Advertise on Bikeforums.net



User Tag List

Results 1 to 7 of 7
  1. #1
    Newbie
    Join Date
    Aug 2011
    Posts
    4
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Loose bottom bracket, what tool do I need? (video and photos inside)

    Hi all

    So the bottom bracket on my bike keeps coming loose, please see 5 second video here that shows the problem:

    http://www.youtube.com/watch?v=DrKmwyHm-Xk&hd=1

    I took it to the shop and they tightened it, which didn't take long at all, however I don't think they tightened it that well because it has started getting loose again already after only 6 miles riding.

    I didnt see them tighten it so I'm not sure what kind of tool they used. I have researched a bit and have found different answers, some say you need lots of special tools, some say just a 32mm wrench,

    The below pics show a close up of the bracket, please can someone help me with which part needs tightening, and what tool I would need to tighten it? I'm thinking if I get the right tool it would save taking it to the shop each time and I can give it a proper tighten.

    The photos have labels on, so if you can specify easily, eg: A or B for example.

    From one side:

    http://img200.imageshack.us/img200/3906/dscf2351o.jpg
    http://img35.imageshack.us/img35/2594/dscf2350copy.jpg


    On the other side:

    http://img823.imageshack.us/img823/6960/dscf2352f.jpg

    The metal part label C is on this side of the bike, just behind all the plastic shielding:

    http://img709.imageshack.us/img709/2963/dscf2353i.jpg

    So yeah, 2 questions really, which tool is needed to tighten the bracket on this bike, and which part do I need to tighten?

    Hope this helps, please let me know if you need any more info to resolve

  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
    19,568
    Mentioned
    27 Post(s)
    Tagged
    1 Thread(s)
    You need a few different tools. First you need a crank remover to take the cranks off so you can service the BB. You'll also need a 14mm socket or crank bolt wrench remount the cranks later. Some cranks removers have the socket built in so you only need one tool. Also, make sure the remover you get is for square taper cranks.

    Now to the bottom bracket. You'll need a lock ring spanner for the left side lock ring, and a wrench to fit the raised slot on the left cup, usually 15mm, but check that. Looking at the video, I suspect it's the right cup that's loose, so you'll need a tool for that, usually a special 36mm box tool, or a hook/lockring spanner. (can't see it in the vieos so I can't advise which).

    BTW, be aware that the right BB cup has a LH thread, and tightens counter-clockwise. Note the right cup should be tightened with all the strength you can muster. We used to call it a "fixed" cup because it was supposed to be fixed to the frame.
    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
    Senior Member
    Join Date
    Apr 2008
    Location
    A Latvian in Seattle
    Posts
    1,020
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    If the BB is shot, a modern cartridge-style replacement square-taper BB should only cost about $20 and uses a splined installation/removal tool. That will also avoid the need to learn how to properly adjust the compression on your BB's bearings. Consider having a local bike shop remove the cranks and old BB; either they or you can then mount the new BB and mount the cranks on the new spindle. The labor charge may be cheaper than buying the extra tools to remove the old BB.

  4. #4
    Member
    Join Date
    Aug 2011
    Posts
    46
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    if you don't know what you're doing take the bike back to the shop before your bike becomes a victim of home repair. i see this happen far too often.

  5. #5
    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
    19,568
    Mentioned
    27 Post(s)
    Tagged
    1 Thread(s)
    Quote Originally Posted by boffenbec View Post
    if you don't know what you're doing take the bike back to the shop before your bike becomes a victim of home repair. i see this happen far too often.
    There's a third alternative, learn how to do the job. There are lots of tutorials available, and if someone isn't mechanically declined they can master this or most jobs.

    None of us were born knowing bike repair, and those who know had to learn. Hopefully the cost of this education won't be expensive damage to the bike or injury, but that too can be part of the process.

    The most important thing is to have a sense of your abilities and recognize when you're in over your head, and be willing to ask for help. 99% of bike repair is easy if you know how, and learning isn't too hard either.
    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.

  6. #6
    Senior Member vredstein's Avatar
    Join Date
    Aug 2008
    Location
    Tucson, Arizona
    My Bikes
    '02 Lemond Buenos Aires, '98 Fuji Touring w/ Shimano Nexus premium, '06 Jamis Nova 853 cross frame set up as commuter, '03 Fuji Roubaix Pro 853 back up training bike
    Posts
    701
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by dave_100 View Post
    Hi all

    So the bottom bracket on my bike keeps coming loose, please see 5 second video here that shows the problem:

    http://www.youtube.com/watch?v=DrKmwyHm-Xk&hd=1

    I took it to the shop and they tightened it, which didn't take long at all, however I don't think they tightened it that well because it has started getting loose again already after only 6 miles riding.

    I didnt see them tighten it so I'm not sure what kind of tool they used. I have researched a bit and have found different answers, some say you need lots of special tools, some say just a 32mm wrench,

    The below pics show a close up of the bracket, please can someone help me with which part needs tightening, and what tool I would need to tighten it? I'm thinking if I get the right tool it would save taking it to the shop each time and I can give it a proper tighten.

    The photos have labels on, so if you can specify easily, eg: A or B for example.

    From one side:

    http://img200.imageshack.us/img200/3906/dscf2351o.jpg
    http://img35.imageshack.us/img35/2594/dscf2350copy.jpg


    On the other side:

    http://img823.imageshack.us/img823/6960/dscf2352f.jpg

    The metal part label C is on this side of the bike, just behind all the plastic shielding:

    http://img709.imageshack.us/img709/2963/dscf2353i.jpg

    So yeah, 2 questions really, which tool is needed to tighten the bracket on this bike, and which part do I need to tighten?

    Hope this helps, please let me know if you need any more info to resolve
    After you've checked the drive side, making sure it's tight, and you don't need to service the bottom bracket (clean, change bearings, etc.) just adjust it, you only two tools and no need to remove the cranks.
    This one fits the 3-notch lock ring.
    http://www.parktool.com/product/cran...t-wrench-hcw-5
    This one fits the adjusting cup.
    http://www.parktool.com/product/adju...-wrench-hcw-11

    This is a nice tool because it's thin enough to fit between the adjustable cup and the crank arm.

    Adjusting these takes quite a bit of patience and good feel. Turning the 3-notch lock ring counterclockwise loosens it, giving you access to tighten or loosen the adjustable cup.
    After you've adjusted the cup and start locking down the ring by turning it clockwise, the cup may start to turn along with the ring, effectively make it tighter, screwing up the initial adjustment. If this happens, just adjust the cup a bit loose before tightening down the ring to make up for this added travel.
    Don't be surprised if you have to go through this procedure four or five times before you get it right. Sometimes you'll have to hold the cup adjusting tool firmly in place with one hand, preventing it from turning while you tighten the lock ring with the three-pronged tool in your other hand. Take care using the lock ring tool, making sure all three prongs of the tool are perfectly engaged in the three notches of the ring. If the ring is made of softer metal, it can get stripped. It's a very narrow fit, and takes a steady hand to remain engaged while tightening. The tool wants to twist left or right, slipping off the notches.
    If I get a unit that is comes loose, I'll be sure to grease the threads of the cup, leaving the last few exposed millimeters of the thread dry. I'll then apply blue thread locker to the threads that are left exposed outside of the frame's bottom bracket shell where the lock ring will be threaded. This can make adjustment more difficult for the reasons above, but it will ensure the ring won't loosen.
    I rarely use a hammer on a bike or tool, but I do find using a hammer on the lock ring tool works well to really cinch it down. This takes a very steady hand with constant clockwise pressure to prevent the tool from slipping off the notches as the hammer hits the other end of the tool.
    Last edited by vredstein; 08-22-11 at 09:45 AM.
    "See, it's not that getting wet is a big deal. Really, it's what you're getting wet with.
    Fenders....because it's probably urine."
    Bike Snob NYC

  7. #7
    Bikaholic blamp28's Avatar
    Join Date
    Dec 2006
    Location
    Western, Michigan
    My Bikes
    Trek Fuel 90, Giant OCR, Rans Screamer Tandem
    Posts
    1,465
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by FBinNY View Post
    There's a third alternative, learn how to do the job. There are lots of tutorials available, and if someone isn't mechanically declined they can master this or most jobs.

    None of us were born knowing bike repair, and those who know had to learn. Hopefully the cost of this education won't be expensive damage to the bike or injury, but that too can be part of the process.

    The most important thing is to have a sense of your abilities and recognize when you're in over your head, and be willing to ask for help. 99% of bike repair is easy if you know how, and learning isn't too hard either.
    Fantasic post FB! Great points and why we are here.
    Trek Fuel XC MTB, Giant OCR Road Bike, Rans Screamer - Tandem

Posting Permissions

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