some very Irritating sounds

Discussion in 'Cycling Equipment' started by Dc, Mar 6, 2003.

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  1. Dc

    Dc Guest

    I have a problem. I am just a recreational bike rider, not a mechanic. I received some great help
    from this group in the past and I am hoping for some insight.

    I have a low end schwinn frontier mountain bike. It is 6 1/2 years old. I have put about 6000 miles
    on it.... a lot of miles in the last year. I put over 1000 miles on it since mid December. Things
    are starting to go.

    Recently, I have experienced a clunking sound that comes from the crank. I lived with it for a
    while. But last month, I needed to get a cable replaced and an adjustment on the front shifter. It
    is the thumb type that is connected to the brake assembly. It would only move into the 1st and 2nd
    position on the front gear sprocket. I also told the bike shop guy about the clunk. He said that he
    would try to tighten the bolt on the bracket.

    When I picked up the bike, the bike shop guy was telling me that things were getting pretty worn on
    the bike..the chain and the rear cassette. He said he adjusted the bolt and the shifter.

    Well ,the clunk was gone but the shifter still didn't work. I brought it back to the bike guy and he
    said that it needed to be replaced. He didn't have the part so I just took it back. I figured I
    would ride it like that for a while.

    Last week, I started to occasionally hear a scraping sound coming from the crank when I pedaled. It
    has gotten gradually worse. Yesterday, it jammed up and was giving me a lot of resistance when I
    pedalled. i stopped and looked at it but i didnt see anything wrong. The noise kinda stopped but I
    knew not for long.

    I rode again today. it was ok until about mile 4 into the ride. then it started up again. i am
    pretty sure the problem is inside the pedal crankset.

    well... I am thinking about this as I am riding.the clunk was gone. but maybe something was knocked
    loose in the process. the noise seems like something is interferring with the rotation of the pedal
    crank. and since it comes and goes( but it is mostly there now), the thing that is touching the
    rotating part is moving around. this also makes sense to me because yesterday when i felt a great
    deal of resistance as i was pedaling, the offending piece must of been jammed at a point that really
    restricted the movement of the pedal.

    it sounds like a scraping. i dont know what the .... is in there.

    Is this a simple thing or what? Should I just get a new bike?

    Thanks,

    Deb
     
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  2. Michael Dart

    Michael Dart Guest

    "dc" <[email protected]> wrote in message
    news:[email protected]...
    > I have a problem. I am just a recreational bike rider, not a mechanic. I received some great help
    > from this group in the past and I am hoping for some insight.
    >
    > I have a low end schwinn frontier mountain bike. It is 6 1/2 years old. I have put about 6000
    > miles on it.... a lot of miles in the last year. I put over 1000 miles on it since mid December.
    > Things are starting to go.
    >
    > Recently, I have experienced a clunking sound that comes from the crank. I lived with it for a
    > while. But last month, I needed to get a cable replaced and an adjustment on the front shifter. It
    > is the thumb type that is connected to the brake assembly. It would only move into the 1st and 2nd
    > position on the front gear sprocket. I also told the bike shop guy about the clunk. He said that
    > he would try to tighten the bolt on the bracket.
    >
    > When I picked up the bike, the bike shop guy was telling me that things were getting pretty worn
    > on the bike..the chain and the rear cassette. He said he adjusted the bolt and the shifter.
    >
    > Well ,the clunk was gone but the shifter still didn't work. I brought it back to the bike guy and
    > he said that it needed to be replaced. He didn't have the part so I just took it back. I figured I
    > would ride it like that for a while.
    >
    > Last week, I started to occasionally hear a scraping sound coming from the crank when I pedaled.
    > It has gotten gradually worse. Yesterday, it jammed up and was giving me a lot of resistance when
    > I pedalled. i stopped and looked at it but i didnt see anything wrong. The noise kinda stopped but
    > I knew not for long.
    >
    > I rode again today. it was ok until about mile 4 into the ride. then it started up again. i am
    > pretty sure the problem is inside the pedal crankset.
    >
    > well... I am thinking about this as I am riding.the clunk was gone. but maybe something was
    > knocked loose in the process. the noise seems like something is interferring with the rotation of
    > the pedal crank. and since it comes and goes( but it is mostly there now), the thing that is
    > touching the rotating part is moving around. this also makes sense to me because yesterday when i
    > felt a great deal of resistance as i was pedaling, the offending piece must of been jammed at a
    > point that really restricted the movement of the pedal.
    >
    > it sounds like a scraping. i dont know what the .... is in there.
    >
    >
    > Is this a simple thing or what? Should I just get a new bike?
    >
    > Thanks,
    >
    > Deb

    It sounds like your bottom bracket bearings are bad. There are probably pieces of them floating
    around in there making the grating sound and occasionally getting wedged preventing the cranks from
    turning. This is usually fixed by getting a new bottom bracket installed. A quick test is to drop
    the chain off the front gears (down onto the frame) so the crank spins freely and put the nose of
    the saddle to your ear and spin the crank. If you hear a whoosh...whoosh...whoosh.. the bearings are
    probably fine but if you hear grrrck...scriiiickk...grrckk...crunch.. well you get the idea. It
    might also be time for a new drivetrain. Gears, bearings and chains do wear out eventually. Of
    course since you are racking up the mileage and apparently enjoying riding maybe you should treat
    yourself to a shiny new ride. ;^)

    Mike
     
  3. Russell Yim

    Russell Yim Guest

    >I have a problem. I am just a recreational bike rider, not a mechanic. I received some great help
    >from this group in the past and I am hoping for some insight.

    I am a mechanic that doesn't ride. j/k!

    >I have a low end schwinn frontier mountain bike. It is 6 1/2 years old. I have put about 6000 miles
    >on it.... a lot of miles in the last year. I put over 1000 miles on it since mid December. Things
    >are starting to go.

    You know what? You are no longer a recreational rider, at least not in my book!

    >Recently, I have experienced a clunking sound that comes from the crank. I lived with it for a
    >while. But last month, I needed to get a cable replaced and an adjustment on the front shifter. It
    >is the thumb type that is connected to the brake assembly. It would only move into the 1st and 2nd
    >position on the front gear sprocket. I also told the bike shop guy about the clunk. He said that he
    >would try to tighten the bolt on the bracket.

    >When I picked up the bike, the bike shop guy was telling me that things were getting pretty worn on
    >the bike..the chain and the rear cassette. He said he adjusted the bolt and the shifter.

    >Well ,the clunk was gone but the shifter still didn't work. I brought it back to the bike guy and
    >he said that it needed to be replaced. He didn't have the part so I just took it back. I figured I
    >would ride it like that for a while.

    I'm curious, when you originally brought in the bike for service, did the "bike guy" ask to look
    over your bike first? Did he ask you about how you used the bike?

    Doesn't sound like he's a very good mechanic, frankly.

    >Last week, I started to occasionally hear a scraping sound coming from the crank when I pedaled. It
    >has gotten gradually worse.

    >Yesterday, it jammed up and was giving me a lot of resistance when I pedalled. i stopped and looked
    >at it but i didnt see anything wrong. =A0 The noise kinda stopped but I knew not for long.

    >I rode again today. it was ok until about mile 4 into the ride. then it started up again. i am
    >pretty sure the problem is inside the pedal crankset. well... I am thinking about this as I am
    >riding.the clunk was gone. but maybe something was knocked loose in the process. the noise seems
    >like something is interferring with the rotation of the pedal crank. and since it comes and goes(
    >but it is mostly there now), the thing that is touching the rotating part is moving around. this
    >also makes sense to me because yesterday when i felt a great deal of resistance as i was
    >pedaling, the offending piece must of been jammed at a point that really restricted the movement
    >of the pedal. it sounds like a scraping. i dont know what the .... is in there. Is this a simple
    >thing or what?

    Here's my edumacted guess: your Schwinn Frontier likely has what is known as an adjustable cup
    bottom bracket. That is the axle, cups, and bearings that the crank turns on. Originally, when you
    brought your bike in for the clunking sound, the "bike guy" probably tightened the adjustable cup
    without giving it a thorough inspection. It made the clunking go away temporarily, but didn't
    actually fix what was wrong in the first place..

    What you bike's bottom bracket probably needed was a bearing overhaul. Now what has happened is that
    a retaining ring that the bearings are typically held in has gotten all mangled up inside the bottom
    bracket...that is why you hear scaping, and also why the crank is sometimes difficult to turn.

    So, the crank bearings need to be replaced at the least, and possibly the whole bottom bracket
    assembly needs to be replaced. Worse case scenario: about $20-25 for the part (the shop will put in
    a more modern cartridge bottom bracket, which never needs adjustment), and about $15 or so in labor.

    >Should I just get a new bike?

    Maybe. I'd be curious to know the condition of the rest of the bearings on your bike. Have you ever
    had the bike overhauled? I'm betting the answer is no. Also, considering your bike is going to need
    a new chain and cassette, there may be other parts that are close to their wear limts.

    Seeing as you ride a lot, I think you deserve a nicer ride...something lighter and livelier!

    Russell

    Trekkie, Disnoid =B0o=B0, and Sheena Easton fan

    "Life will teach you all you need to know, but only Love Will Make You Wise"- Sheena Easton

    http://community.webtv.net/TrekkeRuss/TheTrekkieDisnoido

    Come see Sheena Easton, Live at G-A-Y! http://community.webtv.net/CrazyForSheena/SheenaEastonLiveatG

    Pictures from my trip to the grand opening of the newest Disney theme park in Tokyo, Nippon!
    http://community.webtv.net/TrekkeRuss/TokyoDisneySeaIn
     
  4. Deb wrote:

    >I have a low end schwinn frontier mountain bike. It is 6 1/2 years old. I have put about 6000 miles
    >on it.... a lot of miles in the last year. I put over 1000 miles on it since mid December. Things
    >are starting to go.

    >Recently, I have experienced a clunking sound that comes from the crank.

    Those old Frontiers had a POS BB. I just replaced the one on my granddaughter's Frontier with a low
    end Shimano BB - problem solved cheaply.

    Alexander Gilchrist
     
  5. Dc

    Dc Guest

    [email protected] (Russell Yim) wrote in message
    news:<[email protected]>...

    Thank you very much Russell and Mike.

    >
    > I'm curious, when you originally brought in the bike for service, did the "bike guy" ask to look
    > over your bike first? Did he ask you about how you used the bike?

    Actually ,yes, he did.
    >
    > Doesn't sound like he's a very good mechanic, frankly.

    hmm..well, I have my doubts also.

    >
    > >Should I just get a new bike?
    >
    > Maybe. I'd be curious to know the condition of the rest of the bearings on your bike. Have you
    > ever had the bike overhauled? I'm betting the answer is no.

    "no " would be the correct answer.

    > Also, considering your bike is going to need a new chain and cassette, there may be other parts
    > that are close to their wear limts.
    >
    > Seeing as you ride a lot, I think you deserve a nicer ride...something lighter and livelier!

    Yeah..when I was in the bike shop, I was checking out some of the new bikes...sigh..They are all so
    nice(and shiny). I was lifting them to compare the weight to my bike and they were much lighter.

    But ..sheesh..very expensive.

    Although , I would love a fast new bike, I can't justify spending over $500.00/600.00 on it. I don't
    know if there are even any bikes much better than the one I have for that price.

    What would be a good moderately priced bike... any recommendations ?

    ps

    live long and prosper.
     
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