Advertise on Bikeforums.net



User Tag List

Results 1 to 11 of 11
  1. #1
    Member
    Join Date
    Nov 2009
    Posts
    25
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Removing bike rust on rear cogs?

    Is it possible to remove bike rust on the rear cog of my mountain bike? I've been looking around but can't seem to find anything about the rear cog. This is for aesthetic purposes, I'm trying to make it look nice. The bike is about 1.5 months old.

  2. #2
    Elitist Troglodyte DMF's Avatar
    Join Date
    Jun 2006
    Location
    Dallas
    My Bikes
    03 Raleigh Professional (steel)
    Posts
    6,896
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Yeah, it's possible. Why is it rusty? Are you running your chain dry (i.e. un-lubricated)?
    Stupidity got us into this mess - why can't it get us out?

    - Will Rogers

  3. #3
    sch
    sch is offline
    Senior Member
    Join Date
    May 2003
    Location
    Birmingham. AL
    Posts
    2,591
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    If the bike has 8-9spd rear cluster, then you can easily disassemble the cluster and clean the cogs off
    with degreaser and some nylon abrasive pads which should take care of the rust as well. If the cogs
    are rusty then the chain is even more likely to be so. Flash rust goes away with a bit of lube and
    riding. If the bike is 6-7spd it may have a freewheel, not easily taken apart. Just clean, lube and
    ride it.

  4. #4
    Senior Member
    Join Date
    Feb 2005
    Location
    Oklahoma
    My Bikes
    Trek 5500, Colnago C-50
    Posts
    9,093
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Simple. Oil the chain and ride the bike.

  5. #5
    Member
    Join Date
    Nov 2009
    Posts
    25
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by DMF View Post
    Yeah, it's possible. Why is it rusty? Are you running your chain dry (i.e. un-lubricated)?
    Unfortunately, and I left it in the heavy rain this past month to top it off.

    Quote Originally Posted by sch View Post
    If the bike has 8-9spd rear cluster, then you can easily disassemble the cluster and clean the cogs off
    with degreaser and some nylon abrasive pads which should take care of the rust as well. If the cogs
    are rusty then the chain is even more likely to be so. Flash rust goes away with a bit of lube and
    riding. If the bike is 6-7spd it may have a freewheel, not easily taken apart. Just clean, lube and
    ride it.
    Yes the free wheel does not have a removable pulley or anything. But, you are saying just lube it and it will come off is that corrrect? Do you have a list of things I need to buy? I have lube.

  6. #6
    BeaverTerror Yan's Avatar
    Join Date
    Jan 2006
    Location
    Shanghai, China
    My Bikes
    2013 True North custom touring; 2009 Unicycle.com Club Uni; 1989 Miele Tivoli; 1979 Colnago Sport
    Posts
    1,559
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    You can clean the freewheel with a toothbrush and degreaser. To get deep between the cogs, use a strip of cloth as "floss". You can buy mineral spirits in jugs from your local hardware store. WD-40 will work as well.
    Yan

    2013 True North custom touring; 2010 Novara Randonee; 2009 Unicycle.com Club 24"; 1989 Miele Tivoli; 1979 Colnago Sport

  7. #7
    Member
    Join Date
    Nov 2009
    Posts
    25
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Yan View Post
    You can clean the freewheel with a toothbrush and degreaser. To get deep between the cogs, use a strip of cloth as "floss". You can buy mineral spirits in jugs from your local hardware store. WD-40 will work as well.
    From what I've been reading, WD-40 does not remove rust only prevents it so to say. So I put in the lubricant and the chain and the cassette, which is probably the better term than cog I suppose, and the color looks a lot better. The cassette still looks like it has black-rust on it though. Will a degreaser help with that? I've tried scrubbing with a toothbrush, without any real formulas though. What do you suggest I could buy, specifically, to aid me in removing this rust? Here's the lubricant I have been using. Btw, does lime away work well to get rid of rust? (in other areas as well?)


  8. #8
    Senior Member
    Join Date
    Mar 2005
    Posts
    159
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Take the cassette off and soak it overnight in vinegar. You'll need a cassette lockring and probably a chain whip to get the cassette off. What the vinegar doesn't dissolve you can scrape away with a toothbrush. Wash with water, dry, lightly lube with your Tri-Flow and reinstall. "Black rust" may just be gunk and not rust.

    This is a rather extreme solution. Just oiling the chain and riding a mile or so while shifting through all the back gears should be enough.

  9. #9
    Senior Member
    Join Date
    Nov 2009
    Posts
    221
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by jkmartin View Post
    Take the cassette off and soak it overnight in vinegar. You'll need a cassette lockring and probably a chain whip to get the cassette off. What the vinegar doesn't dissolve you can scrape away with a toothbrush. Wash with water, dry, lightly lube with your Tri-Flow and reinstall. "Black rust" may just be gunk and not rust.

    This is a rather extreme solution. Just oiling the chain and riding a mile or so while shifting through all the back gears should be enough.
    Black rust is most likely on the Zinc Aluminum coating rather than the underlying steel. You can't rub it off with a toothbrush because it's not an expanded molecule like conventional rust, and does not flake. For all intents and porpoises you can just leave it, your cassette will be black from grease soon enough anyway.

    The discussion comes up frequently whether to oil a new chain or leave that waxy crap they put on them at the factory. This is why you should oil the chain, because if you don't your cassette and chain will turn brown with rust the first time you get it wet. I left my well oiled chain sitting in the rain every day for two years while I was at University and never got so much as a spot of rust on it.

  10. #10
    Senior Member BCRider's Avatar
    Join Date
    Mar 2008
    Location
    The 'Wack, BC, Canada
    My Bikes
    Norco (2), Miyata, Canondale, Soma, Redline
    Posts
    5,430
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Just oil the cogs and brush them with a wire brush. Then clean them off a bit with some mineral spirits or WD40 to get rid of the brown rust sludge and re-oil them along with the chain. You don't need a fancy bike oil for this either. Just some regular engine oil will work if you have some. But if you have to go and buy something anyway then get a quart of Mobil 1 synthetic engine oil and you'll have a lifetime supply of top quality oil for your bicycle chain and many other uses. Get the thicker 20-50 if they have it so it doesn't wash out as easily.

    And obviously if you value the investment in your bike you won't leave it outside anymore. It's one thing to ride it in the rain or even leave it locked to a bike rack in the rain. But leaving it out for storage in the rain is unforgivable on a lot of levels.
    Model airplanes are cool too!.....

  11. #11
    Elitist Troglodyte DMF's Avatar
    Join Date
    Jun 2006
    Location
    Dallas
    My Bikes
    03 Raleigh Professional (steel)
    Posts
    6,896
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Check out the links in this thread.
    Stupidity got us into this mess - why can't it get us out?

    - Will Rogers

Posting Permissions

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