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An engineer's take on the creaking bottom bracket problem

Last post 05-15-2017 1:22 AM by mozmo. 7 replies.
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  • 05-08-2017 3:01 AM

    An engineer's take on the creaking bottom bracket problem

     I saw this vid at the weekend and it is relevant to a few people on here. No easy answers. Replace the BBRight setup:

     https://youtu.be/9IlWUVfAVEE

     


  • 05-09-2017 8:38 AM In reply to

    • apwndwest
    • Top 75 Contributor
    • Joined on 09-11-2014
    • Vancouver, British Columbia
    • Posts 244

    Re: An engineer's take on the creaking bottom bracket problem

     Seems like a pretty solid guy who knows his stuff

    2014 R3 (Hills bike)
    2012 Roubaix SL3 (Endurance bike)
  • 05-10-2017 4:32 PM In reply to

    Re: An engineer's take on the creaking bottom bracket problem

    Well I have had this annoying creaking on my R5 for 2 years. Had it on guarantee service where I suggested bearing change to fix it and got it back with the exact same creaking noise. Had sort of accepted it until this spring when I decided to have another go at solving it. So dismantled the crank, and bought new bearings. Could not find/feel any wear or fault with the existing bearing so I re-insert axle and by pulling/pushing transversely on the axle I feel there is room/play in between the axle and the inner bearing surface. Imo this is the cause: the inner axle of S5s has a slightly too small diameter, causing it to alternately contact upper and lower surface of inner bearing as you alternate force on the pedals. So realizing that the axle and the inner surface of the bearings are stationary wrt each other I put on some thin tape on the axle at the position where the bearing rests, after thoroughly degreasing it - and carefully slide it on, then assemble. Voila, creaking is gone and has been gone for some 1500 km. Before doing the above I also put on both the new bearings on to the axle and just by holding them in my hands and alternating pressure I could feel and hear the axle contacting upper and lower surface of the bearing, confirming my suspicion and the solution. Also checked new crank axle on e-bay but realizing this is a longer axle and unique to Cervelo I realized that a new axle would probably have the same problem. Using something like loctite would probably also work.
  • 05-10-2017 9:55 PM In reply to

    Re: An engineer's take on the creaking bottom bracket problem

    The video is good...to a point, and then leaves out or makes unclear the MOST important aspect of the install. He mentions ensuring the bearings are of a good quality and mentions using loctite after installing new bearings, but he fails to mention that you MUST use loctite when installing the cups!!!!! In his demo of pressing in the cups, he does not use and does not mention loctite. Every single instruction from Cervelo specifies the need to use loctite on the install of PF cups. As a first time builder, I followed Cerverlo's instructions to the letter and was rewarded with several thousand miles of creak free use. When I took my bike into my Cervelo-authorized LBS for the bike's first full tune, as part of the work, they removed and reinstalled cups. On the very first ride, creak. When I brought back to LBS they acknowledged creak, reinstalled cups. Next ride, same issue. I had WRONGLY assumed the mechanic knew to and had used loctite on the install. I was wrong. When I asked him about Loctite, the response was "oh, yeah, thanks, I'll try that." Needless to say the third time was the charm. So before you spend money and add weight with the BBinfinite option, make sure you or your mechanic has properly followed the directions and used the loctite and primer to ensure a tight, waterproof, many thousand miles-proof install of the bb cups.
  • 05-11-2017 1:21 AM In reply to

    Re: An engineer's take on the creaking bottom bracket problem

    BBrightTM-Press-Fit-Instructions.pdf from the developing engineers ..
    ___▲___▲___▲___ the surfboard of the Kurpfalz is the road bike .. oSo >>
  • 05-11-2017 11:53 AM In reply to

    Re: An engineer's take on the creaking bottom bracket problem

    I read the BBright Press Fit Instructions, it tells you to use LocTite on the surface between bearing and frame. I used tape on the surface of the crank axle towards the inside of the bearing. Here BBright Press Fit Instructions tell you to use grease. But grease does not prevent creaking as it turns out, the play is too big and the space causes the creak. So added tape but could have added LocTite to the inside I suppose and it would have had same effect.
  • 05-11-2017 9:22 PM In reply to

    • goodboyr
    • Top 10 Contributor
    • Joined on 08-16-2007
    • Thornhill, Ontario
    • Posts 942

    Re: An engineer's take on the creaking bottom bracket problem

    Guys. A simple search will show that this topic has probably been discussed the most of any topic on this forum. A wealth of info, that the video mentioned in the op doesn't add to.
    Bobbo
    2015 COR
    '06 R3, Fully Internal Dura Ace 7970, Zipp 303FC Clinchers
    S5 Team, Ultegra Di2, Zipp 101
    RCA 56cm, Dura Ace 9070, Zipp 404 FC Tubbies

  • 05-15-2017 1:22 AM In reply to

    • mozmo
    • Not Ranked
    • Joined on 01-21-2015
    • Posts 19

    Re: An engineer's take on the creaking bottom bracket problem

    I fixed my tick/creak noise issue by using wheels mfg shimano adapter cups. I tracked my noise down to the contact between the inner bearing race and crank axle, the rotor axle is metal to metal contact, the delrin between the crank axle and bearing race acts as good noise insulator. Also I noticed some wear on the rotor axle, the steel bearing race over time will compress and wear the aluminium axle, which means the axle goes out of spec. This is the same issue you see on cassette freehubs that use softer aluminum with steel. I have a feeling this is why shimano continue to use 24mm steel axles.
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