Advertise on Bikeforums.net



User Tag List

Results 1 to 5 of 5
  1. #1
    kamikaze college commuter
    Join Date
    Oct 2009
    Location
    Bike capital (of the United States, at least)
    My Bikes
    Free spirit FS21 (dead) + Specialized Rockhopper
    Posts
    130
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Time to change my tires?

    Hi all,

    I recently got my third flat in about a year on my rear wheel. I've patched the other two and decided to get a new tube for the third (left my patch kit at home), but that went flat while I put air in it. I got a replacement and was told it could either be something embedded in the tire or the rim tape.

    I've looked at the old tube and none of the punctures are in the rim area. They're all small holes (think pin ******) on the outside so it means something's hitting and getting embedded into the tire. I checked the tire a few times and there appears to be nothing embedded in after checking by hand.

    A check of old threads said it could just be a sticker. What puzzles me is the presence of the weird slash marks on the tire. It's like diagonal slashes that appear every so often on the tire itself. I noticed them around the time of the first flat; I thought they were there because I briefly rode the bike with a flat to get home.

    Here's the thing though. I ride a 2009 Rockhopper that I bought in 2010, which, if my sources are right, means they're three year old tires (delivered to shops in 2008). I've since put about 1000 miles and God knows how many by prospective owners; should I start to get new tires? I do mostly city riding in a relatively rural town. Either way, I'm going to keep the rim tape on.

    TL;DR: I'm getting a lot of fast flats the size of pinholes. Are they related to my rear tire being worn or am I just unlucky/a bad home mechanic? They seem to happen near when I park outside a certain area under a tree.

    Thanks.
    Attached Images Attached Images
    Bikes owned:
    Free Spirit FS21 - the dead one in need of some lovin'
    2009 Specialized Rockhopper - the day-to-day monster
    -(secret)- the one I aspire to.
    1989 Peugeot Ocean Express - "found" bike

  2. #2
    Senior Member
    Join Date
    Apr 2009
    Location
    New Rochelle, NY
    My Bikes
    too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
    Posts
    21,066
    Mentioned
    47 Post(s)
    Tagged
    1 Thread(s)
    I think that what you're seeing is the casing through the wall. Casings have 2 bias plies running at 45° as you see on the side. But tires aren't woven rather each ply consists of strands all running in the same direction and held with glue. These are very delicate, and can come apart when handled, so they weave a cross thread at intervals (not on tubulars) to hold the ply intact during the tire molding process. That cross woven thread is what you're seeing, as the gum cover breaks down with age.

    In any case, worn tires don't cause flats, except as the tread layer gets thinner and easier to cut. Flats depend on how much and where you ride. I commute through some rough areas so glass cuts are common. I've gone a year between flats and had three in a month, it's purely random.
    FB
    Chain-L site

    An ounce of diagnosis is worth a pound of cure.

    “Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin

    “One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

    WARNING, I'm from New York. Thin skinned people should maintain safe distance.

  3. #3
    Constant tinkerer FastJake's Avatar
    Join Date
    May 2010
    Location
    Madison, Wisconsin
    Posts
    6,123
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by graytotoro View Post
    I've since put about 1000 miles...should I start to get new tires? I do mostly city riding in a relatively rural town.
    My opinion is yes, you should get new tires. Not because the old ones are shot, but simply because knobby MTB tires are no fun on pavement. They're slow, noisy, and they corner like crap. Since you suffer frequent flats you could get tires with a flat protection layer. Get some slicks, with a width anywhere from 1.4"-1.75" for much improved performance.

    Or a bike more suited to road riding, like a hybrid commuter or road bike.
    Why "derailer" is the correct way to spell the gear-change mechanism: sheldonbrown.com/derailer.html

  4. #4
    Senior Member BCRider's Avatar
    Join Date
    Mar 2008
    Location
    The 'Wack, BC, Canada
    My Bikes
    Norco (2), Miyata, Canondale, Soma, Redline
    Posts
    5,432
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Something that really helps is to get in the habit of putting the printed name badge of the tire's sidewall at the valve stem. If it's a long name like "Specialized" then put the "S" right at the stem. Then when you have to change a flat carefully remove the tube so you maintain the orientation then inflate it and find the hole. You can then put the tube up to the tire and locate where the glass, wire, thorn pushed through to cause the puncture. Carefully flex and check any marks on the inside of the tire to see if the wire, glass, thorn is still in the tire and ready to push through the tube again.

    In any event only 3 flats in 1000 miles is better than average. These tires aren't thick like car and truck tires and they don't have steel belts. So the number of flats you've gotten would be seen by some as a really low number.
    Model airplanes are cool too!.....

  5. #5
    747 Freight Pilot bicycleflyer's Avatar
    Join Date
    Aug 2008
    Location
    Ohio, USA
    My Bikes
    Rivendell, Bike-Friday Pocket-Rocket and one home made fixed gear
    Posts
    458
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I agree with 2 of the above posters...

    1 .. three flats in 1000 miles is not bad.

    2... If all you ride is pavement, Replace those knobbies with some street friendly tires. You'll see an immediate improvement in performance.
    Flying an airplane is really very simple...Push the stick forward, the house gets big. Pull the stick back, the house gets small. Keep holding the stick back, the house gets big again.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •