Rear tire flatting

[bikeoutback]

I've had about 4 flats this year and it's getting old. I think they are due to running low tire pressure and believe the last two had slow leaks in them which caused them to get too low. I would notice the tire "bulging" while sitting on the bike and would pump it up further just about each time I rode. Then it'd be fine for a couple days. The bike has the tires that came on it a year ago and I'm trying to decide if I maybe need to get new tires, possibly the side walls just aren't stiff enough for my weight, I'm around 260. Do I just need to run the tire pressure higher till I drop a few pounds? The last flat I got I was tooling around the driveway making sure everything was in working order and hopped off a curb and landed just to one side and almost lost the bike right under me, filled the tire pressure up to about 45psi and was tooling around fine, checked an hour later and it was completely flat. I haven't taken it off to check the tube yet, but I'm guessing either the sideways off the curb either damaged the stem or I pinch flatted it somewhere. I guess I'm wondering if I should try new tires or if I should run up around 45-55psi (this is where it seems fine) due to my weight? Maybe I should just run it into Erik's and have them change this one just to be sure there is nothing else wrong?

Thanks
Chris
p.s. I have not had a single flat on the front, rear rim checked each time flats, no "sharps" on it. Front has always been adjusted to run same pressure as the back or at least close.

[Magic]

Chris, try bumping up your tire pressure. Also when you change your tube, put some baby powder in the tire and make sure it goes all the way around the inside of the tire. Doing this helps the tube not stick to the tire over time and will help with pinch flats.

[TrailSquirell]

also, if you want to get rid of flatas completly and beable to run 30 psi wihtout gettin a flat, buy a downhill tube and get a 2.3 tire. you can find light downhill tires that are 2.3 that have exelent traction for xc, like tioga factory downhills. your going to gain a lil weight, but its worth it in the long run.

[Kosk]

Do like Troy said and run higher pressure.

Also, you may have already done this, but didn't mention it so I will: Be sure to pull the tire off completely and inspect the inside of the casing to see if there is a small thorn or piece of glass sticking through to the inside. It may not be visible from outside inspection. If there's nothing sticking through the inside of the tire, and your rim/rim-strip is also clean and covering all the spoke holes, then the only candidate for a "slow leaker" is cronic pinch flats. This is easily fixed with higher pressure / larger volume tires.

[bikeoutback]

thanks for the advice, I forget what size tires it's running stock, They are 2.x is what I remember. I've also checked the rim and tire for anything sharp by running my hand through it with a glove and then just to be sure I checked without a glove even at risk of cutting myself I wanted to be sure. I'll throw on some baby powder and up the psi this time. I may still consider the tires also, been thinking of turning the old one's into studded before they are actually worn. Maybe I should just ride the bike more instead though.

[SpecHR55]

Take of your tire an see if theres metal shavings, rocks, etc. stuck to the rim that could be piercing your tube. That caused my dad 3 flats in a hour road riding. He just brought it to a roadside mechanic and they ground out the inside of the rim so its nice and smooooth then put another thing of tape around it.:cool:

[Fast1]

First thing you should do is determine where your innertube is leaking from. Find the hole. This should have been determined with all your flats. Once you know where the tube is being punctured you can remedy the issue, some of which have allready been mentioned.

Without knowing the source,, you would just be guessing on the solution.

[seejames]

You could also spend the extra $$$ and go tubeless. No pinch flats with those, and you can run pretty low pressure on them without worry. Otherwise, Troy's suggestion of baby powder is pretty good advice.

[Fast1]

Chris, try bumping up your tire pressure. Also when you change your tube, put some baby powder in the tire and make sure it goes all the way around the inside of the tire. Doing this helps the tube not stick to the tire over time and will help with pinch flats.

The problem I've had with this is that patching a tube with baby powder on it becomes more difficult to ensure adequate seal.. unless you have allot of time on your hands.

[bikeoutback]

Okay, I put a brand new tube on last night about 2 hours before the night ride at Leb. Checked the entire rim twice and the inside of the tire casing twice for any possible thorns, glass, etc... and found nothing. Put on a brand new tube and pumped it up to 55psi, tire says run between 35-80psi so figured 55 was a good spot. Rode Leb intermediate and X loop just fine. Since I skipped XX that everyone else took I got back to lot early and decided to run that little loop just off the lot, half way in, pssss and tire goes flat. I take it all apart this morning and check the spot the flat is on, nothing, check rim and tire fully again, place in another brand new tube and fill to just over 50 psi. Go ride Salem today, get about quarter mile from end of trail and pssss again. Erik's will only look at it for $13 to check everything I have already, about 16 times in the last few weeks. This is gettting old!!! I have a $150 mongoose bike I ride pavement with and loan a buddy to ride trails here and there. It is on original tubes and tires after 6 years (4 of them hanging outside) it has NEVER had a single flat, yet I pay good money for a bike and can't even ride 5 miles without a flat tire, this sucks. Well for now I'm just riding pavement, too pissed off to go buy tubes again. Maybe once I buy tubes I'll bring the flat to a group ride and see if someone can look at it for me, but I've been over the rim and tire I swear about 16 times in the last few weeks. Next tube going in also is getting baby powder try also.

[kenn40mpls]

When I change a tube, I inflate then deflate it about three times. Inflating and deflating the tube like that straightens the tube out from possible twisting. Use the baby powder. Sometimes I wrap black electrical tape a few time around the rim to cover the nipple ends. Best-o-luck.

[Ala Carte]

I would bet you have the wrong rim strip. Most bike companies spec rubber strips on double wall rims. You will flat every time. Velox cloth rim tape is about $3 per wheel, give that a try. If you had it changed at a good shop, and they didn't check that for you, the tubes, tape and labor should be on them.

[Paul Swenson]

Did you say these are the original tires that came with the bike? If so you may want to get new treads since the ones that the bike companies are sometimes cheap.

I had the same problem when I bought my Lemond. I had a flat in the rear literally every 75 miles and the front was fine. I finally replaced the tires and have had 1 flat in the last 700 miles.

[Fast1]

Okay, I put a brand new tube on last night about 2 hours before the night ride at Leb. Checked the entire rim twice and the inside of the tire casing twice for any possible thorns, glass, etc... and found nothing. Put on a brand new tube and pumped it up to 55psi, tire says run between 35-80psi so figured 55 was a good spot. Rode Leb intermediate and X loop just fine. Since I skipped XX that everyone else took I got back to lot early and decided to run that little loop just off the lot, half way in, pssss and tire goes flat. I take it all apart this morning and check the spot the flat is on, nothing, check rim and tire fully again, place in another brand new tube and fill to just over 50 psi. Go ride Salem today, get about quarter mile from end of trail and pssss again. Erik's will only look at it for $13 to check everything I have already, about 16 times in the last few weeks. This is gettting old!!! I have a $150 mongoose bike I ride pavement with and loan a buddy to ride trails here and there. It is on original tubes and tires after 6 years (4 of them hanging outside) it has NEVER had a single flat, yet I pay good money for a bike and can't even ride 5 miles without a flat tire, this sucks. Well for now I'm just riding pavement, too pissed off to go buy tubes again. Maybe once I buy tubes I'll bring the flat to a group ride and see if someone can look at it for me, but I've been over the rim and tire I swear about 16 times in the last few weeks. Next tube going in also is getting baby powder try also.


Was the hole in the tube on the tire side or rim side?

[stoneage]

I gotta think that you have a tiny piece of wire imbedded in the casing. You may not even be able to feel it, but it lays just below the inside surface of the tire and eventually rubs through the tube. I have had the problem with road tires and wire and also with MTB tires and goat heads out West. You do have to determine where the puncture is occuring by taking the tube out and keeping it aligned with the tire. Fill it as much as possible and find the leak and see where it lies in relation to the tire. Then look at the casing at that point. Try turning the tire inside out and inspecting it that way. The demon may stick out a little more. Good luck.

[bikeoutback]

Was the hole in the tube on the tire side or rim side?

Rim side. I double checked everything again last night on this new one, rim side tiny split in rube. Checked tire casing entirely and specifically at the point of the hole, same on the rim and no evidence of anything sharp. The strip inside covers only the nipples and is marked 26x2.0. When I finally decide to go and pick up the stuff I'll try the tape, new tube, baby powder, fill and deflate 3 times before riding, and run 55psi again and see if I can get farther than 8 miles without getting a flat. Guess I'll look into some tires too while I'm picking up the tubes and get started on that research also.

[bikeoutback]

I gotta think that you have a tiny piece of wire imbedded in the casing. You may not even be able to feel it, but it lays just below the inside surface of the tire and eventually rubs through the tube. I have had the problem with road tires and wire and also with MTB tires and goat heads out West. You do have to determine where the puncture is occuring by taking the tube out and keeping it aligned with the tire. Fill it as much as possible and find the leak and see where it lies in relation to the tire. Then look at the casing at that point. Try turning the tire inside out and inspecting it that way. The demon may stick out a little more. Good luck.

I've been doing exactly that:
Remove tire, lay it so I know where valve stem aligns
Keep tube on rim, fill with air and find leak.
Check rim at leak spot, check tire casing by flipping inside out at leak spot
Check the rest of the rim
Check the rest of the tire, insert new tube and fill. Ride roughly 8 miles, walk to car with flat tire. Either I'm missing something very very small or something is wrong that I just can't figure out. Just frustrating when I know this is not a hard thing to do, if I can't even successfully change a flat tire..........

[stoneage]

Sounds like a pinch flat or nipple hole to me. Usually a pinch is two small parallel cuts (snake bite) and a rim strip void is a little semi circle cut. A badly finished (rare) rim hole could work through the tape and can be rubbed out with a peice of metal. Sorry for all your trouble.

[Don Youngdahl]

You haven't said whether the punctures are all in the same place relative to the rim and tire. If they're in the same place, then you should be able to zero in on the problem. If they are in different places, maybe the cycling gods are just dealing you a dose of bad karma. I once had 3 totally unexplainable flats on a 50 mile road ride, even after very close inspection with another old roadie with many years experience. Since then, I've ridden about 2000-3000 road miles without a flat. That said, I've probably jinxed my next ride.

Don Youngdahl

[bikeoutback]

You haven't said whether the punctures are all in the same place relative to the rim and tire. If they're in the same place, then you should be able to zero in on the problem. If they are in different places, maybe the cycling gods are just dealing you a dose of bad karma. I once had 3 totally unexplainable flats on a 50 mile road ride, even after very close inspection with another old roadie with many years experience. Since then, I've ridden about 2000-3000 road miles without a flat. That said, I've probably jinxed my next ride.

Don Youngdahl

I haven't said cause I haven't checked.;) I have to go get the old tubes out of the shed, the one from saturday night is either within about an inch farther away from the valve stem as sunday's or it's on the opposite side of the rim, if that makes sense. Basically I don't know exaclty which way the tube was on from saturday as far as direction.

[Fast1]

What type of rim strip tape is on your rims?

As another member suggested, if you are finding punctures on the rim side I would purchase some Velox rim strip tape and replace what you have on your rims now.

[bikeoutback]

What type of rim strip tape is on your rims?

As another member suggested, if you are finding punctures on the rim side I would purchase some Velox rim strip tape and replace what you have on your rims now.

I'll go pick some of that tape up, but I guess that's what is frustrating, pay what is alot of money to me for a bike and have it ride fine for awhile and then have a problem like this, and I suspect it's something along the lines of the rim strip not being thick enough or wide enough. Sometime this week I'll roll all the suggestions into it at once and give it a try again next weekend. Thanks for the help.

[Fast1]

If you purchase the Velox rim tape make sure you get the correct width for your rims.. they make several different widths.. some for road and some for wider mountain bike rims.

[Ala Carte]

The 17 mm will work for most mtb rims.

[bikeoutback]

Hopefully fixed. I went to the local LBS in Apple Valley for some velox tape. I asked the guy if I'd need to remove the rubber strip on the rim now. He asked how the spoke nipples looked on the rim, in my case they are sunk into a hole, double wall rim. He stated that the rubber stip shouldn't be there that it should be tape and it's a factory defect. What is happening is the rubber strip isn't thick enough and allows the tube to push slightly into the spoke hole and pinch causing the small holes I've been getting. He suggested I take it to where I bought it, so I did. The guys at Eriks didn't seem 100% sure on the rubber stip theory, but since I was convinced of it being the problem they without hesitation removed the rubber stip on the rim, velox taped it, put a new tube and got me all set, all at no charge. I'm very appreciative of what all they did for me. The real test will be tomorrow (pending trail conditions) but I'm confident that all will work well tomorrow. While at Erik's I did pick up another backup tube, patches to try on the tube's I've flatted, and I got a great deal on some shoes (50% off). So I now also own my first pair of Mountain biking shoes, now to save $ so I can get the petals to go with them.

[Ala Carte]

The guys at Eriks didn't seem 100% sure on the rubber stip theory.

Um, that is scary. Any half-way competant bike shop employee should realize that you cann't use rubber rim strips on a double wall rim. That would be my last visit to that "bike shop".

[bikeoutback]

Um, that is scary. Any half-way competant bike shop employee should realize that you cann't use rubber rim strips on a double wall rim. That would be my last visit to that "bike shop".

Well in their defense they did velox tape the rim, check the rim and tire casing and replace the tube for no charge and took care of me very well. I've had 3 issues with the bike in the last year that I couldn't take care of myself and all 3 times they have taken care of me very well including no charge on the rim this time, no charge on replacing the plastic platform petals that broke, and giving me a great deal on a seat when I broke that going over a log pile. I would be more apt to blame Specialized, you'd think a major bike company would have made that realization when they put the bike together. My only curiosity now is how come the front tire hasn't had any problems, one fo these days I'll take that one apart to see if it's a rubber rim strip or taped.