Frequent Punctures problem - New Bike



rvijay07

New Member
May 10, 2007
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I recently got a Nakamura road bike for $460 including taxes. After I put a rear fender/sear carrier on it, it has begun to have a lot of punctures, everytime the puncture is on the side of the tube closer to the rim. The first time, even the rim pate was pierced. So the mechanic sand papered the inside of the rim to ensure that the spokes are not sticking out. Still the punctures continue. Punctures are always on the back wheel. Sometimes they even happen when the bike is parked at home and is stationary. Last time the manager himself replaced the tube and wanted to observe what happens. I went on a ride adn in 8 minutes the back wheel was flat. The Manager felt perhaps it can be my weight (approx. 200 lbs) is the issue. He told me last time, if it happens again, the store will buy for me the rim tape and also special puncture resistant tubes. Tires are 700c x 26c.

By the way, the 15 day period to return the bike is over. This store has a lot of repute and is located in a Central area, so I trust in their sincerity/service.

What can be the cause of the problem ? What is the solution ?

Any suggestions, related experiences/sites are welcome.

Thanks in advance.

Vijay
confused.gif
 
This definitely sounds like a spoke that is too long. Is it always punctured in the exact same spot on the tube? If so, you should be able to identify the spoke and replace it.

If it moves around on the tube, then you probably do not have enough spokes for your weight. For a 200 lb rider, your wheel should have at least 32 spokes. If all else fails, I would try to get the bike shop to replace at least the rim.
 
rvijay07 said:
I recently got a Nakamura road bike for $460 including taxes. After I put a rear fender/sear carrier on it, it has begun to have a lot of punctures, everytime the puncture is on the side of the tube closer to the rim. The first time, even the rim pate was pierced. So the mechanic sand papered the inside of the rim to ensure that the spokes are not sticking out. Still the punctures continue. Punctures are always on the back wheel. Sometimes they even happen when the bike is parked at home and is stationary. Last time the manager himself replaced the tube and wanted to observe what happens. I went on a ride adn in 8 minutes the back wheel was flat. The Manager felt perhaps it can be my weight (approx. 200 lbs) is the issue. He told me last time, if it happens again, the store will buy for me the rim tape and also special puncture resistant tubes. Tires are 700c x 26c.

By the way, the 15 day period to return the bike is over. This store has a lot of repute and is located in a Central area, so I trust in their sincerity/service.

What can be the cause of the problem ? What is the solution ?

Any suggestions, related experiences/sites are welcome.

Thanks in advance.

Vijay
confused.gif
Are these namebrand rims? I don't understand why your rims don't have rim tape to begin with:confused:. That's the first thing they should of done, besides finding the long, sharp spoke end. I might wonder about the spoke count/weight thing. 200lbs. isn't to heavy. My son rides on way less than 32 spokes on Xero Lites and he is pushing 215lb. He hasn't flatted once. Try pumping your tires up near the 110psi mark if they'll handle it. You might be pinching just the tiniest bit on a rough spoke end. Any large flex in the tire might aggravaite the issue. But definately rim tape is a must. Ideally clothe. My 2¢....:)
 
rvijay07 said:
Sometimes they even happen when the bike is parked at home and is stationary.
Definitely a spoking/rim tape issue if that happens. It's not your weight or the rear fender.
 
I've seen twice in 2 months now where a low end rim manufacturer uses a hard plastic as rim tape. Where the valve goes through the rim the plastic is VERY sharp & in both cases was poking a hole in the tube at the valve "reinforced" area. If it's a clear plastic rim tape remove it & buy a better one from your LBS. 2 bucks per rim should cover it. (ha, I made a pun!)
 
Lionfish said:
I've seen twice in 2 months now where a low end rim manufacturer uses a hard plastic as rim tape. Where the valve goes through the rim the plastic is VERY sharp & in both cases was poking a hole in the tube at the valve "reinforced" area. If it's a clear plastic rim tape remove it & buy a better one from your LBS. 2 bucks per rim should cover it. (ha, I made a pun!)
The rim tape is made of rubber in this case. However, yes a good number of times, the punctures occured closer to the valve.

Vijay
 
rwinthenorth said:
Are these namebrand rims? I don't understand why your rims don't have rim tape to begin with:confused:. That's the first thing they should of done, besides finding the long, sharp spoke end. I might wonder about the spoke count/weight thing. 200lbs. isn't to heavy. My son rides on way less than 32 spokes on Xero Lites and he is pushing 215lb. He hasn't flatted once. Try pumping your tires up near the 110psi mark if they'll handle it. You might be pinching just the tiniest bit on a rough spoke end. Any large flex in the tire might aggravaite the issue. But definately rim tape is a must. Ideally clothe. My 2¢....:)
It has a rubber rim tape but that doesn't seem to be doing a good job so far. If I pump to near 110 psi and the pressure drops further during the ride, then the ride may not be that good, also regular punctures can happen.
 
kdelong said:
This definitely sounds like a spoke that is too long. Is it always punctured in the exact same spot on the tube? If so, you should be able to identify the spoke and replace it.

If it moves around on the tube, then you probably do not have enough spokes for your weight. For a 200 lb rider, your wheel should have at least 32 spokes. If all else fails, I would try to get the bike shop to replace at least the rim.
Yes, the punctures move around, either close to the valve or at its opposite end.

I think they are hesitant to replace the rim/wheel immediately. What if the same issue occurs with the replaced wheel ? For eg., we can try changing the front and back wheels as a trial to see if the same issue persists.

Just counter, 32 spokes on the rim, probably one or two more. Also, on the rim is written PLYER.
 
rvijay07 said:
Yes, the punctures move around, either close to the valve or at its opposite end.

I think they are hesitant to replace the rim/wheel immediately. What if the same issue occurs with the replaced wheel ? For eg., we can try changing the front and back wheels as a trial to see if the same issue persists.

Just counter, 32 spokes on the rim, probably one or two more. Also, on the rim is written PLYER.
They're not interchangeable because of the gear cassette issue. Are you losing air during rides as you mentioned above? That's a different issue. 110psi is well within a 700cc rim/tires abilities. I'd still try the clothe rim tape and see what happens.
 
rwinthenorth said:
They're not interchangeable because of the gear cassette issue. Are you losing air during rides as you mentioned above? That's a different issue. 110psi is well within a 700cc rim/tires abilities. I'd still try the clothe rim tape and see what happens.
Yes, you are correct, they are not interchangeable.

I requested the manager to get the rim tape/better tube, install then and then see what happens. They have placed the order and we are waiting for it to arrive.

Vijay
 
A general question, will use of the rim tape solve the problem, or will down the road tehre will be more problem with the spokes poking more and causing punctures ? If this happens then the wheel itself could be of bad quality. Can the wheel break then ? Please adviced.

eek.gif
 
rvijay07 said:
A general question, will use of the rim tape solve the problem, or will down the road tehre will be more problem with the spokes poking more and causing punctures ? If this happens then the wheel itself could be of bad quality. Can the wheel break then ? Please adviced.

eek.gif
I couldn't promise no failure on a wheel I've never seen, but it's unlikely any failure of the wheel would occur or spokes moving around. Really this is not as big an issue as it may seem. I had this problem with my original Mavics. I just replaced the rim tape, which was plastic, with good quality Velox cloth tape. I then checked the rim myself for rough places and spoke ends. After that, the issue went away. If it happens again, save the tube and put some air in it then squeeze. You should hear or feel air coming out. Check the location of the hole or slit against where the valve stem has been inserted into the rim hole. You will find what is causing the punctures. This is a great exercise in starting to do a little maintenance yourself. Also, I think it's important to know how to change a tire in the field. Even the best wheels and riders pick something up along the way and being 40 miles from home out in country backroads doesn't make it any easier. Good luck.:)
 
rvijay07 said:
Yes, the punctures move around, either close to the valve or at its opposite end.

I think they are hesitant to replace the rim/wheel immediately. What if the same issue occurs with the replaced wheel ? For eg., we can try changing the front and back wheels as a trial to see if the same issue persists.

Just counter, 32 spokes on the rim, probably one or two more. Also, on the rim is written PLYER.
I apologize if the following proceedure is what you are already doing to diagnose your problem. It does appear to me that your approach is not as rigorous as the following, but I could be wrong about that. I hope this helps you find your problem:

You need to start relating - exactly - between the rim, the tire, and the tube to diagnose your problems. If you are not already doing so, start installing the tire so that the tire label is centered - as close as you can get it - on the valve stem (and, resultingly, on the rim's valve hole). When you flat and remove the tube, make sure you keep the tube lined up with where it came out of the rim. Now take the flatted tube and pump it up until it leaks. Once it starts leaking lay it over the rim and tire and begin inspecting very carefully. Using a magnifying glass and a bright light is not a bad idea. The causes of your punctures should start identifying themselves clearly by doing this in a meticulous manner. Take the guess work out of your flats and start diagnosing them properly.
 
I returned this bike and got a Touring Road bike. This fitted my needs better, also the store made more money. This was a win-win.
 
I would think something was wrong with the rim. I wiegh in at 220lbs and ride a 24 spoke rear wheel and have never had a flat and I ride with 120psi in my tire.