just finished a credit card tour of Vancouver Island and each of us had an inordinate number of flats riding the Trans-Canada Highway which had a large amount of debris ont he shoulders.

The causes of each flat were different. A pinchflat for me after running over a large piece of gravel; a piece of sheet metal shaped like a spear for Machka; a Michelin wire for Machka; a thorn from a bramble for me (with another right next door set to have another go); and a staple for me right at the ferry that brought us back to the mainland.

We have our routines in fixing flats, and they include aligning the valve with the brand on the casing, inflating the punctured tube (so it's good and fat) and checking the position of the hole against the tyre. Pinch flats, of course, are really obvious if there are two holes.

But one of the key elements in reducing flats is to watch where you are riding, and try to avoid debris. In some cases, it becomes almost impossible (as was the case on some parts of the Trans-Canada despite the wide shoulders). But in many cases, glass, gravel and rubber from blown truck tyres are quite obvious and can be avoided.