Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 01-20-03, 09:04 PM   #1
joelr
Member
Thread Starter
 
Join Date: Oct 2002
Location: Philadelphia, PA
Bikes:
Posts: 36
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
What on earth is causing my flats?

I've been getting a lot of flats lately, like 1 flat every 3 times I ride (only 8 mile rides). The most recent flat has made me wonder what is really going on... you see, this flat happened on my *first* ride, after putting on Armadillo tires (to prevent the flats). Since these were new tires, it was easy to check for glass in them. There was only one piece of glass in the whole tire, and it didn't even get to the inside. Now, this I find odd, but then I notice that this puncture (which was larger than any I've had before, it was about 1cm around when stretched), was located on the inside, that is, it should have been pressed against the rim.

You must be thinking that my rim spokes are exposed. They are not... there is not one "bulge", and I do have rim tipe all around. I checked the part of the rim where the puncture had been, and there was nothing there that was sharp. There are slight depressions though at each spoke (rather than bulges). But, again, they are covered and so are not sharp.

Is it possible that a tube,when fully inflated (it was at 125psi) may not be facing the right way? That is, when I put the inner tube in the tire, it is often crumpled up and twisted a bit, but I expect that to fix itself as I inflate it, no?

Please, someone give me the answer. I'm sick of changing flats in 20 degree (F) weather.
joelr is offline   Reply With Quote
Old 01-20-03, 09:19 PM   #2
AndrewP
Senior Member
 
Join Date: Sep 2001
Location: Montreal
Bikes: Peugeot Hybrid, Minelli Hybrid
Posts: 6,521
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
One day last summer I had 3 flats on the 27km ride to work. I have Armadillos too. The flats were on the inside of the tubes. The rim strip wasnt covering the holes over the spokes 100%, so the 105psi was enough to make the edge of the holes cut the tube. When I got home I put a file to the holes to round the edges, and was careful how the new rim strip lay. I havent had a flat since.
AndrewP is offline   Reply With Quote
Old 01-21-03, 02:26 AM   #3
trmcgeehan
Senior Member
 
trmcgeehan's Avatar
 
Join Date: Oct 2002
Location: Somerset, KY -- near Lake Cumberland
Bikes: 1980 Univega; 1985 Ross; 1994 Trek 1400 -- all road bikes
Posts: 757
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I too had multiple flat problems, and the culprit turned out to be "goathead" thorns. They are very small, but very sharp. They cut through my new Michelin Axial Carbon tires like nothing. So, I bought some flexible plastic tire liners from BikeNashbar. These are long plyable plastic strips that go inside your tire before you put the tube in. These strips ($5.95 for two) are virtually impenatrable by thorns or glass or whatever. Since putting them on, I have had 0 flat problems. They do add a little weight to your wheel, but I haven't noticed any performance difference.
__________________
"I am a true laborer. I earn that I eat, get that I wear, owe no man hate, envy no man's happiness, glad of other men's good, content with my harm." As You Like It, Act 3, Scene 2. Shakespeare.
"Deep down, I'm pretty superficial." Ava Gardner.
trmcgeehan is offline   Reply With Quote
Old 01-21-03, 02:33 AM   #4
Hants Commuter
Senior Member
 
Hants Commuter's Avatar
 
Join Date: Sep 2002
Location: Hampshire UK
Bikes:
Posts: 232
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
It does sound as if your rim tape is moving or something to expose the spoke end. I personally have had this problem, in particular after I've pumped the tyres up to full pressure the night before.

Are you using a rubber rim tape or one of the tougher woven type?
Hants Commuter is offline   Reply With Quote
Old 01-21-03, 02:58 AM   #5
chewa
The Flying Scot
 
chewa's Avatar
 
Join Date: Aug 2001
Location: North Queensferry Scotland and London (and France)
Bikes: Custom (Colin Laing) 531c fast tourer/audax, 1964 Flying Scot Continental, 1995 Cinelli Supercorsa, Holdsworth Mistral single speed, Dahon Speed 6 (folder), Micmo Sirocco and a few more
Posts: 1,904
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally posted by trmcgeehan
I too had multiple flat problems, and the culprit turned out to be "goathead" thorns. They are very small, but very sharp. They cut through my new Michelin Axial Carbon tires like nothing. So, I bought some flexible plastic tire liners from BikeNashbar. These are long plyable plastic strips that go inside your tire before you put the tube in. These strips ($5.95 for two) are virtually impenatrable by thorns or glass or whatever. Since putting them on, I have had 0 flat problems. They do add a little weight to your wheel, but I haven't noticed any performance difference.
I've had the same problem, and put tape in the back. Since then the only flats I have had have been in the front wheel.

I'm gettting more tape for that this weekend.

Could the problem be that torsion on the tube when installing is tearing it.?

When installing a tube I always slightly inflate it so that it doesn't kink.
__________________
plus je vois les hommes, plus j'admire les chiens

1985 Sandy Gilchrist-Colin Laing built 531c Audax/fast tourer.
1964 Flying Scot Continental (531)
1995 Cinelli Supercorsa (Columbus SLX)
1980s Holdsworth Mistral fixed (531)
2005 Dahon Speed 6 (folder)
(YES I LIKE STEEL)
2008 Viking Saratoga tandem
2008 Micmo Sirocco Hybrid (aluminium!)
2012 BTwin Rockrider 8.1
chewa is offline   Reply With Quote
Old 01-21-03, 08:35 AM   #6
D*Alex
Banned
 
Join Date: Aug 2001
Location: upstate New York
Bikes:
Posts: 1,688
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
OK, now, the guy lives in Pennsylvania, so it's not goathead thorns.....

Here are a few things to look for:

Burrs on the rim surface, especially at the edge of the rim tape.

Burrs on a spoke nipple: it doesn't take much of a metal sliver to poke though the rim tape and puncture your tube.

Wires sticking out from the tyre bead: i've seen this happen on my own Armadillos. I'm betting this is what's happening.

Stray threads from the tyre belts sticking out on the inside: not likely here, since you mentioned that the punctures were on the inside, but this happens fairly often. Kevlar (or similar aramid fabric) is often quite abrasive. I've known several people that have had kevlar-belted tyres destroy their tubes, as ironic as that sounds.
__________________
Je vais vlo, donc je suis!
D*Alex is offline   Reply With Quote
Old 01-21-03, 01:46 PM   #7
roadrage
Senior Member
 
roadrage's Avatar
 
Join Date: Dec 2002
Bikes:
Posts: 118
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Two points I will make. One is to slightly fill the tube with air so that it holds it's shape so that you don't put it in twisted. Twisted is bad and should not be done. Second, make sure you have the right size(width) rim tape for your rims.

Oh, and third, get Velox cloth rim tape and make sure the bead of the tire is not pinching the tube when you put the last part of the tire onto the rim after changing a flat.

Is the puncture in the same place every time? If so, check for something sharp inside the tire at that area and make sure to pump up adequately so you don't pinch flat constantly just in case that is the problem.
roadrage is offline   Reply With Quote
Old 01-21-03, 05:35 PM   #8
dan the gimp
Member
 
Join Date: Dec 2002
Location: Derbyshire, England
Bikes:
Posts: 36
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
straighten the inner tube before you pump!

also, if your inner tube is a size or more too small for the tyre, then a friction build up will cause it to puncture.
When the two surfaces rub together.
dan the gimp is offline   Reply With Quote
Old 01-21-03, 09:20 PM   #9
John E
feros ferio
 
John E's Avatar
 
Join Date: Jul 2000
Location: www.ci.encinitas.ca.us
Bikes: 1959 Capo; 1980 Peugeot PKN-10; 1981 Bianchi; 1988 Schwinn KOM-10;
Posts: 17,304
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 136 Post(s)
If possible, avoid using tyre levers when installing the tyre. (Do as I say, not as I do, since I absolutely have to use tyre levers to put Conti Ultra-2000s on my Campag. Omega rims.) The other suggestions in this thread are quite sound.
__________________
"Early to bed, early to rise. Work like hell, and advertise." -- George Stahlman
Capo [dschaw'-poe]: 1959 Modell Campagnolo, S/N 40324; 1960 Sieger, S/N 42624
Peugeot: 1970 UO-8, S/N 0010468
Bianchi: 1981 Campione d'Italia, S/N 1.M9914
Schwinn: 1988 Project KOM-10, S/N F804069
John E is offline   Reply With Quote
Old 01-22-03, 02:06 AM   #10
trmcgeehan
Senior Member
 
trmcgeehan's Avatar
 
Join Date: Oct 2002
Location: Somerset, KY -- near Lake Cumberland
Bikes: 1980 Univega; 1985 Ross; 1994 Trek 1400 -- all road bikes
Posts: 757
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
And don't forget to use talc powder on your new tube before installing it in the tire. This cuts down on pinching. I always carry a new tube in a ziplock bag with plenty of talc in it.
__________________
"I am a true laborer. I earn that I eat, get that I wear, owe no man hate, envy no man's happiness, glad of other men's good, content with my harm." As You Like It, Act 3, Scene 2. Shakespeare.
"Deep down, I'm pretty superficial." Ava Gardner.
trmcgeehan is offline   Reply With Quote
Old 01-26-03, 08:59 PM   #11
Bike Spokesman
Senior Member
 
Bike Spokesman's Avatar
 
Join Date: Dec 2001
Location: Toronto Canada
Bikes:
Posts: 70
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Its been said before and I'll say it again. Inflate the tube partially when putting it in so that it will hold it's shape. It's hard to diagnose if it's the rim or the tire over the internet, without seeing it, but the one obvious problem is that the tube needs to be straight and not crunched up when you are installing it. I work at a B-shop and I have changed more than my share of tubes and tires for a lifetime, and one of the mistakes I made when I started was cramming the tube in. It resulted in many brand new unridden tubes exploding VERY LOUDLY by my ears. Good luck.
Bike Spokesman is offline   Reply With Quote
Old 01-27-03, 12:28 PM   #12
Bandit
Senior Member
 
Join Date: Sep 2002
Location: Fremont, Calif.
Bikes:
Posts: 147
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
sounds like you might be pinching the tube with the tire tool. if you don't have a bit of air in the tube so that it holds its shape, it has a tendency to get lodged between the tire and rim. when you pry the last bit of tire over the rim you may be pinching the tube.

here's how to avoid it:

1) put a small bit of air in the tube so that it holds its shape.
2) practice using only your hands (no tools) to remount the tire.
3) you can also pinch the tube when taking OFF the tire. try to stick the tire removal tool only far enough in that it snags the tire, not so far in that it reaches the tube.

it might be a good idea to visit your local bike shop and let them watch your tire-changing techniques. they may be able to pinpoint your problem.

i use armadillo tires and i hardly ever flat.
Bandit is offline   Reply With Quote
Old 01-27-03, 03:32 PM   #13
dirtbikedude
Gravity Is Yer Friend
 
dirtbikedude's Avatar
 
Join Date: May 2002
Location: "Over the Hill" and going down fast in the 805.
Bikes: Scott Gambler, Scott Ransom, Kona Bear, Bianchi 928 Carbon/Chorus, C'Dale Rize4
Posts: 2,961
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
What on earth is causing my flats?
Loss of air in your tires. (jk)

I went through the same prob for a while but with sew-ups. Finnaly figured out I can not run them on hot days because the combination of my weight, speed and heat the glue would soften letting the tire slide and therefore tear the valve stem.

Slainte
dirtbikedude is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 10:44 PM.