Advertise on Bikeforums.net



User Tag List

Results 1 to 11 of 11
  1. #1
    Member
    Join Date
    Aug 2011
    Posts
    31
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Ride is kinda bumpy, I think its the tires

    So, last night, riding home from work, when switching to my largest chain ring, my chain fell off. Now, I know that is due to a poorly adjusted limit screw. I can fix that.

    However, instead of stopping immediately to put the chain back on, I decided to just coast until I stopped. Not pedaling allowed me to feel a bump.

    It feels like I'm riding on a rumble strip, that is very spread apart. It feels like one bump per rotation of the wheel. I feel it in my butt, so I believe its the rear wheel. I know its not the road, because I intentionally rode slow / coasted on quite a few different roads (maybe 1/2 mile) and it occurred on all of the roads, some of which are quite new roads.

    While pedaling quickly, I don't notice the bump - probably because of all the movement that's going on involved in pedaling. The bump feeling is more pronounced when I am rolling faster (coasting down a hill), which leads me to believe it is based on rotations of the tire. I do not need to be pedaling to make this happen. I do not hear a noise, I just feel it.

    Any ideas?

  2. #2
    Galveston County Texas 10 Wheels's Avatar
    Join Date
    Nov 2007
    Location
    In The Wind
    Posts
    25,650
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Bulge in the rear tire. Get a new tire.

    Take the wheel off the bike and spin it while holding with your hands.
    Look for the bulge as it rotates.
    [SIZE=1][B]What I like about Texas[/B]
    http://www.youtube.com/watch?v=PGukLuXzH1E

    Set F1re To The Ra1n ( NY Night Rain Ride)
    http://www.youtube.com/watch?v=W7jfcWEkSrI

  3. #3
    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
    21,523
    Mentioned
    51 Post(s)
    Tagged
    1 Thread(s)
    Spin the wheel while holding a finger near the tire and see if the gap gets larger and smaller. If so, the next step is watching the rim in the brake shoes to see if it too rises and falls.

    If the rim isn't round, you need a wheel alignment. OTOH if the rim is true or has much less eccentricity than the tire then you have a tire problem. Often it's a matter of poor seating, with on section deeper or higher in the rim. Confirming by spinning the wheel slowly and watching the molded lines nearest the rim. If the seating is OK but the tire isn't round or has a local bump, it's a warning sign that the cord is fractured and beginning to let go. This isn't repairable and calls for a new tire.
    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.

  4. #4
    Member
    Join Date
    Aug 2011
    Posts
    31
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    So I bought a new tire... but it seemed like my tube was too big for it. It folded on itself inside the tire. Is this normal?

  5. #5
    Guest
    Join Date
    Jul 2008
    Location
    Grid Reference, SK
    My Bikes
    I never learned to ride a bike. It is my deepest shame.
    Posts
    3,769
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    A single size of tube is able to accommodate many sizes of tire. Sometimes the tube is folded and sometimes it is stretched inside the tire. As long as the tube is not pinched between the rim and sidewall of the tire then there will not be a problem.

    Try to figure out why your old tire was having problems. Sometimes it is caused by a brake pad hitting the tire and cutting the threads. If this was the cause of the first tire failure, it is likely to be the cause of a second.

    Also, an out-of-true rim is much less likely to be felt in the saddle than a bulge in a tire.

  6. #6
    Senior Member
    Join Date
    Apr 2010
    Location
    Sunnyvale, CA USA
    Posts
    3,056
    Mentioned
    5 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Binarycow View Post

    It feels like I'm riding on a rumble strip, that is very spread apart. It feels like one bump per rotation of the wheel. I feel it in my butt, so I believe its the rear wheel. I know its not the road, because I intentionally rode slow / coasted on quite a few different roads (maybe 1/2 mile) and it occurred on all of the roads, some of which are quite new roads.
    Unseated tire (fix this before it blows off), broken cords (replace the tire), or flat spot in the rim (replace it).

  7. #7
    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
    21,523
    Mentioned
    51 Post(s)
    Tagged
    1 Thread(s)
    Quote Originally Posted by Binarycow View Post
    So I bought a new tire... but it seemed like my tube was too big for it. It folded on itself inside the tire. Is this normal?
    No, a tube should never fold on itself inside the tire. I've seen a few that were marginally long and had to be slightly compressed, but like a roundworm, not folded.

    Take it out put some air into the tube and stuff it into the tire spreading it evenly all the way around. Then finish mounting the tire, letting the air back out of the tube if it helps.

    The only way I could see a tube folded in on itself inside a tire is if you had, for example, a 700c tube in a 26" tire. In hindsight, maybe that's what was wrong with your prior lumpy tire.
    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.

  8. #8
    Member
    Join Date
    Aug 2011
    Posts
    31
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by FBinNY View Post
    No, a tube should never fold on itself inside the tire. I've seen a few that were marginally long and had to be slightly compressed, but like a roundworm, not folded.

    Take it out put some air into the tube and stuff it into the tire spreading it evenly all the way around. Then finish mounting the tire, letting the air back out of the tube if it helps.

    The only way I could see a tube folded in on itself inside a tire is if you had, for example, a 700c tube in a 26" tire. In hindsight, maybe that's what was wrong with your prior lumpy tire.
    Disclaimer: I bought this bike at a Walmart-type store, and it is a piece of crap

    I've never even taken the rear wheel off once it was assembled. After noting the tube was "too big," I put the old tire back on. I don't ride THAT much, figure it won't hurt. The two tires APPEAR to be the same diameter, but the tube is perfect size for the old tire, but too big for the new tire.

    I wasn't able to figure out what was wrong with the old tire either. No apparent physical damage, the seating of the tire seemed fine. I tried to eyeball it, but couldn't see anything. I did re-mount the tire, twice, and the bump seems to be less pronounced, but I still feel it.

  9. #9
    Senior Member Homebrew01's Avatar
    Join Date
    Jul 2004
    Location
    Ffld Cnty Connecticut
    My Bikes
    Old Steelies I made, Old Cannondales
    Posts
    15,779
    Mentioned
    6 Post(s)
    Tagged
    1 Thread(s)
    Quote Originally Posted by Binarycow View Post
    Disclaimer: I bought this bike at a Walmart-type store, and it is a piece of crap

    I've never even taken the rear wheel off once it was assembled. After noting the tube was "too big," I put the old tire back on. I don't ride THAT much, figure it won't hurt. The two tires APPEAR to be the same diameter, but the tube is perfect size for the old tire, but too big for the new tire.

    I wasn't able to figure out what was wrong with the old tire either. No apparent physical damage, the seating of the tire seemed fine. I tried to eyeball it, but couldn't see anything. I did re-mount the tire, twice, and the bump seems to be less pronounced, but I still feel it.
    The tires should have the size printed on the sidewall, for example 26 x 1.25, 26 x 1.5, 26 x 1.75. Those are all 26" tires, but differnt widths.

    By the way, next time your chain comes off, try gently pedaling and shift it back onto the chainring instead of stopping. Works quite often.
    Bikes: Old steel race bikes, old Cannondale race bikes, less old Cannondale race bike, crappy old mtn bike

  10. #10
    Member
    Join Date
    Aug 2011
    Posts
    31
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Homebrew01 View Post
    The tires should have the size printed on the sidewall, for example 26 x 1.25, 26 x 1.5, 26 x 1.75. Those are all 26" tires, but differnt widths.

    By the way, next time your chain comes off, try gently pedaling and shift it back onto the chainring instead of stopping. Works quite often.
    The box said it was good for 26", and listed a bunch of widths. The thing is, the tube seems to be a larger diameter than the new tire, but it fits in the old tire. Which is funny, because both tires look the same size....

    Also, the chain fell off and was hanging around where the crank meets the chainrings... I don't think I can pedal the chain back up there?

  11. #11
    Senior Member CaptCarrot's Avatar
    Join Date
    Feb 2009
    Location
    Dorset, SW England, United Kingdom
    My Bikes
    Heavily modded Cannondale Hooligan 1 (2009) and an upgraded Raleigh Max Zero-G
    Posts
    425
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Binarycow View Post
    ... The two tires APPEAR to be the same diameter, but the tube is perfect size for the old tire, but too big for the new tire. ...
    Quote Originally Posted by Homebrew01 View Post
    The tires should have the size printed on the sidewall, for example 26 x 1.25, 26 x 1.5, 26 x 1.75. Those are all 26" tires, but differnt widths. ...
    Quote Originally Posted by Binarycow View Post
    The box said it was good for 26", and listed a bunch of widths. The thing is, the tube seems to be a larger diameter than the new tire, but it fits in the old tire. Which is funny, because both tires look the same size.... ...
    Ignoring the tube, what is printed/written on the sidewall of the tyres? If the truly are the same size I don't understand how the tube should fit one an not the other.
    Not as green as I might be cabbage looking!

Posting Permissions

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