4 flats in a fortnight
 

http://bikeforums.net/attachment.php...hmentid=288059

So I bought this bad boy about a month ago for next to nothing, and since then I've fully serviced it including brakes, gears, new chain, new tyres and spokes alignment. But after six rides I've come away with four flat tyres. While two came simultaneously from hitting a decent-sized pothole, the other two seem to have come out of nowhere. It's frustrating as hell because I keep getting stranded miles away from home, and it's getting costly forking out for new tubes. It's a 1980(ish) Nishiki Aero with a 56cm frame - I'm 172cm and 76kg - Am I too heavy for this bike? Or are the old alloys just simply too weak? Any other suggestions as to how I can prevent further flats? I just use it for road riding

Cheers,
Ryan

Sounds like pinch flats,please check tyre pressures,keep `em high:thumb:

Thanks Grishnak, but they've been pumped to 110psi as recommended.

It seems incredibly unlikely that you are too heavy for that bike. The alloys have nothing to do with flat tires. What's causing the flats? If there are two small holes near each other, this is commonly called a snakebite flat, and is caused by insufficient tire pressure for your weight and the terrain you've ridden over. I am a similar weight and height, and on 700x23mm tires I typically run 90/120PSI (front, rear) and I don't think I've ever pinch flatted at those pressures, despite hitting some minor pot holes etc at speed. Try increasing your tire pressure and/or running wider tires.

If it's just caused by punctures from road debris: A) avoid as much as possible: B) buy tires with better flat protection. The schwalbe marathon line is well regarded, as are conti gatorskins, though I've personally never run either. I find where I ride that road debris doesn't cause so many flats that I need especially resistant tires.

Also, it is bogus to replace tubes every time you get a flat. Spend a few bucks and get a flat kit. If you've done all that work on your bike, you can figure it out. Seriously patched tubes are good as new.

Other things to check would be any burrs in the rim, or badly applied rim tape.

Sweet looking bike, nice score.

Thanks cpach. I'm thinking you could be on the money with the rim tape thing. Does this look a bit dodgy?

I can patch flats now, so I have something when I'm on the go, but I can't help but think there must be another way to prevent these flats. I don't think it's tyre pressure related as they're at 110 front and back, and I have brand new gator skin tyres. There's been barely any debris on the roads I've been using, but there is the odd bump. I don't know why the bike's been so sensitive. But maybe it could be the rim tape. Photo is attached.

http://bikeforums.net/attachment.php...hmentid=288061

I do have the gatorskins.

I don't see anything wrong in that picture. The problem with the rim tape would be it not fully covering all the spoke holes. That's at least legit rim tape. Also there could be a burr somewhere inside the rims.

Conti Gatorskins with a rider your weight at 110PSI should only flat with really pretty extreme impacts or with very obvious punctures.

One trick is to see if punctures are recurring at the same spot on the wheel. Aligning the tire label with the valve stem helps in doing this. Anytime you get a flat you should check the interior of the the rim, tape, and the inside of the tire in the area near the puncture.

Ryan, Adding to the above, sometimes we just have the worst of luck WRT punctures. Use a cotton ball to determine if anything in the tire is causing the flats. Just lightly wipe it along the inside of the tire, or any other tube contact points and it'll leave a tuff of cotton if anything is still protruding through the tire. Check the bead as it could've been damaged by the pothole.

Brad

+1 your rim tape looks perfect.

Are you getting small punctures, or blowouts?

When you mount the tire, before inflating, check both sides very carefully all the way around the rim to be sure you haven't pinched the tube.

Finally, everyone flats at least occasionally. Get yourself a good frame pump or CO2 kit and carry a spare tube and levers! The old adage is carry that stuff, or only ride as far as you'd like to walk home.

Nice looking bike!

btw I once had a crazy run of bad luck like you're having, and it seemed to be the particular marriage of rim and tire I was using. I can't explain why, but in my case, switching to Gatorskins cured it. If all else fails you might try a different tire and see what happens.

Flats are random events...unless there is a underlying mechanical cause like rim tape or failure to remove the puncturing object. Others have covered this. I'll cover technique.

You say that 2 flats came from 'hitting decent-sized pothole(s)'. Therein lies some of your problem. You aren't particularly heavy but you can still do damage to you tires, tubes and wheels if you don't ride properly. Hitting a pothole hard enough to cause a pinch flat says to me that you are sitting on the saddle like a sack of potatoes and letting the bike take the impact. You need to ride 'light' in the saddle by using your arms and legs to absorb the shock of impacts. You don't 'sit' in a bicycle saddle like you would a chair. You hover over the saddle most of the time and when you see an impact coming...you should be watching for them too...you lift your body up and used flexed arms and legs to absorb the impact. Your body's suspension can provide several inches of travel and allow the bike to bounce upward on impact so that the wheels don't take the brunt of the hit.

I'm a lot heavier then you and I ride bikes with lower pressures but seldom experience pinch flats. That's because no matter what bike I ride...mountain bike, road bike, commuter bike or loaded touring bike...I always ride light in the saddle. I even jump mountain bikes and seldom set down with a KERTHUNK! because I let my arms and legs absorb the impact.

Just to add to the good advice above watch were you are going and avoid holes and other objects best you can that will help the most!

Thorn resistant inner tubes are heavier, because they are much thicker, but they hold air longer
and will resist punctures long enough to stop and pull out the offending glass shard.

Just to verify, you did check the pressure right before the ride correct? I can pump up my road tires and they will be down 20-30psi in a day or two. The air leaks out of road tubes pretty quickly. Other than that, I agree with others to check your tires for something that is still in there from a previous flat. Also, why not carry a small flat kit with you out on rides. That will prevent being stranded when you flat.

Pump your tires up before each ride.
After a flat analyze until you know exactly what caused the flat. Is the hole on the rim side or the tread side? Where is the hole relative to the valve stem (index the tires as cpach said in post #6). There is a reason for every flat. Most flats could have been avoided.

Thanks for everyone's tips. It was a tiny hole on the seam of the tube, must've been a bit of debris floating around. I've given it a good clean but didn't find anything. No spokes are sticking through the rim tape either. I reckon it must've been a tiny shard of glass or something. I have a patch kit and small pump now just in case. Fingers crossed I can finally finish a long ride!

Good luck with your ride! Also, one thing I have had before was a little piece of glass that only showed up whenever I flexed the tire. If the tire wasn't flexed, the glass was completely hidden in the rubber. Whenever it flexed, such as when you would hit a bump or have it compress just wrong, the glass would puncture the tube. An easy way to check for this is to bend the tire at any points where you see small cuts and look for something shiny in them. You didn't buy really cheap tubes did you? Once, I had 2 out of 4 really cheap tubes in a pack that had small punctures in seams near the valve when they were brand new. Luckily, I found the leaks whenever I put a bit of air in them before installing.